Surgical Neurology International

Surgical Neurology International

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Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Case Report

Atypical pleomorphic neoplasms of the pineal gland: Case report and review of the literature M. Praver, R. D’Amico, C. Arraez, B. E. Zacharia, H. Varma1, J. E. Goldman1, J. N. Bruce, P. Canoll Departments of Neurological Surgery and 1Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA E‑mail: *Praver M ‑ mep2170@columbia.edu; D’Amico R ‑ rd2398@columbia.edu; Arraez C ‑ cinta.arraez@gmail.com; Zacharia B. E. ‑ bez2103@columbia.edu; Varma H ‑ hv2108@cumc.columbia.edu; Goldman J. E. ‑ jeg5@cumc.columbia.edu; Bruce J. N. ‑ jnb2@columbia.edu; Canoll P ‑ pc561@columbia.edu *Corresponding author Received: 10 June 14 Accepted: 02 December 14 Published: 30 July 15 This article may be cited as: Praver M, D'Amico R, Arraez C, Zacharia BE,Varma H, Goldman JE, et al. Atypical pleomorphic neoplasms of the pineal gland: Case report and review of the literature. Surg Neurol Int 2015;6:129. http://surgicalneurologyint.com/surgicalint_articles/Atypical-pleomorphic-neoplasms-of-the-pineal-gland:-Case-report-and-review-of-the-literature/ Copyright: © 2015 Praver M. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Pineal region tumors are rare and diverse. Among them exist reports of pleomorphic xanthroastrocytoma (PXA) and pleomorphic granular cell astrocytoma (PGCA) of the pineal gland. These related tumors are remarkably similar sharing pleomorphic histologic features with only minor immunohistochemical and ultrastructural differences.

Case Description: We present a case of a 42‑year old right‑handed woman presented with a longstanding history of migraine headaches which had worsened over the two months leading up to her hospitalization. MRI revealed a 1.7 × 1.3 × 1.6 cm intensely enhancing lesion originating in the pineal gland. The tumor closely resembled PGCA but did not strictly fit the diagnostic requirements of either PGCA or PXA. Conclusion: The present case highlights the exotic nature of pineal region tumors with pleomorphic cell histology. Given the diverse range of tumors encountered in the pineal region, pathological confirmation is mandatory. Favorable clinical outcomes demonstrate that surgical resection alone can yield excellent long‑term results for tumors falling within the spectrum of pleomorphic lesions of the pineal gland.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161790 Quick Response Code:

Key Words: Pineal gland, pleomorphic granular cell astrocytoma, pleomorphic xanthoastrocytoma

INTRODUCTION Pineal region tumors are rare, representing less than 0.5–2% of all intracranial tumors.[8,40] Broadly, these tumors can be divided into germ cell tumors, glial cell tumors, and pineal parenchymal tumors as well as a diverse group of miscellaneous tumors.

The pineal parenchymal group extends the range from benign to malignant including pineocytoma, parenchymal tumors of intermediate differentiation, and

pineoblastoma.[4,34] The glioma group is largely comprised of pilocytic astrocytomas, fibrillary astrocytomas, anaplastic astrocytomas, glioblastomas, ependymomas, and oligodendrogliomas.[16,20] Tumors with pleomorphic histology are exceptionally rare in this location with only seven reports in the literature.[18,26,28,32‑34] These cases roughly fall into the diagnostic categories of pleomorphic xanthoastrocytoma (PXA) or pleomorphic granular cell astrocytoma (PGCA). In this report we present a surgical case of a pineal tumor with pleomorphic histology and

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discuss the diagnostic and therapeutic considerations for these exotic tumors.

CASE PRESENTATION A 42‑year‑old right‑handed female presented with a longstanding history of migraine headaches, which had worsened over the 2 months leading up to her hospitalization. She was otherwise healthy with no additional past medical history, taking only rizatriptan and fenoprofen. Her neurological examination was normal.

Magnetic resonance imaging (MRI) revealed a 1.7 × 1.3 × 1.6 cm intensely enhancing lesion originating in the pineal gland and inseparable from the superior aspect of the tectum inferiorly. The lesion appeared slightly hyperintense relative to cerebrospinal fluid (CSF) on T1‑weighted images (WI) [Figure 1] and resulted in inferior displacement of the tectum causing partial obstruction of the aqueduct of Sylvius with associated dilation of the lateral and third ventricles.

Fluid-attenuated inversion recovery (FLAIR) sequences demonstrated paraventricular hyperintensity suggestive of transependymal flow due to early obstructive hydrocephalus. Serum levels of human chorionic gonadotropin and α‑fetoprotein were negative.

The patient initially underwent successful endoscopic third ventriculostomy for relief of obstructive

hydrocephalus. CSF glucose and protein were 38 and <10 mg/dL, respectively. Surgical resection took place 18 days later through a supracerebellar, infratentorial approach with the patient in the sitting position.[5] The tumor seemed to arise from the pineal gland itself with areas of calcification along the dorsal surface. Gross total tumor resection was obtained and the patient was sent to the intensive care unit in satisfactory condition.

Postoperatively the patient did well with a transient mild Parinaud syndrome and gait disturbance that resolved over the following 2 weeks. Follow‑up MRI on postoperative day 3 demonstrated complete resection of the tumor [Figure 2].

On hematoxylin and eosin stain [Figure 3], the tumor cells exhibited highly pleomorphic, hyperchromatic nuclei. Frequent multinucleated and enlarged cells with giant, bizarre‑shaped nuclei were seen. There were many vessels with hyalinized walls, but no areas of vascular proliferation or necrosis. Rare mitotic figures were seen with a low Ki67 proliferation index reaching up to 1.6% in some areas. Reticulin staining did not reveal peri‑tumoral reticulin fibers. Immunohistochemically, the tumor was positive for and synaptophysin and class III β‑tubulin with diffuse, weak epidermal growth factor receptor (EGFR) staining. Glial fibrillary acidic protein (GFAP) staining primarily demonstrated focal positivity resembling a reactive process but there were discrete areas of diffuse positive staining of tumor cells.

a

b

c

d

e

f

Figure 1: Preoperative Magnetic Resonance Images. (a) Axial T1-weighted image demonstrating lesion in the pineal region with evidence of early hydrocephalus. (b) Coronal contrast enhanced T1-weighted image showing an enhancing lesion extending inferiorly. (c) Sagittal contrast enhanced T1-weighted image demonstrating enhancing lesion displacing the quadrigeminal cistern and dorsal midbrain. (d) Axial FLAIR demonstrating moderate hyperintense lesion. (e) Axial T2-weighted image showing moderate hyperintense lesion. (f) Axial DWI showing moderate hyperintense lesion

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There was scattered positive immunostaining for p53, Phosphatase and tensin homolog (PTEN), and Olig2, while staining for IDH‑R132H mutation, CK, HMB45, and CD34 were negative.

DISCUSSION Pineal region tumors are rare, representing 0.5–2% of all intracranial tumors.[8,40] PXAs were first described by Kepes et al. in 1979 and are currently recognized as WHO grade II

tumors.[11,19] The majority of PXAs have been reported in children and young adults.[6] Lesions are often cystic, typically occurring supratentorially, with a predilection for cortical and leptomeningeal involvement.[11,17,19] However, rare lesions have been reported in the cerebellum, cerebellopontine angle (CPA), spinal cord, hypothalamus, sella, and retina, as well as occurring multifocally.[1,3,7,13‑15,21, 22,24,25,29‑31,36,38,39] Only three cases of histologically confirmed PXA in the pineal gland have been reported, of which two were benign,[33,34] and one featured anaplastic elements.[18] Notably, four cases of PXA‑like tumors have been reported in the pineal gland, including PGCAs[28,32] and an atypical pleomorphic astrocytoma.[26] Symptoms of pineal PXA/PGCA at presentation are commonly due to hydrocephalus from mass effect from aqueduct compression and include headache, nausea, and vomiting [Table 1]. Patients may also present with Parinaud syndrome and less commonly, gait disturbances, seizures, and cranial nerve palsies.[4,35]

a

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Figure 2: Postoperative Magnetic Resonance Images (a) Axial T1-weighted MRI demonstrating normal postoperative changes. (b) Sagittal T1-weighted postcontrast MRI demonstrating normal postoperative changes

MRI characteristics of pineal PXA/PGCA are variable.

Srinivas et al. described an enhancing homogenous lesion with a speck of calcification.[33] In contrast, Thakar et al. described a lesion with solid and cystic components,

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Figure 3: Histology (a and b) Hematoxylin and eosin stained section demonstrating a moderately cellular neoplasm with highly pleomorphic, hyperchromatic nuclei. Frequent multinucleated and enlarged cells with giant, bizarre-shaped nuclei are present. Vessel walls are hyalinized and no areas of vascular proliferation or necrosis are noted. Rare mitotic figures are seen. (c and d) Photomicrograph of GFAP immunostaining demonstrating primarily focal positivity resembling a reactive process with discrete areas of diffuse positive staining. (e) Photomicrograph showing representative Ki-67 immunostaining. Cells show a low proliferation index with focal areas up to 1.6%. (f) Photomicrograph showing representative reticulin immunostaining. Staining can be seen in perivascular connective tissue but there is no reticulin network between the tumor cells. (g) Photomicrograph of Olig2 immunostaining demonstrating scattered positive cells. Magnification: ×20 (h) Photomicrograph of synaptophysin immunostaining demonstrating a diffuse, strongly positive pattern. (i) Photomicrograph of Class III β-tubulin immunostaining demonstrating a diffuse, strongly positive pattern

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Table 1: Summary of clinical presentations of pleomorphic neoplasms of the pineal region in the literature Case

Age Sex Presentation

Examination

Imaging

Hydrocephalus

PXA (Srinivas et al)

30 M

1-month headache

Papilledema

Yes (VPS)

PXA (Thakar et al)

15 M

Papilledema

Anaplastic PXA (Katayama et al) PGCA (Ohta et al) PGCA (Snipes et al)

61 M

1-month history of headache and vomit 1 month cognitive impairment, difficutly walking Headache, gait disturbance 3 year headache

Isointense T1, hyperintense T2, contrast enhancement, calcifications Hypointense T1, heterogeneous T2, contrast enhancement, cystic component Isointense T1, hyperintense T2, heterogeneous, calcifications T1 hypointense, contrast enhancement contrast enhancement

PGCA (Snipes et al)

38 M

Atypical pleomorphic astrocytoma (Nitta et al)

30 M

67 F 25 F

Atypical pleomorphic 42 F astrocytoma (Bruce et al)

Gait disturbance, Parinaud syndrome Normal Right hand fine movements altered 5 days of headache, nausea Papilledema, incomplete T2 isointense and vomiting Parinaud syndrome Sudden right weakness and Right hemiparesis, left Partial enhancement loss of conciousness homonoymous lower quadrantonopsia 2-month history of Normal Hyperintense T1, hyperintense T2, headache hyperintense FLAIR

Yes Yes (ventriculostomy) Yes Yes (VPS) Yes (VPS) Yes (VPS)

Yes (ventriculostomy)

PXA: Pleomorphic xanthroastrocytoma, FLAIR: Fluid-attenuated inversion recovery,

hypointense on T1WI and heterogenous on T2WI, with a contrast‑enhancing solid component and a larger, peripherally enhancing cystic component located ventrally.[34] The favorable prognosis of these tumors coupled with the lack of a unique radiological appearance emphasizes the need for histological confirmation of all pineal lesions.

Histologically, PXA tumor cells appear markedly pleomorphic with bizarre, multinucleated giant cells that vary in size and shape. Intracytoplasmic lipid droplets are often present. There is variable infiltration of the underlying brain parenchyma.[11] Mitoses can sporadically be present but necrosis is usually not seen. A basement membrane surrounding the tumor cells might suggest an origin in a subpial astrocyte population.[26] GFAP immunoreactivity is usually positive within the cytoplasm of pleomorphic cells and a reticulin stain shows a rich reticulin network among the tumor cells. Granular bodies with various degrees of eosinophilia are also a regular feature of the tumor.[11] PXAs also contain neuronal antigens, such as betaIII tubulin, synaptophysin, and neurofilament proteins.[12] Pleomorphic granular cell astrocytoma (PGCA) is a tumor with many histologic features that resemble PXA. However, unlike PXA, it has large numbers of mitochondria and does not have reticulin fibers or a basement membrane between adjacent cells.[26,28] Additionally, PGCA features coarse granular cells containing d‑periodic acid Schiff‑stained material.[26] It has also been proposed that the presence of retinal S‑antigen and a lack of desmoplasia are distinguishing factors between PXA and PGCA.[32] Ohta et al. also report focal immunostaining for synaptophysin.[28] Nitta et al. described a pineal gland tumor that could not strictly be defined as PXA or PGCA and was labeled

an atypical pleomorphic astrocytoma.[26] This tumor resembled PXA/PGCA in its histopathological and morphological features but lacked the d‑periodic acid Schiff‑stained material, and was negative for retinal S‑antigen. Furthermore, electron microscopy failed to demonstrate increased mitochondria within the tumor cells. Despite inconclusive studies, the overall favorable prognosis remained consistent with PXA/PGCA and the patient was followed for 7 years without signs of recurrence following surgery without adjuvant therapy.

Similarly, the tumor reported here lacks specific criteria to meet a strict diagnostic category. While it demonstrates pleomorphic nuclei, a strong reticulin network as seen in PXA is lacking. Of even greater peculiarity is the GFAP staining, which, in most areas, resembles a reactive astrocytic process. However, there are discrete areas in which the tumor cells themselves are GFAP positive.

This is similar to what was encountered in the atypical pleomorphic astrocytoma described by Nitta et al. While the tumor reported here has features of PXA and of PGCA, perhaps it is best described as a pleomorphic neuroepithelial neoplasm of the pineal gland.

Astrocytes of the pineal gland are largely believed to give rise to these pleomorphic tumors.[20] In the presented case, the tumor appears to predominantly contain an astrocytic signature only insofar as a reactive process. There are, however, limited focal areas with tumor cells that stain positive for GFAP. Kumar et al. noted that involvement of adjacent brain is variable with tumors of the pineal region.[20] In addition to the native astrocytes and interstitial cells of the pineal gland, ependymal cells of the third ventricle and glial cells from the brainstem may also contribute to tumor mass. It is possible that the range of tumor histology

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Table 2: Summary of treatment and outcome of pleomorphic neoplasms of the pineal region in the literature Case

Approach

Postop deficits

Expression markers

Additional treatment

Outcome

1 - PXA (Srinivas et al)

Occipital transtentorial

Upward gaze palsy

No additional treatment

2 - PXA (Thakar et al)

Occipital transtentorial

-

Ki67<1%, GFAP+, S100+, CD34GFAP+

3 - Anaplastic PXA (Katayama et al)

Interhemispheric transtentorial

Parinaud syndrome

4 - PGCA (Ohta et al)

Occipital transtentorial

Left homonymous hemianopsia

Biopsy only + TMZ + vincristine + INF-b + local radiation therapy (54 Gy) No additional treatment

5 - PGCA (Snipes et al)

Unknown

-

Ki67 32.7%, GFAP+, S100+, Synaptophysin-, CD34Ki67 6%, GFAP+, S100+, Synaptophysin+, EMA-, CD68-, PAS+ GFAP+, S100+

No recurrence at 1 year No recurrence at 1 year Tumor reduction at 10 months

6 - PGCA (Snipes et al)

Unknown

GFAP+, S100+, Vimentin+

45 Gy + reoperation on residual tumor

7 - Atypical pleomorphic astrocytoma (Nitta et al) 8 - Atypical pleomorphic astrocytoma (Bruce et al)

Occipital transtentorial

Posterior fossa diffuse edema with comatose state -

S100+, Vimentin-

No additional treatment

No recurrence at 7 years

Parinaud syndrome

Ki67 1.6%, GFAP+, Synaptophysin+, EGFR+, CD34-

No additional treatment

No recurrence at 3 months

Supracerebellar infratentorial

No additional treatment

56 Gy

No recurrence at 2 years No recurrence at 8 years No recurrence at 1.5 years

PXA: Pleomorphic xanthroastrocytoma, PGCA: Pleomorphic granular cell astrocytoma, GFAP: Glial fibrillary acidic protein, EGFR: Epidermal growth factor receptor

encountered among these pleomorphic neoplasms is a result of varying degrees of contribution from the local cell populations.

Interestingly, the pathological and immunohistochemical variability seen among PXA, PGCA, and the atypical tumor described here and encountered by Nitta et al. are of less clinical consequence than the overall proliferation indexes of these tumors. All seven reported pleomorphic tumors of the pineal gland shared favorable outcomes [Table 2]. This suggests that absence of frequent mitoses and necrosis may be more predictive of favorable clinical outcome in these pleomorphic neoplasms. As a result, surgical treatment alone appears curative across the larger family of these neoplasms.

Pineal region tumors span a highly diverse spectrum of histologies ranging from benign to malignant. Accurate histologic diagnosis is essential for optimal clinical management but can be difficult to achieve because of the propensity for mixed tumor pathologies and heterogeneity in the pineal region. In this case, the patient was managed with craniotomy and open microdissection to achieve the goals of definitive diagnosis by maximizing the amount of tissue provided to the pathologists. Open microsurgical procedures have the added benefit of facilitating gross total resection while minimizing the potential for tumor‑associated hemorrhage. Alternate approaches including stereotactic biopsy or endoscopic biopsies are acceptable but provide only limited tissue sampling

and ignore the benefits of tumor debulking achievable with open resection, especially for benign, encapsulated tumors. While multiple studies have demonstrated safety and efficacy of endoscopic techniques[2,9,10,27,37] the decision between endoscopic biopsy and open craniotomy depends on several factors including ventricular size, the relative position of the tumor, the dimension of the massa intermedia, the surgical goals of resection/tissue sampling, and, particularly, the vascularity of the tumor and the likelihood of biopsy‑associated hemorrhage.[23]

CONCLUSION The present case highlights the exotic nature of pineal region tumors with pleomorphic cell histology. Given the diverse range of tumors encountered in the pineal region, pathological confirmation is mandatory. Favorable clinical outcomes demonstrate that surgical resection alone can yield excellent long‑term results for tumors falling within the spectrum of pleomorphic lesions of the pineal gland.

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Surgical Neurology International

OPEN ACCESS For entire Editorial Board visit : http://www.surgicalneurologyint.com

Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Letter to the Editor

The death of Stalin – was it a natural death or poisoning?

Miguel A. Faria Clinical Professor of Neurosurgery (ret.) and Adjunct Professor of Medical History (ret.), Mercer University School of Medicine; President, www.haciendapub.com, Macon, Georgia, USA E‑mail: *Miguel A. Faria - hfaria@windstream.net *Corresponding author Received: 20 May 15 Accepted: 08 June 15 Published: 30 July 15 This article may be cited as: Faria MA. The death of Stalin - was it a natural death or poisoning?. Surg Neurol Int 2015;6:128. http://surgicalneurologyint.com/surgicalint_articles/The-death-of-Stalin-–-was-it-a-natural-death-or-poisoning?/ Copyright: © 2015 Faria MA. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Dear Editor, The late scholar and medical researcher Plinio Prioreschi (1930–2014) MD., Ph.D., warned physicians and surgeons of the danger of neglecting medical history and delegating the task to social historians or journalists with little or no medical or surgical knowledge. Dr. Prioreschi summarized the point by stating that competent medical history is medicine. Medicine being a very esoteric field cannot easily be mastered by nonphysicians. Prioreschi wrote, “the asymmetry (in esoterism) between science and the humanities…allows the physicist to be a poet but forbids a poet to be a physicist.”[5] The same goes for historians and physicians. Because of the high degree of esoterism involved in medicine, physicians can be historians, but historians cannot be physicians without training in medicine.[5] The mysterious death of Stalin is an excellent and instructive case in point.

On the fiftieth anniversary of Joseph Stalin’s death, the British newspaper, the Daily Mail, headlined, “It’s official! Stalin died of natural causes: Autopsy published for 1st time says Soviet leader suffocated after suffering a stroke death as from ‘natural causes.’”[4] Neither the journalist nor historian involved in this article apparently were aware of the article I wrote in Surgical Neurology International 2 years previously concluding with the strong possibility of the complete opposite. Two previous books[2,6] had already done a lot of footwork on Stalin’s final hours and ended, as I did, strongly suggesting the possibility that Stalin was poisoned by members of his own inner circle, led by the head of the secret police, Minister of State Security Lavrenti Beria.[3] The work of those authors was supported by the portion of the autopsy report that was published in Pravda in 1953 and which I cited in my article:

“AUTOPSY OF THE BODY OF J. V. STALIN: Postmortem examination disclosed a large hemorrhage in the sphere of the subcortical nodes of the left hemisphere of the brain. This hemorrhage destroyed important areas of the brain and caused irreversible disorders of respiration and blood circulation. Besides the brain hemorrhage there were established substantial enlargement of the left ventricle of the heart, numerous hemorrhages in the cardiac muscle and in the lining of the stomach and intestine, and arteriosclerotic changes in the blood vessels, expressed especially strongly in the arteries of the brain.

These processes were the result of high blood pressure.

“The findings of the autopsy entirely confirm the diagnosis made by the professors and doctors who treated J. V. Stalin.

“The data of the postmortem examination established the irreversible nature of J. V. Stalin’s illness from the moment of the cerebral hemorrhage. Accordingly, the energetic treatment which was undertaken could not have led to a favorable result or averted the fatal end.

“U.S.S.R. Minister of Public Health A. F. Tretyakov; Head of the Kremlin Medical Office I. I. Kuperin; Academician N. N. Anichkov, President of the Academy of Medicine; Prof. M. A. Skvortsov, Member of the Academy of Medicine; Prof. S. R.”[1] Access this article online Quick Response Code: Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161789

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What the Daily Mail journalist and the social historian did not understand is that if there was evidence of hemorrhage in any body system other than the brain, then this was strong evidence for a bleeding diathesis or poisoning as I described. Stalin did not have a history of a bleeding diathesis or treatment with anticoagulation, therefore poisoning by systemic anticoagulation is the most likely cause for the “numerous hemorrhages in the cardiac muscle and in the lining of the stomach and intestine.”[1] If the bleeding had been restricted to the brain, as with a hypertensive cerebral hemorrhage, then we could have safely ascribed the cause of death as “suffocation after suffering a stroke,”[4] but that was not the case.

I conveyed this information to the historian consulted by the Daily Mail and asked for clarification, comment or rebuttal but received no response. And so I correct the record with this correspondence in SNI. I explained in my article why the Soviet doctors, who signed the autopsy report, may have been reluctant to propound any cause of death other than natural causes.

Lavrenti Beria, the head of the secret police, was then the head of the ruling hierarchy in the Soviet Union, and it was he who would have been the number one suspect. The admission of poisoning of Stalin would have led to Beria as a suspect if not the culprit. So poisoning as the cause of death would have been out of the question as the official cause of Stalin’s death in the official autopsy report.

new masters at the Kremlin. High blood pressure, per se, commonly results in hypertensive cerebral hemorrhage and stroke but does not usually produce concomitant hematemesis (vomiting blood), as we see here in the clinical case of Stalin, and a further bleeding diathesis affecting the heart muscle, scantily as it is supported by the positive autopsy findings.

As I have written elsewhere, we now possess clinical and forensic evidence supporting the long‑held suspicion that Stalin was indeed poisoned by members of his own inner circle, most likely Lavrenti Beria, and perhaps even Nikita Khrushchev, all of whom feared for their lives.

However, Stalin, the brutal Soviet dictator, was (and still is in some quarters of Democratic Russia) worshipped as a demigod – and his assassination would have been unacceptable to the Russian populace. So it was kept a secret until now.[3] I have concluded this letter citing my previous article above, as it remains unchallenged with no new disputing scholarship in the medical or historical literature. We continue to believe Stalin was poisoned unless the autopsy findings cited above are found to be erroneous or fabricated, which is very doubtful.

REFERENCES 1.

2.

The doctors from the Ministry of Health who signed the autopsy and other medical reports acted cautiously:[3]

3.

As much as was possible to put in writing from a political standpoint, without getting their own heads into the repressive Soviet noose (was included in the autopsy report)! They also correctly protected the physicians who treated Stalin. Needless to say, the Doctors’ Plot episode was very fresh in their minds.[2]

4.

While prudently citing hypertension as the culprit, the good doctors left behind enough traces of pathological evidence in their brief report to let posterity know they fulfilled their professional duties, as best they could, without compromising their careers or their lives with the

5.

6.

Autopsy of the Body of J.V. STALIN. Pravda, March 7, 1953, p. 2.

Brent J and Naumov VP. Stalin’s Last Crime — The Plot Against the Jewish Doctors, 1948-1953. New York, NY: HarperCollins; 2003, p. 312-22.

Faria MA. Stalin’s mysterious death. Surg Neurol Int 2011 2:161. Available from: http://surgicalneurologyint.com/surgicalint_articles/stalins-mysteriousdeath/ [Last accessed on 2015 May 20].

Hall A. It’s official! Stalin died of natural causes: Autopsy published for first time says Soviet leader suffocated after suffering a stroke. Daily Mail, March 12, 2013. Available from: http://www.dailymail.co.uk/news/article-2292123/Stalindied-natural-causes-Autopsy-published-time-says-Soviet-leader-suffocatedsuffering-stroke.html#ixzz3YcALIvD4 [Last accessed on 2015 May 20].

Prioreschi P. A History of Medicine. Vol. I: Primitive and Ancient Medicine.

Omaha, Nebraska: Horatius Press; 1995. p. xvii-xxx. [See my review of this book in Surg Neurol Int 2015;6:87.Available from: http://surgicalneurologyint. com/surgicalint_articles/a-fascinating-look-at-primitive-and-ancient-medicineby-medical-historian-and-classical-scholar-plinio-prioreschi-md-phd/ [Last accessed on 2015 Jun 15].

Radzinsky E. Stalin: The First In-depth Biography Based on Explosive New Documents from Russia’s Secret Archives. Translated by Willetts H T. Anchor Book Edition. September 1997, p. 566-82.

Surgical Neurology International

OPEN ACCESS For entire Editorial Board visit : http://www.surgicalneurologyint.com

Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Original Article

Chronic subdural hematoma: Surgical management and outcome in 986 cases: A classification and regression tree approach Aristedis Rovlias, Spyridon Theodoropoulos, Dimitrios Papoutsakis Department of Neurosurgery, Asclepeion General Hospital, Athens, Greece E‑mail: *Aristedis Rovlias - arovlias@yahoo.com; Spyridon Theodoropoulos - spyridon.theodoropoulos@yahoo.gr; Dimitrios Papoutsakis - dim.tsakis@yahoo.gr *Corresponding Author Received: 06 April 15 Accepted: 19 June 15 Published: 30 July 15 This article may be cited as: Rovlias A, Theodoropoulos S, Papoutsakis D. Chronic subdural hematoma: Surgical management and outcome in 986 cases: A classification and regression tree approach. Surg Neurol Int 2015;6:127. http://surgicalneurologyint.com/surgicalint_articles/Chronic-subdural-hematoma:-Surgical-management-and-outcome-in-986-cases:-A-classification-and-regression-treeapproach/ Copyright: © 2015 Rovlias A. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Chronic subdural hematoma (CSDH) is one of the most common clinical entities in daily neurosurgical practice which carries a most favorable prognosis. However, because of the advanced age and medical problems of patients, surgical therapy is frequently associated with various complications.

This study evaluated the clinical features, radiological findings, and neurological outcome in a large series of patients with CSDH. Methods: A classification and regression tree (CART) technique was employed in the analysis of data from 986 patients who were operated at Asclepeion General Hospital of Athens from January 1986 to December 2011. Burr holes evacuation with closed system drainage has been the operative technique of first choice at our institution for 29 consecutive years. A total of 27 prognostic factors were examined to predict the outcome at 3‑month postoperatively.

Results: Our results indicated that neurological status on admission was the best predictor of outcome. With regard to the other data, age, brain atrophy, thickness and density of hematoma, subdural accumulation of air, and antiplatelet and anticoagulant therapy were found to correlate significantly with prognosis. The overall cross‑validated predictive accuracy of CART model was 85.34%, with a cross‑validated relative error of 0.326.

Conclusions: Methodologically, CART technique is quite different from the more commonly used methods, with the primary benefit of illustrating the important prognostic variables as related to outcome. Since, the ideal therapy for the treatment of CSDH is still under debate, this technique may prove useful in developing new therapeutic strategies and approaches for patients with CSDH.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161788 Quick Response Code:

Key Words: Chronic subdural hematoma, neurological outcome, prediction tree INTRODUCTION Chronic subdural hematoma (CSDH) represents one of the most frequent types of intracranial disorder which carries a most favorable prognosis when diagnosed accurately and treated adequately. A steady increase in

the incidence of CSDH has been observed in developing countries due to the rise in life expectancy.[20,35,52,67] The standard treatment for CSDH is a surgical evacuation, which usually results in improvement of the neurological picture. This condition has been

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treated by various surgical procedures such as burr holes evacuation, the most popular technique worldwide, twist – drill craniostomy, craniotomy, endoscopic removal, and subdural – peritoneal shunt.[3,19,32‑34,42,44,46] However, all these procedures are associated with various complications.[6,27,32,33,45] Numerous factors potentially associated with the outcome of patients with CSDH have been reported, although the postoperative neurological outcome of CSDH has not improved substantially over the past 30 years.[1,7‑9,14,17,20,24,25,35‑38,60‑62,64,66] Classification and regression tree (CART) is an alternative statistical method of making predictions from data based on repeated partitioning of the dataset into more homogeneous subgroups.[5,54,55] CART searches for combinations of values of independent variables that best predict the value of the dependent variable and results are presented as “decision trees.”

In our department, burr holes evacuation with closed system drainage has been the operative technique of first choice for 28 consecutive years. The aim of this study is to present our experience of the surgical management of a 986 patients with CSDH and to emphasize the importance of the factors that contribute to neurological outcome, by developing a simple CART model involving a wide set of several variables and parameters possibly related to prognosis. The constructed tree shows that the sequence of important prognostic factors varies among a different group of patients.

MATERIALS AND METHODS

Patient characteristics

This clinical study includes 986 adult patients with CSDH, who were treated surgically at the Neurosurgical Department of Asclepeion General Hospital of Athens, from January 1986 to December 2011. This series represents the experience of our neurosurgical unit, a reference center covering a wide area, in managing 986 CSDH cases with burr holes and a closed drainage system of a total of 1039 CDSH patients. Patients were included in this study if the clinical presentation was because of CSDH alone. We excluded all patients who had been previously operated elsewhere or with incomplete medical records. Subdural hygromas, calcified or ossified CSDHs (the so‑called “armored brain”), asymptomatic CSDHs, and patients who were inadequately followed up were also excluded from this study. Information was obtained retrospectively by reviewing the clinical histories.

The sample population was composed of 650 males and 336 females (ratio 1.9:1), with a mean age of 69 years (range 29–96 years). Five‑hundred and three patients (51%) had a history of head trauma, most of which were minor or moderate.

The neurological status on admission was classified according to the most common neurological grading scheme for CSDH, as proposed by Markwalder et al.[32,33]: 751 patients were in Grades 0–2 and 235 patients were in Grades 3 and 4. The leading symptom for the over 70s was behavioral disturbance (37.4%), whereas the most frequent symptom in the under 70s was a headache (28.7%).

Predisposing factors included the administration of anticoagulant (AC) or antiaggregant therapy (237 patients), alcohol abuse (132 patients), coagulopathy (89 patients), and ventriculo – peritoneal shunt (6 patients). Arterial hypertension and diabetes mellitus presented in 19% and 14% of patients, respectively. Other concomitant pathological conditions are summarized in Table 1.

In all cases, diagnosis was based on computed tomography (CT), and CSDHs were classified into four groups according to the density on CT scan: Hypodense (144 cases), isodense (426 cases), hyperdense (61 cases), or Table 1: Prognostic factors in 986 patients with CSDH Variable

Grades and definitions

Age Sex Markwalder’s clinical grade CT density of hematoma

Age in years Male or female Integer values, 0-4 0: Hypodense 1: Isodense 2: Hyperdense 3: Mixed In mm In mm 0: Absent, minor 1: Medium, large 0: Absent, minor 1: Medium, large 0: Absent 1: Present

Hematoma thicknessa,b Midline shifta,b Brain atrophy Residual air collectionb Anticoagulant - antiplatelet agents Alcohol abuse Coagulopathyc CSF shunt Arterial hypertension Diabetes mellitus Cardiovascular disease Cerebrovascular disease Chronic pulmonary disease Seizurea,b Recurrenceb Acute intracranial hematoma Superficial wound infection Subdural empyema Pathological complicationsb

Prognostic factors recorded preoperatively, bPrognostic factors recorded postoperatively, Medical condition having bleeding tendency such as liver function abnormality, hematological disorders, chronic renal failure, or receiving chemotherapy. CSDH: Chronic subdural hematoma, CT: Computed tomography, CSF: Cerebrospinal fluid

a

c

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mixed (355 cases), on the basis of the density of hematoma relative to brain tissue.[9,26,35,49,66] Radiological measures of the CSDH, including the width of hematoma and midline shift were determined based on CT scans obtained before the operational procedure. The CSDH was right sided in 434 patients (44%), left sided in 473 patients (48%), and bilateral in the remaining 79 (8%). Moreover, evidence of brain atrophy received particular attention; brain atrophy was classified into two grades: No or minor atrophy and medium or severe atrophy.[2,9,30,39,40] Routine laboratory studies before surgery included a complete blood count, platelet count, international normalized ratio, prothrombin time and activated partial thromboplastin time, and biochemical investigations.

Any antiaggregant and AC therapy was temporarily discontinued upon admission and re‑established no earlier than 4 weeks after the operation. Coagulopathy, if present, was corrected preoperatively by intravenous (IV) infusion of fresh frozen plasma, Vitamin K, or platelets.

Surgical management

Surgery was performed with mild neuroleptanalgesia and local anesthesia, and perioperative antibiotic prophylaxis was given in all cases. Moreover, all patients received postadmissionally anticonvulsants in the usual way for at least 3‑month.

The operative technique of first choice in our clinic for all these years was to deal with the hematoma through burr holes and slow evacuation and irrigation with continuous closed system drainage. Thus, the uniformity of the surgical procedure was maintained. We never tried to remove the subdural hematoma vigorously. A flat Jackson‑Pratt drain was introduced under direct vision into the subdural space, and particular precaution was taken not to injure the inner membrane of the hematoma or the brain. A mild vacuum generated suction applied, and the drainage was maintained for a period ranging from two to a maximum of 6 days postoperatively depending on the amount of draining liquid obtained. All bilateral CSDHs were operated upon at the same session.

No attempt was made to reinflate the brain by intrathecal injection of the isotonic solution in any patient.

Postoperatively, the patients were kept supine for 48 h to enhance gravitational drainage of residual subdural fluid, were adequately hydrated given 2000cc of IV fluids a day for 3–4 days to promote expansion of the brain, and were mobilized as soon as possible. If early postoperative anticoagulation was required, low molecular weight heparin was administrated.

According to our protocol, a control CT scan was done before taking out the drainage, or earlier as judged clinically appropriate. Postoperative CT scan of all patients were evaluated, and we focused on the maximum residual hematoma thickness, the midline displacement, and the amount of residual air into the subdural cavity.

The patients were assessed periodically, and CT scans were normally repeated at 6 and 12 weeks after discharge if there was any residual collection shown in the first postoperative scan, or earlier if the symptoms reoccurred.

CSDH was considered to have recurred when neurological signs and/or symptoms increased, reappeared, or did not improve within 3‑month of the original procedure and the hematoma cavity volume increased. Only patients who fulfilled both criteria underwent repeated operation.

Residual hematoma into subdural cavity following the first operational procedure without accompanying signs and symptoms, and with no high‑grade mass effect was not recognized as recurrence or as an indication for repeated surgery in this study.

All patients included in this series were followed up for at least 3‑month postoperatively. The outcome was assessed at 3‑month according to the Glasgow Outcome Scale.[21] Good recovery and moderate disability were considered to be favorable outcomes; severe disability, persistent vegetative state, and dead to be unfavorable.

Statistical analysis

It is well‑known that a certain combination of factors yields a more effective prediction of outcome than when factors are used singly. We studied a total of 27 parameters that may be related to outcome [Table 1].

The CART approach is an alternative to the traditional methods for prediction.[5,54,55] It relies on statistically optimum recursive splitting of the patients into smaller and smaller subgroups, based on the critical levels of the prognostic variables. The dataset is split into the two subgroups that are the most different with respect to the outcome. This procedure is continued on each subgroup until some minimum subgroup size is reached. Other desirable properties of CART include incorporation of nonlinear relationships and interactions between predictors, and the ability to predict the outcome of cases despite some missing data, which may be difficult or impossible using traditional multivariate techniques.

For this analysis, the selected method for growing the classification tree was Gini splitting rule, with the extra condition that, whenever possible, at least 10 patients were available at each of the final subgroups. To assess the performance of the prediction tree and the independent predictive accuracy of the model, CART uses cross‑validation. The tree presented is the one that minimizes the overall cross‑validated relative error estimate that which most accurately predicts data excluded from forming the tree.

RESULTS Postoperative complications occurred in 224 patients (22.7%). The most common complication was a recurrence of CSDH. In a total of 117 patients (11.8%)

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further surgery was required to remove a symptomatic recurrence of CSDH, and 9 cases underwent a third operation. The first recurrence was again treated by reopening the burr holes, but in patients with a second symptomatic recurrence a craniotomy was performed. The interval from the primary procedure to the re‑operation ranged from 4 days to 9 weeks.

Early major postoperative air accumulation into the subdural cavity was detected on 39 patients. None of these suffered tension pneumocephalus. In 5 patients, surgery was complicated by the development of small intraparenchymatous bleeds in the cerebral hemispheres.

All resolved gradually with no need for additional surgery.

Two patients developed an acute subdural hematoma due to preexisting severe coagulation disorder and underwent a craniotomy.

Four patients developed a superficial wound infection and underwent local debridement in addition to IV antibiotic therapy. Two patients developed subdural empyema which required a craniotomy.

Although in our series all patients were treated prophylactically with anticonvulsants, 17 (1.7%) developed early postoperative seizures.

Two more patients had a cerebral infarction, in the territory of posterior cerebral and internal carotid artery respectively.

Serious postoperative complicating diseases were recognized in 48 patients (4.8%) and were treated by methods standard at the time. Atelectasis and bronchopneumonia were the most common medical complications in 25 cases. Other postoperative pathological conditions were cardiologic problems (11 cases), thromboembolic (7 cases), renal (4 cases), and septic complications (1 case).

A prediction tree for 986 patients with CSDH based on their known 3‑month Glasgow Outcome Scale is presented in Figure 1. The ovals in this diagram denote intermediate subgroups subject to further splitting. The name of the corresponding split variable is recorded within each oval, and the actual split values are indicated in the branches of the tree. The terminal prognostic subgroups are represented by squares; within each square, the predicted rate of unfavorable outcomes and the total number of patients having that pattern in the tree are given. The subgroups, ranked according to the proportion of bad outcomes, are numbered 1–8 as denoted below the squares. Thus, for example, subgroup 1 is the group with the worst prognostic pattern (unfavorable outcome 90.6%) while subgroup 8 is the group with the best prognostic pattern (favorable outcome 97.5%).

The patients are first split on the basis of their Markwalder’s grading score (MGS) on admission, with

Figure 1: Prediction tree based on 986 patients with chronic subdural hematoma. Ovals denote intermediate subgroups subject to further splitting; squares denote terminal prognostic subgroups.

The numbers below the squares represent the prognostic rank of each subgroup based on the proportion of unfavorable outcomes.

ACs: Anticoagulants, Aps: Antiplatelet agents, CT: Computed tomography, MGS: Markwalder’s grading score

the cut‑off point at 2. Patients with a good neurological status on admission (Grades 0–2) are separated from those having poor neurological grades of 3 and 4.

Subsequent splits in these two major branches of the tree show different patterns. Patients who were very drowsy or worse (Grades 3 and 4) tend to have reasonably an unfavorable outcome unless they have both an absence of AC taking and are not very aged. For those no very elderly patients without ACs and antiplatelets, CT density of CSDH, the next split of the tree, also plays an important role in determining the outcome in certain patients. Thus, two of the earliest splits for the MGS ≥3 are based on age and usage of AC – antiaggregant agents, suggesting that these variables have a greater effect on outcome in these patients.

Patients with a MGS of two or less tend to have a favorable neurological outcome, with pre‑ and post‑operative CT scan findings appearing in subsequent splits. Considerable brain atrophy, high preoperative hematoma thickness, and a large amount of postoperative subdural air predispose an unfavorable outcome.

Prediction of outcome for a patient is accomplished by simply running that patient down the CART tree, according to the values of the prognostic variables.

For example, a very elderly patient with a poor MGS of three or four would be placed in subgroup 1. The predicted outcome for such a patient is severely disabled, vegetative, or dead. In contrast, a patient with a better

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clinical score with neither brain atrophy nor postoperative subdural air would fall into subgroup 8, and the expected outcome is good recovery or moderately disabled.

Because the conventional methods of assessing tree accuracy can be wildly optimistic, cross‑validation is the method CART normally uses to obtain objective measures for smaller data sets. This CART model, with eight terminal nodes, had a grossly accuracy rate of 89.56%, a cross‑validated predictive accuracy of 85.34%, and a cross‑validated relative error of 0.326. The proportion of cases correctly classified in each outcome category and for the entire dataset is summarized in Table 2. Moreover, the application of bootstrap aggregation and adaptive resampling and combining methods did not change the predictions from the single CART tree (model stability).

DISCUSSION Treatment of CSDH has improved dramatically in recent years because of advances in diagnostic tools and surgical techniques. However, there is still some debate regarding the best strategy for treatment. The burr holes evacuation, irrigation, and subsequent closed drainage technique is a simple treatment which is able to achieve good results with minimal complications and is at present favored.[2,35,38,40,43,48] Although this method may lead to recurrences, it is preferable to postpone craniotomy until the subdural collections repeatedly re‑accumulate, or there is a solid hematoma or marked cerebral swelling underneath the CSDH site.[13,19,33,34,57] Some authors suggest that the applied operative technique is not always of major importance, as long as it is able to suck out the subdural fluid slowly, is performed properly without injuring again the subdural space, and is followed by precise and competent nursing.[29,46,64,65] Early identification of reliable prognostic factors for patients with CSDH is of great importance. Many of the previous clinical studies have begun with several variables from which the best candidates determined on statistical criteria were selected. However, this approach to the problem ignores the potential differences between the candidate predictors among various patient subgroups.

Table 2: Prediction success table for cross‑validated sample based on in 986 patients with CSDHa Predicted class Actual class Unfavorable outcome Favorable outcome Predicted total Correct (%)

Unfavorable outcome

Favorable outcome

Actual total

142 71 213 85.02

25 748 773 91.33

167 819 986

a Overall cross‑validated accuracy rate=85.34%, Cross‑validated relative error=0.326.

CSDH: Chronic subdural hematoma

Another common problem is that only a few of the previous clinical studies provide information about the critical point thresholds of each indicator beyond which the risk of a good outcome is substantially increased or decreased.

The results of this study reinforce many previous findings on prediction of outcome for patients with CSDH. Previous studies have clearly reported the bad outcome in patients with lower neurological status on admission.[2,11,12,32,33,45,62] As always in neurosurgery, poor neurological condition on admission has a negative effect on the outcome. In the past, comparisons between the reported series of CSDH were frequently difficult to make as outcome was influenced by the proportion of patients who were drowsy or comatose, with or no neurological symptoms and focal defects, and MGS of clinical state was a valuable contribution to this problem, in the same way that grading has been for head injury and spontaneous subarachnoid hemorrhage.[32,33] This well‑recognized scale has been adopted by many authors because of its simplicity and becomes more useful when combined with other variables. Our results suggest that a higher MGS of three and four was closed related to an unfavorable neurological outcome in agreement with earlier reports.

As medical science and public health measures brought the majority of diseases of elderly patients under control, the number of elderly people increased and will continue to do so. Many studies support the belonging of CSDH to brain aging pathology and with the advent of CT scan, an increasing number of aged patients affected by CSDH are diagnosed at an earlier stage of the disease. Age is also generally thought to be a strong predictor of prognosis, and most studies have shown worse prognosis in patients with increasing age.[11,28,35,43] In our series, an unfavorable outcome was associated with increasing age beyond the CART threshold of 76 years. Although elderly did tend to do less well, advancing age was not always bar to success.

No elderly patient should be denied low‑invasive surgery, as the chances of recovery are not zero.[18,41,67] After the introduction of CT scanning, diagnosis and outcome of CSDH became much improved. Several authors have proposed various radiological classifications for CSDH, concentrating on the density of hematoma relative to brain tissue,[9,26,35,37,39,49,66] internal architecture which corresponds to possible stages in the natural history of CSDH,[37] and location of hematoma according to the intracranial extension.[37] Our CT variable was designed to be a simple easily identifiable density feature, and CT results were simplified to four diagnostic categories.

Evidence of brain atrophy received particular attention since several studies have shown that the presence of brain atrophy in CSDH is associated with a worse outcome.[2,30,39,40]

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The density of hematoma on CT scan represents the proportion of fresh blood clots in hematoma cavity.

The imaging appearance of the CSDH on CT scans may help identify fresh blood from re‑bleeding, suggest the age of the hematoma, and reflect upon the protein concentration from plasma exudation.[16,37,59] Thus, hyperdense and mixed appearances are considered to have a greater tendency to re‑bleeding and higher protein exudation rates.[20,39,59] Recent experimental studies have revealed that blood in the subdural space evokes an inflammatory reaction and because of this, the CSDH is more active.[9,15] Our data indicated that high density and mixed hematomas were related to an unfavorable postoperative outcome. In contrast, patients with isodense and hypodense CSDH had a better neurological prognosis. These findings correspond well to some previous results reported in the literature.[2,11,23‑25,37,39] In our opinion, for the initial treatment of CSDH, complete withdrawal of the subdural fluid, which contains the fibrinolytic agents, by adequate rinsing of the hematoma cavity, is more important per se than the selected operative procedure or membranectomy.

The size of a CSDH at the time of diagnosis can be impressive, and its volume may be a predictor of the postoperative course.[20,40,56] Increased size of hematoma is often attributed to brain atrophy associated with aging, which may provide the CSDH with a potential space in which to grow.[52] The intracranial pressure – volume function reflects the elastic properties of the brain parenchyma, the cerebrovascular bed, and the supporting dural structures within the rigid cranium.

Intracranial volume changes are superimposed on the intracranial pressure – volume function of brain elasticity.

The elasticity function may be altered by advanced age, brain atrophy, a large amount of CSDH, and prolonged compressed parenchyma. Brains with high elastance tend to re‑expand poorly since postoperative subdural space is larger, and this may lead to persistence of postoperative midline shifting and residual air.[17,39,45,50,51,60] In previous studies, the recurrence rate and the bad outcome of CSDH were higher in patients with greater width of hematoma, cerebral atrophy, and significant subdural air accumulation, and this is in agreement with our series.[2,22,23,35,37,39,40,45,58,60,62,66] In the present study, wider hematomas with a preoperative maximum thickness superior to 20 mm, considerable brain atrophy, and larger amounts of residual air into hematoma cavity were related to the worst prognosis. In these patients, caution not to tear the inner membrane of the CSDH or arachnoid membrane, complete replacement of CSDH fluid by normal saline to prevent intraoperative influx of air into the subdural cavity, postoperative bed rest with adequate IV fluid administration, and maintenance of the drain for a longer period with continuum of antibiotics as long as the catheter remains inserted might prevent a

worse outcome by facilitation of brain re‑expansion and elimination of the possibility of systemic and intracranial hypotension.[1,34,35,39] Recently, with increasing numbers of elderly people in the general population, the number of patients who are treated with ACs and antiplatelets is also increasing.

These agents are commonly used as prophylactics against cerebral ischemic stroke, myocardial infarction, valvular heart disease or deep venous thrombosis. Bleeding diatheses is well‑known risk of these drugs and both have historically been considered as risk factors for CSDH. Anticoagulation and antiplatelet agents are certainly dangerous, because are the causes of the pathology in some cases without evidence of trauma, may add to the risk of CSDH by as much as 42.5 times, have a positive influence on the recurrence of CSDH, and are at least partly responsible for the unfavorable outcome of several patients.[7,8,10,11,14,31,47,62,65] Considering the increasing number of aged patients who use antiplatelet and AC medications, attention should be focused on the possible risks of these treatments. Since the exposure to antiplatelets and ACs increases the risk of developing a CSDH, as well as the risk of reoperation and of a worse prognosis after surgery, the indication to these therapies should strictly follow the current evidence in order to avoid a dangerous undue risk‑benefit imbalance.[68] Furthermore, it’s of outmost importance the preoperative discontinuation of any therapy with these agents or the correction of any preexisting coagulopathy in patients with CSDH. It is a basic assumption that CSDH should be removed by simple means. Convincing evidence has accumulated that burr holes technique is a safe, time‑saving, and rational treatment which can be performed for elderly patients or those with multiple medical problems using local anesthesia and is usually able to achieve favorable results with minimal complications.[8,12,25,38,43] Postoperative recurrence of CSDH is not rare and has always been a source of frustration for neurosurgeons. Thus, it comes as no surprise that the vast majority of the published articles focus on this matter.[11,26,28,38,40,45,61,62,64,68] Asymptomatic persistent subdural fluid may take up to several weeks for a complete resolution, and can be followed with serial studies until its resolution without surgical intervention.

Thus, to evaluate this outcome, longer follow‑up periods are necessary.[4,53] Because of these, we were mainly interested in the overall outcome of patients with CSDH based principally on the evolution of the clinical course and all our patients had a postoperative follow‑up during an interval up to 3‑month. In this period, many cases slowly improved, but some deteriorated or died of related or unrelated causes; multiple internal diseases might affect prognosis more than hematoma’s management.

A zero mortality rate in any large series is impossible as there will always be late cases on poor MGS or those

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patients with serious complicating illnesses, particularly in the elderly.

In this analysis, CART was used as an alternative method to predict neurological outcome in 986 patients with CSDH, who were treated surgically with specific inclusion and exclusion criteria. Our results indicate that neurological status on admission (MGS) was the best predictor of outcome. With regard to the other data, the most already widely examined variables such as age, brain atrophy, CT scan findings, or usage of antiplatelet and AC agents proved again to be strong predictors and were found to correlate significantly with prognosis.

The sequence of “splits” points out possible interactions between predictors. For example, effects of aging and AC – antiplatelet therapy appear sooner among patients with a high Markwalder functional score, whereas CT scan findings tend to exert an early influence when the neurological status is less severe. However, these different splits in different branches may just represent variations in small samples with uncertain interaction or clinical importance and need probably to be investigated in a larger prospective clinical study.

Moreover, although the neurological grade on admission emerges as the most powerful early predictor of outcome, radiological variables, such as thickness and density of subdural collection and postoperative accumulation of air into the subdural cavity, might help identify different groups of patients even within the same levels of neurological severity.

Although 27 potential prognostic factors were considered in this study, only seven were actually used in the construction of the CART tree. Several of these have been shown to be effective predictors of outcome in previous studies. The fact that one predictor does not appear in the tree does not necessarily reflect a lack of relationship: This relationship may be subsumed by another variable.[5,54,55] We found that for each split, a short list of “competitor” splits describes the best alternative splits at that point. For example, severe associated diseases, midline displacement, and postoperative pathological complications often appear as competitors in CART analyses and possess a significant predictive power, even though they do not appear in Figure 1.

In our knowledge, this is the first study using a CART model to predict the neurological outcome of patients with CSDH. The overall cross‑validated predictive accuracy of our CART tree was 85.34%, with a cross‑validated relative error of 0.326. We compared these rates with those obtained with the most traditional method of the logistic regression analysis performed with the same prognostic factors. There was only a slight difference which did not seem to be impressive.

Methodologically, however, CART is quite different from the more commonly used statistical methods. Predictions are read directly from the tree diagram with no requiring specific measurements to derive the patients’ outcome.

Based on subgroups, the CART system may indicate important relationships between study variables more clearly than corresponding regression analyses when the relationships are not linear or additive. In addition, one can use CART if some predictors are missing. One disadvantage of the model is the need to split each prognostic factor into two possible groups at each stage of a tree’s construction. Although this is fine for variables that could take only two values, it might produce slightly arbitrary categorizations of continuous variables. Thus, care should be taken with patients near the cut‑off point, with perhaps the more optimistic route being explored first.[5,54,55] A large number of papers have been published on the subject of CSDH and many methods of treatment have been proposed, although the ideal standard therapy has not been definitely established and is still under debate. The mechanism by which the subdural collection increases in size and induces anatomical and biological changes is still a fascinating problem. A further research on the complex pathophysiology, methodology of management, and extent of surgical treatment of CSDH might give explanations, but the standard treatment will probably not change much in the near future. Thus, there is a need for properly conducted prospective trials on therapeutic approaches for CSDH. It might also be worthwhile seeking alternative strategies in the treatment of this frequent condition.[63] Although the present study was retrospective, and, therefore, imposes certain limitations, or may have sources of bias and variations, this CART technique is a visually useful simple way to look at the late prognosis of patients with CSDH. A tree diagram, illustrating the prognostic pattern, provides some threshold values that split the patients into subgroups with varying degrees of risk.

It is of outmost importance, however, that this technique is meant to supplement, not to replace or cloud the neurosurgeon’s clinical judgment and other predictive factors. Moreover, course and outcome of patients with a CSDH can be influenced, and often irrevocably altered, by several factors and unsuspected serious medical complications.

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Surgical Neurology International

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Case Report

C1–C2 cryptic cerebrospinal fluid leak directly identified by pressurized radionuclide cisternography: Case report and review of the literature Stephanie Reed Falatko1, Prashant Kelkar1, Pradeep Setty1, Doris Tong2, Teck Mun Soo1,2 Department of Surgery, Section of Neurosurgery, Providence Hospital and Medical Centers, Michigan State University, East Lansing, 2 Department of Neurosurgery, Michigan Spine and Brain Surgeons PLLC, Providence Hospital and Medical Centers, MI 48075, United States of America 1

E‑mail: *Stephanie Reed Falatko ‑ sreed.falatko@gmail.com; Prashant Kelkar ‑ DrPSetty@gmail.com; Pradeep Setty ‑ pkelkar1981@gmail.com; Doris Tong ‑ doris.tong@michiganspineandbrainsurgeons.com; Teck Mun Soo ‑ tsoo111292MI@comcast.net *Corresponding Author Received: 16 February 15 Accepted: 19 May 15 Published: 29 July 15 This article may be cited as: Falatko SR, Kelkar P, Setty P, Tong D, Soo TM. C1-C2 cryptic cerebrospinal fluid leak directly identified by pressurized radionuclide cisternography: Case report and review of the literature. Surg Neurol Int 2015;6:126. http://surgicalneurologyint.com/surgicalint_articles/C1–C2-cryptic-cerebrospinal-fluid-leak-directly-identified-by-pressurized-radionuclide-cisternography:-Case-report-andreview-of-the-literature/ Copyright: © 2015 Falatko SR. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Patients with chronic postural headaches may suffer from spontaneous intracranial hypotension (SIH). Trauma, degenerative disc spurring and connective tissue disorders are documented risk factors; in most cases there is no inciting event. Despite sophisticated means of evaluating the neuraxis, many cerebrospinal fluid (CSF) leaks are radiographically occult and treatment is focused on thoracic and cervical‑thoracic regions. Although lumbar epidural blood patch (EBP) is the initial treatment of choice after failed conservative management, several studies document the need for treatment aimed at the specific leak area.

Case Description: This report describes the case of a 42‑year‑old female with scleroderma and sudden onset postural headaches. Magnetic resonance imaging revealed diffuse pachymeningeal enhancement suggestive of intracranial hypotension. Computed tomographic myelography demonstrated a collection of fluid ventral to the cervical thecal sac; an exact location for CSF egress was not identified. Conservative measures followed by lumbar EBP failed to alleviate her symptoms. The patient underwent placement of a lumbar drain and dynamic radionuclide cisternography (RIC). Panoramic images of the spine were taken at the time of the pressurized saline injection. The CSF leak was clearly visualized at C1–2. Treatment was focused at this region using percutaneous injection of autologous blood and fibrin glue.

Conclusion: SIH is disabling if left untreated. Spinal CSF leaks are often discrete and difficult to identify using static imaging. The use of pressurized, RIC by lumbar drain injection allows for the real‑time evaluation of CSF dynamics and can more precisely identify slow flow leaks often missed with static imaging.

Key Words: Epidural blood patch, percutaneous, radionuclide cisternography, spontaneous cerebrospinal fluid leak, spontaneous intracranial hypotension

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161787 Quick Response Code:

Surgical Neurology International 2015, 6:126 http://www.surgicalneurologyint.com/content/6/1/126

INTRODUCTION

Background and importance

Spontaneous intracranial hypotension (SIH) typically results from a spontaneous cerebrospinal fluid (CSF) leak,[17,21] most common in the thoracic or cervical‑thoracic regions.

Descent of the brain due to CSF hypovolemia causes tension on pain sensitive structures such as the meninges and blood vessels, leading to headaches that initially improve with recumbence. Mechanical factors combined with an underlying structural dural disorder cause the primary spontaneous spinal CSF leak.[20,21,24,28,30] SIH, including its various clinical presentations as well as pathophysiological mechanisms, has been well documented in the literature.[14,25‑27,28] Despite our understanding of the disease and the advanced imaging modalities available to evaluate the cranial‑spinal axis, often a structural lesion is not identified and small or radiographically occult tears in the dura or nerve sleeves are considered responsible.[24] Most studies that have examined the utility of the different imaging modalities‑magnetic resonance imaging (MRI) or computed tomographic myelography (CTM), digital subtraction myelography (DSM) or radionuclide cisternography (RIC)‑acknowledge that in a subset of patients the CSF leak flow pattern falls below the resolution of standard imaging.[5,9,10,15,23,32,35] In this population of patients standard imaging misses slow flow, intermittent CSF leaks that can be identified using pressurized, dynamic RIC.

Clinical presentation Presentation and examination

This patient is a 42‑year‑old Caucasian female with a history of scleroderma who presented with sudden onset holocranial headache associated with nausea, vomiting, and photophobia, improving with recumbence. The onset of symptoms was unprovoked. The patient denied recent trauma, lumbar puncture or history of headaches.

Physical examination revealed a nontoxic‑appearing female with stable hemodynamic parameters; who was neurologically intact. The patient had no obvious physical manifestations of scleroderma, and home medications were geared toward symptom management.

Neuro‑diagnostics

Noncontrast CT and CT angiography were negative for intracranial hemorrhage, mass or vascular lesion. An attempt was made by the emergency room physician to obtain a lumbar puncture. However, the procedure was aborted as CSF pressures were sub‑atmospheric and a fluid sample could not be obtained. The patient was admitted for bed rest and intravenous fluid hydration with the presumptive diagnosis of SIH. The patient was further assessed with an MRI of the brain with gadolinium. Diffuse smooth pachymeningeal

enhancement over the cerebral convexities was consistent with meningeal hyperemia and intracranial hypotension[28] [Figure 1]. Twice, the patient underwent lumbar epidural blood patch (EBP), followed by bed rest and continued hydration. The patient experienced transient symptom relief, but the postural headaches recurred with 2 weeks.

Diagnostic intervention

Efforts were then focused at identifying the source of the leak, as lumbar EBP had proved unsuccessful. CTM of the entire spinal axis demonstrated a subtly enhancing epidural fluid collection anterior to the cervical spinal cord [Figure 2]. However, the exact location of the CSF leak was not defined. The working hypothesis was that this might be attributable to an intermittent, slow flow dural rent with pressure too low to be observed with static imaging. To mitigate this problem, a lumbar drain was placed at L4–5 under fluoroscopy for the purpose of controlled dynamic imaging.

The patient was then brought to nuclear medicine for injection of radiotracer via the lumbar drain. The patient was placed in the left lateral position and two cubic centimeters (cc) of indium‑111‑diethyl‑enetriamine penta‑acetic acid radiotracer was administered via lumbar drain. Immediate postinjection static images revealed a photopenic region in the mid‑cervical spine likely attributable to the extradural fluid accumulation seen on CTM [Figure 3]. Extravasation of radiotracer was not demonstrated. Following this observation, 20‑cc of sterile saline were pushed through the lumbar drain by the attending neurosurgeon. Dynamic images were taken at the same time as the saline push. Extravasation of radiotracer was seen dorsally at C1‑2 [Figure 4].

Surgical intervention

The patient was referred to the pain clinic for definitive treatment achieved by percutaneous, targeted epidural blood and fibrin patch. Postprocedure, the patient was kept on bed rest for 48 h, followed by a progression of activity as tolerated. She was discharged home on postoperative day six without headache.

DISCUSSION Spontaneous CSF leaks can result from an abnormality in the cranial or spinal dura. Unlike those in the cranial dura in which patients present with otorrhea or rhinorrhea, spinal CSF leaks generally do not cause any local symptoms and remain undetected unless the diagnosis is actively pursued in a patient suspected of SIH.[28,29] One‑third of patients with SIH will have a history of trivial trauma,[30] while two‑thirds will have intrinsic dural weakness from an underlying connective tissue disorder.[17,21,22] Occasionally a dural tear from a spondolytic spur may lead to a CSF leak.[34]

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a

Figure 1: Sagittal magnetic resonance imaging of the brain with gadolinium demonstrates diffuse, smooth enhancement of the pachymeninges suggestive of meningeal hyperemia and intracranial hypotension

Spontaneous intracranial hypotension secondary to CSF hypovolemia is primarily a self‑limited condition; most patients will improve with conservative management.[17,28,35] It is pertinent to neurosurgical practice because if the diagnosis is missed and treatment delayed, patients may suffer from a considerably compromised quality of life. Patients often seek specialty care, including pain management, and may undergo unnecessary surgery for secondary manifestations of the disease, such as sub‑occipital craniotomy for pseudo ‑ Type 1 Chiari Malformation or evacuation of subdural hematoma.[17,24] It is important to understand risk factors and symptoms for SIH in order to obtain appropriate imaging and identify these patients to avoid delays in care. Otherwise, chronic pain and disability ensue with the potential for more serious neurological sequelae such as cranial nerve palsy, cerebellar dysfunction, and even coma.[4,6,19,25] The diagnosis of spontaneous CSF leak can be obtained by lumbar puncture with evidence of low CSF pressure. Variable readings, including pressures within the normal range, may be obtained if the CSF leak is intermittent.[1,23,24] Cranial MRI with gadolinium and CTM[24,28] have been described as the initial studies of choice for diagnosing SIH. Characteristic findings of SIH by MRI include diffuse smooth pachymeningeal enhancement from meningeal venous hyperemia.[7,17,24] CTM is mostly utilized for demonstrating the actual site of CSF leak or an extradural fluid collection, but limitations in CSF flow dynamics through the leak can limit its utility.

Radionuclide cisternography is also used to identify radioactivity outside the dural sac.[1,11,17,35] However, as is seen with CTM, if there is no active flow of CSF at the time of the study the ability to identify the leak is limited.[5,15,32] Therefore, the possibility of locating a dural

b

Figure 2: Computed tomography (CT) of the cervical spine following intrathecal administration of contrast. (a) Sagittal and (b) axial CT demonstrates contrast anterior to the cervical thecal sac.This collection is attenuated in comparison to the intra-dural contrast.

The presence of this ventral epidural fluid collection suggests cerebrospinal fluid-contrast egress

fistula or rent is reduced if the leakage is intermittent[15] or is so slow the tracer does not egress from the subarachnoid space by the time the imaging is completed. Several published studies attempt to rectify this limitation for cranial CSF leaks. Curnes et al. employed the use of controlled, pressurized RIC for the localization of CSF rhinorrhea with good result.[5] Magnaes and Solheim demonstrated improved localization of CSF rhinorrhea by adapting infusion cisternography.[15] However, the use of infusion or pressurized cisternography is limited for evaluation of spinal CSF leaks. One study employed the use of digital subtraction myelography (DSM) as a means of localizing spinal CSF leaks.[9] In this retrospective study by Hoxworth et al., patients with extradural fluid collections by CTM or spinal MRI with an ill‑defined location of dural breach were subjected to localized DSM with contrast injection by lumbar drain. Of the patients meeting inclusion criteria, 18% (2 of 11 patients) of leaks were not identified presumably because the CSF leaks were too slow to be readily visualized during the brief 20–30 s DSM acquisition.[9] The authors posit that this technique is useful for identifying rapid CSF leaks when dynamic CTM was insufficient to identify the precise location due to rapid egress of dye from the subarachnoid space.[9] However, the challenge of identification of cryptic or intermittent CSF leaks[8,13] in patients suspicious for SIH remains. Our case offers a possible solution for this problem.

The case presented here provides an alternative for addressing CSF leaks in which the flow characteristics are slow or intermittent, and thus below the resolution of study for “standard static imaging.” The authors modify the use of an already widely accepted form of neuroimaging for SIH (i.e., RIC) in order to identify cryptic CSF leaks.

The use of pressurized RIC to identify the precise location of the CSF leak offers some notable diagnostic

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a

b

c Figure 3: Static nuclear medicine cerebrospinal cisternography following injection of indium-111-diethyl-enetriamine-penta-acetic acid. (a) Right and (b) left lateral initial static images as well as (c) 5 min delayed images were obtained following administration of radiotracer.

No evidence of abnormal accumulation of radioisotope is seen with initial or delayed injections. A photopenic region is demonstrated in the mid-cervical spine suggesting extrinsic pressure on the cervical subarachnoid space and corresponding to the epidural fluid collection seen on computed tomography myelography

advantages to practitioners that may encounter this entity. First, it allows the clinician to obtain a panoramic view[35] of the spine in real‑time. Also, the use of the lumbar drain allows for optimal positioning of the patient without compromising intrathecal access; which is more tedious with the Tuohy needle. Furthermore, once the radiotracer is injected, the lumbar drain allows the surgeon to perform a controlled “saline push” which serves to pressurize the CSF leak. RIC then becomes a

dynamic study as the gamma camera provides real‑time images of the flow of radiotracer throughout the spinal axis at the time of the saline push.

Historically, RIC has been used as a means of confirming SIH when the accumulation of radioactivity is noted outside the subarachnoid space. Its utility was first applied in the setting of SIH when early accumulation of radiotracer in the urinary bladder and kidneys suggested

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a

b

Figure 4: Dynamic nuclear medicine cerebrospinal cisternography following pressurized injection of saline through the lumbar drain. (a) Right and (b) left lateral views are obtained at the time of pressurized saline injection. Evidence of an abnormal accumulation of radioisotope is seen dorsally at C1-2 on both views

extravasation of intrathecal tracer with reabsorption via the epidural venous plexus.[1,18] Two issues overcome by the technique employed, in this case, include the lack of sensitivity of RIC in smaller, slower leaks and the lack of spatial detail that precludes direct localization of the CSF leak in many cases.[11,16,17] This case illustrates that the use of a pressurized injection via lumbar drain with dynamic cisternography can circumvent these limitations.

Extravasation of radiotracer is seen in real‑time and the panoramic view of the spine allows for localization of the dural breach.

Increasing support for targeted treatment in SIH is found in the literature, especially when initial lumbar epidural blood patching fails to resolve symptoms. Defining the CSF leak as secondary to dural rent or meningeal diverticulum, allows choice of the most appropriate management, whether by targeted percutaneous blood patch or open surgical treatment. EBP is the treatment of choice in patients who have failed an initial trial of conservative management.[3,31] EBPs have been shown to spread within the epidural space over many spinal levels,[3,30,33] which argues the necessity of finding the precise level of dural rent when percutaneous treatment measures are used. Failure of EBP therapy or recurrence after initial success seems to be common in patients with a cervical CSF leak. Recently, “targeted” blood patching delivered near or at the level of a CSF leak has been gaining in clinical utility.[8,13] Furthermore, when an EBP does not alleviate symptoms, several studies have demonstrated that targeted delivery of fibrin glue, by epidural catheter[12] or by traditional percutaneous

methods[2,23,29]‑as demonstrated in this case‑provides resolution of neurological symptoms and headaches.

CONCLUSIONS Slow flow or intermittent CSF leaks represent a diagnostic challenge. Failing to establish a diagnosis and localize the area of a dural breach can lead to disability and chronic pain for patients. Pressurized RIC for spinal CSF leaks offers a means of identifying CSF leaks that were previously considered beyond the resolution of standard imaging. Furthermore, this test can be performed with relatively low risk to the patient, as lumbar drain placement is commonplace in neurosurgical practice. Most importantly, this technique provides a means of avoiding excessive testing in patients with signs of SIH and no identifiable source of CSF leak.

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Angelo F, Giuseppe M, Eliana M, Luisa C, Gennaro B. Spontaneous intracranial hypotension: Diagnostic and therapeutic implications in neurosurgical practice. Neurol Sci 2011;32 Suppl 3:S287‑90.

Beleña JM, Nuñez M, Yuste J, Plaza‑Nieto JF, Jiménez‑Jiménez FJ, Serrano S. Spontaneous intracranial hypotension syndrome treated with a double epidural blood patch. Acta Anaesthesiol Scand 2012;56:1332‑5.

Brady‑McCreery KM, Speidel S, Hussein MA, Coats DK. Spontaneous intracranial hypotension with unique strabismus due to third and fourth cranial neuropathies. Binocul Vis Strabismus Q 2002;17:43‑8.

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Ferrante E, Savino A, Brioschi A, Marazzi R, Donato MF, Riva M. Transient oculomotor cranial nerves palsy in spontaneous intracranial hypotension.

J Neurosurg Sci 1998;42:177‑9.

Fishman RA, Dillon WP. Dural enhancement and cerebral displacement secondary to intracranial hypotension. Neurology 1993;43(3 Pt 1):609‑11.

Hayek SM, Fattouh M, Dews T, Kapural L, Malak O, Mekhail N. Successful treatment of spontaneous cerebrospinal fluid leak headache with fluoroscopically guided epidural blood patch: A report of four cases. Pain Med 2003;4:373‑8.

Hoxworth JM,Trentman TL, Kotsenas AL,Thielen KR, Nelson KD, Dodick DW. The role of digital subtraction myelography in the diagnosis and localization of spontaneous spinal CSF leaks. AJR Am J Roentgenol 2012;199:649‑53.

Huang C, Chuang Y, Lee C, Lee R, Lin T. Spontaneous spinal cerebrospinal fluid leak and intracranial hypotension. Clin Imaging 2000;24:270‑2.

Hyun SH, Lee KH, Lee SJ, Cho YS, Lee EJ, Choi JY, et al. Potential value of radionuclide cisternography in diagnosis and management planning of spontaneous intracranial hypotension. Clin Neurol Neurosurg 2008;110:657‑61.

Kamada M, Fujita Y, Ishii R, Endoh S. Spontaneous intracranial hypotension successfully treated by epidural patching with fibrin glue. Headache 2000;40:844‑7.

Kantor D, Silberstein SD. Cervical epidural blood patch for low CSF pressure headaches. Neurology 2005;65:1138.

Leep Hunderfund AN, Mokri B. Second‑half‑of‑the‑day headache as a manifestation of spontaneous CSF leak. J Neurol 2012;259:306‑10.

Magnaes B, Solheim D. Controlled overpressure cisternography to localize cerebrospinal fluid rhinorrhea. J Nucl Med 1977;18:109‑11.

Mokri B. Spontaneous cerebrospinal fluid leaks: From intracranial hypotension to cerebrospinal fluid hypovolemia – Evolution of a concept. Mayo Clin Proc 1999;74:1113‑23.

Mokri B. Spontaneous intracranial hypotension. Curr Neurol Neurosci Rep 2001;1:109‑17.

Moriyama E, Ogawa T, Nishida A, Ishikawa S, Beck H. Quantitative analysis of radioisotope cisternography in the diagnosis of intracranial hypotension.

J Neurosurg 2004;101:421‑6.

Pleasure SJ, Abosch A, Friedman J, Ko NU, Barbaro N, Dillon W, et al.

Spontaneous intracranial hypotension resulting in stupor caused by diencephalic compression. Neurology 1998;50:1854‑7.

20. Rando TA, Fishman RA. Spontaneous intracranial hypotension: Report of two cases and review of the literature. Neurology 1992;42(3 Pt 1):481‑7.

21. Schievink WI, Gordon OK, Tourje J. Connective tissue disorders with spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension: A prospective study. Neurosurgery 2004;54:65‑70.

22. Schievink WI, Louy C. Precipitating factors of spontaneous spinal CSF leaks and intracranial hypotension. Neurology 2007;69:700‑2.

23. Schievink WI, Maya MM, Louy C, Moser FG, Tourje J. Diagnostic criteria for spontaneous spinal CSF leaks and intracranial hypotension. AJNR Am J Neuroradiol 2008;29:853‑6.

24. Schievink WI, Meyer FB, Atkinson JL, Mokri B. Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension. J Neurosurg 1996;84:598‑605.

25. Schievink WI, Moser FG, Pikul BK. Reversal of coma with an injection of glue.

Lancet 2007;369:1402.

26. Schievink WI, Smith KA. Nonpositional headache caused by spontaneous intracranial hypotension. Neurology 1998;51:1768‑9.

27. Schievink WI, Wijdicks EF, Meyer FB, Sonntag VK. Spontaneous intracranial hypotension mimicking aneurysmal subarachnoid hemorrhage. Neurosurgery 2001;48:513‑6.

28. Schievink WI. Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension. JAMA 2006;295:2286‑96.

29. Schievink WI. Spontaneous spinal cerebrospinal fluid leaks. Cephalalgia 2008;28:1345‑56.

30. Schievink WI. Spontaneous spinal cerebrospinal fluid leaks: A review.

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33. Szeinfeld M, Ihmeidan IH, Moser MM, Machado R, Klose KJ, Serafini AN. Epidural blood patch: Evaluation of the volume and spread of blood injected into the epidural space. Anesthesiology 1986;64:820‑2.

34. Vishteh AG, Schievink WI, Baskin JJ, Sonntag VK. Cervical bone spur presenting with spontaneous intracranial hypotension. Case report. J Neurosurg 1998;89:483‑4.

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Case Report

Multiple cerebral hydatid cysts in 8‑year‑old boy: A case report and literature review of a rare presentation Muhammad Babar Khan, Muhammad Riaz, Muhammad Ehsan Bari Department of Surgery, Section of Neurosurgery, Aga Khan University Hospital, Karachi, Pakistan E‑mail: Muhammad Babar Khan ‑ babarkhan08@gmail.com; Muhammad Riaz ‑ muhammad.riyaz@aku.edu; *Muhammad Ehsan Bari ‑ ehsan.bari@aku.edu *Corresponding Author Received: 08 February 15 Accepted: 09 June 15 Published: 29 July 15 This article may be cited as: Khan MB, Riaz M, Bari ME. Multiple cerebral hydatid cysts in 8-year-old boy: A case report and literature review of a rare presentation. Surg Neurol Int 2015;6:125. http://surgicalneurologyint.com/surgicalint_articles/Multiple-cerebral-hydatid-cysts-in-8‑year‑old-boy:-A-case-report-and-literature-review-of-a-rare-presentation/ Copyright: © 2015 Khan MB. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Multiple cerebral hydatid cysts are very rare with only a few reports in the literature detailing diagnostic workup, medical management, surgical techniques, possible complications, and outcomes.

Case Description: We present the case of an 8‑year‑old boy who presented with progressively worsening headaches, vomiting, and intermittent fever since 20 days.

Diagnostic workup was performed, and magnetic resonance imaging revealed multiple intracranial cysts predominantly in the right frontal region with significant mass effect. A total of 19 intracranial cysts were removed surgically, and the child recovered uneventfully.

Conclusions: Neurosurgeons should keep hydatidosis in the list of differentials when evaluating patients with cystic diseases of the brain. Although the removal of such cysts is challenging, outcomes are excellent when cysts are evacuated without rupture and patients show complete resolution of symptoms.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161785 Quick Response Code:

Key Words: Albendazole, Echinococcus, hydatid cysts, intracranial, surgical

excision

INTRODUCTION Infection with Echinococcus larvae causes hydatid disease in humans.[5,13] Hydatid cysts occur most commonly in the lung and liver with intracranial involvement reported in 0.5–3% of all hydatid disease.[2,5] Cerebral hydatidosis is thus a rare disease entity and represents 0.05% of all intracranial mass lesions in the developed world.[3,6,9,13,14] Primary cysts are often solitary, spherical, unilocular lesions, and can be surgically excised.[13] Multiple cysts are very rare with only a few reports in the current literature.[2,3,6,8‑10,13,14] Surgical excision of multiple cysts can be very challenging as these are often disseminated and involve vital structures.[13]

Here, we report the case of an 8‑year‑old boy with 19 intracranial cysts, which were successfully removed surgically and also review the literature with an emphasis on diagnosis and management of patients with multiple cerebral cysts.

CASE REPORT This 8‑year‑old boy presented with complaints of progressively worsening headaches along with vomiting and intermittent fever since 20 days. There were no significant findings on general physical and neurological examination.

The patient’s routine laboratory investigations were normal. A magnetic resonance imaging (MRI) brain was performed which showed

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multiple intracranial cysts predominantly in the right frontal region with significant mass effect [Figure 1]. The patient’s chest X‑ray, ultrasound abdomen, and eosinophil counts were normal. The patient was started on dexamethasone, leviteracetem, and albendazole and scheduled for surgery.

A frontoparietal craniotomy was performed. There was significant dural tension, and a c‑shaped durotomy was done which revealed a huge hydatid cyst extending toward the lateral ventricle [Figure 2a]. A soft rubber catheter was inserted between the brain parenchyma and the cyst capsule (Dowling’s technique); a cleavage plane was established using warm hypertonic saline and the cyst was delivered unruptured [Figure 2d]. Numerous daughter cysts were then identified which were carefully delivered unruptured using the same technique [Figure 2b and c]. We were able to remove all of the 19 cysts without rupturing the cyst capsule this way. An endoscope was used after removing all the cysts to make sure that none of the daughter cysts was left behind.

The cavity was copiously irrigated with hypertonic saline and hydrogen peroxide. Histopathological examination confirmed hydatid cyst and no bacterial agent was isolated.

The patient continued taking albendazole (200 mg, BID), dexamethasone, cefazolin, and levetiracetam postoperatively and had an uneventful postoperative course. The patient was seen in clinic on 3 months postoperative visit and his complaints of headache and vomiting had completely resolved. His neurological examination was completely normal and considering financial constraints a follow‑up computed tomography (CT) scan was thus not performed.

a

c

DISCUSSION Hydatid disease is a potentially fatal parasitic infection that can affect wildlife animals, commercial stock, and humans.[2,5] Humans act as intermediate hosts in the tapeworm lifecycle and become infected either due to direct contact with an infected animal or ingestion of food contaminated with the feces of an infected animal.[2,5] The most common infecting larvae are of Echinococcus multilocularis and Echinococcus granulosus.[2,5,13] Most of the cases have been reported in the pediatric age group.[13] Hydatid cysts are generally located in the territory of the middle cerebral artery and posterior fossa, or infratentorial lesions are very rare.[2,6] These cysts are benign in nature, and symptoms depend on the size and location of the cyst. The first signs of cranial involvement are usually an increase in intracranial pressure secondary to the mass effect of the cysts.[13] Other commonly reported symptoms include speech disorders, urinary incontinence motor weakness, and seizures.[3,9,14] A viable primary lesion could rupture spontaneously or due to trauma or surgery. The spillage of the scolices in the brain parenchyma results in multiple secondary hydatid cysts.[1,6,14] Multiple cysts could also occur as a result of rupture of a cyst located in the left atrium or ventricle and in the great arterial vessels.[1,14] Another rarely reported possibility is ingestion of multiple larvae and their arterial embolism causing multiple cerebral cysts.[1,14] Such rare multiple secondary cysts are infertile as they lack brood capsules and scolices.[1,6,14] Both CT and MRI scan have been reported to be useful in the correct preoperative diagnosis of cerebral hydatid cysts.[4,6,9,13] The lesions appear as hypodense, intraparenchymal circular lesions without perifocal edema, and a hyperdense rim on noncontrast CT

b

a

b

c

d

d

Figure 1: (a) T1-weighted magnetic resonance imaging axial section demonstration multiple cysts generating a hypointense signal.

Multiple septations can be appreciated significant mass effect can be appreciated. (b) T2-weighted magnetic resonance imaging axial section representing multiple cysts with a hyperintense signal and the cyst walls generating a hypointense signal. (c) T1-contrast enhanced magnetic resonance imaging axial cut showing contrast enhancement of the cyst wall in some regions. (d) Fluid attenuated inversion recovery sequence coronal section showing multiple cysts as hypointense signals and significant mass effect

Figure 2: (a) Intraoperative photograph demonstrating the durotomy incision and the capsule of a huge hydatid cyst. (b and c) Photograph of daughter/secondary cysts in the brain parenchyma after the first cyst was removed. (d) The main cyst and two daughter cysts after excision with intact capsules

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scans.[1,13,14] However, MRI is superior to CT scan as it shows greater soft tissue detail and can define the anatomical location of the lesion relative to sulci and ventricles, which aid in operative planning.[13,14] On MRI, the cyst gives hypointense signals on T1‑weighted images, and hyperintense signals on T2‑weighted images, and the cyst wall gives hypointense signals on both T1‑ and T2‑weighted images.[5] Calcification of the cyst wall is rare and reported in about 1% of the cases.[2] The presence of daughter cysts is considered pathognomonic.[2] Other differentials for cystic lesions include cystic tumors, pyogenic brain abscess, and cystic lesions such as porencephalic cysts or arachnoid cyst.[6,11] These can be differentiated from hydatid cysts as cystic tumors have an enhancing mural nodule and tumor edges, and the central necrosis of pyogenic abscess is almost always accompanied by peripheral edema with contrast enhancing margins. Similarly, unlike hydatid cysts, porencephalic and arachnoid cysts are not spherical and are not surrounded by brain parenchyma.[2] Moreover, arachnoid cysts are always extra‑axial, and porencephalic cysts have a rim of gliotic white matter that is, easily observable on MRI.[2] Serological tests have traditionally had low sensitivity and specificity in diagnosing intracerebral hydatid cysts.[2,5] Serological tests were normal in our patient as well, and thus we believe that serology has limited use in the diagnosis and postoperative follow‑up of intracerebral cysts. However, serological tests and especially the newer enzyme‑linked immunosorbent assays maybe more useful in diagnosing hydatid disease involving multiple organs.[5] Successful medical treatment of liver and abdominal hydatid cysts with albendazole, mebendazole, and praziquantel has been well reported in the literature.[14] However, there is only scarce literature on the successful use of these drugs as the sole treatment of cerebral hydatidosis and there are concerns about the penetration of these drugs across the blood‑brain barrier and the cyst capsule.[5,7,10,13,14] There is no uniform consensus on the normal rate of growth of these cysts intracranially and growth rates of 1–10 cm/year have been reported.[5,8,9,12,13] It may thus be difficult to assess objectively the effect of medical therapy alone on these cysts. Moreover, albendazole has been reported ineffective in cases of large cerebral hydatid cysts.[14] We believe that surgical excision of the cyst is always warranted in cases of elevated intracranial pressure with no other contraindications to surgery. Two surgical techniques have been described for the excision of these cysts in literature. The Dowling‑Orlando technique is the preferred option and involves inserting a rubber catheter between the cyst wall and parenchyma and irrigation with normal saline in order to establish a cleavage plane and deliver the cyst intact.[5,9] Alternatively, deeply seated cysts can be

punctured and aspirated, however, this technique has an increased risk of cyst rupture.[5] Cyst rupture can result in local recurrence and secondary cysts, meningitis, and anaphylaxis. It is recommended that the whole cyst cavity be copiously irrigated with hypertonic saline after the surgery and especially if a cyst has ruptured. In the later case, all the cyst contents should also be carefully sucked out. Albendazole therapy maybe continued after excision to prevent any recurrences.[13] However, at present there are no evidence based guidelines on the efficacy or duration of treatment with albendazole postoperatively.[5] Known surgical complications are rare but include subdural effusion, hemorrhage, and hydrocephalus.[5] These might require a second procedure and ventriculoperitoneal shunting.

CONCLUSION Neurosurgeons should keep hydatidosis in the list of differentials when evaluating patients with cystic diseases of the brain. An MRI can greatly aid in diagnosis and surgical planning. The goal of surgery should be total excision of intact cyst which should be followed by antibiotic and antihelminthic treatment to avoid recurrence. Surgical outcomes are excellent, and patients show complete resolution of symptoms after complete excision of the cyst.

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Boles DM. Cerebral echinococciasis. Surg Neurol 1981;16:280‑2.

Bükte Y, Kemaloglu S, Nazaroglu H, Ozkan U, Ceviz A, Simsek M. Cerebral hydatid disease: CT and MR imaging findings. Swiss Med Wkly 2004;134:459‑67.

Cavusoglu H, Tuncer C, Ozdilmaç A, Aydin Y. Multiple intracranial hydatid cysts in a boy. Turk Neurosurg 2009;19:203‑7.

Diren HB, Ozcanli H, Boluk M, Kilic C. Unilocular orbital, cerebral and intraventricular hydatid cysts: CT diagnosis. Neuroradiology 1993;35:149‑50.

Duishanbai S, Jiafu D, Guo H, Liu C, Liu B, Aishalong M, et al. Intracranial hydatid cyst in children: Report of 30 cases. Childs Nerv Syst 2010;26:821‑7.

Gana R, Skhissi M, Maaqili R, Bellakhdar F. Multiple infected cerebral hydatid cysts. J Clin Neurosci 2008;15:591‑3.

M a r t í n O t e r i n o J A , C h i m p é n R u i z VA , R e v i r i e g o J a é n G , Sánchez Rodríguez A. Repeated strokes as a sign of multiple cerebral hydatid cysts. Neurologia 1996;11:307‑9.

Pasaoglu A, Orhon C, Akdemir H. Multiple primary hydatid cysts of the brain.

Turk J Pediatr 1989;31:57‑61.

Sen N, Laha D, Gangopadhyay PK, Mohanty BC. Young girl with multiple intracranial hydatid cyst. Ann Neurosci 2012;19:96‑8.

Todorov T, Vutova K, Petkov D, Balkanski G. Albendazole treatment of multiple cerebral hydatid cysts: Case report.Trans R Soc Trop Med Hyg 1988;82:150‑2.

Tüzün M, Hekimoglu B. Hydatid disease of the CNS: Imaging features. AJR Am J Roentgenol 1998;171:1497‑500.

Vaquero J, Jiménez C, Martínez R. Growth of hydatid cysts evaluated by CT scanning after presumed cerebral hydatid embolism. Case report. J Neurosurg 1982;57:837‑8.

Yüceer N, Güven MB, Yilmaz H. Multiple hydatid cysts of the brain: A case report and review of the literature. Neurosurg Rev 1998;21:181‑4.

Yurt A, Avci M, Selçuki M, Ozer F, Camlar M, Uçar K, et al. Multiple cerebral hydatid cysts. Report of a case with 24 pieces. Clin Neurol Neurosurg 2007;109:821‑6.

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Erratum

Pedunculated intraventricular subependymoma: Review of the literature and illustration of classical presentation through a clinical case: Erratum In the article, “Pedunculated intraventricular subependymoma: Review of the literature and illustration of classical presentation through a clinical case”, which appeared in the article number 117, Issue 1, Vol 5 of Surgical Neurology International[1], the acknowledgement section is missing. The acknowledgement section will be as follows: “The authors would like to thank Dr. Fernando Alvarado-Calderón, MD, pathologist at the Hospital Calderón Guardia, for his invaluable help in providing the definite histologic diagnosis and the corresponding images for this case.”

This has now been corrected and reposted online.

REFERENCE 1.

Hernandez-Duran S,Yeh-Hsieh T, Salazar-Araya C. Pedunculated intraventricular subependymoma: Review of the literature and illustration of classical presentation through a clinical case. Surg Neurol Int 2014; 5:117.

DOI: 10.4103/2152-7806.161421

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Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Case Report

Temporary deep brain stimulation in Gilles de la Tourette syndrome: A feasible approach?

Edvin Zekaj, Christian Saleh, Mauro Porta, Domenico Servello Department of Neurology and Neurosurgery, IRCCS Galeazzi, Milan, Italy, Via Riccardo Galeazzi 4, Milan, Italy Cap 20161 E‑mail: Edvin Zekaj - ezekaj@yahoo.com; Christian Saleh - chs12us75010@yahoo.com; Mauro Porta - mauroportamilano@gmail.com; *Domenico Servello - servello@libero.it *Corresponding author Received: 06 August 14 Accepted: 20 April 15 Published: 21 July 15 This article may be cited as: Zekaj E, Saleh C, Porta M, Servello D. Temporary deep brain stimulation in Gilles de la Tourette syndrome: A feasible approach?. Surg Neurol Int 2015;6:122. http://surgicalneurologyint.com/surgicalint_articles/Temporary-deep-brain-stimulation-in-Gilles-de-la-Tourette-syndrome:-A feasible-approach?/ Copyright: © 2015 Zekaj E. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, d ­ istribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Gilles de la Tourette Syndrome (GTS) is a complex neuropsychiatric disorder, characterized by chronic motor and vocal tics, associated in 50–90% of cases with psychiatric comorbidities. Patients with moderate and severe clinical picture are treated with psychotherapy and pharmacological therapy. Deep brain stimulation (DBS) is reserved for pharmacological refractory GTS patients. As GTS tends to improve with time and potentially resolves in the second decade of life, the major concern of DBS in GTS is the age at which the patient undergoes surgical procedure. Some authors suggest performing DBS after 18 years, others after 25 years of age.

Case Description: We present a 25‑year‑old patient with GTS, who was aged 17 years and was treated with thalamic DBS. DBS resulted in progressive and sustained improvement of tics and co‑morbidities. After 6 years of DBS treatment, it was noted that the clinical improvement was maintained also in OFF stimulation setting, so it was decided to keep it off. After 2 years in off‑setting and stable clinical picture the entire DBS device was removed. Six months after DBS device removal the patient remained symptom‑free.

Conclusions: DBS is a therapeutic option reserved for severe and refractory GTS cases. In our opinion DBS might be considered as a temporary application in GTS.

Video Available on:

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Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161242 Quick Response Code:

Key Words: Deep brain stimulation, Gilles de la Tourette syndrome, management,

timing

INTRODUCTION Gilles de la Tourette syndrome (GTS) is a chronic neuropsychiatric disorder, characterized by multiple vocal and motor tics.[2] Co‑morbidities such as attention deficit hyperactivity disorder (ADHD), obsessive compulsive disorder (OCD), depression and anxiety disorders are present in 50–90% of patients.[8] GTS commences with simple motor tics by the age of 4–6 years, aggravated

subsequently by complex motor and simple and complex vocal tics. GTS has a waxing and waning nature, with periods of remission and periods of aggravations.

Remission with adult age has been reported.[5] Observational approach with regular follow‑ups should be reserved to mild cases without social impairment and interferences with daily activities. In moderate and severe cases with social impairment pharmacological treatments and/or psychotherapeutic treatments should be applied.

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CASE REPORT

DISCUSSION

We present a patient with GTS,[10] who at the age of 17 years underwent bilateral deep brain stimulation (DBS) for severe and refractory GTS. The patient history started at the age of 7 with simple motor tics associated with ADHD. Two years later, vocal and complex motor tics appeared. The patient suffered a relevant social impairment with important difficulties in learning and education due to tics and ADHD. Several pharmacological treatments and psychological treatments were tried without any benefit. Three months prior to surgery, the patient developed a severe “status ticcosus” (continuous motor and vocal tics) that obliged him to leave school. His clinical condition did not respond to any treatment. After careful multidisciplinary examination that involved a neurologist, psychiatrist, and a psychotherapist, DBS of the ventro‑oralis internus centromedian parafasciular complex (Vo‑Cm/ Pf) was considered. The Vo‑Cm/PF coordinates were 5 mm lateral to the anterior commissure‑posterior commissure (AC‑PC), 2 mm posterior to the AC‑PC midpoint, and at AC‑PC (Electrodes Model 3389 Medtronic Minneapolis, MN, USA). The procedure was done following compassionate use. The DBS procedure was uneventful. The patient was evaluated at 1, 3, 6 months, and subsequently every 6 months with progressive improvement in his Yale Global Tic Severity Scale (YGTSS) scores [Table 1]. Twelve months after intervention, his YGTSS had improved by 58.2%.

However, 3 years after surgery, the patient started to worsen. Examination revealed that the internal pulse generator (IPG, Kinetra) was discharged. After IPG substitution, the patient’s motor and vocal tics improved as evidenced by regular follow‑up visits. Three years after IPG replacement, it was noticed that the IPG was turned off once again, but surprisingly this time the patient (now aged 23 years) did not present any aggravation of symptoms. In light of his stable clinical status the patient and his caregivers decided to leave the IPG in OFF state. Close follow‑up for 2 years confirmed his stable clinical status in OFF IPG setting. Consequently, together with the patients and his family the decision was taken, to remove the entire DBS device. At the last follow‑up visit, that is, 8 months after DBS‑device removal, the patient remained clinically stable. Video available at www.surgicalneurologyinternational.com/ video/GTS_DBS.wmv.

In the late 1990s, Vandewalle et al. applied the first stereotactic bilateral DBS for refractory GTS targeting the Vo‑Cm/Pf complex.[11] This approach was based on previous experience by Hassler and Dickmann lesioning the thalamus.[4] The thalamus was selected as prime target as a thalamic over‑activity was thought to be the pathophysiological basis of GTS.[1] For 41 GTS patients treated since 1999 with thalamic DBS a significant mean YGTSS decrease of 58% (standard deviation [SD] =15) was reported.[9] Several guidelines have been published for DBS in GTS. One of the main decisive topics in these guidelines is the age of inclusion. The European guideline[7] suggest that DBS should be reserved to patients older than 18 years, while the American guidelines suggest 25 years as the age limit for DBS.[6] The age limit of 25 years is related to the observation that in some patients GTS resolves spontaneously in the second decade of life. On one hand we approve this line of reasoning, but on the other hand we have to consider that the time period between 15 and 25 years is a critical part of the life of a young adult for educational, professional and social reasons. Consequently patients with severe GTS in this age range (15–25 years) have decisively lower chances to optimize their quality of life. In our opinion, severely and refractory patients younger than 18 years old should be screened and evaluated as potential candidates for DBS. Our proposal of a temporary application of DBS in GTS is based on the observation that the patient did not present any worsening of his clinical status even after a prolonged period without stimulation. For this reason we did not substitute the IPG and arrived gradually to the decision to remove the entire DBS device. The likelihood of temporary DBS application is especially given for GTS as some patients experience a complete cure or at least a clinical amelioration in young adulthood. Before DBS, our patient was not able to confront the challenges of school and had to leave without qualification. After DBS he had an optimal professional formation and social insertion in the most crucial period of his young adult life.

CONCLUSION DBS is experimental in GTS and unfortunately large clinical trials remain rare in DBS, whatever its indication.

This has several reasons, as the important financial aspects of a complex surgical intervention, the difficulties

Table 1: YGTSS pre‑DBS and post‑DBS Age at surgery

Target

17 years

Voa‑CM/Pf

YGTSS pre‑DBS

YGTSS post‑DBS 3 months

YGTSS post‑DBS 6 months

YGTSS post-DBS 1 year

YGTSS post‑DBS 2 years

YGTSS post‑DBS 5 years FU

YGTSS pre‑removal

YGTSS post‑DBS removal 10 months

91

50

44

38

14

5

5

2

YGTSS:Yale Global Tic severity scale, DBS: Deep brain stimulation, FU: Follow up,Voa‑CM/PF:Ventro‑oralis internus‑centromedian‑parafascicular complex

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to standardize the procedure and the strict eligibility criteria for DBS, foremost for subjects per definition refractory to conventional treatment. The publication of every case, favorable and unfavorable outcomes,[3] becomes therefore still more imperative, in order to gather important information to evaluate, despite the known limitations of class IV studies, the efficacy of DBS. DBS application needs to be weighted against the severity of the disease and its co‑morbidies, for which no other therapeutic means are available.

REFERENCES 1.

2.

3.

Ackermans L, Neuner I,Temel Y, Duits A, Kuhn J,Visser‑Vandewalle V.Thalamic deep brain stimulation for tourette syndrome. Behav Neurol 2013;27:133‑8.

American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 4th ed., text revision (2000). Washington, DC. Dueck A, Wolters A, Wunsch K, Bohne‑Suraj S, Mueller JU, Haessler F, et al.

Deep brain stimulation of globus pallidus internus in a 16‑year‑old boy with severe tourette syndrome and mental retardation. Neuropediatrics 2009;40:239‑42.

4.

Hassler R, Dieckmann G. Stereotaxic treatment of tics and inarticulate cries or coprolalia considered as motor obsessional phenomena in gilles de la tourette’s disease. Rev Neurol 1970;123:89‑100.

5. Leckman JF, Zhang H, Vitale A, Lahnin F, Lynch K, Bondi C, et al. Course of tic severity in tourette syndrome: The first two decades. Pediatrics 1998;102:14‑9.

6. Mink JW, Walkup J, Frey KA, Como P, Cath D, Delong MR, et al. Patient selection and assessment recommendations for deep brain stimulation in tourette syndrome. Mov Disord 2006;21:1831‑8.

7. Muller‑Vahl KR, Cath DC, Cavanna AE, Dehning S, Porta M, Robertson MM, et al. European clinical guidelines for tourette syndrome and other tic disorders. Part IV: Deep brain stimulation. Eur Child Adolesc Psychiatry 2011;20:209‑17.

8. Robertson MM. Gilles de la tourette syndrome: The complexities of phenotype and treatment. Br J Hosp Med 2011;72:100‑7.

9. Saleh C, Gonzalez V, Cif L, Coubes P. Deep brain stimulation of the globus pallidus internus and gilles de la tourette syndrome:Toward multiple networks modulation. Surg Neurol Int 2012;3:S127‑42.

10. Servello D, Sassi M, Brambilla A, Defendi S, Porta M. Long‑term, post‑deep brain stimulation management of a series of 36 patients affected with refractory gilles de la tourette syndrome. Neuromodulation 2010;13: 187‑94.

11. Vandewalle V, van der Linden C, Groenewegen HJ, Caemaert J. Stereotactic treatment of gilles de la tourette syndrome by high frequency stimulation of thalamus. Lancet 1999;353:724.

SUPPLEMENTAL VIDEO INFORMATION Pre-DBS, at 9 months post-DBS, 1 year DBS off Pertinent translations: 9 months post-DBS: MP (Mauro Porta): How are you Simone?

Patient: I feel much better now.

MP: When did you have the implantation of the pacemaker?

Patient: Last year in April.

MP: And now you do not have any more tics?

Patient: No, not now anymore.

MP: Also no vocal tics?

Patient: No, no.

MP: So, you feel fine.

Patient: Yes. At one year DBS off the patient is saying that he benefited much from DBS and that he could also take the driving license, thanks to it. He works now as an electrician.

Surgical Neurology International

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Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Technical Note

Midline as a landmark for the position of the superior sagittal sinus on the cranial vault: An anatomical and imaging study Cassius Vinicius C. Reis, Sebastião N. S. Gusmão1, Ali M. Elhadi2, Alexander Dru2, Uédson Tazinaffo, Joseph M. Zabramski2, Robert F. Spetzler2, Mark C. Preul2 Departamento de Neurocirurgia, Hospital Mater Dei, Belo Horizonte, Brazil, 1Departamento de Neurocirurgia, Federal University of Minas Gerais, Belo Horizonte, Brazil, 2Division of Neurological Surgery and Department of Neurosurgery Research, Barrow Neurological Institute, Phoenix, Arizona, USA E‑mail: Cassius Vinicius C. Reis - Neuropub@dignityhealth.org; Sebastião N. S. Gusmão - Neuropub@dignityhealth.org; Ali M. Elhadi - Neuropub@dignityhealth.org; Alexander Dru - Neuropub@dignityhealth.org; Uédson Tazinaffo - Neuropub@dignityhealth.org; Joseph M. Zabramski - Neuropub@dignityhealth.org; Robert F. Spetzler - Neuropub@dignityhealth.org; *Mark C. Preul - Neuropub@dignityhealth.org *Corresponding author Received: 12 February 15 Accepted: 03 April 15 Published: 21 July 15 This article may be cited as: Reis CC, Gusmão SN, Elhadi AM, Dru A, Tazinaffo U, Zabramski JM, et al. Midline as a landmark for the position of the superior sagittal sinus on the cranial vault: An anatomical and imaging study. Surg Neurol Int 2015;6:121. http://surgicalneurologyint.com/surgicalint_articles/Midline-as-a-landmark-for-the-position-of-the-superior-sagittal-sinus-on-the-cranial-vault:-An-anatomical-and-imaging-study/ Copyright: © 2015 Reis CVC. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Craniotomies involving the midline are regular practice in neurosurgery, during which injury to the superior sagittal sinus (SSS), an uncommon yet devastating event, may occur. The midline tends to be the most common landmark used to identify the position of the SSS. In this study we examined the reliability of the midline as a landmark for the SSS. Methods: We performed bilateral craniectomies on eight cadaveric heads, preserving the coronal, sagittal, and lambdoid sutures. The width of the SSS and its displacement from midline were measured on the cadaveric specimens and on 105 normal magnetic resonance images (MRIs) of the head at the following locations: halfway between nasion and bregma (NB), bregma (B), halfway between bregma and lambda (BL), lambda (L), and inion (I).

Results: In all cadaveric specimens, the SSS was partially or totally displaced toward one side of midline, usually to the right. It tended to be closer to midline in the frontal region and more displaced posteriorly. The SSS usually drained into the right‑side transverse sinus. The mean width of the SSS was 4.3, 5.9, 6.9, 7.9, and 7.8 mm, and the average displacement from midline was 4.3, 6.3, 5.5, 6.9, and 6.0 mm for NB, B, BL, L, and I, respectively. These measurements were then compared with those obtained from the MRIs. Conclusion: The SSS was consistently displaced on either side of midline. Thus, the midline is not reliable for identifying the SSS, and caution should be used within 6–10 mm on either side of midline.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161241 Quick Response Code:

Key Words: Confluence of sinuses, superior sagittal sinus, sagittal suture, torcular

Herophili

INTRODUCTION Understanding the anatomy of the superior sagittal sinus (SSS) and its position in relation to the midline

has been problematic and is poorly understood in the literature.[5] In fact, most of our knowledge on the position of the SSS has been derived from radiological studies.[8] Interestingly, the SSS was one of the earliest

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anatomical structures to be described. During the ancient period of anatomical investigation in Alexandria, Herophilus studied the cerebral sinuses and named the confluence of sinuses the “torcular Herophili.”[7,9] Several other anatomists, such as Vesalius, redescribed the anatomy of the SSS.[9] Neurosurgically relevant anatomical description can be attributed to Cushing, who attempted to divide the SSS into segments for the purpose of understanding meningioma origin and creating classifications based on location.[6] Damage to the SSS is a potential complication of any paramedian midline cranial vault approach. Inadvertent injury of the sinus, usually during craniotomy, can lead to severe bleeding. Such injuries are difficult to repair and can result in devastating consequences. To avoid such complications, neurosurgeons typically use the midline, which is the line on the surface of the skull connecting the nasion and the inion, as a reference to estimate the position of the SSS. Correlation between the SSS and the sagittal suture was previously described in the literature;[16] however, there has not been a correlation between the SSS and the sagittal midline, which is more relevant for neurosurgical case planning (especially when image‑guided surgical navigation is unavailable or inadequate).

In this study, we used anatomical specimens and magnetic resonance images (MRIs) of the head to evaluate the reliability of using the midline as an anatomical reference for the position of the SSS. The results can be used to avoid injuring the SSS during paramedian and midline cranial approaches, especially when intraoperative image guidance is unavailable.

METHODS Eight silicone-injected/formalin‑fixed Caucasian cadaveric heads were used. All heads were normal in structure, that is, without disease processes of the face, scalp, cranium, or cranial contents. None of the specimens had signs of craniosynostosis or hyperostosis. Major vessels of these specimens were identified and injected with colored silicone to trace the intracranial and extracranial vessels and dural venous sinuses. After reflection of all soft tissue of the scalp, the midline was identified and marked on the skull from the nasion to the inion. A bilateral craniectomy was performed that preserved the coronal, sagittal, and lambdoid sutures. Through a small gap in the sagittal suture, the SSS was exposed completely at five points: (i) Halfway between the nasion and bregma (NB), (ii) bregma (B), (iii) halfway between bregma and lambda (BL), (iv) lambda (L), and (v) inion (I). The roof of the sagittal sinus was opened, and the width of the sinus and any displacement from midline [Figure 1] were measured with calipers at all five points.

Figure 1: Anatomical measurements at bregma. D1 and D2 represent displacements of the superior sagittal sinus from midline.

Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

We randomly chose 105 normal MRIs of the head from the archives of the Department of Radiology at the Madre Teresa Hospital in Belo Horizonte, Brazil. The sample consisted of 63 women and 42 males, with a mean age of 42.4 years (range, 7–87 years; all patients Caucasian).

Studies with intra‑ and extracranial pathology were excluded. MRIs (postcontrast T1‑weighted sequence) were ordered by physicians for other medical reasons and were performed with a Siemens Magnetom Vision 1.5 T scanner (Siemens Corporation, Washington, DC). No special sequences were performed for the purpose of this study that would interfere with the T1‑weighted sequence image results.

The landmark used to identify the midline on the images was the longitudinal fissure of the brain. The width of the SSS and its displacement from midline were measured using Voxar 3D (Toshiba Medical Visualization Systems Europe, Ltd., Edinburgh, United Kingdom) software at NB, B, BL, and L. This software enables advanced analysis of the uploaded image sequences in any plane and in large volumetric datasets. This means that image quality and technical tilt of the scan can be eliminated as variables affecting measurement and interpretation.

We also observed which transverse sinus drained the SSS (dominant transverse sinus). The four points of interest were first identified on sagittal MRIs. The measurements were then taken from coronal and/or axial MRIs of the head.

RESULTS [Table 1] shows the mean width of the SSS as measured on the cadaveric specimens and the MRIs. [Table 2] shows the mean lateral displacement of the SSS in the cadaveric specimens and on the MRIs.

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In all specimens, the SSS was a single structure. In one specimen the sagittal suture was deviated to the left of midline. Despite the ectopic sagittal suture, the SSS was related to midline. The lateral displacement of the SSS from midline followed a similar pattern. The lateral displacement of the torcular Herophili to the inion was a mean of 6.0 ± 2.1 mm [Figure 2]. The positions of the SSS were classified as exactly underneath midline, displaced to the left of midline, or displaced to the right of midline. [Figure 3] summarizes the positions of the SSS in relation to the midline for the anatomical specimens at the five measurement points.

Table 1: Width of the SSS on anatomical specimens and MRIs Point NB Bregma BL Lambda Inion

Width of SSS (mean±SD (mm)) Anatomical specimens

MRIs

4.3±0.9 5.9±1.1 6.9±1 7.9±2.4 7.8±1.6

7±2.6 9.3±2.5 12.4±2.6 12±3 NA

The positions of the SSS in relation to the midline in the MRIs are summarized in [Figure 4]. The SSS tended to be closer to midline in the frontal region and displaced as it coursed back toward the inion [Figure 5]. The SSS was usually completely outside the boundaries of the midline at the inion and drained into one of the transverse sinuses, usually the right side [Figure 6]. A dominant transverse sinus was present in 89.4% of the patients.

DISCUSSION

Historical considerations

The first modern neurosurgical attempt to systematically divide the SSS and illustrate its course was by Harvey Cushing and Louise Eisenhardt in 1938. Initially, Cushing sketched a two-dimensional rendering of the SSS with origin from the crista galli and termination from the torcular Herophili. When he superimposed the approximate location and size of 51 cases of parasagittal global tumors on the drawing, he astutely observed that the SSS could be divided into three regions based on the symptomatology and shared tumor characteristics. The ‘central’ third of the SSS housed 32 of the 51 tumors

BL: Halfway between the bregma and lambda, MRIs: Magnetic resonance images, NA: Not applicable, NB: Halfway between the nasion and bregma, SD: Standard deviation, SSS: Superior sagittal sinus

Table 2: Mean lateral displacement of the SSS from midline on anatomical specimens and MRIs Point NB Bregma BL Lambda Inion

Displacement of SSS (mean±SD (mm)) Anatomical specimens

MRIs

4.3±1.6 6.3±5.8 5.5±3.5 6.9±2.4 6±2.1

2.4±3.5 4.5±3.5 5.9±3.5 6±3.6 NA

BL: Halfway between the bregma and lambda, MRIs: Magnetic resonance images, NA: Not applicable, NB: Halfway between the nasion and bregma, SD: Standard deviation, SSS: Superior sagittal sinus

Figure 2: Anatomical measurements at lambda and inion. D is the displacement of the superior sagittal sinus (SSS) from midline (solid red line). TS, transverse sinus. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Figure 3: Schematic representation of the displacement of the superior sagittal sinus (SSS) from midline in the anatomical specimens. The frequencies of the SSS exactly at midline are represented in the black shaded areas. Sinuses partially displaced to the left or right are in the gray shaded areas. Sinuses completely displaced toward one side are outside the shaded areas. The midline is represented by the black longitudinal line. NB, halfway between the nasion and bregma; BL, halfway between bregma (B) and lambda (L); ML, midline. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

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Figure 5: Coronal magnetic resonance image shows the displacement of the superior sagittal sinus toward the right at halfway between bregma and lambda. The sagittal suture is the hypointense gap at the top of the head (arrowheads). Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

5 cm, and the average length of the posterior segments (segments 3 and 4) was approximately 7 cm.[8] Figure 4: Schematic representation of the displacement of the superior sagittal sinus (SSS) from midline on magnetic resonance images. The frequencies of the SSS exactly at midline are represented in the black shaded areas.The sinuses displaced to the left or right are listed outside the black shaded areas. The midline is represented by the solid black longitudinal line. NB, halfway between the nasion and bregma; BL, halfway between bregma and lambda; ML, midline. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

and consistently had the smallest tumors of the series.

In addition, 30 of the 32 cases were associated with convulsive seizures with Jacksonian progression. The ‘frontal’ third of the SSS included 13 of the 51 tumors, and the ‘occipital’ third of the SSS included 6 of the 51 tumors. Tumors in these regions were consistently larger than those found in the central region. According to Cushing, presenting symptoms of tumors in the frontal and occipital zones were identical, with headache and failing vision secondary to optic atrophy in all of the frontal tumor cases and in five of the six occipital cases.[6] More recently, angiography of the SSS has led to describing the its sections according to relative quantity of bridging veins (BVs) and direction of drainage of the veins.”[3,8,12] In 2007, Han et al. demonstrated, based on dural entrance of BVs, that a given SSS could have four segments, with segment 1 being the most anterior and segment 4 being the most posterior. In this model, segments 1 and 3 are those that contain clusters of BVs; segments 2 and 4 have a relative paucity of venous drainage. In the 30 cadaver heads studied

by Han et al., the average length of the two anterior segments (segments 1 and 2) was approximately

Anatomical considerations

The SSS is the longest cranial dural venous sinus and extends posteriorly from the crista galli to the sinus confluence at the internal cranial surface. Its mean length ranges from 23 to 30 cm, which makes the dural sinus the most vulnerable to injury.[4,6] The embryology of the SSS is complex. Its position on the cranial vault seems to depend on embryological signals from the falx cerebri between the cerebral hemispheres rather than on signal from the bone at the midline.[10] This likelihood probably accounts for cases in which the SSS is unrelated to the sagittal suture and is displaced with the falx to one side.[10,15] Basically, the SSS begins as a plexiform structure that develops during embryonic and fetal life, transforming into the single venous channel of the adult.[10,14] Tubbs et al.[16] studied 30 formalin‑fixed adult cadavers to establish the relationship between the sagittal suture and SSS. All specimens had a midline sagittal suture. In most specimens, the SSS deviated to the right: 53.7% at B, 67% at BL, and 63% at L. The sinus was exactly beneath the midpoint of the sagittal suture in 37% of the specimens at B, in 33% at BL, and in 20% at L. Displacement of the sinus toward the left side was uncommon.

Unlike these previous studies, we used the midline, which extends backward from the nasion to the inion, as a reference for the position of the SSS. This landmark was chosen for several reasons. First, it is different from the sagittal suture, which can be used only between B and L. In contrast, the midline can be used to estimate

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transverse sinuses. In 20 hemispheres the SSS drained exclusively into the right transverse sinus. In our study, the SSS drained into the right transverse sinus on 62.8% of the MRIs and in 62.5% of the anatomical specimens.

Surgical considerations

Median and paramedian cranial vault approaches always risk injuring the SSS. Such injuries usually occur during the craniotomy, when the Gigli saw or the bit of the high‑speed drill lacerates the walls of the sinus. Even before Cushing's advances, surgeons were fearful of causing such damage and therefore habitually cut bone flaps 2 cm lateral to midline.[6]

Figure 6: Axial magnetic resonance image shows the displacement of the superior sagittal sinus toward the right at the region of the torcular. The internal occipital protuberance is indicated by the arrowhead. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

the position of the entire length of the SSS, including the segment covered by the suture. Second, the midline is visible on MRI and computed tomography images.

Consequently, it is a relevant landmark for estimating the position of the SSS before surgery, especially when image guidance is unavailable. Finally, from an embryological perspective, the position of the SSS seems to be more closely related to the midline than to the sagittal suture.[10] Our findings reinforce and expand upon the conclusions of Tubbs et al.[16] and Samadian et al.[11] The entire length of the SSS was usually displaced from midline, typically toward the right. We used the Voxar 3D software to estimate the displacement of the SSS on MRIs. Although this method may be less accurate than direct measurement, the differences between the position of the SSS and the midline on MRIs would likely be distorted only a short distance and hence would not influence our final results.

Traditionally, the inion has been used to estimate the position of the torcular Herophili on the cranial vault.

The torcular Herophili is found at one side of the external occipital protuberance, typically on the right side, where the transverse sinus is more developed.[2,18] Tubbs et al. failed to confirm this finding,[17] and they did not consider the inion to be a reliable landmark for estimating the position of the torcular Herophili. In another study, the right transverse sinus was dominant in 75% of 30 cadaveric specimens.[16] Ziyal et al.[19] found the center of the torcular to be 1.7 cm below the inion in 30 cadaveric specimens. Bisaria et al.[2] studied 110 adult cadavers to evaluate the variations of the torcular. They concluded that in most cases the SSS was divided by a dural partition, which was rarely found at midline, and formed two unequal channels that drained into the

The medial margin of a unilateral frontal craniotomy tends to be in close proximity of the midline. Therefore, the segment of the SSS halfway between the nasion and B can be exposed, especially if the craniotomy is placed on the right side. When the SSS is severely injured during a craniotomy, the sinus can be treated by ligation if the involved segment is near the nasion. We strongly recommend repairing the sinus if it is injured beyond the NB point. Ligation distal to this point is likely to lead to venous infarction.[13] The bone flap of the anterior transcallosal approach is usually planned so that two‑thirds extend anterior and one‑third extends posterior to the coronal suture.

Therefore, the SSS is at risk of damage at two of the craniometric points used in this study: NB and B. Depending on the objective, the surgeon can plan the bone flap to expose the entire width of the SSS or only its border. In our study, the incidence of the SSS displaced to the right of midline at both of these points was high, but the exact location of the SSS is best identified on coronal MRIs before surgery. When MRI is unavailable, burr holes should be placed at least 1 cm lateral of midline on the left side and 2 cm lateral of midline on the right side to avoid injuring the SSS. Parasagittal tumors of the rolandic region can be exposed through a median interhemispheric approach. Typically, the craniotomy reaches or crosses midline. The SSS is partially or completely exposed at the segment related to the midpoint between B and L.[1] The sinus is seldom beneath midline at this point; it will likely be displaced to the right of midline. This segment of the sinus cannot be interrupted, and damage to the sinus can be difficult to repair. Some surgeons therefore place burr holes a few millimeters away from midline to avoid placing a hole exactly above the SSS. Such burr holes are either placed toward the ipsilateral or contralateral side of the craniotomy, depending on the surgeon’s objective. Because the SSS is usually displaced from midline, a paramedian burr hole could expose the SSS. At this segment of the sinus, we suggest identifying the position of the SSS on MRI when possible to avoid poor placement of the burr hole.

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The posterior transcallosal approach exposes about half of the course of the SSS anterior to L. The borders of the craniotomy can expose the margin or the entire width of the SSS at BL and L. Because the SSS is usually displaced toward the right in this region, we recommend applying the same surgical principles described for reaching rolandic parasagittal lesions through a posterior transcallosal approach.

The torcular Herophili, transverse sinus, and segment of SSS between the inion and L can be exposed during an occipital craniotomy. The SSS is widest in this area, and damage to the sinus or torcular can lead to catastrophic bleeding. Therefore, the craniotomy must be planned and performed carefully to avoid injuring the SSS. Because of the trajectory of the SSS toward the dominant right transverse sinus, the sinus is usually displaced (often completely) toward the right side in this region.[2,16,18]

CONCLUSIONS The midline is not an accurate landmark for determining the course of the entire SSS across the cranial vault.

In most cases, the sinus is partially and sometimes completely displaced from midline, usually toward the right side. The position of the SSS is easily observed on MRIs. We therefore recommend obtaining this study, when possible, to avoid damaging the SSS when performing surgical approaches in the vicinity of midline.

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Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Case Report

Neuroendoscopic treatment of symptomatic giant Virchow–Robin spaces Kyle Anthony Smith, Paul Lavin1, Roukoz Chamoun Department of Neurosurgery, University of Kansas Medical Center, 1School of Medicine, University of Kansas Medical Center, Kansas City, KS, USA E‑mail: *Kyle Anthony Smith ‑ ksmith9@kumc.edu; Paul Lavin ‑ plavin@kumc.edu; Roukoz Chamoun ‑ rchamoun@kumc.edu *Corresponding Author Received: 11 February 15 Accepted: 22 May 15 Published: 20 July 15 This article may be cited as: Smith KA, Lavin P, Chamoun R. Neuroendoscopic treatment of symptomatic giant Virchow-Robin spaces. Surg Neurol Int 2015;6:120. http://surgicalneurologyint.com/surgicalint_articles/Neuroendoscopic-treatment-of-symptomatic-giant-Virchow–Robin-spaces/ Copyright: © 2015 Smith KA. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Virchow–Robin spaces (VRS) or perivascular spaces are interstitial cystic spaces surrounding the vasculature of brain parenchyma and course from the subarachnoid space. Small VRS (<2 mm) appear in all age groups, but can enlarge and be confused with other lesions like cystic neoplasms. These enlarged VRS are termed giant tumefactive perivascular spaces (GRPVS).

Case Description: We present the case of a 50-year-old male who presents with right eye pain, blurred vision, headache, and gait imbalance. He was diagnosed with GRPVS and underwent an endoscopic third ventriculostomy and cyst fenestration. Postoperative imaging showed a decrease in size of the ventricular system with evidence of fl ow through the aqueduct and ventriculostomy. Brainstem VRS cysts decreased in size.

Conclusion: Unlike the other small number of case reports, this patient is unique in his age of presentation and successful endoscopic method of treatment. The endoscopic approach provided great exposure and adequate access to the lesions.

Clinically, symptoms improved, cyst size decreased, and need for permanent shunt placement was averted.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161240 Quick Response Code:

Key Words: Cyst fenestration, endoscopy, neuroendoscopy, Virchow–Robin

spaces

INTRODUCTION

CASE REPORT

Virchow–Robin spaces (VRS) are spaces that surround the walls of vessels within the brain parenchyma. VRS are found in all age groups but may increase in size and frequency with age.[4] These spaces may also become very large and assume bizarre configurations and cause a mass effect.[4] Expanded VRS causing the mass effect is uncommon but can result in hydrocephalus requiring shunting. This case describes a 50‑year‑old man with dilated VRS and secondary hydrocephalus who was treated surgically with endoscopic third ventriculostomy (ETV) and cyst fenestration.

History

This 50‑year‑old male presented to our inpatient neurosurgical serve with complaints of right eye pain, blurred vision and occasional diplopia, headache, and gait difficulty with frequent falls due to imbalance. He denies numbness or weakness of extremities. Past medical history included type II diabetes, hypertension, and hyperlipidemia.

Examination

On exam, he was alert and oriented to person, place, and time. He had decreased vision in right eye and diplopia

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on extreme lateral gaze. Subtle horizontal nystagmus was noted. The remaining cranial nerve exam was grossly intact. Patient had normal strength and sensation in all four extremities. He had negative Romberg sign but mildly ataxic gait. Magnetic resonance imaging (MRI) without contrast showed a stable cluster of three cysts centered within the tegmentum of the right midbrain, which in aggregate measured 2.2 cm × 1.4 cm × 1.4 cm [Figure 1].

There was a dominant dorsomedial cyst upto 1.7 cm in maximum dimension with associated compression on the adjacent cerebral aqueduct. There was mild associated hydrocephalus with distention of the lateral and third ventricles [Figure 2].

Operation

Under general anesthesia, the patient was fixed in Mayfield head holder, and stereotactic navigation was registered for use during the procedure. Two burr holes were placed. A posterior burr hole was planned in the right frontal area near the coronal suture in order to perform the ETV. A second burr hole was planned anterior to the first one in order to access the brainstem cyst and the posterior third ventricle. The endoscope was introduced through the posterior burr hole into the lateral ventricle and through the foramen of Monro into the third ventricle. Third ventriculostomy was performed in the usual fashion in the floor of the ventricle, anterior to the mammillary bodies. Next, the endoscope was introduced through the anterior frontal burr hole and taken into the third ventricle through the foramen of Monro in a more posterior trajectory in order to reach the brainstem cyst. Fenestration of the cyst was performed with the endoscopic bipolar. Contents of the cyst were consistent with pure cerebrospinal fluid. An external ventricular drain (EVD) was left for intracranial pressure monitoring following the procedure. The closure was done using burr hole covers and routine skin closure. The patient tolerated the procedure well and was transferred to the intensive care unit for further monitoring and care.

Figure 1: Magnetic resonance imaging sagittal T2-weighted sequence demonstrating cystic perivascular spaces in midbrain tegmentum with distention of the third ventricle and bowing of the corpus callosum

Figure 2: Magnetic resonance imaging axial T2-weighted sequence demonstrating cystic perivascular spaces in midbrain tegmentum with local mass effect on aqueduct of Sylvius

Postoperative course

Intracranial pressures remained within normal limits, and the EVD was removed the following morning after surgery. Patient was able to ambulate without assistance with minimal pathway deviations and perform daily activities of living independently. Cognition remained intact, and he conversed appropriately. Postoperative MRI showed a decrease in size of the ventricular system with evidence of flow through the aqueduct and ostium of the ETV. There was a stable appearance of cystic lesions in the brain stem with some decrease in size [Figure 3].

At 1‑month follow‑up his gait, diplopia, and headache had significantly improved. At 5 months, headache, and diplopia had essentially resolved, and computed tomography scan showed well‑decompressed cyst and ventricles [Figure 4].

Figure 3: Postoperative magnetic resonance imaging sagittal T2-weighted sequence demonstrating decompression of cystic perivascular spaces and resolving distention of the third ventricle

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or ventriculocystostomy.[3,5,7] One case report of a 6‑year‑old boy described the use of endoscopic drainage of a midbrain cyst abutting the ventricular system, but remaining endoscopy could not be performed due to anatomic distortion.[1] The patient improved and showed a decrease in cystic size. In our patient, an ETV was performed successfully in combination with cyst fenestration resulting in resolution of hydrocephalus without additional shunt placement. We believe that the endoscopic approach provided great exposure and adequate access to the lesion and allowed a method of cerebrospinal fluid diversion which averts the need for shunting.

REFERENCES Figure 4: Five-month follow-up computed tomography axial sequence showing decompression of lateral and third ventricles

1.

DISCUSSION

2.

Virchow–Robin spaces are interstitial fluid‑filled potential spaces that surround cerebral arteries and arterioles.[4,8] These spaces are normal anatomical structures within the brain and are believed to be in contact with the lymphatic drainage channels of the head and neck and drain to the cervical lymph nodes.[4] The purpose of VRS are not completely understood, but one theory postulates they provide a route of entry for macrophages and lymphocytes into cerebrospinal fluid spaces.[9] Sometimes, VRS can be markedly enlarged and assume bizarre cystic configurations that can cause a mass effect.[4] Expanding dilation of perivascular spaces is uncommon. There are a few previous case reports of patients with mesencephalic‑diencephalic lesions treated surgically, primarily with ventricular shunting.[2,6] There are several surgical options including ventriculoperitoneal or cystoperitoneal shunting to neuroendoscopic decompression with cysteocisternotomy

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Fayeye O, Pettorini BL, Foster K, Rodrigues D. Mesencephalic enlarged Virchow‑Robin spaces in a 6‑year‑old boy:A case‑based update. Childs Nerv Syst 2010;26:1155‑60.

Flors L, Leiva‑Salinas C, Cabrera G, Mazón M, Poyatos C. Obstructive hydrocephalus due to cavernous dilation of Virchow‑Robin spaces. Neurology 2010;74:1746.

House P, Salzman KL, Osborn AG, MacDonald JD, Jensen RL, Couldwell WT. Surgical considerations regarding giant dilations of the perivascular spaces.

J Neurosurg 2004;100:820‑4.

Kwee RM, Kwee TC. Virchow‑Robin spaces at MR imaging. Radiographics 2007;27:1071‑86.

Morisako H, Tuyuguchi H, Nagata T, Chokyu I, Ichinose T, Ishibashi K, et al.

Enlarged perivascular spaces associated with hydrocephalus: A case report.

No Shinkei Geka 2009;37:681‑6.

Papayannis CE, Saidon P, Rugilo CA, Hess D, Rodriguez G, Sica RE, et al.

Expanding Virchow Robin spaces in the midbrain causing hydrocephalus.

AJNR Am J Neuroradiol 2003;24:1399‑403.

Rohlfs J, Riegel T, Khalil M, Iwinska‑Zelder J, Mennel HD, Bertalanffy H, et al.

Enlarged perivascular spaces mimicking multicystic brain tumors. Report of two cases and review of the literature. J Neurosurg 2005;102:1142‑6.

S a l z m a n K L , O s b o r n AG , H o u s e P, J i n k i n s J R , D i t c h f i e l d A , Cooper JA, et al. Giant tumefactive perivascular spaces. AJNR Am J Neuroradiol 2005;26:298‑305.

Staines DR, Brenu EW, Marshall‑Gradisnik S. Postulated role of vasoactive neuropeptide‑related immunopathology of the blood brain barrier and Virchow‑Robin spaces in the aetiology of neurological‑related conditions.

Mediators Inflamm 2008;2008:792428.

Surgical Neurology International

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Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Technical Note

Endovascular management of fusiform aneurysm of anterior temporal artery: Technical report Aqueel Hussain Pabaney, Paul A. Mazaris1, Max K. Kole, Kevin A. Reinard Department of Neurosurgery, Henry Ford Hospital, Detroit, MI, 1Department of Neurosurgery, Hartford Hospital, Hartford, CT, USA E‑mail: *Aqueel Hussain Pabaney ‑ apabane1@hfhs.org; Paul A. Mazaris ‑ mazaris19@gmail.com; Max K. Kole ‑ mkole1@hfhs.org; Kevin A. Reinard - kreinar1@hfhs.org *Corresponding author Received: 25 January 15 Accepted: 27 May 15 Published: 20 July 15 This article may be cited as: Pabaney AH, Mazaris PA, Kole MK, Reinard KA. Endovascular management of fusiform aneurysm of anterior temporal artery: Technical report. Surg Neurol Int 2015;6:119. http://surgicalneurologyint.com/surgicalint_articles/Endovascular-management-of-fusiform-aneurysm-of-anterior-temporal-artery:-Technical-report/ Copyright: © 2015 Pabaney AH. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: The treatment of a rare, nontraumatic, fusiform aneurysm of the anterior temporal artery (ATA) via endovascular techniques is presented, and procedural nuances are highlighted.

Methods: We performed a retrospective chart review and collected demographic and clinical data on the patient presented here; procedural details were extracted from operative notes.

Results: Following successful balloon test occlusion (BTO) of the ATA, complete coil embolization of the ATA, and its associated fusiform aneurysm was performed.

Postprocedurally, the patient did not suffer any adverse neurological sequelae.

Conclusion: Selective BTO of intracranial branch vessels is safe, technically feasible, and could serve as a useful technical tool in the treatment of complex, fusiform intracranial aneurysms.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161239 Quick Response Code:

Key Words: Anterior temporal artery, balloon test occlusion, coil occlusion, fusiform aneurysm

INTRODUCTION Approximately 20% of all clinically significant intracranial aneurysms involve the middle cerebral artery (MCA).[7] While most aneurysms that originate at the MCA bifurcation or trifurcation have a saccular geometry, some MCA aneurysms may exhibit a fusiform morphology and incorporate not only the proximal MCA trunk but also major MCA branches. In contrast to saccular aneurysms, fusiform aneurysms represent a distinct subset of intracranial aneurysms with unique underlying pathological features, hemodynamic forces, anatomical distribution, as well as natural history that governs their treatment. There have been several reports of fusiform aneurysms of various MCA segments and

the various modalities utilized to treat them; however, a paucity of reports exists with a focus on spontaneous, fusiform anterior temporal artery (ATA) aneurysms.[1,14] Here, we present a case of an incidental, fusiform ATA aneurysm that was coiled and highlight the endovascular techniques that resulted in excellent radiologic and clinical outcome.

CASE PRESENTATION A 37‑year‑old, right‑handed female with no significant past medical history presented to our Emergency Department with several days of holocranial headaches.

Her neurological examination was benign with no evidence of meningismus. Computed tomography (CT)

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of the head revealed a hyperdense mass in the left temporal lobe immediately inferior to the Sylvian fissure.

Magnetic resonance imaging/arteriography demonstrated a partially thrombosed aneurysm in an atypical location [Figure 1]. Digital subtraction angiography with conscious sedation revealed a large fusiform and partially thrombosed ATA aneurysm from which emanated a small vessel [Figure 2]. Balloon occlusion of the ATA was performed using Hyperform™ Occlusion balloon system (ev3/Covidien, Irvine, California, USA) for approximately 30 min and the patient’s systolic blood pressure was lowered by 10%, from 130 to 115 mmHg [Figure 3]. The neurological evaluation was conducted every 2–3 min for the duration of the balloon test occlusion (BTO). Because the patient tolerated the BTO of the ATA without any changes in her neurological status, the senior author (M.K.K.) proceeded and completely occluded the fusiform ATA aneurysm, as well as the distal portion of the ATA by deploying multiple Guglielmi detachable coils in the aneurysm while the patient remained awake using protocols described by Qureshi et al. [Figure 4].[9] Postprocedurally, the patient was observed in the neurosurgical Intensive Care Unit overnight and was discharged home the following day with no new neurological deficits. A CT angiogram performed 12 months after the coiling procedure confirmed stable aneurysm and parent vessel occlusion with no evidence of de novo aneurysms [Figure 5].

Figure 1 (original): Pretreatment magnetic resonance imaging (MRI). Coronal view of T1-weighted, postcontrast MRI brain, demonstrating contrast enhancement of partially thrombosed left anterior temporal artery aneurysm, just inferior to the sylvian fissure

DISCUSSION The MCA is the largest and most complex of the three major cerebral arteries.[10] It is generally divided into four segments: M1 – The segment between the internal carotid artery (ICA) bifurcation and the genu; M2 – The segments that run over the deep insular surface; M3 – The segments that traverse the opercular surface of the sylvian fissure; and M4 – The cortical branches. The M1 segment gives rise to multiple lenticulostriate vessels from its posterior‑superior surface while an anterior temporal branch often takes off from its anterior‑interior surface. According to cadaveric studies, the ATA arises from the proximal M1 in a common trunk shared with the temporal‑polar artery approximately 79% of the times and could have a variable course.[12] In the past, the ATA has been utilized for bypassing complex MCA bifurcation aneurysms[2] and has been successfully embolized for the treatment of skull base meningiomas.[15] More recently, functional studies have demonstrated that strokes in the ATA or temporal‑polar artery could produce semantic errors in auditory comprehension and object naming tasks.[13] Therefore, the selective sacrifice of the ATA may not be as inconsequential as once thought.

With the advent of sophisticated neuroimaging modalities, intracranial fusiform aneurysms are reported with increasing frequency. To date, most studies have

Figure 2 (original): Precoiling angiogram. An anterior-posterior view of left internal carotid artery injection demonstrates the fusiform aneurysm of left anterior temporal artery. Vessel exiting the aneurysm is also visualized (black arrow)

Figure 3 (original): Balloon test occlusion. Artist’s depiction of the placement and inflation of balloon in the anterior temporal artery while performing BTO

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Figure 4 (original): Postcoiling angiogram. Left internal carotid artery injection is demonstrating complete occlusion of the aneurysm and the distal anterior temporal artery (ATA) following balloon occlusion test. Contrast stasis is seen in proximal ATA (black arrow)

focused on fusiform aneurysms of the vertebrobasilar system. As such, the pathogenesis, clinical features, radiographic features, and treatment options available for fusiform aneurysms of the posterior circulation are well documented.[6] Fusiform aneurysms involving the anterior circulation, however, are rare. Most tend to arise from the MCA and predominantly occur in children and adolescents.[16] Various etiologies such as cystic medial necrosis, fibromuscular dysplasia, moya‑moya disease, atherosclerosis, homocystinuria, and intimal fibroelastic abnormal have been implicated in the pathogenesis of similar non‑traumatic aneurysms of ICA. Curiously, all of the aforementioned pathological processes were absent in our patient.

It has been hypothesized that spontaneous fusiform MCA aneurysms may develop as a result of arterial dissection with intramural hemorrhage between the layers of the intima and the media.[4] Patients can present either with ischemic symptoms or with subarachnoid hemorrhage with the latter group demonstrating better recovery and long‑term neurological outcomes, according to some reports.[3] No specific treatment guidelines exist for the management of fusiform aneurysms of the anterior circulation. However, various authors have reported outcomes based on a wide spectrum of treatment options that includes observation, surgical treatment (clip reconstruction, ligation and excision, revascularization), and endovascular treatment (stent or balloon assisted coiling or parent vessel occlusion). Only two reports that focus on the surgical treatment of a single fusiform[14] and a saccular[1] aneurysm of ATA are available. To date, endovascular treatment of an ATA aneurysm has not been reported. Our patient was a young woman with an incidental, partially thrombosed, fusiform, left ATA aneurysm. Given her young age and the left‑sided

Figure 5 (original): Follow-up imaging. Computed tomography angiogram performed 1-year postoperatively displays stable aneurysm occlusion with persistent filling of proximal segment of anterior temporal artery (arrow) with no evidence of recanalization or new aneurysms

location, we recommended endovascular treatment to minimize the surgical morbidity associated with lesions involving the dominant hemisphere.

Advancements in endovascular neurosurgery and the development of modern stents and coil material have provided clinicians with innovative and minimally invasive treatment modalities for the management of disparate and complex intracranial vascular pathologies.

Given the small caliber and fragile nature of the dissected vessel involved, endovascular reconstruction techniques using flow‑diverting stents were deemed not feasible.

In this case, the senior author (M.K.K.) performed a BTO of the ATA prior to aneurysm occlusion and parent vessel sacrifice. BTO of the ICA has a reported positive predictive value that approaches 90%[8] and could help endovascular neurosurgeons determine whether or not a patient is able to tolerate permanent occlusion for an extra‑ or intracranial vessel. Superselective BTO of intracranial vessels has been performed in the past prior to parent vessel sacrifice with satisfying results.[11] However, great care should be taken when selecting a diseased vessel for BTO as the fragile nature of the vessel wall may increase the risk of rupture and catastrophic neurologic compromise. Eckard et al. made use of selective injection of 30 mg of Amytal prior to performing parent vessel occlusion in the management of peripheral intracranial aneurysms.[5] However, we elected not to use Amytal injection because the technique could grossly overestimate the risk of neurological deficit following vessel occlusion. In contrast, BTO may accurately evaluate the efficacy of collateral circulation and the likelihood of neurologic compromise in the event of parent vessel sacrifice. In addition, contrast stasis– which is a reliable indicator of sluggish distal flow that may promote the pial collateral formation and, therefore, decrease the likelihood of infarction following

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vessel occlusion was noted on angiography. Since our patient tolerated the test for 30 min with no signs of neurological deterioration, the fusiform ATA aneurysm and the parent vessel were occluded with coils. Due to proximity to the main trunk of the MCA, we elected to use detachable coils for precise embolization instead of embolic glue, which carries a higher complication risk secondary to glue reflux into the parent vessel. If the patient failed the BTO, both the patient and the senior author (M.K.K.) were prepared for microsurgical trapping of the aneurysm and bypass.

CONCLUSION We present a rare case of an incidental, fusiform aneurysm of ATA that was treated by endovascular coil occlusion and resulted in no neurological sequelae after patient displayed tolerance for balloon occlusion.

Superselective BTO could serve as a powerful assessment tool prior to parent vessel sacrifice. Large‑scale studies are required to determine the long‑term safety and applicability of superselective, intracranial BTO to diverse vascular pathologies.

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Asakura K, Tasaki T, Okada K. A case of unruptured anterior temporal artery aneurysm showing pupil‑sparing oculomotor palsy. No Shinkei Geka 1986;14:777‑82.

Bederson JB, Spetzler RF. Anastomosis of the anterior temporal artery to a secondary trunk of the middle cerebral artery for treatment of a giant M1 segment aneurysm. Case report. J Neurosurg 1992;76:863‑6.

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Day AL, Gaposchkin CG,Yu CJ, Rivet DJ, Dacey RG Jr. Spontaneous fusiform middle cerebral artery aneurysms: Characteristics and a proposed mechanism of formation. J Neurosurg 2003;99:228‑40.

Eckard DA, O’Boynick PL, McPherson CM, Eckard VR, Han P, Arnold P, et al.

Coil occlusion of the parent artery for treatment of symptomatic peripheral intracranial aneurysms. AJNR Am J Neuroradiol 2000;21:137‑42.

Hosoya T, Adachi M, Yamaguchi K, Haku T, Kayama T, Kato T. Clinical and neuroradiological features of intracranial vertebrobasilar artery dissection.

Stroke 1999;30:1083‑90.

Locksley HB, Sahs AL, Knowler L. Report on the cooperative study of intracranial aneurysms and subarachnoid hemorrhage. Section II. General survey of cases in the central registry and characteristics of the sample population. J Neurosurg 1966;24:922‑32.

Narayanan S, Singer R, Abruzzo TA, Hussain MS, Powers CJ, Prestigiacomo CJ, et al. Reporting standards for balloon test occlusion.

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Qureshi AI, Suri MF, Khan J, Kim SH, Fessler RD, Ringer AJ, et al. Endovascular treatment of intracranial aneurysms by using Guglielmi detachable coils in awake patients: Safety and feasibility. J Neurosurg 2001;94:880‑5.

Rhoton AL Jr. The supratentorial arteries. Neurosurgery 2002;51 Suppl 4:53‑120.

Senbokuya N, Kanemaru K, Kinouchi H, Horikoshi T. Giant serpentine aneurysm of the distal anterior cerebral artery. J Stroke Cerebrovasc Dis 2012;21:910.e7‑11.

Tanriover N, Kawashima M, Rhoton AL Jr, Ulm AJ, Mericle RA. Microsurgical anatomy of the early branches of the middle cerebral artery: Morphometric analysis and classification with angiographic correlation. J Neurosurg 2003;98:1277‑90.

Tsapkini K, Frangakis CE, Hillis AE. The function of the left anterior temporal pole: Evidence from acute stroke and infarct volume. Brain 2011;134:3094‑105.

Umeoka K, Shirokane K, Mizunari T, Kobayashi S, Teramoto A. Dissecting aneurysm of the anterior temporal artery: Case report. Neurol Med Chir (Tokyo) 2011;51:777‑80.

Wa l d ro n J S , S u g h r u e M E , H e t t s S W, W i l s o n S P, M i l l s S A , McDermott MW, et al. Embolization of skull base meningiomas and feeding vessels arising from the internal carotid circulation. Neurosurgery 2011;68:162‑9.

Yonas H, Agamanolis D, Takaoka Y, White RJ. Dissecting intracranial aneurysms. Surg Neurol 1977;8:407‑15.

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Original Article

The odontoid process invagination in normal subjects, Chiari malformation and Basilar invagination patients: Pathophysiologic correlations with angular craniometry Jânio A. Ferreira, Ricardo V. Botelho Department of neurosurgery, Hospital do servidor público do estado de São Paulo, 1800 Pedro de Toledo, 04039‑901, São Paulo, Capital, Brazil, 551145738379 E‑mail: *Ricardo V. Botelho ‑ bitbot@uol.com.br; Jânio A. Ferreira ‑ janio_21@yahoo.com.br *Corresponding author Received: 02 November 14 Accepted: 14 April 15 Published: 08 July 15 This article may be cited as: Ferreira JA, Botelho RV. The odontoid process invagination in normal subjects, Chiari malformation and Basilar invagination patients: Pathophysiologic correlations with angular craniometry. Surg Neurol Int 2015;6:118. http://surgicalneurologyint.com/surgicalint_articles/The-odontoid-process-invagination-in-normal-subjects,-Chiari-malformation-and-Basilar-invagination-patients:-Pathophysiologic-correlations-with-angular-craniometry/ Copyright: © 2015 Botelho RV. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, ­distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Craniometric studies have shown that both Chiari malformation (CM) and basilar invagination (BI) belong to a spectrum of malformations. A more precise method to differentiate between these types of CVJM is desirable. The Chamberlain’s line violation (CLV) is the most common method to identify BI. The authors sought to clarify the real importance of CLV in the spectrum of craniovertebral junction malformations (CVJM) and to identify possible pathophysiological relationships.

Methods: We evaluated the CLV in a sample of CVJM, BI, CM patients and a control group of normal subjects and correlated their data with craniocervical angular craniometry.

Results: A total of 97 subjects were studied: 32 normal subjects, 41 CM patients, 9 basilar invagination type 1 (BI1) patients, and 15 basilar invagination type 2 (BI2) patients. The mean CLV violation in the groups were: The control group, 0.16 ± 0.45 cm; the CM group, 0.32 ± 0.48 cm; the BI1 group, 1.35 ± 0.5 cm; and the BI2 group, 1.98 ± 0.18 cm. There was strong correlation between CLV and Boogard’s angle (R = 0.82, P = 0.000) and the clivus canal angle (R = 0.7, P = 0.000).

Conclusions: CM’s CLV is discrete and similar to the normal subjects. BI1 and BI2 presented with at least of 0.95 cm CLV and these violations were strongly correlated with a primary cranial angulation (clivus horizontalization) and an acute clivus canal angle (a secondary craniocervical angle).

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.160322 Quick Response Code:

Key Words: Arnold–Chiari malformation, basilar impression, cephalometry,

platybasia

INTRODUCTION The most common adult craniocervical junction malformations (CVJM) are Chiari malformation (CM) [Figure 1] and basilar invagination (BI).[18]

Craniometric studies have shown that both of these malformations belong to a spectrum of malformations whose common characteristic is the underdevelopment of the occipital bone and consequent neural and cerebrospinal fluid (CSF) flow compression at the craniocervical junction.

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Figure 1: Chiari malformation patient. Solid line is the Chamberlain´s line. Dotted arrow above CL represent Chamberlain’s line violation

BI is the more substantial malformation and differs from CM by the displacement of the cervical spine toward the foramen magnum and ventral brainstem compression.[18] Increasing evidence has identified two subgroups of BI: One is associated with craniovertebral instability in which the tip of the odontoid process projects inside the foramen magnum,[7,8,10,11,17,19,21,24] and the other is not associated with instability, but with greater cranial deformity [Figures 2 and 3]. Angular craniometric studies have identified differences between the types of adult CVJM.[1] Classically, the Chamberlain’s baseline violation (CLV) has been used to diagnose BI, but in the literature, this criterion has varied between extreme values of 1 and 6.6 mm above the CLV.[6,22] A precise definition of CLV for diagnosing BI is lacking.[22] In order to reveal the relationship between CLV in BI, CM patients and normal subjects, we correlated their data with craniocervical angular craniometry to identify possible pathophysiological relationships.

MATERIALS AND METHODS This study was approved by the Research Ethics Committee (Instituto de Assistencia Médica ao Servidor Público Estadual – sp‑caae07284212000005463).

To study the degree of odontoid process invagination, we evaluated magnetic resonance imaging (MRI) scans of the craniocervical junction in T1 and T2 midline sagittal scan acquisitions from a CVJM patient sample consecutively treated by the authors between 1996 and 2012. Computed tomography (CT) scans were used only in specific cases, when necessary, to clarify details of bone anatomy.

The measurements were performed by an observer who was unaware of other study data.

Figure 2: Basilar Invagination type 1. Note that in all cases the odontoid process is inside foramen magnum. The white arrows point to the anterior atlas assimilation and black arrow point to the posterior atlas assimilation. D: Dorsum sellae; B: Basium; O: Opistium

Patients with CVJM were divided into three groups: CM patients, basilar invagination type 1 (BI1) patients and basilar invagination type 2 (BI2) patients.[1,6] Patients with CM had symptomatic cerebellar tonsil herniation and/or posterior fossa structure and cisterna magna compressions [Figure 1].

Patients with BI were divided into two groups: Those with axis dens invagination into the foramen magnum were referred to as type I (BI1) [Figure 2].

Patients with invagination of the dens toward the base of the skull but not toward the inside of the foramen magnum were classified as BI2 [Figure 3].[1,6] The studied sample was based on primary craniovertebral junction malformations without any immediate evident inflammatory, bone, or connective tissue disease.

To compare these findings with the odontoid process invagination in normal subjects (control group), images from 32 consecutive normal subjects were evaluated [Figure 4].

Patients who had normal MRI scans that were performed by the Radiology Department of the Hospital do Mandaqui to clarify cervical spine or head symptoms and who were matched by age and sex to the CCJM group made up the control group. Patients with tumors, trauma, and any diagnostic pathology were excluded from this study.

The amount of Chamberlain’s basal line violation (CLV) was measured as follows [Figure 5]: Images from the midline craniocervical MRI (or CT) were digitalized, and the CLV was traced from the hard palate to the opistion. The distance above or below the CLV was measured using the Meazure 3.2 software

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and the image ruler. The distance above the CLV was considered positive measurements, and the distance below the CLV was considered negative measurements.

The 95% confidence interval was set as the limits for BI diagnosis.

One study evaluating craniovertebral angulations among CCJM and normal subjects revealed significant differences between the groups.[1] To analyze the possible physiopathological association between the degree of CL violation and the angular craniometric variables, the following angles divided into two groups were studied in the craniocaudal direction in a previous study:[1] • Primary cranial angles: Basal (Welcher’s angle) and Boogard’s angle (BOO) • Secondary craniocervical angles: Clivus canal angle (CC) and cervical spine lordosis angle (CL) are illustrated in Figures 5 and 6.

Figure 3: Type 2 Basilar Invagination. At left, CT scan. Lower black line represents Chamberlain’s Line (CL). Upper line represents foramen magnum line. Black arrow is inserted in the C2 axis. The Odontoid above CL is the amount of odontoid CL violation

Figure 5:Type 2 Basilar invagination.The red line is the Chamberlain’s Line (CL).The dotted red arrow represents CLV. Dotted white lines above represents Welcher’s angle.The angle formed by the inferior dotted white line and solid black line is the Boogard’s angle. The vertical lines along with C2 and C7 axis forms the cervical spine lordosis angle

Basal angle (BA): Defined as the angle measured from the nasion, top of the dorsum sellae, and the basion.[1,12,23] CC: The angle between the line extending from the top of the dorsum sellae to the basion and the line between the inferodorsal portions of C2 to the most superodorsal part of the dens.

BOO: The angle between the top of the dorsum sellae, basion, and opisthion.[1,12,23] CL: The angle between a line drawn from the most inferodorsal to the most superodorsal part of C2 (dens of the axis) and another line drawn between the supero‑ and inferodorsal regions of the C7 posterior vertebral body.[1] The larger CL resulted in a more straightened spine, and the shorter CL resulted in a more lordotic spine.

Figure 4: Control group image. Note the odontoid tip at the Chamberlain’s line and the vertical clivus

Figure 6: At left are represented the primary angles: Basal angle (Welcher) and Boogard’s angle. The Chamberlain’s line is represented from the hard palate to the opistion. At right are represented secondary craniocervical angles: Clivus canal angle and cervical lordosis

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The degree of CLV was correlated to the primary cranial angles and secondary craniovertebral angles.

Table 1: Chamberlain’s line violation and craniometric values of CVJM and normal subjects

Statistics: Demographic data and descriptive statistics are expressed as the media, standard deviation and 95% confidence intervals. The Kolmogorov–Smirnov test was used to evaluate the normality of the numeric variable distribution. The Levine test was used to verify the variance homogeneity. Gender distributions were compared with the Chi‑squared test. The ANOVA Kruskal–Wallis test was used to compare the media of the four groups, and Bonferroni’s (correction) test was used as a post hoc test. The correlations between CLV and the cranial and craniovertebral angles were tested with the Spearman correlation test. The correlation strength was classified as follows: 0: Absence of correlation; 0.1–0.3: Weak correlation; 0.4–0.6: Moderate correlation; >0.6–0.9: Strong correlation; and 1: Perfect correlation.

Craniometric variables

RESULTS A total of 97 subjects were studied: 32 normal subjects in the control group, 41 CM patients, 9 BI1 patients and 15 BI2 patients.

The mean age of the control group was 44.8 ± 12 years, and the mean age in the craniovertebral junction malformation groups was 46.9 ± 11 years (t test: P = 0.40).

Among the 32 normal subjects, 17 were male, and among the 65 malformation patients, 30 were male (Chi‑square, P = 0.51).

Descriptive data for CLV, Welcher angle, CC, BOO, and CL for all groups are described in Table 1.

Chamberlain’s line violation Normal subjects Chiari BI1 BI2 Welcher’s angle Normal subjects Chiari BI1 BI2 Clivus canal angle Normal subjects Chiari BI1 BI2 Boogard’s angle Normal subjects Chiari BI1 BI2 Cervical lordosis angle Normal subjects Chiari BI1 BI2

Mean

Std. Deviation

0.16 0.32 1.35 1.98

0.45 0.48 0.51 0.71

118.86 117.38 127.78 128.60

7.21 7.09 16.92 12.21

148.50 150.60 123.33 120.33

10.10 12.86 23.29 15.71

126.20 134.31 157.44 181.86

9.68 15.43 18.92 23.94

158.03 156.23 146.88 137.28

13.99 14.28 14.81 14.39

CVJM: Craniocervical junction malformations, BI1: Basilar invagination type 1, BI2: Basilar invagination type 2.

Chamberlain’s line violation

The mean and 95% confidence intervals of CLV in the three groups are illustrated in Figure 7.

The mean CLV values were as follows: The control group (CTRL), 0.16 ± 0.45 cm; the CM group, 0.32 ± 0.48 cm; the BI1 group, 1.35 ± 0.5 cm; and the BI2 group, 1.98 ± 0.18 cm.

The CLV differed among the four groups (ANOVA– Kruskal–Wallis, P < 0.001).

The post hoc (Bonferroni) test revealed that CLV between the CTRL and CM groups did differ (P = 1.0). Both groups differed from the and BI2 groups (Bonferroni; P < 0.001). The group exhibited significantly greater CLV than the group (1.98 × 1.35, Bonferroni, P = 0.029).

the not BI1 IB2 BI1

Correlation among CLV and the craniometric Welcher, Clivus canal, Boogard, and cervical lordosis angle To evaluate the physiopathological association with the cranial or craniocervical angles, a Spearman correlation

Figure 7: The Chamberlain’s line violation by odontoid process in Control group, Chiari malformation, Basilar type1 (BI1) and Type 2 groups (BI2). Upper and lower values are the 95% confidence limit values and the median value is the media of sample values

among these variables was tested [Figures 8 and 9].

There was a strong correlation between CLV and BOO (R = 0.81, P = 0.000) and between CLV and the CC (R = ‑0.688, P = 0.000) and a moderate correlation between CLV and CL (R = ‑0.39, P = 0.000) and between CLV and Welcher’s angle (R = 0.32, P = 0.002). The scatter dot plot does not illustrate a significant correlation between CLV and Welcher’s angle.

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Figure 8: Illustration of descriptive statistcs for Chamberlain’s line violation, Boogard’s angle, Clivus canal angle, cervical lordosis angles (Lordosis) and Welcher’s angle (Welcher). In the x-axis, 1, 2, 3, and 4 is referred to control group, Chiari malformation, Basilar Invagination type 1 and Basilar invagination type 2 groups, respectively. Note that as the as the CLV increases, Boogard’s values increase and Clivus canal and Cervical lordosis angle decrease

DISCUSSION BI was originally described by Ackermann in cretins from the Alps.[20,23] In 1939, Chamberlain described four cases of basilar impression, and his method for diagnosing this condition was the “base line.”[3] Since then, the most cited way of precisely diagnose BI was measuring the amount of base line violation or CLV. However, the cited CLV criterion varies widely (between 1 and 6.6 mm of CLV).[1,6,22] Craniocervical junction patient’s identification has significantly improved in the last three decades. MRI has increased the diagnosis of tonsillar herniation through the foramen magnum and has facilitated the identification of BI patients with and without craniovertebral instability but a more precise definition of the malformation types is lacking.[15,16] With the use of MRI, the precise diagnosis of BI type and the nature of neural compression facilitate the selection of the best surgical approach for each CCJM case.[13,25] BI may be “primary” (resulting from a congenital or developmental anomaly) or “secondary” (basilar

impression), resulting from bony softening and molding.[17] We only investigated primary cases in this study.

The term CM, as currently defined, have included heterogeneous group of disorders with different pathogenetic origins.[15] Due to the great variability in CLV described in the literature, many BI cases may have been described under the common term, Chiari malformation.

Two relatively new treatment modalities have been used for treating BI: The anterior transnasal endoscopic approach and the posterior reduction and stabilization approach.[2,4,9,14,18,19,21‑24] Some authors have performed both anterior and posterior approaches in unstable BI1 cases.[13] It is likely that isolated posterior approaches could be indicated in these instability cases.

A careful observation of a series of publications on adult BI cases revealed that BI invaginations associated with instability are a homogeneous group with common characteristics: Anterior atlas assimilation and ventral brainstem compression by the odontoid process invagination through the foramen magnum.[1,10,14,21] These cases have been reduced promptly under only head extension or skull traction [Figure 10].

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Figure 9: Scatter dot plot. Upper part: At left, data from CLV are plotted against Boogard’s angle. The “R” numbers are referred to the amount of correlation between data. At right, data from CLV and Clivus canal angle are plotted. Lower left: Relation between cervical lordosis angle and CLV. At right, relation between Welcher angle and CLV

BI without instability is associated with greater cranial deformity, greater clivus horizontalization, an acute CC, and associated platybasia [Figures 3 and 5].[1,6,23] The anterior approach and endscopic transnasal approach play an important role in these complications. Recent experience has revealed that the most difficult cases for the transoral approach, in which the odontoid process was located very high, has been the most appropriate cases for the transnasal approach.[5] CLV analysis suggests fundamental differences among the CCJM groups. In the CM group, the upper confidence limit is set to below 5 mm. The amount of CLV in this group is small and was not significantly different from the control group. Other angular craniometric CM values did not differ from those in normal subjects.[1] CLV is more significant in BI than in CM. The CLV lower confidence interval limit was set at 9.56 mm in the BI1 group. This 95% lower confidence interval value is suggested to be the lower limit of CLV for BI diagnosis. For the BI2 group, the 95% lower limit of the confidence interval was set at 1.6 cm.

The strongest correlation with CLV was shown by the clivus horizontalization measured by BOO, and the second strongest correlation with CLV was shown by the CC. The association of CLV with one primary cranial angle suggests that the skull shape has is a direct determinant of the physiopathology of CLV and ventral brainstem compression. Published data shows that clivus horizontalization is associated with craniovertebral angulation and craniocervical kyphosis.[1] Craniocervical kyphosis is associated with ventral brainstem compression. These associations have practical and clinical importance: Although BOO is an unchangeable characteristic, the CC may be modified by head extension or traction.[2,4,8‑11,14,17,19,21,24] Clivus canal reduction may decrease the CLV and ventral neural compression [Figures 10 and 11].[2] The hyperlordosis associated with these cases may decrease secondary to the more physiologic values if the fixation system does not stop below C2.[1,2] These findings have potential clinical implications in a better selection of CVJ type and amplification of those patients who would be candidates

Surgical Neurology International 2015, 6:118 http://www.surgicalneurologyint.com/content/6/1/118 2.

3.

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Figure 10: Upper part: T1 (left) and T2 acquisitions showing BI1.

Note the ventral cord and brainstem compression by odontoid process. Lower part: CT scan sagittal reconstruction. At left, the odontoid process in inside foramen magnum (Dotted line passing below anterior assimilated C1 arc)

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Figure 11: The importance of head in reducing BI1. Note the reduction of ventral brainstem compression and CLV with extension of head and caniocervical junction kyphosis normalization

17.

for single posterior alignment and correction rather than ventral approaches or circumferential surgeries.

18.

CONCLUSIONS CM patients presented with discrete CLV similar to normal subjects. BI1 presented a CLV of at least of 0.96 cm and BI2 patients had at least 1.5 cm of CLV. There is strong correlation with CLV and clivus horizontalization, suggesting pathopysiologic relationship with the primary cranial angle and, with and CC, a secondary craniocervical angle.

19.

20.

21.

22.

23.

24.

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Botelho RV, Beco Neto E, Patriota GC, Daniel JW, Dumont PAS, Rotta JM. Basilar invagination: Craniocervical instability treated with cervical traction and occipitocervical fixation. J Neurosurg Spine 2007;7:444–9.

Chamberlain WE. Basilar Impression (Platybasia): A Bizarre Developmental Anomaly of the Occipital Bone and Upper Cervical Spine with Striking and Misleading Neurologic Manifestations.Yale J Biol Med 1939;11:487‑96.

Dahdaleh NS. Dlouhy BJ, Menezes AH.Application of neuromuscular blockade and intraoperative 3D imaging in the reduction of basilar invagination.

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El‑Sayed IH, Wu J, Dhillon N, Ames CP, Mummaneni P. The Importance of Platybasia and the Palatine Line in Patient Selection for Endonasal Surgery of the Craniocervical Junction: A Radiographic Study of 12 Patients. World Neurosurg 2011;76:183‑8.

Goel A, Bhatjiwalem M, Desai K. Basilar invagination: A study based on 190 surgically treated Patients. J Neurosurg 1998;88:962‑8.

Goel A, Shah A. Reversal of longstanding musculoskeletal changes in basilar invagination after surgical decompression and stabilization. J Neurosurg Spine 2009;10:220‑7.

Goel A.Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation. J Neurosurg Spine 2004;1:281‑6.

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Yu Y, Wang X, Zhang X, Hu F, Gu Y, Xie T, et al. Endoscopic transnasal odontoidectomy to treat basilar invagination with congenital osseous malformations. Eur Spine J 2013;22:1127‑36.

Surgical Neurology International

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Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Case Report

Strategy for endovascular coil embolization of a penetrating vertebral artery injury Hiroki Uchikawa, Yutaka Kai1, Yuki Ohmori1, Jun‑Ichi Kuratsu1 Department of Neurosurgery, Saiseikai Kumamoto Hospital, 1Department of Neurosurgery, School of Medicine, Kumamoto University, Kumamoto, Japan E‑mail: *Hiroki Uchikawa ‑ h.uchikawa.1223@gmail.com;Yutaka Kai ‑ ykai_1961@yahoo.co.jp;Yuki Ohmori ‑ ohmori4497@gmail.com; Jun‑ichi Kuratsu ‑ jkuratsu@kumamoto‑u.ac.jp *Corresponding author Received: 15 January 15 Accepted: 05 May 15 Published: 08 July 15 This article may be cited as: Uchikawa H, Kai Y, Ohmori Y, Kuratsu JI. Strategy for endovascular coil embolization of a penetrating vertebral artery injury. Surg Neurol Int 2015;6:117. http://surgicalneurologyint.com/surgicalint_articles/Strategy-for-endovascular-coil-embolization-of-a-penetrating-vertebral-artery-injury/ Copyright: © 2015 Uchikawa H. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Penetrating vertebral artery injuries (VAIs) are even rarer than carotid artery injuries. For anatomical reasons, the surgical management of VAI is difficult, and endovascular management often yields a good outcome. We report our strategy for the endovascular treatment of a patient with a penetrating VAI at the V2 segment of the left vertebral artery.

Case Description: In a fall on a large rake, a 76‑year‑old man was stabbed in the left neck by three tines. Although he manifested no neurological deficits, computed tomography (CT) suggested penetrating VAI. Digital subtraction angiography confirmed VAI and extravasation, and he underwent endovascular coil embolization.

Two microcatheters, inserted proximal and distal to the injury sites, were used for successful endovascular coil embolization. Postoperative magnetic resonance imaging ‑ and single photon emission CT studies denied cerebral infarction and a decrease in cerebral perfusion. The patient exhibited no neurological deficits and was able to leave the hospital on foot.

Conclusion: This is the rare documentation of a patient whose penetrating VAI was treated by simultaneous coil embolization and foreign body removal. Imaging studies confirmed the patency and perfusion of the intracranial artery. Our treatment strategy produced a good outcome in this unusual patient.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.160320 Quick Response Code:

Key Words: Embolization, penetrating neck trauma, stab wound, traumatic vertebral artery injury

INTRODUCTION

CASE REPORT

Only approximately 0.5% of all trauma patients present with traumatic vertebral artery injury (VAI) which is even more rare than carotid artery injury.[9] We encountered a patient with a penetrating VAI at the V2 segment of the left vertebral artery and report our strategy for his endovascular treatment which involved simultaneous coil embolization and foreign body removal.

In a fall on a large rake, this 76‑year‑old man was stabbed in the left neck by three tines [Figure 1]. He was taken to our emergency department with three metal tines penetrating his left neck; he was fully conscious and exhibited no neurological deficits. His vital signs were stable, and there was no apparent active bleeding. All laboratory data were normal.

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A plain computed tomography (CT) scan showed that one of the tines penetrated between the C3/4 transverse foramen suggesting left vertebral artery damage. The other tine was attached to the hyoid bone and thyroid cartilage. His epiglottis was slightly swollen; there was no air leak, and he reported no respiratory discomfort.

Other important structures such as the spinal cord and other major arteries and veins were intact. CT angiography (CTA) demonstrated obstruction of the left vertebral artery at the V2 segment proximal to the penetrating tine [Figure 2]. Because the metal artifact limited detailed evaluation we performed digital subtraction angiography (DSA) under general anesthesia to study his hemodynamic status and to select treatment. Angiography through the left vertebral artery revealed obstruction of the left vertebral artery and some oozing beside the metal tine [Figure 3]. Blood flow from the contralateral vertebral artery perfused the posterior fossa, and bilateral posterior communicating arteries were fetal type. We selected endovascular embolization to prepare for extravasation from the damaged vertebral artery.

After inserting a 6‑Fr guiding catheter (Slim guide®, Medikit, Japan) into the left vertebral artery, we navigated two microcatheters (Excelsior®, Stryker Neurovascular, USA) into the proximal and distal sides to the injury point. It might be better that we use a stent to suppress the bleeding point and preserve anterograde blood flow, but vertebral artery at the injury point was too narrow to pass the stent device. A 4‑Fr catheter was then inserted into the right vertebral artery for evaluation of the contralateral circulation. In the middle of slowly and carefully withdrawing the metal tine, we noted extravasation and decided that endovascular embolization was indicated. We first performed coil embolization at the entry ‑ and the proximal side using the microcatheter inserted at the proximal side. Then we embolized the distal side to the site of entry using the distal microcatheter. Extravasation ceased after complete embolization of the left vertebral artery [Figure 4].

The tine was withdrawn, and the other two tines were removed at the same time. There was neither bleeding nor cerebrospinal fluid leakage after their removal and drainage tubes were inserted into the three stab wounds.

As postembolization laryngoscopy revealed laryngeal wall damage by one of the tines, we performed tracheotomy.

Postoperative magnetic resonance imaging showed no evidence of cerebral infarction and single photon emission CT (SPECT) demonstrated normal cerebral perfusion [Figure 5]. His laryngeal swelling disappeared after a few weeks, and he was extubated. The perioperative administration of antibiotics prevented focal or general infection. He manifested no neurological deficits and was able to leave the hospital on foot.

Figure 1: Paramedics on the scene carefully cut down the tines.The patient’s vital signs were stable, and he manifested no neurological deficits

a

b

Figure 2: (a) A plain computed tomography (CT) scan (axial view) indicated vertebral artery injury. (b) An enhanced CT scan (coronal view) demonstrated left vertebral artery interruption

a

b

Figure 3: Digital subtraction angiography showed vertebral artery injury.The left vertebral artery was interrupted at the V2 segment at a site proximal to the tip of the tine (a).The contralateral vertebral artery was perfused on both sides of the posterior circulation (b)

DISCUSSION Traumatic VAIs are seen in approximately 0.5% of all trauma patients.[9] VAI is strongly associated with head and neck injuries such as cervical spine fractures[5,7] and penetrating VAI is even less common than carotid artery injury in patients with trauma or blunt VAI. Without proper management, the morbidity ‑ and mortality rates of patients with penetrating VAI are relatively high.[4] Among patients with gunshot ‑ and stab wounds

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a

b

a

b

Figure 5: (a) The axial diffusion-weighted magnetic resonance imaging scan revealed no ischemic region. (b) On the single photon emission computed tomography image, there is no evidence of a decrease in cerebral perfusion in the posterior circulation c Figure 4: (a) Digital subtraction angiography (DSA) performed after injecting the left vertebral artery via a microcatheter showed extravasation from the vessel upon removal of the tine. (b) DSA performed after injecting the left vertebral artery via a guiding catheter showed no extravasation from the left vertebral artery after embolization. (c) DSA performed after right vertebral artery injection showed good contralateral vertebral artery flow. The damaged vessel was not contrast-enhanced

Table 1: Cerebrovascular injury grading scale Injury Description grade I II

Luminal irregularity or dissection with <25% luminal narrowing (nonclinically significant narrowing) Dissection or intramural hematoma with >25% luminal narrowing, intraluminal thrombus, or raised intimal flap (potentially clinically significant) Pseudoaneurysm Occlusion Transection with free extravasation (usually lethal injuries)

the incidence of penetrating VAI is 1.0% and 7.4%, respectively.[13] Based on their angiographic appearance, VAI are classified into five types. Grade V, the most severe grade, is vessel transection [Table 1].[3,15]

III IV V

The major problem in the management of VAI is the severe limitation with direct open access to the vertebral artery. Because these vessels pass into the transverse foramen, proximal and distal ‑ and surgical local control is difficult.[6] Consequently, we often select endovascular treatment to address traumatic VAI and we and others obtained good outcomes even in unstable trauma patients.[1] However, the diagnosis of VAI is difficult especially in the absence of neurological deficits or spinal cord injury and the appropriate modality to screen for VAI is controversial. DSA has been the gold standard for the diagnosis and treatment of VAI when a foreign body is located near a vital structure.[10] Eastman et al. who used 16‑slice CTA and catheter angiography to screen 146 trauma patients suspected of blunt vascular injury reported that in 98% the findings were concordant.[8] This suggests CTA as the first choice for screening for VAI.

symptomatic case of the vertebrobasilar ischemia, we treated in the same way, because active bleeding was most fatal. Furthermore, it would be difficult to rescue ischemia because it took too long time from the onset.

We inserted two microcatheters at sites proximal and distal to the damaged artery to embolize both sides simultaneously because their proximal introduction alone would not have allowed control of the distal flow after embolization of the proximal side. Although distal control might not always be necessary, we purposely inserted microcatheter at the distal side to the damaged point for safety. If microcatheter could not be inserted at the distal side anterogradely, we would insert microcatheter from right vertebral artery retrogradely. Our use of the 6‑Fr guiding catheter, which facilitates the application of advanced techniques that involve multiple microdevices rendered endovascular treatment safe and easy.[12]

In our patient, plain cervical CT revealed no severe spinal or vertebral damage. However, immediate withdrawal of the tines would have worsened our patient’s situation.

We confirmed our suspicion of VAI by performing CTA before their removal. DSA showed no flow in the posterior circulation on the affected side. Collateral circulation from the right vertebral artery was good, and the bilateral posterior communicating arteries were of the fetal type. These findings indicated that safe embolization of the left vertebral artery was possible. If

Traumatic VAI can be endovascularly treated with coils, balloons, or stents.[2,11,14] Although what is best or common treatment is controversial, coil embolization would be most common treatment in the literature, especially for bleeding cases.[1,2] We chose coil embolization because the damaged vessels were too narrow for the passage of stents or balloons. Xia et al. encountered a case similar to ours; they treated their patient’s VAI with coils and also obtained a good outcome.[16] The long‑term results of endovascular treatment for VAI remain unclear. In

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patients manifesting a decrease in cerebral perfusion we would consider extracranial‑intracranial arterial anastomosis. While posttreatment SPECT confirmed normal cerebral perfusion in our patient, additional studies are needed to identify the optimal strategy for the treatment of patients with VAI.

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Kai Y, Ohmori Y,Watanabe M, Kaku Y, Morioka M, Hirano T, et al. A 6‑fr guiding catheter (slim guide(®)) for use with multiple microdevices.An experimental study. Interv Neuroradiol 2013;19:7‑15.

Karadag O, Gürelik M, Berkan O, Kars HZ. Stab wound of the cervical spinal cord and ipsilateral vertebral artery injury. Br J Neurosurg 2004;18:545‑7.

Lee YJ, Ahn JY, Han IB, Chung YS, Hong CK, Joo JY. Therapeutic endovascular treatments for traumatic vertebral artery injuries. J Trauma 2007;62:886‑91.

Miller PR, Fabian TC, Bee TK,Timmons S, Chamsuddin A, Finkle R, et al. Blunt cerebrovascular injuries: Diagnosis and treatment. J Trauma 2001;51:279‑85.

Xia X, Zhang F, Lu F, Jiang J, Wang L, Ma X. Stab wound with lodged knife tip causing spinal cord and vertebral artery injuries: Case report and literature review. Spine (Phila Pa 1976) 2012;37:E931‑4.

Surgical Neurology International

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Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Letter to the Editor

Ethical and methodological considerations on conducting clinical research in poor and low‑income countries: Viewpoint of the authors of the BEST TRIP ICP randomized trial in Latin America Randall M. Chesnut, Nancy Temkin1, Sureyya Dikmen2, Carlos Rondina3, Walter Videtta4, Silvia Lujan5, Gustavo Petroni5, James Pridgeon6, Jason Barber6, Joan Machamer7, Kelley Chaddock6, Juanita M. Celix6, Marianna Cherner8, Terence Hendrix9 Departments of Neurological Surgery and Orthopaedics and Sports Medicine, 1Neurological Surgery and Biostatistics, 2Rehabilitation Medicine and Neurological Surgery, 6Neurological Surgery, 7Rehabilitation Medicine, Harborview Medical Center, University of Washington, Seattle, USA, 3President Fundacion ALAS, Hospital de Emergencias, “Dr. Clemente Alvarez,” 4President Latin American Brain Injury Consortium, Hospital Nacional Professor Alejandro Posadas, 5Latin American Outcomes Examiner/Trainer/Coordinator/Data monitor, Hospital de Emergencias, “Dr. Clemente Alvarez,” CIIC, 8Department of Psychiatry, Neuropsychologist, Outcome measures consultant (Spanish), 9Latin America Site Outcomes Coordinator, Clinical Research Study Coordinator, HIV Neurobehavioral Research Programs (HNRP), University of California, San Diego, California, USA E‑mail: * Randall M. Chesnut ‑ chesnutr@uw.edu; Nancy Temkin ‑ temkin@uw.edu; Sureyya Dikmen ‑ dikmen@uw.edu; Carlos Rondina ‑ rodinac@arnet.com.ar; Walter Videtta ‑ wvidetta@yahoo.com.ar; Silvia Lujan ‑ silviablujan@gmail.com; Gustavo Petroni ‑ gustavopetroni@ gmail.com; James Pridgeon ‑ pridgeon@uw.edu; Jason Barber ‑ barber@uw.edu; Joan Machamer ‑ machamer@uw.edu; Kelley Chaddock ‑ chaddk@uw.edu; Juanita M. Celix ‑ celixj@u.washington.edu; Marianna Cherner ‑ mcherner@ucsd.edu; Terence Hendrix ‑ thendrix@ucsd.edu *Corresponding author Received: 13 August 14 ­Accepted: 08 October 14 Published: 02 July 15 This article may be cited as: Chesnut RM, Temkin N, Dikmen S, Rondina C,Videtta W, Lujan S, et al. Ethical and methodological considerations on conducting clinical research in poor and low-income countries:Viewpoint of the authors of the BEST TRIP ICP randomized trial in Latin America. Surg Neurol Int 2015;6:116. http://surgicalneurologyint.com/surgicalint_articles/Ethical-and-methodological-considerations-on-conducting-clinical-research-in-poor-and-low‑income-countries:-Viewpoint-ofthe-authors-of-the-BEST-TRIP-ICP-randomized-trial-in-Latin-America/ Copyright: © 2015 Chesnut RM. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

We read with interest the editorial critique of Sahuquillo and Biestro[10] regarding the BEST TRIP trial,[2] and appreciate Hunt’s editorial response.[6] However, we believe that the several oversights and misinterpretations that flaw the structure of the editorial, although resolvable by careful reading of the paper, will benefit by clarification by us who were directly involved with the study. Our major concerns are regarding the misrepresentation of the study’s focus and the sterile analysis of equipoise.

As stated in the BEST TRIP report, this was not a study of intracranial pressure (ICP) monitoring per se. It was designed as an investigation of two protocols of aggressive treatment of intracranial hypertension, one driven by monitored ICP and based on recommendations from the Guidelines for the Management of Acute Brain Injury in Adults[1] and the other based on current practices at the study (non‑monitoring) institutions, which were guided by serial neurological examination and CT imaging. There was no placebo group in this study; both groups were afforded highly aggressive neurological management. As presented in the BEST TRIP report, there was no difference in the incidence of pre‑specified clinical neurological deterioration

criteria (one hallmark of inadequate ICP management) between the monitor‑driven and the non–monitor‑driven protocols. Recognizing the absence of a placebo control group renders specious the suggested parallels between the BEST TRIP trial and ethically questionable studies such as the African zidovudine studies and the Tuskegee and Willowbrook investigations.

From a position of academics in high‑income countries (HICs), it is argued that ICP monitoring is the standard of care. However, the guidelines themselves note that the weakness of the literature supporting ICP monitoring reflects the lack of randomized control trial (RCT)‑level data. There is no doubt that elevated ICP is a bad prognostic indicator; the evidentiary frisson exists because it has not Access this article online Quick Response Code: Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.159841

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been definitively shown that lowering ICP improves recovery.

The correlative nature of the available Class II and III studies cannot differentiate treatment‑related selection of patient subgroups with different prognoses versus actually increasing recovery. An objective indication that there is no consensus on ICP monitoring, even in HICs, is the wide variation of its routine use in actual practice (77.4% in the US,[5] 44.5% in Australia and New Zealand,[7] 63% in Canada,[9] and 37% in Europe[12]). Perhaps naïvely, we believe that these frequencies reflect clinical or global equipoise at HIC centers rather than non‑compliance with a true standard of practice.

In low‑ and‑middle‑income countries (LMICs), although ICP monitoring is generally available (via ventriculostomy), it is rarely used, with availability of neurological surgeons, expense, complications, and labor intensity quoted as reasons. As a result, aggressive treatment of suspected intracranial hypertension is based on serial imaging and neurological examination. The widespread environment of competition for funding and resources in LMICs places the implications of the lack of scientific rigor in a unique context quite different from that in HICs. It is perhaps germane to realize that most, if not all, of the authors of the guidelines have never managed a severe traumatic brain injury (TBI) patient without an ICP monitor.

This brings us to our second major area of concern with the Sahuquillo and Biestro critique, which revolves around the sterility of their analysis of equipoise. As noted in the commentary of Hunt, equipoise may be considered to have superficial and deep aspects. Superficially, it is likely true that our Latin American investigators would have been using ICP monitoring before the trial if it were readily available. Of course, cardiac surgeons would have routinely employed internal mammary artery ligation for angina in the 1950s[3] and intensivists would have chosen pulmonary artery catheterization for managing critically ill ICU patients four decades later.[4,8,11] We would all likely benefit from confessing to “medical magpie‑ism” and admitting that practice in the high‑resource environment of HICs greatly facilitates (and obscures) such a non‑scientific proclivity. However, the benefits of living in a high‑resource environment also strongly inhibits us from understanding the profoundly different visceral viewpoint that arises from having experienced one’s entire medical career in LMICs. Indeed, the BEST TRIP investigators from the US and Argentina were initially taken aback when the site investigators involved in designing a multicenter prospective observational study suggested that they would be interested in performing an RCT involving ICP‑monitor‑driven care. Not until after much discussion among ourselves and with our site PIs did we realize that their position of equipoise, although difficult for us initially to understand, was internally valid.

Without the indispensable experience that we had gained over a decade of working in Latin America, learning and experiencing their reality, it is quite possible that some

of the BEST TRIP authors might have co‑authored the editorial critique of Sahuquillo and Biestro.

It is notable that this trial was evaluated and approved by ethical committees and FWA‑approved IRBs in all participating Latin American institutions, as well as by the IRB at the University of Washington in the US. Although there were myriad ethical questions from each entity during these reviews, none found the study unacceptable based on ethical concerns.

As far as conflict of interest is concerned, the site PIs who suggested and performed this study had no interest in its implications in HICs, but were very much interested in finding whether the application of our current ICP‑monitor‑driven protocols in their environment would warrant the required resources. Although the editorial states that “BEST TRIP is a good example of research that has no practical relevance to the health needs of the host country, but it is apparently important to the foreign sponsors and researchers …,” we fail to see how demonstrating inadequacies in our use of an important monitoring device is not relevant to the health needs of both the US and Latin American countries involved in the study. We also take issue with their strong implication that this study was influenced by industry. Given the highly limited funding that comes with Fogarty International Center directed/NIH sponsored research awards, there was no way for us to purchase the required monitors.

Integra Life Sciences responded positively to our request that they would supply the necessary hardware, despite explicit prohibitions against their having input into the design, execution, analysis, or publication of the study results. This is collaboration, not collusion, and allegations otherwise would benefit from supporting evidence.

In contrast to the implications of the editorial, the BEST TRIP publication explicitly cautions against ready generalization of the results to HIC centers. This is based on the many important differences between these environments and our inability to adequately control for them in our analyses. As the editorial correctly states, the logical next step would be repeating the study at trauma centers in HICs. However, it also posits, “these countries would never allow such a trial to be conducted,” which we believe is incorrect. As noted above, there were sizeable percentages of HIC trauma centers not monitoring prior to the trial, and we perceive an increasing willingness for practitioners who do not routinely monitor to publically admit this following the BEST TRIP publication. A shift in HIC‑equipoise balance might not be required to perform such a study.

Finally, our site PIs almost to a person took umbrage at the implication in this editorial that the study ICUs were of limited quality due to lack of resources. Anyone who has spent time in these ICUs will immediately recognize the high level of education, diligence, and

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application represented by the involved intensivists, which is clearly reflected in the data presented in the BEST TRIP publication and the online supplement.

We offer a standing invitation to Professor Sahuquillo and Dr. Biestro to visit any or all of the BEST TRIP ICUs toward rectifying their difficulty in differentiating resource limitations and quality of care.

We believe that proper response to a careful, thorough reading of the BEST TRIP report is to recognize the critical value of aggressive and attentive management of TBI patients in all settings and to admit that our field’s employment of ICP monitoring is under‑developed at present, rather than to deny the study’s findings.

Refinements in threshold setting, TBI subgroup identification, and integration of ICP data with other monitored values and trends appear wanting, but there is no evidence that ICP monitoring should be abandoned.

On the larger stage, it is also important to realize that the medical and ethical literature almost exclusively emanates from academic centers in HICs. The only valid method for assessing the generalizability of this literature to LMICs is to make an unbiased, protracted effort to understand their reality, as perceived by them. In this light, it is notable that none of our Latin American colleagues have ever expressed regret that they suggested this study or participated in its execution.

REFERENCES 1.

Bratton S, Bullock R, Carney N, Chesnut R, Coplin W, Ghajar J, et al. Guidelines for the Management of Severe Brain Injury: 2007 Revision. J Neurotrauma

2007;24 Suppl 1:S1‑106.

Chesnut RM, Temkin N, Carney N, Dikmen S, Rondina C, Videtta W, et al.

A trial of intracranial‑pressure monitoring in traumatic brain injury. N Engl J Med 2012;367:2471‑81.

3. Cobb LA, Thomas GI, Dillard DH, Merendino KA, Bruce RA. An evaluation of internal‑mammary‑artery ligation by a double‑blind technic. N Engl J Med 1959;260:1115‑8.

4. Harvey S, Harrison DA, Singer M, Ashcroft J, Jones CM, Elbourne D, et al.

Assessment of the clinical effectiveness of pulmonary artery catheters in management of patients in intensive care (PAC‑Man):A randomised controlled trial. Lancet 2005;366:472‑7.

5. Hesdorffer DC, Ghajar J. Marked improvement in adherence to traumatic brain injury guidelines in United States trauma centers. J Trauma 2007;63:841‑7.

6. Hunt CD. Commentary on Sahuquillo and Biestro ‘Is intracranial pressure monitoring still required in the management of severe traumatic brain injury?

Ethical and methodological considerations on conducting clinical research in poor and low‑income countries.” Surg Neurol Int 2014;5:86.

7. Myburgh JA, Cooper DJ, Finfer SR, Venkatesh B, Jones D, Higgins A, et al.

Epidemiology and 12‑month outcomes from traumatic brain injury in Australia and New Zealand. J Trauma 2008;64:854‑62.

8. Richard C, Warszawski J, Anguel N, Deye N, Combes A, Barnoud D, et al.

Early use of the pulmonary artery catheter and outcomes in patients with shock and acute respiratory distress syndrome: A randomized controlled trial. JAMA 2003;290:2713‑20.

9. Sahjpaul R, Girotti M. Intracranial pressure monitoring in severe traumatic brain injury-results of a Canadian survey. Can J Neurol Sci 2000;27:143‑7.

10. Sahuquillo J, Biestro A. Is intracranial pressure monitoring still required in the management of severe traumatic brain injury? Ethical and methodological considerations on conducting clinical research in poor and low‑income countries. Surg Neurol Int 2014;5:86.

11. Sandham JD, Hull RD, Brant RF, Knox L, Pineo GF, Doig CJ, et al.

A randomized, controlled trial of the use of pulmonary‑artery catheters in high‑risk surgical patients. N Engl J Med 2003;348:5‑14.

12. Stocchetti N, Penny KI, Dearden M, Braakman R, Cohadon F, Iannotti F, et al. Intensive care management of head‑injured patients in Europe: A survey from the European brain injury consortium. Intensive Care Med 2001;27:400‑6.

2.

Commentary I read with progressively eager enthusiasm the response of the BESTTRIP authors to the editorial by Drs Sahuquillo and Biestro and my comment on their editorial. It is clear that Chesnut et al. of BESTTRIP took aggressive umbrage at their inference that their study was ethically challenged.

Before giving a more specific response to the issue raised by them, I would like to make two points. First, as an early reviewer of the editorial of Sahuquillo et al. I apologize that I failed to recognize that an opportunity for acute response by the BESTTRIP authors was not only legitimate but also arguably demanded by the tone of the editorial. I hope to carry out my editorial responsibilities more effectively in the future.

Second, their very arthus‑like reaction to the editorial demonstrates both the seriousness with which they took their ethical obligations and the importance of addressing

these concerns upfront, as well. As a past chairman of an active bioethics committee, I am gratified by the weight given to these ethical issues, a weight not always in clear evidence, and applaud any opportunity to better discuss the moral underpinnings of any research projects, particularly thosewith major transcultural or transnational components.

Chesnut’s first point is his weakest. To argue that a study group cared for without monitoring does not constitute a “placebo” group, within the common understanding of the phrase, seems disingenuous, if factually accurate. The risk of ethical compromise of the study is not affected by whether or not this is technically a placebo group.

Their subsequent defense is far more persuasive. The lack of clear research or international consensus on the efficacy–regarding outcome–of monitoring is indeed important in the establishment of equipoise.

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I would also affirm their point that ventriculostomy, as a diagnostic, and even therapeutic, methodology is inexpensive and virtually universally available. Even the Becker Bolt is remembered by some.

Issues of herd mentality in the understanding of best treatment and the generalizability of data due to cross‑cultural distinctions are all also valid attenuators of scientific “certainty.” Ultimately, I believe the expanded defensive arguments of Chesnut et al. are fully persuasive.

I eagerly await any continuation of this important conversation with Sahuquillo et al. and look forward to their responses. Vigilance in defense of all our patients in the face of any ethical uncertainty is always appropriate, and I applaud both sets of authors for fully engaging in this important conversation.

Charles David Hunt 1031 Garden St., Hoboken, NJ, USA E‑mail: *Charles David Hunt ‑ huntneurosurgery@mac.com

Surgical Neurology International

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Editor: James I. Ausman, MD, PhD University of California, Los Angeles, CA, USA

Case Report

Craniocervical junction tuberculosis: Usual pathology at an unusual site Biswaranjan Nayak, Sanjeev Patnaik1, Prafulla Kumar Sahoo, Debabrata Biswal Department of Neurosurgery, 1Orthopaedics, Apollo Hospital, Bhubaneswar, Odisha, India E‑mail: *Biswaranjan Nayak - dr.bnayak@gmail.com; Sanjeeb Patnaik - sportho1973@yahoo.co.in; Prafulla Kumar Sahoo - prafullksahoo@hotmail.com; Debabrata Biswal - dr.bnayak@yahoo.com *Corresponding author Received: 30 March 15 Accepted: 06 May 15 Published: 02 July 15 This article may be cited as: Nayak B, Patnaik S, Sahoo PK, Biswal D. Craniocervical junction tuberculosis: Usual pathology at an unusual site. Surg Neurol Int 2015;6:115. http://surgicalneurologyint.com/surgicalint_articles/Craniocervical-junction-tuberculosis:-Usual-pathology-at-an-unusual-site/ Copyright: © 2015 Nayak B. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Tuberculosis (TB) of the craniocervical junction is rare even where the condition is endemic. It poses problems in both diagnosis and management if not managed in time it may cause life‑threatening complications.

Case Description: An 18‑year‑old male patient presented with pain in the nape of the neck since 12 months duration which was not improving with medication.

After magnetic resonance imaging of cervical spine, he was diagnosed as craniocervical junction TB. We did a transoral decompression of abscess with biopsy along with posterior decompression of cord and occipitocervical fusion.

Biopsy of pathological material came as TB. He was advised for anti‑tubercular therapy for 18 months.

Conclusion: Although craniocervical junction TB is a rare disease, the outcome of treatment is good. Antituberculous drug therapy remains the mainstay of treatment after confirming the diagnosis. The surgical management options include transoral decompression with or without posterior fusion, depending upon the presence and persistence of atlantoaxial instability.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.159835 Quick Response Code:

Key Words: Craniocervical junction, posterior fusion, transoral decompression,

tuberculosis

INTRODUCTION Tuberculosis (TB) is a worldwide health problem, according to the World Health Organization it is the leading infectious cause of mortality worldwide killing 1.45 million people.[13] Spinal TB, first described by Sir Percival Pott in the 18th century, accounts for 50% of these cases[2] and results in immense morbidity and mortality. TB of the craniocervical junction is rare[5] and accounts for only about 1% of all cases of spinal TB. It is difficult to diagnose and manage and is a therapeutic challenge. It primarily involves the atlas and axis and in some cases, the occipital

region. Because of potential fatal complications, any infection at this site must be diagnosed early and treated promptly. Death is usually due to atlantoaxial dislocation causing compression of the cord.[9] Although the clinical spectrum of spinal TB is variable, back pain is the major symptom. Spinal TB can lead to bone destruction and vertebral collapse resulting in paravertebral abscess and deformity. If prompt management is not employed, severe neurological symptoms ensue, which can lead to a debilitating consequence. Moreover, spinal TB still remains the leading cause of nontraumatic paraplegia in developing nations.

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CASE REPORT An 18‑year‑old male patient presented with pain in the nape of the neck since 12 months duration which was not improving with medication. The patient had stiffness of the neck with decreased range of movement in all directions.

Routine hematological investigations were within the normal limit, and he was screened for rheumatologic problems without revealing any pathology. On magnetic resonance imaging of cervical spine [Figure 1], there were irregular lytic bony destruction in anterior arch and left lateral mass of C‑1, left occipital condyle, left half of C‑2 vertebra with prevertebral and left para vertebral collection, mild erosion in the odontoid process, with cranial migration of odontoid with tip up to the level of foramen magnum, there was compression of cord at this level with cord edema, suggestive of Koch’s. We did a transoral decompression of abscess with biopsy along with posterior decompression of cord and occipitocervical fusion [Figure 2]. Biopsy of the pathological material shows the background of extensive necrosis and inflammatory granuloma containing lymphocytes, plasma cells, epithelioid cells, and multinucleated Langhan’s type of giant cells suggestive of TB. Postoperatively, he was advised for antitubercular therapy for 18 months. Now, the patient has relief of pain and leading a normal life.

DISCUSSION The occipitocervical junction, a transitional zone between the skull and the spinal column, serves as the most mobile part of the axial skeleton. Bony abnormalities affecting this complex results in dysfunction of the neural structures by compression along the entire circumference, altering the arterial supply, venous drainage, and changing the cerebrospinal fluid dynamics.

Lymphatic channels play a dominant role in the etiopathogenesis of any infective process at the craniovertebral junction (CVJ). The infection probably begins in the retropharyngeal space with secondary involvement of bone, and is rarely primarily in the bone itself. Progression of the disease causes increasing ligamentous involvement, and the later stages involve increased destruction of bone.[3,6] Retrograde infection may spread to the CVJ resulting in instability or effusion as an inflammatory response.[7,8,10] The lateral masses are the initial to be affected, and destruction of these will eventually lead to collapse or weakening of the bony pillars. Depending on the severity of the disease process, varying degree of bony destruction of the atlas may ensue. This bony destruction may manifest as neck pain, torticollis, occipital neuralgia, dysphagia, dyspnea (retropharyngeal abscess) or even as neurologic dysfunction.[4] At this stage, the disease if unabated will cause ligament destruction aggravating the instability at the CVJ. Atlanto-axial dislocation (AAD) may result and if the prodens interval is more than 5 mm, it signifies the destruction of the transverse ligament of the atlas.

Varying degree of rotatory malalignment is commonly associated and needs to be considered during treatment of the condition.

It is very unusual to find the disease advanced to the stage of complete liquefaction and dissolution of the atlas. When this occurs (as in our case), the instability at the CVJ is severe and demands urgent immobilization.

It also forewarns complete osteoligamentous destruction and warrants emergency management. The associated problems of pressure such as dysphagia and asphyxia may assume alarming proportions. This may as in our case necessitate tracheostomy for effective airway ventilation.

As a sequelae, secondary basilar invagination may occur adding a different clinical dimension to the disease. An occipital bone may be involved as an extension of the

Figure 1: On magnetic resonance imaging of cervical spine shows irregular lytic bony destruction C-1, C-2, and occipital condyle, with cranial migration of odontoid with tip up to the level of foramen magnum, compression of cord with cord edema, suggestive of Koch’s

Figure 2: Posterior occipitocervical fusion

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disease with softening allowing the spinal column to further telescope into the posterior fossa. The proximity of the lower cranial nerves makes them vulnerable to be affected.

Conservative management for postinfective AAD,[12] and a regime of bed rest, skull traction and anti‑tuberculous treatment with mobilization only after 6–9 months,[11] have been advocated. Such management can lead to skin and pulmonary complications, especially in patients with neurological deficit. One‑stage anterior surgical debridement and fusion of the atlantoaxial joint have also been recommended, but had a failure rate of 50% and is technically more difficult than a posterior fusion.[13] Posterior fusion allows rapid neurological recovery, prompt relief of pain and a high rate of fusion with minimal morbidity.[6] In view of this and the early healing and stability afforded by fusion, it is recommended that patients with instability and neurological compromise should be stabilized by means of a posterior fusion.[1] Early diagnosis and treatment should be the goal with avoidance of fatal instability. The surgical option should be considered, in light of the patient’s general condition, associated cranial nerve palsies, and neurologic status.

CONCLUSION Although CVJ TB is a rare disease, the outcome of treatment is good. Antituberculous drug therapy remains the mainstay of treatment after confirming the diagnosis.

The surgical management options include transoral decompression with or without posterior fusion, depending upon the presence and persistence of atlantoaxial instability.

REFERENCES 1.

Bhojraj SY, Shetty N, Shah PJ. Tuberculosis of the craniocervical junction.

J Bone Joint Surg Br 2001;83:222‑5.

2. Buxi TB, Sud S, Vohra R. CT and MRI in the diagnosis of tuberculosis. Indian J Pediatr 2002;69:965‑72.

3. De Oliveira E, Rhoton AL Jr, Peace D. Microsurgical anatomy of the region of the foramen magnum. Surg Neurol 1985;24:293‑352.

4. Fang D, Leong JC, Fang HS. Tuberculosis of the upper cervical spine. J Bone Joint Surg Br 1983;65:47‑50.

5. Kanaan IU, Ellis M, Safi T, Al Kawi MZ, Coates R. Craniocervical junction tuberculosis: A rare but dangerous disease. Surg Neurol 1999;51:21‑5.

6. Lifeso R. Atlanto‑axial tuberculosis in adults. J Bone Joint Surg Br 1987;69:183‑7.

7. Michie I, Clark M. Neurological syndromes associated with cervical and craniocervical anomalies. Arch Neurol 1968;18:241‑7.

8. Nicholson JT, Sherk HH.Anomalies of the occipitocervical articulation. J Bone Joint Surg Am 1968;50:295‑304.

9. Pandya SK. Tuberculous atlanto‑axial dislocation (with remarks on the mechanism of dislocation). Neurol India 1971;19:116‑21.

10. Parke WW, Rothman RH, Brown MD. The pharyngovertebral veins: An anatomical rationale for Grisel’s syndrome. J Bone Joint Surg Am 1984;66:568‑74.

11. Tuli SM. Tuberculosis of the craniovertebral region. Clin Orthop Relat Res 1974;104:209-12.

12. Watson Jones R. Spontaneous hyperaemic dislocation of the atlas. Lancet 1932;25:586.

13. World Health Organization. World Health Organization Global tuberculosis control: WHO report 2011 [Internet]. 2011. Available from: http://www. who.int/tb/publications/ global_report/2011/gtbr11_full.pdf

Surgical Neurology International

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Editor: Sandi Lam, M.D. Baylor College of Medicine; Houston, TX, USA

SNI: Pediatric Neurosurgery, a supplement to Surgical Neurology International

Huge familial colloid cyst of the third ventricle: An extraordinary presentation Hamid Reza Niknejad, Amir Samii1, Shang‑Hang Shen1, Majid Samii1 Departments of Neurosurgery, University Hospitals Leuven, Belgium, 1International Neuroscience Institute, D‑30625 Hannover, Germany E‑mail: *Hamid Reza Niknejad ‑ hamidreza.niknejad@uzleuven.be; Amir Samii ‑ a.samii‑office@ini‑hannover.de; Shang‑Hang Shen ‑ shenshanghang@126.com; Majid Samii ‑ samii.office@ini‑hannover.de *Corresponding author Received: 23 April 15 Accepted: 06 June 15 Published: 23 July 15 This article may be cited as: Niknejad HR, Samii A, Shen SH, Samii M. Huge familial colloid cyst of the third ventricle: An extraordinary presentation. Surg Neurol Int 2015;6:S349-53. http://surgicalneurologyint.com/surgicalint_articles/Huge-familial-colloid-cyst-of-the-third-ventricle:-An-extraordinary-presentation/ Copyright: © 2015 Niknejad HR. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Since the use of computed tomography and magnetic resonance imaging, colloid cysts (CCs) are discovered more frequently and subsequently their true incidence exceeds the numbers previously estimated. In 1986, the first familial case was reported in two identical twin brothers. To date, a total of 17 of these cases have been reported, all differing in the pattern of affected family members.

Case Description: Here, we describe a unique presentation of a familial case and review the relevant literature on CCs and their natural history to improve our understanding of these cases.

Conclusion: Familial CC can present in various patterns, sizes, and forms.

A genetic factor is likely to be responsible in these cases, and further research is warranted to clarify this phenomenon.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161416 Quick Response Code:

Key Words: Colloid cyst, familial, genetics, tumor

INTRODUCTION Colloid cysts (CC’s) of the third ventricle are benign intra‑cranial cysts that account for approximately 1% of all intra‑cranial tumors. Considering the intraventricular lesions only, they comprise up to 20% of all tumors, and they are the most common mass found in the third ventricle.[4,10,22,27,29] The true incidence of CC’s can only be estimated, because of the large cohort of asymptomatic individuals. Usually, the patients are middle‑aged though the cysts can occur at virtually all ages.[9,17] The first case report dates from 1858 by Wallmann, who described the lesion both clinically and pathologically.[48] From there, it took several decades and progress in the field of neurosurgery to allow Dandy to successfully remove a CC in 1921.[13] Since this achievement, these lesions were considered curable as surgery offered a definite solution

for the disease. Nowadays, CC’s are not considered to be a neoplasm, rather a developmental malformation composed of a fibrous outer layer, internally bordered by a ciliated or mucus‑producing epithelium. It is the activity of this very epithelium that determines their growth and expansion, leading to the capacity to cause the neurological decline. Although they are known for their slow growth and indolent character, their strategic position at the foramen of Monro not seldom gives them malicious traits.[36] This is often inconsistent with their usually small size. More precisely, they most often lay in the anterior part of the third ventricle, between the forniceal columns, obliterating the foramen of Monro and causing hydrocephalus.

They mainly present with signs and symptoms related to hydrocephalus such as headache and nausea, which are S349

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too unspecific to pinpoint an exact etiology. On the other hand, we have the silent cases diagnosed incidentally by means of magnetic resonance imaging (MRI) or computed tomography (CT).[34] On imaging, these structures are seen as spherical isodense to hyperdense lesions on CT. On T2‑weighted MRI, they usually appear hyperintense, and unless the surrounding fibrous capsule is vascular, they do not enhance on contrast agents.

Finally CC’s may incidentally be found at autopsy, as in the case of Dr. Harvey Cushing.[15] To date, a total of 17 familial cases has been reported.[1‑3,5‑7,24,25,30,32,33,35,37,38,43,44,47] We would like to replenish the series with a case that is, unique, as it concerns two middle‑aged nontwin brothers with large to gigantic CC’s. The cyst sizes of all familial case reports are listed in Table 1. In our case descriptions, we also report the technical notes of how we surgically managed the cases.

CASE REPORTS

First case

In 2006, a 43‑year‑old Saudi man was referred to our institution, the International Neuroscience Institute in Hannover, for the treatment of a cystic intra‑cranial lesion.

Table 1: Overview of the literature on familial CC of the third ventricle Authors and year

Affected family members

Size on imaging (largest diameter)

Ibrahim et al. 1986 Bengtson et al. 1990 Vandertop et al. 1995 Akins et al. 1996 Mathiesen et al. 1997 Stoodley et al. 1999 Aggarwal et al. 1999 Nader‑Sepahi et al.

2000 Ahmad et al. 2002

Identical male twins Two nontwin brothers Three sisters Father and son Mother and son Brother and sister Mother and son Mother and two daughters Monozygotic twin brothers Two half‑sisters Brother and two sisters Father and daughter Nontwin sisters

25 mm and <10 mm 20 mm and 20 mm Not available§ 18 mm and <10 mm 15 mm and 13 mm 13 mm and <10 mm 16 mm and 20 mm* Not available, 10 mm and <10 mm§ 13 mm and 4 mm

Socin et al. 2002 Sadeghi et al. 2003 Partington et al. 2004 Joshi et al. 2005 Bavil et al. 2007 Romani et al. 2008 Salaud et al. 2012 Benoiton et al. 2014 Current report

10 mm and 15 mm 18 mm, 14 mm and <10 mm* Not available§ Not available§ and <10 mm* Nontwin sisters 20 mm and 10 mm* Dizygotic twin brothers 12 mm and 20 mm* Mother and daughter 17 mm and 13 mm Mother and daughter Not available§ Two nontwin brothers 52 mm and 25 mm

The presentation in terms of family members affected and cyst sizes are listed. *Cyst sizes were assessed on imaging when they were not explicitly mentioned in the paper. § Not mentioned and no imaging available. CC: Colloid cyst

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During the week before admission, the primary complaint was sudden onset headaches accompanied by episodes of vomiting. At the time of evaluation, the headaches were described as constant, very severe and diffuse.

Sensorimotor evaluation showed mild numbness in the right hand, with a slight weakness of the hand extensors on the right side. A CT‑scan performed in the country of origin revealed a cystic lesion that appeared to be a CC of the third ventricle. On T1‑weighted gadolinium‑enhanced images a 25 mm × 25 mm × 20 mm measuring cystic lesion was seen [Figure 1] causing mild obstructive hydrocephalus. The mass itself was also strongly contrast enhanced, leading us to believe the cyst wall contained some aberrant vessels.

The patient underwent a right fronto‑dorsal parasagittal craniotomy for a microsurgical extirpation of the lesion through a transcallosal approach. Total removal of the cyst and its colloidal content, together with its aberrant vascular steel was achieved.

Histological examination of the biopsy specimens confirmed the diagnosis of a CC. Surprisingly, the vascular steel consisted of a cluster of markedly abnormal arteries together with tortuous and dilated veins, in accordance with our pathological diagnosis of an arteriovenous malformation (AVM).

Postoperatively the patient recovered quickly and there were no complications. At discharge, the headaches and vomiting were no longer present and the patient was free of any other neurological deficits.

Second case

After a 6‑year interval, the 39‑year‑old brother of our first patient was admitted to our clinic with a 1‑month history of vertigo together with episodes of nausea and vomiting. One week prior to admission the patient had lost consciousness after having an acute onset headache and was transported to a local hospital.

His past medical history and familial history were unremarkable for brain diseases. However, a detailed familial history was not obtained, nor were any other family members examined at our center. A CT‑scan was performed showing hydrocephalus and a huge cystic lesion in the third ventricle. In the acute setting, he was treated by means of a ventricular drain. Preoperative gadolinium‑enhanced T1‑weighted MRI showed a huge, 52 mm × 42 mm × 39 mm measuring, hypointensive cystic lesion in the third ventricle that had progressively expanded upward to the corpus callosum, displacing the septum pellucidum and bulging in the lateral ventricles [Figure 2]. Diffusion tensor imaging (DTI) fiber tracking visualized a pronounced displacement of the fornices to the right [Figure 3]. Therefore, we planned a left frontal parasagittal craniotomy to gain access to the lesion through a transcallosal approach from the opposite side of the forniceal structures. The

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b

Figure 1: First case. (a) Preoperative gadolinium enhanced T1-weighted axial magnetic resonance imaging, showing an in homogenously enhancing mass in the third ventricle causing mild hydrocephalus. (b) Postoperative axial computed tomography-scan showing complete removal of the lesion and absence of hydrocephalus

a

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Figure 2: Second case. (a) Preoperative gadolinium enhanced T1-weighted axial magnetic resonance imaging, showing a gigantic cystic lesion in the third ventricle causing hydrocephalus. Note the enhancing vessels on the cyst wall. Artifact is due to the occipital venticuloperitoneal-shunt. (b) Postoperative axial computed tomography-scan showing extirpation of the cyst content and no signs of increased intra-cranial pressure

a

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Figure 3: Second case diffusion tensor imaging (DTI). Preoperative DTI fiber tracking. Coronal (a) and axial (b) images showing a pronounced displacement of the fornices inferiorly and to the right.

The artifact is due to the ventriculoperitoneal-shunt

surgery was performed under intraoperative MRI control with DTI fiber tracking in order to visualize the forniceal structures. After puncturing the cyst and aspirating the entire glue like the content, the capsule was partially removed. To restore the liquor flow a large and wide‑opening was made in the cyst wall ventro‑cranially, to ensure outflow to the lateral ventricles. Moreover, a second opening was created caudally in the area of the lamina terminalis, to form a connection between the

third ventricle and the suprasellar cisterns. The foraminae of Monro were identified, as they were displaced more ventrally, and their patency was secured. Intra‑operative MRI showed total extirpation of the cyst content as well as the artificial “cysto‑cisternal” and “cysto‑ventricular” openings. Finally, endoscopic inspection was performed to ensure hemostasis. There were no postoperative complications and no memory deficits were detected on subsequent serial examinations. Histology confirmed the diagnosis of a CC, showing a single layered AE1/AE3 positive ciliated epithelium.

DISCUSSION

The origin of colloid cysts

Ever since their discovery, CC’s have remained a curious clinicopathological entity. More than a century ago Sjovall presumed the cysts originated out of the paraphysis cerebri, an evanescent vestigial embryonic structure.[42] This theory held state until the advent of the term “neuroepithelial cyst” in 1929 by Fulton and Bailey. They discussed the presence of cilia and certain cyst contents in their specimens along with the variability in the location of the cysts, holding both a pathological and an anatomical argument against a paraphyseal origin. In 1955 Kappers partially restored Sjovall’s theory by explaining that an ectopic location of the cyst results from inclusion of peripheral paraphyseal “anlagen,” which is of ependymal origin and may arise along variable locations along the ventricular axis.[26] Electron microscopy allowed Coxe and Luse to subscribe an ependymal epithelial origin in 1964 though their findings were based on a single case.[11] One year later Shuangshoti et al. introduced their theory of neuroepithelial origin.[41] Based on a review of the literature combined with embryological and comparative anatomical studies, they classified the paraphysis as the extraventricular choroid plexus. The suggestion that both choroid plexus and ependyma are derived from a common neuroepithelium can balance the arguments Fulton and Bailey held against the paraphyseal origin, somewhat unifying the former theories. Besides this, some authors have proposed an extraneural origin, namely out of the ectopic endodermal tissue. The argument for this theory is the similarity of the cyst epithelium to the respiratory mucosa, described by Tsuchida et al.[45] Concurrently Ho and Garcia found the presence of ciliated cells and goblet cells upon ultrastructural analysis of their specimens.

In their arrangement, the cells were interconnected by desmosomes and met the criteria of an endodermal lineage.[23] These findings have led to the supposition that CC’s and Rathke’s cleft cysts may share the same pathophysiology and represent comparable lesions at different locations.[18] Still the true origin of the CC’s remains a matter of debate.

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Colloid cysts and genetics

Another approach of trying to clarify the mechanisms involved in the development of familial CC’s is the search for a genetic abnormality that could lead to an inheritable disease. Interestingly in this respect, insights into the function of “paired”‑like homeodomain transcription factor (Prop1) in the development of the Rathke’s pouch, the pituitary primordium, have been described in mice. Prop1 seems to have a crucial role in cell proliferation and differentiation and thus in the organogenesis and function of the pituitary gland.

A dysregulation in Prop1 expression is correlated with an increased susceptibility for pituitary tumors and Rathke’s cleft cysts. The latter were found in 40% of the alpha glycoprotein subunit (αGSU)‑Prop1 transgenic mice, which express a high level of Prop1 under the αGSU promoter (gain of function).[12] In humans the Prop1 gene fulfills the same function, and several loss‑of‑function mutations have been known to cause dysfunction and cystic dysplasia of the pituitary.[49,51] By analogy with Rathke’s cleft cysts it is likely that a genetic factor is involved in causing CC’s as well. Especially since these clinical conditions may constitute the same entity.

The idea of an inheritable genetic factor involved in the pathophysiology of familial CC’s of the third ventricle has already risen. This assumption is made, because of the improbable statistical chance of co‑occurrence in first‑degree relatives (1:1011).[46] Despite the fact that this phenomenon can occur in a very variable way with regard to the family members affected, an autosomal dominant inheritance seems to be the most likely form of inheritance.[17,32,44] Our case shows that huge cysts, earlier described solely in individual cases,[20,50] can also arise in kinship. In addition, we found an AVM in the first case.

Previous reports have mentioned the solitary occurrence of AVM in the third ventricle.[8,21,39] On the other hand, some intra‑cranial anomalies have been described in association with CCs, such as craniopharyngioma,[28] xanthogranuloma,[19,31] astrocytoma,[16] and agenesis of the corpus callosum.[14] To the best of our knowledge, it is the first time that an AVM is reported in association with a CC of the third ventricle. These ascertainments, revealing an additional variable factor in how this phenomenon may present, advocate in favor of a developmental malformation.[40] Yet it remains worthwhile to invest in research to pinpoint a genetic defect that would offer an explanation for the cases observed.

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Cushman LJ, Watkins‑Chow DE, Brinkmeier ML, Raetzman LT, Radak AL, Lloyd RV, et al. Persistent Prop1 expression delays gonadotrope differentiation and enhances pituitary tumor susceptibility. Hum Mol Genet 2001;10:1141‑53.

Dandy WE. Diagnosis, localization and removal of tumours of the third ventricle. Bull Johns Hopkins Hosp 1922;33:188‑9. del Carpio‑O’Donovan R, Cardinal E. Agenesis of the corpus callosum and colloid cyst of the third ventricle: Magnetic resonance imaging of an unusual association. Can Assoc Radiol J 1990;41:375‑9.

Fulton JF. Harvey Cushing:A Biography. Spring‑field: Charles C Thomas; 1946. p. 713‑4.

Gelabert M, Bollar A, Martinez R, Allut AG. Coincidence of a frontal lobe astrocytoma and colloid cyst of the third ventricle. Neurochirurgia (Stuttg) 1991;34:69‑70.

Gemperlein J. Paraphyseal cysts of the third ventricle. Report of two cases in infants. J Neuropathol Exp Neurol 1960;19:133‑4.

Graziani N, Dufour H, Figarella‑Branger D, Donnet A, Bouillot P, Grisoli F. Do the suprasellar neurenteric cyst, the Rathke cleft cyst and the colloid cyst constitute a same entity? Acta Neurochir (Wien) 1995;133:174‑80.

Hadfield MG, Ghatak NR, Wanger GP. Xanthogranulomatous colloid cyst of the third ventricle. Acta Neuropathol 1985;66:343‑6.

Hamlat A, Casallo‑Quiliano C, Saikali S, Adn M, Brassier G. Huge colloid cyst: Case report and review of unusual forms. Acta Neurochir (Wien) 2004;146:397‑401.

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Hernesniemi J, Romani R, Dashti R,Albayrak BS, Savolainen S, Ramsey C 3rd, et al.

Microsurgical treatment of third ventricular colloid cysts by interhemispheric far lateral transcallosal approach – Experience of 134 patients. Surg Neurol 2008;69:447‑53.

Ho KL, Garcia JH. Colloid cysts of the third ventricle: Ultrastructural features are compatible with endodermal derivation. Acta Neuropathol 1992;83:605‑12.

Ibrahim AW, Farag H, Naguib M, Ibrahim E. Neuroepithelial (colloid) cyst of the third ventricle in identical twins. Case report. J Neurosurg 1986;65:401‑3.

Joshi SM, Gnanalingham KK, Mohaghegh P, Wilson A, Elsmore A. A case of familial third ventricular colloid cyst. Emerg Med J 2005;22:909‑10.

Kappers JA.The development of the paraphysis cerebri in man with comments on its relationship to the intercolumnar tubercle and its significance for the origin of cystic tumors in the third ventricle. J Comp Neurol 1955;102:425‑509.

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Surgical Neurology International

OPEN ACCESS For entire Editorial Board visit : http://www.surgicalneurologyint.com

Editor: Sandi Lam, M.D. Baylor College of Medicine; Houston, TX, USA

SNI: Pediatric Neurosurgery, a supplement to Surgical Neurology International

Management of hydrocephalus in children with posterior fossa tumors Sandi Lam, Gaddum D. Reddy, Yimo Lin, Andrew Jea Department of Neurosurgery, Baylor College of Medicine, Texas Children’s Hospital, Houston, TX 77030, USA E‑mail: * Sandi Lam ‑ sklam@texaschildrens.org; Gaddum D. Reddy ‑ gdreddy@bcm.edu;Yimo Lin ‑ yimolin@gmail.com; Andrew Jea ‑ ahjea@texaschildrens.org *Corresponding author Received: 09 April 2015 Accepted: 27 April 2015 Published: 23 July 15 This article may be cited as: Lam S, Reddy GD, Lin Y, Jea A. Management of hydrocephalus in children with posterior fossa tumors. Surg Neurol Int 2015;6:S346-8. http://surgicalneurologyint.com/surgicalint_articles/Management-of-hydrocephalus-in-children-with-posterior-fossa-tumors/ Copyright: © 2015 Lam S. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Key Words: Endoscopic third ventriculostomy, hydrocephalus, pediatric, posterior fossa tumor, ventriculoperitoneal shunt

Case 1: A 2‑year‑old male with no prior medical history presented to the emergency room with a 3‑week history of constant headache and daily vomiting. Computed tomography (CT) and subsequent magnetic resonance imaging (MRI) of the brain [Figure 1] showed a minimally enhancing mass in the fourth ventricle, which extended out through the foramen of Luschka on the left.

There was associated supratentorial hydrocephalus. He had no evidence of spinal metastasis on MRI of the spine.

There was no papilledema on the fundoscopic exam. He underwent placement of a right frontal external ventricular drain (EVD) and gross total resection of the tumor through a modified telovelar approach at the same time. The pathology was consistent with a grade II ependymoma.

Postoperatively, the ventricular drain was unable to be weaned, and he underwent ventriculoperitoneal shunt placement without complication 1.5 weeks after initial surgery. He was eating and ambulatory after recovery. He went on to radiation therapy.

Case 2: A 9‑year‑old male with no prior medical history presented to an outside hospital emergency room with 2 weeks of progressive headaches and 1‑day of vomiting. A CT of the head showed a posterior fossa mass. MRI of the brain [Figure 2] showed an enhancing fourth ventricular tumor with associated metastatic lesions throughout both cerebellar hemispheres and supratentorial hydrocephalus. There was no evidence of spinal metastasis. Fundoscopic exam was positive for papilledema. He underwent placement of a right S346

frontal EVD and resection of the fourth ventricular mass through a modified telo‑velar approach at the same time. The infiltrative lesions in the cerebellum were not resected. The pathology was consistent with medulloblastoma. Postoperatively, his EVD was weaned over the course of 2 weeks and removed. He did not require permanent cerebrospinal fluid diversion. He was discharged home after recovery and went on for adjuvant radiation therapy.

INTRODUCTION Central nervous system tumors are the most common solid tumors in children, and they predominantly occur in the posterior fossa.[7] Due to the anatomic relationships of these tumors to cerebrospinal fluid (CSF) drainage pathways, hydrocephalus is common, occurring in 71–90% of children with posterior fossa tumors.[11] Hydrocephalus after tumor resection occurs in 10–36% of cases,[2,4] with a worldwide average of 30%.[10] Access this article online Quick Response Code: Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161413

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Figure 1: Magnetic resonance images of patient described in case 1. (a) Sagittal precontrast. (b) Axial fluid‑attenuated inversion recovery. (c) Axial postcontrast

Figure 2: Magnetic resonance images of patient described in case 2. (a) Sagittal precontrast. (b) Axial fluid‑attenuated inversion recovery. (c) Axial postcontrast

MANAGEMENT

FACTORS PREDICTIVE OF POSTRESECTION HYDROCEPHALUS

The optimal management of hydrocephalus in a child with a posterior fossa tumor is a topic of debate.[13] The question of whether to place an external ventricular drain (EVD), insert a ventriculoperitoneal shunt (VPS), perform an endoscopic third ventriculostomy (ETV), or defer CSF diversion procedures before resective surgery depends on the clinical presentation and individual surgeon practice; there exists no class I evidence to guide management. In 2001, Sainte‑Rose et al. reported that preoperative ETV was associated with a lower rate of postoperative hydrocephalus (27% vs. 6%) in a retrospective series of pediatric patients with posterior fossa tumors (n = 196).[11] Only a portion of these patients would have gone on to develop postresection hydrocephalus, so performing a preresection ETV in every case potentially exposes over 70% of patients to unnecessary surgery.[4,6] Purported benefits of permanent preresection CSF diverting surgery, such as ETV of VPS other than the reduced incidence of postresection hydrocephalus, include the following: (1) Being able to delay resection surgery, thus avoiding resection under emergent conditions or allowing for preresection adjuvant therapy in certain circumstances;[3] (2) reducing the likelihood of needing external CSF diversion, which may carry risk of infection;[3] and (3) potentially reducing risk of postresection CSF leak or pseudomeningocele.[2] Purported disadvantages of permanent preresection CSF diversion surgery include the following: (1) Performance of a procedure that ultimately may not be clinically indicated, exposing patients to the risks of unnecessary surgery; (2) ETV may be less reliable in controlling intracranial pressure (ICP) and does not allow for ICP monitoring; and (3) no ability to externally drain spillage of blood products after the resection. The exact cause of postresection hydrocephalus is not completely characterized, with absorptive and obstructive processes implicated.

Ideally, we would be able to predict which patients will develop postresection hydrocephalus. The benefits of early CSF diversion could be captured while simultaneously avoiding the harm of subjecting patients to unnecessary procedures. Many groups have attempted to analyze retrospective data looking for clinical factors associated with a need for postoperative CSF diversion. Culley et al. (n = 117, 1976–1990) found that age <3 years, midline tumor location, subtotal resection, prolonged EVD requirement, cadaveric (vs. autologous) dural grafts, pseudomeningocele formation, and CSF infections were statistically significant factors associated with the need for postoperative shunt placement.[2] Due‑Tønnessen and Helseth (n = 87, 1990–2003) found that patients with medulloblastoma and ependymoma had much higher rates of postoperative shunt requirement than astrocytomas.[4] Kumar et al. (n = 175, 1983–1993) found age <3, ependymoma/medulloblastoma tumor histology, and subtotal resection to be risk factors.[8] Santos de Oliveira et al. (n = 64, 1990–2006) found younger age, midline location, and greater ventricular index at presentation to be risk factors.[12] Morelli et al. (n = 160, 1989–2004) found medulloblastoma histology and severe preoperative hydrocephalus to be risk factors.[9] Bognár et al. (n = 180, 1990–2000) found younger age, tumor histology, and presence of EVD to be predictive of postoperative need for CSF diversion, but they found that tumor location, extent of resection, and postoperative CSF leak or pseudomeningocele were not predictive.[1] In 2009, Riva‑Cambrin et al. used a cohort of 343 patients to develop a clinical prediction rule for postresection hydrocephalus and validated it against another cohort of 111 patients from another institution in an attempt to identify high‑risk patients who would benefit most from prophylactic ETV.[10] The group analyzed demographic, clinical, and radiographic factors. They performed stepwise multivariate regression to determine which S347

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factors were associated with a greater risk of needing CSF diversion after tumor resection and assigned point values reflecting the relative weights. The final scale is out of 10 points, with 3 points given for age <2 years, 1 point given for papilledema, 2 points given for moderate or severe hydrocephalus, 3 points given for cerebral metastases, and 1 point given for ependymoma, medulloblastoma, or dorsally exophytic brainstem glioma pathology predicted by preoperative radiology report. A score of >4 points was chosen as the cut‑off for “high‑risk.” Those with a score of 0–2 are predicted to have <20% chance of developing postresection hydrocephalus while the likelihood is >80% for those with a score of 7–10. High‑risk (score 5–10) and low‑risk (score 0–4) groups differed in posttest probabilities for developing postresection hydrocephalus by 48% (73% for high‑risk, 25% for low‑risk).[10] Foreman et al. later validated and modified Riva‑Cambrin et al.’s predictive model, using fewer variables in a much smaller cohort (n = 99 patients): Age <2 years, moderate/severe hydrocephalus, preoperative tumor diagnosis per radiology report, and transependymal edema. These posterior fossa tumor patients were also stratified into high‑ and low‑risk categories for development of postresection hydrocephalus.[5]

TREATMENT RECOMMENDATIONS There exists no class I evidence in the literature to guide the management of hydrocephalus in children with posterior fossa tumors. It is possible to draw guidance from the extant data highlighted above. As the overall incidence of postresection hydrocephalus is typically 30%, any anticipated benefit should be weighed against exposing the patient to more surgery or permanent shunt implantation. It is noted that in lower resource settings, there may be other considerations, including the cost of care, access to the operating room and need to minimize the number of surgeries. In our practice, in cases where there is no hydrocephalus on presentation, preresection CSF diversion is not done. In cases where there is symptomatic hydrocephalus on presentation, preresection EVD, VPS or ETV should be applied as clinically appropriate. EVD is favored for its advantages of expedient placement, external control over drainage perioperatively, and egress of resection‑related blood

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and protein products. In cases where the child possesses multiple described risk factors for the development of postresection hydrocephalus, preresection prophylactic CSF diversion may be considered. Overall, close observation is recommended, with a preference for expectant management, rather than prophylactic surgery, and postresection definitive CSF diversion procedures undertaken only as clinically necessary.

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Surgical Neurology International

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Editor: Sandi Lam, M.D. Baylor College of Medicine; Houston, TX, USA

SNI: Pediatric Neurosurgery, a supplement to Surgical Neurology International

How I Do It: Management of spina bifida in a hospital in The People's Republic of China Nan Bao, 1Jorge Lazareff Department of Neurosurgery, Shanghai Children’s Medical Center Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China, 1Department Neurosurgery, UCLA Center for World Health at David Geffen School of Medicine, Tiverton Drive, Los Angeles, CA 90024, USA E-mail: *Nan Bao - bnscmc@shsmu.edu.cn; Jorge Lazareff - jalazareff@mednet.ucla.edu *Corresponding author Received: 25 November 14 Accepted: 02 December 14 Published: 23 July 15 This article may be cited as: Bao N, Lazareff J. How I Do It: Management of spina bifida in a hospital in The People's Republic of China. Surg Neurol Int 2015;6:S337-45. http://surgicalneurologyint.com/surgicalint_articles/How-I-Do-It:-Management-of-spina-bifida-in-a-hospital-in-The-People's-Republic-of-China/ Copyright: © 2015 Bao N. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract We present our personal experience on patients with Spina Bifida. It is the result of having treated 1600 children for 12 years at Shanghai Children’s Medical Center.

We classify the cases on Spina Bifida Manifesta (myelomeningocele, myelocele, lypomyelomeningocele) or Spina Bifida Oculta (lipoma, dermal sinus and thickened filum terminale). For the former, we recommend surgery within 24–48 h after birth.

For the latter we recommend preventive surgery months after birth. We acknowledge that the diameter of the spinal canal is a problem for large remnant lesions. In cases of myelomeningocele, we prefer to place the shunt and close the defect in the same procedure, it reduces the risks inherent to exposure to anesthesia, reduces hospital stay, and related costs. If there is a suspicious of infection, we do not place the shunt on the same procedure. The personal description of the preferred techniques for closure of the different defects is described.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161410 Quick Response Code:

Key Words: Myelomeningocele, spina bifida, surgical technique, spinal lipoma,

tethered cord

CLASSIFICATION There are several types of neural tube defects and each type can be divided into various subtypes. According to our experience in the treatment of nearly 1600 patients with different types of neural tube defects at the Neurosurgery Department of Shanghai Children’s Medical Center over the past 12 years, we divided common neural tube defects into the following types:

Spina bifida manifesta

This type can be further divided into the following subtypes according to the pathological morphology:

Myelomeningocele

Patients with this subtype of neural tube defect have a mass on their back. The surface of the mass is a thin cyst wall and in some cases there is no skin [Figure 1]. In

other cases, the mass is covered by skin but the color is blue; there is no subcutaneous fat tissue, and the dermis shows scar‑like degeneration and adheres directly to the cyst wall [Figure 2]. The cyst wall is composed of the dura mater, arachnoid mater, pia mater, and deformed spinal cord, which protrudes outside the skin via the spinal defect. According to differences in the diseased segments and morphologies of spinal cord herniation, this subtype can be further divided into two subtypes.

Type I is a herniation of the end of the spinal cord, in which the herniated spinal cord terminates at the roof of the bulging dura mater. It is commonly seen in the lumbosacral and sacral segments [Figures 1 and 2].

Type II is an omega‑shaped (Ω‑shaped) herniation of the spinal cord, in which the middle part of the herniated spinal cord makes up the roof of the bulging dura mater, but the end of the spinal cord is located in the distal S337

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spinal canal. This type is commonly seen in the lumbar and thoracolumbar segments [Figure 3].

Neurological damage is very serious in patients with myelomeningocele. Most patients with type I myelomeningocele have bladder‑sphincter dysfunction and most patients with type II myelomeningocele have lower extremity dysfunction, foot deformities, and even bladder‑sphincter dysfunction and spinal deformities, etc., The incidence of Chiari malformation and hydrocephalus is as high as 99%, and these conditions are followed in incidence by syringomyelia, diastematomyelia, arachnoid cyst, etc.

Myelocele

Patients with this subtype of neural tube defect have a mass on their back. There is purple granulation at the center of the mass, which is surrounded by a thin cyst wall. The purple granulation is actually the Ω‑shaped herniated spinal cord, which is directly exposed outside of the skin [Figure 4].

This subtype is commonly seen in the lumosacral, lumbar, and thoracolumbar segments is accompanied by the most serious neurological damage, and is associated with lower extremity dysfunction, foot deformities, bladder‑sphincter dysfunction, spinal deformities, Chiari malformation, hydrocephalus, etc.

Lipomyelomeningocele

In this subtype the enlarged spinal cord protrudes dorsally via the defect in the spinal canal to form a mass that protrudes over the skin surface. The skin on the surface of the mass is intact. The mass contains subcutaneous fat tissue, cerebrospinal fluid (CSF), and spinal cord. The

subcutaneous fat grows together with the herniated spinal cord and dura mater to form the cyst roof. Similar to myelomeningocele, this subtype can be divided into two subtypes according to the different morphologies of the herniated spinal cord. Type I is a herniation of the end of the spinal cord and is commonly seen in the lumbosacral and sacral segments [Figure 5]. Type II is an Ω‑shaped herniation of the spinal cord and is commonly seen in the lumbar and thoracolumbar segments [Figure 6].

Lipomyelomeningocele is a mass covered with normal skin, and there may be abnormal pigmentation or skin depression on the mass surface. Patients with lipomyelomeningocele may have varying degrees of lower extremity paralysis, foot deformities, gait abnormality, and bladder‑sphincter dysfunction. Severe cases are often associated with Chiari malformation, hydrocephalus, cerebral dysplasia, hydromyelia, diastematomyelia, etc. Late symptoms include scoliosis, hydronephrosis, etc.

Simple meningocele

This subtype is characterized by bulging of the dura mater from the bone defect, and the cyst contains only CSF without spinal cord or cauda equina. If the cyst protrudes dorsally from the spinal canal, it is called a posterior simple meningocele [Figure 7]. If the cyst protrudes ventrally from the spinal canal, it is called an anterior sacral meningocele [Figure 8]. It was previously believed that simple meningocele usually has no neurological symptoms. However, more and more investigators have found that simple meningocele is associated with a very high rate of tethered spinal cord, which results in gradual neurological symptoms with increasing age. During the

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Figure 1: (a and b) Myelomeningocele.The tumor surface is a thin cyst wall, and the end of the spinal cord protrudes into the bulging dural sac via the spinal defect

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Figure 3: (a and b) Myelomeningocele. There is a Ω-shaped protrusion of the spinal cord into the bulging dural sac

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Figure 2: (a) Myelomeningocele. The tumor surface is covered by skin, there is no subcutaneous fat tissue, the dermis shows a scarlike degeneration, and (b) the end of the spinal cord protrudes into the bulging dural sac via the spinal defect

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Figure 4: (a) Myelocele.There is a purple granulation surface, and a Ω-shaped protrusion of the spinal cord is directly exposed outside the skin. (b) Sagittal MRI of the lesion

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Figure 5: (a) Lipomyelomeningocele. The skin on the surface of a bulging dural sac is completely covered with subcutaneous fat tissue. (b)The end of the spinal cord protrudes into the bulging dural sac and grows together with the subcutaneous tissue to form the cyst roof

Figure 7: Posterior simple meningocele. There is no neural tissue in the bulging dural sac, the conus medullaris is located low at the level of L5, and there is associated fat degeneration

last 4 years of continuous observation, we found that in 37 of 38 cases (97%) simple meningocele was associated with other spinal cord diseases, such as tight filum terminale, arachnoid cyst, epidermoid cyst, tethered spinal cord due to fibrous bands, adhesion between the dura mater and the spinal cord or cauda equina, etc.

Occult spinal bifida

Skin in the affected area often has characteristic features including pigmentation, capillary hemangioma, skin depression, local hirsutism, small skin tags, etc.

No significant symptoms can be observed in infants, and tethered spinal cord syndrome appears during the gradual development of the child after abnormal traction of the spinal cord occurs. It was reported that many patients have symptoms only after they grow up. Neural injury is mostly caused by the compression, traction, or increased tension of the spinal cord. If there is no surgical treatment, neural injury will become further aggravated and irreversible. Therefore, early diagnosis is very important for performing surgical intervention as soon as possible.

Occult spinal bifida is further divided into the following subtypes:

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Figure 6: (a and b) Lipomyelomeningocele. There is a capillary hemangioma on the tumor surface and a skin depression in the sacrococcygeal region, an Ω-shaped protrusion of the spinal cord can be seen within the bulging dural sac, and subcutaneous fat grows into the spinal cord

Figure 8: Anterior sacral meningocele. The cyst protrudes toward the ventral side of the sacrum and coccyx, the end of the spinal cord, which is located at the base of the bulging dural sac, sends out a band growing into the bulging dural sac, which results in spinal cord tethering

Spinal cord lipoma

A large amount of subcutaneous fat moves into the spinal canal via the spinal defect, and the dorsal dura mater is completely invaded by the subcutaneous lipoma and loses its normal structure. The lipoma enters the subdural space and grows with the lower located spinal cord. If the lipoma grows into the superficial part of the dorsal spinal cord, it is called a dorsal spinal cord lipoma [Figure 9]. If the lipoma grows deep into the spinal cord unilaterally or bilaterally and even reaches the ventral side, it is called a ventral spinal cord lipoma [Figure 10]. Hence, the spinal cord is compressed and pulled, which results in a tethered spinal cord.

A spinal cord lipoma is seen as a subcutaneous lipoma in the back with a capillary nevus or skin depression.

Sometimes, it is only evident as a small skin tag. Affected patients may have varying degrees of bladder‑sphincter dysfunction, lower extremity paralysis, foot deformities, and gait abnormality.

Spinal cord lipomas are commonly seen in the lumbosacral and sacrococcygeal segments, and are called lumbosacral spinal cord lipoma [Figure 11] and sacrococcygeal spinal cord lipoma, respectively [Figure 12]. These two types S339

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Figure 9: Dorsal spinal cord lipoma. The lipoma grows into the superficial layer of the spinal cord

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Figure 11: Lumbosacral spinal cord lipomas. (a) subcutaneous lipoma in the lumbosacral region. (b) MRI evidences that it grows into the spinal canas via the defects in the lumbosacral fascia, spinous process, dura mater and pia mater, and grows together with the lower located spinal cord

have slightly different pathological changes and the corresponding surgical procedures are also different.

A spinal defect of a lumbosacral spinal cord lipoma is located in the lumbosacral segment, and the conus medullaris is located at the lumbosacral region or even lower. A subcutaneous lipoma invades the dura mater via the spinal defect and grows together with the spinal cord.

Due to the lack of dorsal dura mater, bilateral residual dura tissues grow into the spinal cord inferior to the lipoma and lie superior to the bilateral nerve roots and the end of the conus medullaris. Therefore, the spinal cord is pulled downward and is tethered to the dura mater. Meanwhile, the lipoma grows cephalically and caudally within the spinal canal. In general, a cephalically growing lipoma enters the normal subdural space and grows into the dorsal part and/or one side of the spinal cord, while a caudally growing lipoma is mostly located outside the dura mater.

Unlike a lumbosacral spinal cord lipoma, a sacrococcygeal spinal cord lipoma is located in the sacral canal. The subcutaneous lipoma in the sacrococcygeal region invades the dura mater via the sacral canal defect and grows together with the lower located spinal cord. Instead of terminating in the middle of the lumbosacral dural sac, the conus medullaris terminates in the distal end of the dural sac.

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Figure 10: Ventral spinal cord lipoma. The lipoma grows deep into the spinal cord and even grows to the ventral side

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Figure 12: Sacrococcygeal spinal cord lipomas. (a) subcutaneous lipoma in the sacrococcygeal region. (b) MRI evidences that it grows into the dura mater via the sacral defect and grows together with the lower located spinal cord

Therefore, the cauda equina does not extend longitudinally from the end of the conus medullaris in accordance with normal anatomy, but extends obliquely downward from the ventral side of the conus medullaris. The lipoma is located in the superficial layer of the conus medullaris and grows into the conus medullaris. Differences in surgical procedures will be described in detail in the part on treatment.

Back dermal sinus

This subtype develops on the dorsal side of the cerebrospinal axis, at any site between the occiput and the sacrococcygeal region, most commonly in the lumbosacral region. The sinus may terminate outside or inside the dura mater. At the termination of the sinus is often a dermal cyst, which is located at the end of the spinal canal or grows into the spinal cord and causes tethered spinal cord [Figure 13].

It is seen as pinprick‑like holes on the skin with peripheral abnormal hairs, pigmentation, or capillary hemangioma‑like changes. Surgery should be performed as early as possible to prevent serious results such as secondary cyst infection, cerebrospinal meningitis, etc.

Diastematomyelia

This subtype can be further divided into two subtypes according to the presence or absence of clinical symptoms:

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Type I (presence of symptoms): There are two dural sacs and two spinal cords, that is, the spinal cord is divided into two parts. Each has its own dura mater and arachnoid mater and there is fibrous tissue, cartilage, or bone crest between the two parts, which causes tethered spinal cord [Figure 14]. Type II (absence of symptoms): The spinal cord is divided into two parts at the diastemata, but these two parts share a common dura mater and arachnoid mater and there are no foreign bodies causing tethering, so most cases do not have clinical symptoms.

It is commonly seen in the thoracic and lumbar segments, and is seen as an abnormal hair clump in the center of the back. Ninety percent of patients with diastematomyelia have associated scoliosis.

Thickened filum terminale syndrome

When the terminal filament is invaded by fat and fibrous tissues, it degenerates and becomes thickened, consequently pulling down the spinal cord and causing neural symptoms. The neural symptoms caused by the tethered terminal filament are often relatively mild, and patients only have pain, enuresis, urinary urgency, fecal leakage, pes cavus, slight foot varus or valgus, etc.

Location of the conus medullaris may be normal or lower [Figure 15].

Intradural lipoma

There is a localized fat accumulation in the subdural space without connection to the subcutaneous fat tissue in the back. The lipoma is often adhered to the dura mater on one side and located on the surface of the spinal cord on the other side. It also can grow into the spinal cord and cause tethered spinal cord [Figure 16].

Smaller lipomas do not develop symptoms for life if they do not enlarge significantly as children grow.

Treatment

Aims: The goal of treatment is to improve neurological function and prevent further neural degeneration.

Ideal age and indication for surgery: Myelocele and myelomeningocele without skin covering may result in continuous CSF leakage due to the thin cyst wall.

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c Figure 14: Diastematomyelia. (a) there is an abnormal hair bundle n the back. (b) Three dimensional CT shows that the bone crest grows into the spinal canal. (c) MRI show two spinal cords divided by a central bone crest

c Figure 13: Back dermal sinus. (a) there is a pinprick-like hole in the skin. (b, c) MRI shows that a subcutaneous sinus enters the spinal canal via the dura mater, and the terminal is a dermal cyst, which grows form the outside into the spinal cord

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Figure 15: (a) MRI shows that the conus medullaris is located at the L2 level, and there is fat signal inside the distal end of the filum terminale. (b) intraoperative endoscopy shows fat degeneration in the filum terminale

Figure 16: A dorsal spinal cord lipoma compresses the spinal cord

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To reduce the risks of CSF leakage and infection, and subsequent continuous degeneration of neurological function, we often perform surgery to close the defect within 24–48 h after birth. For skin‑covered neural tube defects, such as lipomyelomeningocele, elective surgery should be performed after considering the patient’s age, body weight, general condition, and tolerance of the delicate spinal cord to outside intervention.

Because the tethering and compression caused by the disease during the growth of the spinal cord may lead to further dysfunction, we perform surgery for patients with lipomyelomeningocele and spinal cord lipomas within 2–3 months after birth. However, the spinal canal is thinner in 2‑ to 3‑month‑old infants while the protruded spinal cord is abnormally thick, which makes complete reduction of the spinal cord difficult, produces extensive spinal cord adhesion, and increases the risk of subsequent tethered spinal cord. Therefore, the most suitable age for surgery in these children should be further investigated.

In patients with occult spinal bifida the disease is often detected a few years after birth based on manifestations including thickened filum terminal syndrome, diastematomyelia, and back dermal sinus. Surgery is often performed late in these patients.

Myelocele and myelomeningocele are associated with a high incidence of hydrocephalus. With regard to hydrocephalus requiring shunt surgery, there are differing opinions about whether shunt surgery should be performed together with surgeries for the original diseases or whether surgery should be carried out in two stages. We agree with those who advocate one‑stage surgery because it allows the patients to undergo surgery and anesthesia only once, shortens the length of hospital stay, and reduces the medical cost. Because surgery for hydrocephalus is relatively less associated with problems, and CSF loss occurs during myelomeningocele repair, which may decrease the volume of the cerebral ventricle and make ventricular puncture become difficult, we perform shunt surgery after placing the patient in the supine position and then carry out myelomeningocele repair after turning the patient over to the prone position. To reduce the rate of complications including shunt occlusion and infection, we carry out strict decontamination of the surgical site, use very strict aseptic technique during surgery, minimize intraoperative loss of CSF, prevent cephalic spread of bloody CSF, reduce the time of wound exposure, etc., Of course, for patients with definite or potential infection of the central nervous system, myelomeningocele repair is done first and second‑stage hydrocephalus shunt surgery is performed after the infection of the central nervous system is controlled.

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Surgical principle: The spinal cord should be separated from the adhered lesion and the lesion removed to relieve spinal cord compression and tethering.

Surgical technique: Because the tumor surface is not covered by skin in patients with myelocele and myelomeningocele, the site of defect should be wrapped with saline‑moistened gauze immediately after the patient is brought into the NICU to avoid drying and direct injury of the neural substrates due to exposure.

The patient should be placed in a supine or lateral recumbent position and administered antibiotics intravenously.

Various measures should be used to prevent possible intraoperative hypothermia. For example, we increase the temperature of the operating room and put a heating pad underneath the child, avoid wrapping the abdomen and chest using wet towels during operation, and perform surgery as soon as possible according to the plan. The whole procedure should be carried out under microscope. The patient is placed in a prone position and a soft pad is placed underneath the lower abdomen to elevate the lower abdomen and buttock to the level of the head to maximally reduce CSF leakage during the procedure.

At the beginning of the surgery, an incision is made along the margin of exposed neural placode and the placode is separated from the peripheral tissue to get it back into the spinal canal. All the contents are trimmed including skin and granulation tissue on the placode. A neural tube resembling the spinal cord is then reconstructed, and the pia mater and arachnoid mater are drawn close to the midline from the bilateral margins of the placode and sutured. All the neural tissues are carefully protected and special attention is paid to electrocoagulation in order to avoid thermal burn injury to the placode, which may have residual function.

The dura mater is then dissected. One side of the dura mater is adjacent to the margin of the skin defect and is completely isolated from the skin. The dura mater is closed using 5‑0 absorbable suture line without compressing the spinal cord.

Finally, the skin is sutured. If a patient has a large myelomeningocele, the large‑area skin defect cannot be repaired by simple closure. Therefore, Z‑shaped skin flaps are used or large‑scale subcutaneous dissection is performed as far as both sides of the back to ensure a tension‑free skin closure. Blunt finger dissection is carried out to avoid damaging large blood vessels. This kind of dissection can be performed quickly, which not only reduces bleeding but also ensures blood supply to the skin flap. Use of Z‑shaped skin flaps or performing large‑scale subcutaneous dissection guarantees direct skin suture for all patients.

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In patients with a lipomyelomeningocele, after the cyst is separated, most of the time, half of the laminae of the vertebrae superior and inferior to the spina bifida is removed to sufficiently expose the base of the cyst. The normal dura mater is cut open to identify the relationship between the herniated spinal cord and myelomeningocele to avoid damaging the spinal cord when separating the cyst wall. An incision is made at the side of the apex of the cyst containing protruded spinal cord, the nerve within the cyst is carefully protected, and annular resection of the remaining parts is done under direct vision.

Complete dissection is performed to release the spinal cord and neural fibers adhered to the cyst wall. Because a subcutaneous lipoma invades the spinal cord in cases with lipomyelomeningocele, the fat outside the spinal cord should be removed using a scissor and the fat inside the spinal cord should be removed using a micro scissor or an ultrasonic aspirator as much as possible to expose the layer of neural placode. Finally, interrupted suturing is performed for the split spinal cord, which is placed into the spinal canal. The redundant bulging dura mater is trimmed, and expanded suturing to the dural sac is done to prevent neural tissue compression and adhesion.

Surgical procedures for the two subtypes of myelomeningocele or lipomyelomeningocele are similar.

For type I, the only requirement is to dissect and cut off the herniated distal end of the spinal cord from the bulging dura mater [Figure 17]. For the Ω‑shaped spinal cord herniation in type II, the herniated spinal cord cannot be cut off as is done in type I because it may break the spinal cord into two parts and result in irreversible neurological damage. The spinal cord should be separated from the bulging dural sac along the course of the spinal cord and placed back into the spinal canal [Figure 18].

For simple meningocele, a fusiform incision should be made around the mass and dissection should be

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Figure 17: (a) MRI, (b) skin lesion, (c) cord tethered to the bottom of the canal and to the extradural fat, (d) cord untetehered

performed from the outside of the cyst wall to the neck of the cyst. The cyst wall should be cut open at the apex to explore the presence of neural tissue. According to the preoperative MRI findings, the bottom of the cyst cavity should be slightly expanded to explore the spinal canal, and find out whether there is fat degeneration of filum terminale, fibrous band tethering of the spinal cord, and adhesion between the dura mater and the spinal cord or the cauda equina. Corresponding tethering should be released. The redundant cyst wall should be trimmed and the dura mater sutured at the base. The par spinal muscle and fascia should be dissected around the laminar defect and the spinal defect covered using the reinforced suture technique.

Because there is no definite boundary between an intramural lipoma and normal spinal cord, complete resection of the lipoma is impossible. The aim of surgery is to dissect adhesion between the lipoma and the dura mater, reduce the volume of the lipoma, and release spinal cord tethering and compression to allow the reconstructed spinal cord to be suspended in the subarachnoid space satisfactorily.

The surgical technique for a spinal cord lipoma involves cutting open the dura mater from the cephalic normal site until the lipoma is completely exposed. The tumor membrane should be cut open and the lipoma should be gradually removed outside the spinal cord with a micro scissor. After most lipoma lesions outside the spinal cord are removed and the spinal cord is decompressed, the spinal cord should be slowly lifted from the ventral side of the spinal canal. At this point, the boundary of spinal cord is not yet isolated and the lipoma close to the spinal cord surface should not be removed in a hurry to avoid damaging the spinal cord below it. The spinal cord should be gently retracted to one side to expose

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Figure 18: (a) MRI evidencing cord herniated in omega shape, (b) the bulging dura sac has been opened, (c) the spinal cord is separated from the sac, (d) the freed cord is about to be placed in the spinal canal

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the dura mater on the lateral side. The spinal cord should be dissected and cut off from both sides of the dura mater using a micro scissor in a cephalic to caudal direction to release the tethering and expose the spinal cord boundary. Then the fat and fibrous tissue should be further removed from the spinal cord surface safely, effectively, and maximally using the ultrasonic aspirator or CO2 laser knife until the layer of the neural plate is exposed. The small amount of fat tissue within the spinal cord should not be forcefully removed in order to protect spinal cord function.

Surgery for sacrococcygeal spinal cord lipoma is more difficult than surgery for lumbosacral spinal cord lipoma. In patients with lumbosacral spinal cord lipoma, the conus medullaris is located in the middle segment of the lumbosacral dura mater and the boundary is easily observed. As long as the normal dura mater is dissected at the caudal end of the lipoma and cut open cephalically, the conus medullaris can be identified and isolated from the dura mater.

However, in patients with sacrococcygeal spinal cord lipoma, the conus medullaris is located in the distal end of the dural sac. The lipoma on the surface of the conus medullaris not only grows together with the conus medullaris, but also grows outside the sacral canal and connects with the normal fat tissue in the sacrococcygeal area without boundaries. Because the lipoma completely covers the conus medullaris and distal end of the dura mater, it is extremely difficult to identify the boundary between the conus medullaris and distal end of the dura mater during surgery and separate them. Our method is to diminish the fat from the cephalic end, lift the spinal cord from the ventral side after the fat becomes thinned, and then cut off the spinal cord from the dura mater. When the spinal cord boundary is exposed, the fat inside the spinal cord should be further removed in a cephalic to caudal direction, and the lipoma of the conus medullaris and tethering should then be treated. The key point is to accurately identify the boundary between the distal end of the dural sac and the conus medullaris in order to move toward the midline from both sides, dissect the conus medullaris, and release it from the end of the dural sac. If dissection toward the midline is performed too early, it will cut off and damage the conus medullaris, and if the dissection is carried out too late, it may cause disorientation and result in the manipulation being moved outside the caudal thecal sac or even the sacral canal, which not only cannot release the conus medullaris tethering, but also may damage the sacrococcygeal epidural spinal nerve. The fat on the surface of the conus medullaris should be diminished. When the fibrous fat layer is exposed, the dural sac end on the surface of the conus medullaris should be initially identified. The conus medullaris S344

should be gently pulled aside at this point to further identify the distal end of the dural sac inside the sacral canal because the course of the dural sac end slants upward within the sacral canal. After the sacral sac end is reached, dissection should be carried out from both sides to the midline to completely isolate the conus medullaris from the end of the dural sac and entirely release the tethered spinal cord. After the boundary of the conus medullaris is totally exposed, the fibrous fat tissue on the surface of the conus medullaris should be removed safely and effectively and the neural plate reached.

Finally, the opened spinal cord should be repaired with interrupted suture to reduce the risk of postoperative adhesion between the dorsal side of the spinal cord and the suture site in the dura mater, and minimize the possibility of secondary tethering.

The key point of surgery for diastematomyelia is to remove the septum, regardless of bone, fat, or cartilage, because it is the cause of tethering. The bony septum outside the dura mater should be removed as much as possible using a ranger or small awl. In most cases, there are many blood vessels around the septum, which may cause massive bleeding if injured. The dura of the two spinal cords should be cut open. Often there are fibrous adhesions between the spinal cord and the dura mater at the site of the septum, and any such adhesions should be completely separated.

Surgery for thickened filum terminale syndrome should be performed via an incision between L4 and L5 or L5 and S1 spinouts processes. The dura mater and arachnoid mater should be cut open and the filum terminale identified according to midline location, yellow or silver change of filum’ color, disappearance of nodes of Rangier, and fat infiltration. The filum terminale should be separated from the peripheral nerve and slightly rotated to identify the presence of nerve adhesion on the ventral side. After electrocoagulation, 5 mm of filum terminale should be cut off as a specimen for pathological evaluation.

Surgery for a back dermal sinus requires complete removal of the dermal cyst and sinus inside and outside the spinal cord. It is necessary to identify the terminal of the sinus.

Though sometimes a back dermal sinus that terminates on the surface of the dura mater is shown in imaging examinations, cutting open the dura mater is still needed for exploration because some tiny dermal cysts within the dura mater are often not shown on MRI.

Postoperative follow‑up

Because some changes such as swelling caused by surgery disappears at least 1 month after surgery on MRI images, we often perform MRI 2–3 months after surgery to learn the postoperative status of the spinal

SNI: Pediatric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgical Neurology International

cord. Close observation is carried out for patients with myelocele or myelomeningocele to identify the presence or absence of progressive aggravation of hydrocephalus. If the neurological function is stable, we regularly follow‑up our patients 1, 3, and 5 years after surgery. We have a complete patient database and every patient is followed up by an experienced doctor.

This may help doctors obtain first‑hand information,

learn the postoperative status of neurological function, find problems, and in time, adjust or improve surgical procedures.

ACKNOWLEDGEMENT This work has been supported by the UCLA Center for World Health.

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“Countersinking” of reservoir in an irradiated patients can decrease tension on scalp closure Mansher Singh, Arturo J. Rios Diaz1, Alexandra J. Golby2, Edward J. Caterson Department of Surgery, Division of Plastic Surgery, Brigham and Women’s Hospital, 1Department of Surgery, Center for Surgery and Public Health, Brigham and Women’s Hospital, 2Departmant of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA E‑mail: Mansher Singh - msingh8@partners.org; Arturo J. Rios Diaz - arios-diaz@partners.org; Alexandra J. Golby - agolby@partners.org; *Edward J. Caterson - ecaterson@partners.org *Corresponding author Received: 04 March 15 Accepted: 07 May 15 Published: 23 July 15 This article may be cited as: Singh M, Rios Diaz AJ, Golby AJ, Caterson EJ. "Countersinking" of reservoir in an irradiated patients can decrease tension on scalp closure. Surg Neurol Int 2015;6:S334-6. http://surgicalneurologyint.com/surgicalint_articles/“Countersinking”-of-reservoir-in-an-irradiated-patients-can-decrease-tension-on-scalp-closure/ Copyright: © 2015 Singh M. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Subcutaneous reservoirs are used to provide therapy by establishing access to cerebrospinal fluid. However, it is associated with complications such as hemorrhage, infection, malfunction, and malpositioning. In an irradiated field with thin skin, use of reservoir can result in wound dehiscence, wound infection, and device extrusion.

Case Description: We introduced a “countersinking” technique for the reservoir placement which involves the creation of bony recess in the skull to effectively accommodate the reservoir and decrease the protrusion. “Countersinking” of the reservoir can result in tension‑free closure of the scalp and allow durable coverage of the reservoir. In the representative case, the incisional wound healed completely without any concern for wound dehiscence and the countersink technique may have contributed to effective healing of the radiated scalp.

Conclusion: Countersinking of the reservoir can be a strategy to prevent complications such as wound dehiscence, and device extrusion in any patient, but in irradiated patients with very thin skin it also enables tension‑free closure of the wound.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161409 Quick Response Code:

Key Words: Countersinking, ommaya reservoir, wound dehiscence

INTRODUCTION Subcutaneous reservoirs such as ommaya reservoir are used to administer intraventricular antibiotics for chronic meningitis, intrathecal chemotherapy for central nervous system lymphoma, and aspirate fluids from cystic tumors.[2,5,10,13,14] However, their use is associated with a complications such as hemorrhage, malfunction, and misplacement.[3,7‑9,11,12] Placement of a protruding device underneath a thin irradiated skin can exert increased tension on the already weakened wound and result in S334

wound dehiscence and wound infection.[1,4,6] We propose a “countersinking” technique of reservoir placement which creates a tailored bony recess to accommodate the reservoir [Figure 1].

CASE REPORT The patient was a 46‑year‑old woman who underwent right frontal craniotomy in1998 for tumor resection.

Pathology was consistent with astrocytoma requiring adjuvant chemoradiation therapy. Her follow‑up

SNI: Pediatric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgical Neurology International

a

a b Figure 1: Protrusion of the reservoir increases the tension on the overlying wound (a) while countersinking of the reservoir between the outer and inner table of the skin bone (b) promotes tension-free wound closure. This technique facilitates wound healing prevents complications such as wound dehiscence

magnetic resonance imaging in 2012 showed interval cyst enlargement in the right frontal lobe. A plan was made to proceed with aspiration of the cyst contents and then leave a catheter into the cavity which would then be connected to a reservoir for access in case the cyst reaccumulates.

Due to the history of radiation and very thin skin, there was a significant concern for wound breakdown and a modified technique was used for reservoir placement.

A U‑shaped incision was made adjacent to the previous incision outside the borders of the radiated skin and a pericranial flap was then raised. The skull bone was drilled through the outer table and the diploic layer to the level of the inner table to provide a tailored bony recess for countersinking the reservoir in the skull so that it would not protrude. The BrainLab navigation system was used to establish the oblique trajectory of the catheter. The dura was opened and the catheter was passed into the cyst. About 20 ml of yellowish thick fluid was aspirated and sent to cytology. The catheter was then secured to the reservoir which was effectively countersunk in the bony recess. The patient had no complications from the reservoir placement at 2 months follow‑up appointment.

CONCLUSION Subcutaneous reservoirs provide an effective way of establishing external access to cerebrospinal fluid (CSF) and other intracranial fluid spaces.[2,5] However, technical complications in the form of malpositioning and infectious complications leading to meningitis can be life threatening.[7] Placement of a reservoir in an irradiated wound with thin skin increases the risk of wound dehiscence and device extrusion. With wound dehiscence, a superficial wound infection can easily track to the CSF and intracranial cavity resulting in serious intracranial complications. Any technical modification toward preventing such potential complications would have far reaching consequences.

b

Figure 2: Coronal (a) and axial (b) section of computed tomography scan demonstrating the placement of the ommayma reservoir in the bony recess of the skull through the outer table and the diploic layer up to the inner table

In our patient, there was a high risk of wound dehiscence and reservoir extrusion given the thin irradiated skin.

Countersinking of the reservoir into the bone decreases the protuberance and by doing so, minimizes the stretching of the overlying skin [Figure 2]. This simple modification decreases the risk of wound dehiscence and device extrusion. It also results in effective “soft tissue lengthening” and allows a tension free closure. We used an oblique trajectory, facilitated by neuronavigation and a tracked stylet for catheter placement, to ensure that the incision is outside the boundaries of previous radiation and the reservoir is not directly underneath the incision.

Since a large number of brain tumor patients require chemoradiation and these patients often have significant other co‑morbidities resulting in poor wound healing, the “countersinking” of the reservoir can potentially prevent the risk wound dehiscence and device extrusion in these patients and enable tension free intra‑operative closure of the wound.

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Barnett GC, West CM, Dunning AM, Elliott RM, Coles CE, Pharoah PD, et al.

Normal tissue reactions to radiotherapy: Towards tailoring treatment dose by genotype. Nat Rev Cancer 2009;9:134‑42.

Bernardi RJ, Bomgaars L, Fox E, Balis FM, Egorin MJ, Lagattuta TF, et al. Phase I clinical trial of intrathecal gemcitabine in patients with neoplastic meningitis.

Cancer Chemother Pharmacol 2008;62:355‑61.

Dinndorf PA, Bleyer WA. Management of infectious complications of intraventricular reservoirs in cancer patients: Low incidence and successful treatment without reservoir removal. Cancer Drug Deliv 1987;4:105‑17.

Hom DB, Adams GL, Monyak D. Irradiated soft tissue and its management.

Otolaryngol Clin North Am 1995;28:1003‑19.

Jiang PF, Yu HM, Zhou BL, Gao F, Shen SX, Xia ZZ, et al. The role of an Ommaya reservoir in the management of children with cryptococcal meningitis. Clin Neurol Neurosurg 2010;112:157‑9.

Kulkarni S, Ghosh SP, Hauer‑Jensen M, Kumar KS. Hematological targets of radiation damage. Curr Drug Targets 2010;11:1375‑85.

Lishner M, Perrin RG, Feld R, Messner HA, Tuffnell PG, Elhakim T, et al.

Complications associated with Ommaya reservoirs in patients with cancer.

The Princess Margaret Hospital experience and a review of the literature.

Arch Intern Med 1990;150:173‑6.

Obbens EA, Leavens ME, Beal JW, Lee YY. Ommaya reservoirs in 387 cancer patients: A 15‑year experience. Neurology 1985;35:1274‑8.

Ratcheson RA, Ommaya AK. Experience with the subcutaneous

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SNI: Pediatric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgical Neurology International cerebrospinal‑fluid reservoir. Preliminary report of 60 cases. N Engl J Med 1968;279:1025‑31.

10. Rubenstein JL, Fridlyand J, Abrey L, Shen A, Karch J, Wang E, et al. Phase I study of intraventricular administration of rituximab in patients with recurrent CNS and intraocular lymphoma. J Clin Oncol 2007;25:1350‑6.

11. Sandberg DI, Bilsky MH, Souweidane MM, Bzdil J, Gutin PH. Ommaya reservoirs for the treatment of leptomeningeal metastases. Neurosurgery 2000;47:49‑54.

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12. Shapiro WR, Posner JB, Ushio Y, Chemik NL,Young DF.Treatment of meningeal neoplasms. Cancer Treat Rep 1977;61:733‑43.

13. Witorsch P, Williams TW Jr, Ommaya AK, Utz JP. Intraventricular administration of amphotericin B. Use of subcutaneous reservoir in four patients with mycotic meningitis. JAMA 1965;194:699‑702.

14. Yang S, Dai J, Zhang X, Jin Y. Intracerebral arachnoid cyst treated with Ommaya reservoir implantation in a patient younger than two years. J Craniofac Surg 2014;25:e378‑80.

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CSF hydrothorax without intrathoracic catheter migration in children with ventriculoperitoneal shunt Joon‑Hyung Kim, David W. Roberts, David F. Bauer Section of Neurosurgery, Dartmouth‑Hitchcock Medical Center, Lebanon, NH, USA E‑mail: *Joon‑Hyung Kim ‑ Joon‑Hyung.Kim@hitchcock.org; David W. Roberts ‑ David.W.Roberts@hitchcock.org; David F. Bauer ‑ David.F.Bauer@hitchcock.org *Corresponding author Received: 20 December 14 Accepted: 05 March 15 Published: 23 July 15 This article may be cited as: Kim JH, Roberts DW, Bauer DF. CSF hydrothorax without intrathoracic catheter migration in children with ventriculoperitoneal shunt. Surg Neurol Int 2015;6:S330-3. http://surgicalneurologyint.com/surgicalint_articles/CSF-hydrothorax-without-intrathoracic-catheter-migration-in-children-with-ventriculoperitoneal-shunt/ Copyright: © 2015 Kim JH. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Thoracic complications of ventriculoperitoneal (VP) shunts have been extensively reported in the literature. Cerebrospinal fluid (CSF) hydrothorax without catheter migration, however, has been rarely described and poorly understood.

Case Description: We describe development of pleural effusion and respiratory distress in a 3‑year‑old boy with no evidence of VP shunt catheter displacement on plain radiograph and stable ventricle size on rapid sequence magnetic resonance imaging (MRI) brain. Chest X‑ray revealed complete opacity of right hemithorax.

Pleural effusion was consistent with transudate. Beta‑2 transferrin returned positive. The patient underwent externalization of VP shunt, and upon resolution of effusion, re‑internalization with new distal shunt catheter. A literature review of CSF hydrothorax in children without intrathoracic shunt migration was performed. Eleven cases were identified in the English literature. Age at VP shunt placement ranged from birth to 8 years of age. Interval from VP shunt placement to CSF hydrothorax ranged from 1.5 months to 5 years. History of shunt revision was reported in two cases. Presenting symptoms also included ascites and inguinal hernia or hydrocele.

Reported diagnostic studies consist of CSF culture, radionuclide shuntogram, beta‑2 transferrin, and beta‑trace protein. Laterality of the VP shunt and development of pleural effusion were predominantly right sided. Definitive surgical treatment included VA shunt, repositioning of the peritoneal catheter, and endoscopic choroid plexus coagulation.

Conclusion: CSF hydrothorax is a rare thoracic complication of VP shunt placement with no radiographic evidence of shunt migration or malfunction. Postulated mechanisms include limited peritoneal capacity to resorb CSF in children and microscopic communications present in congenital diaphragmatic hiatuses.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161408 Quick Response Code:

Key Words: Cerebrospinal fluid hydrothorax, shunt malfunction, ventriculoperitoneal

shunt

INTRODUCTION Complications of ventriculoperitoneal (VP) shunt have been reported extensively in the literature.

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Thoracic manifestations include pleural effusion, bronchial perforation, pneumothorax, and pneumonia.

Cerebrospinal fluid (CSF) pleural effusion in the absence of migration of distal VP shunt catheter in

SNI: Pediatric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgical Neurology International

children, however, has been rarely described and poorly understood.[11] We report a case of CSF hydrothorax in a child with no radiographic evidence of VP shunt migration and review the literature on associated clinical findings.

CASE HISTORY

History and Examination

The patient is a 3‑year‑old boy born at 40 weeks by Cesarean section who initially presented with congenital hydrocephalus. He had right VP shunt placement at birth, with subsequent revisions at 13 and 23 months of age.

He became symptomatic 10 days prior to presentation with progressive viral‑like upper respiratory symptoms, including poor oral intake, intermittent fever, cough, irritability, and an ill appearance. Patient’s co‑morbidities include intractable epilepsy and craniosynostosis.

On examination, he was somnolent, but he would open his eyes spontaneously. He had full strength in all extremities. His shunt incisions and shunt track were nonerythematous and nontender. No swelling was seen along the track. He demonstrated intermittent cough with mild desaturations to 89%. Laboratory studies were within normal limits aside from mild thrombocytopenia (79 × 103/mcL) and elevated valproic acid level (183 mg/L; reference therapeutic range 50–100 mg/L).

Imaging

Chest radiograph revealed complete opacification of the right hemithorax with mediastinal displacement [Figure 1]. Radiographic shunt series revealed radiographically intact VP shunt without migration into the thorax [Figure 2]. Quick‑brain magnetic resonance imaging (MRI) revealed stable appearance of the ventricles without change in ventricular

Figure 1: Chest radiograph demonstrates pleural effusion in right hemithorax

size or new extra‑axial fluid collections. Ultrasound of the abdomen and the thorax confirmed right sided pleural effusion, underlying atelectatic lung, and a small amount of ascites.

Hospital course

A chest tube was inserted on the right side with drainage of 800 ml of straw colored fluid under pressure. The fluid profile was that of a transudate without infection.

The patient’s mental status immediately improved.

Chest tube output was brisk with 500 ml over the initial 24 h, and increasing to an output of approximately 50 ml/h. The valproic acid dose was decreased given the supratherapeutic level.

Beta‑2 transferrin was sent from the chest tube drainage, resulting in a positive study. The final CSF culture was negative for infection. A decision was made to externalize the VP shunt at the abdomen, following which the chest tube output decreased considerably. The chest tube was placed to water seal with no re‑accumulation of pleural fluid. The patient returned to the operating room for replacement and internalization of distal peritoneal tubing.

Postoperatively, the chest tube was maintained on water seal for 48 h without an increase in output. Serial ultrasound exam demonstrated no re‑accumulation of pleural fluid, and the chest tube was subsequently removed. At 1 year follow‑up, he has no re‑accumulation of pleural fluid, and no signs or symptoms of shunt malfunction.

DISCUSSION Upon initial presentation, the right chest opacity on chest radiograph was initially thought to be related to valproate toxicity resulting in an eosinophilic effusion. Consistent with this diagnosis was the patient’s depressed mental state and thrombocytopenia. When the chest tube was

Figure 2: X-ray shunt series show no evidence of shunt disconnect

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inserted, however, pleural fluid analysis was negative for eosinophils. Pleural fluid was transudative with mostly macrophage predominant cellularity and no evidence of malignant cells. The patient did not have symptoms of common etiologies for transudative effusions, such as congestive heart failure (no cardiomegaly on chest X‑ray, no S3 on auscultation, no hepatomegaly, normal pulses and blood pressure), nephrotic syndrome (normal urine output, normal serum albumin, no peripheral edema), and liver failure (normal hepatic function tests, normal coagulation tests). Despite improved respiratory status following pleural drainage, the patient continued to have persistent clear fluid drainage from his chest tube at approximately 50 ml/h. Beta‑2 transferrin was sent, and its positive result confirmed the diagnosis of CSF hydrothorax.

Thoracic complications of VP shunts have been previously outlined into three categories:[11] intrathoracic trauma during placement of a shunt, migration of the peritoneal catheter into the chest, or pleural effusion accompanying CSF ascites. In the absence of iatrogenic injury or migration of the peritoneal catheter, symptomatic CSF hydrothorax may infrequently result with and without concomitant CSF ascites.[12] Absence of radiographic signs of shunt malfunction, disconnect, or intrathoracic migration of the catheter, however, raises a diagnostic challenge. Radionuclide shuntogram and beta‑2 transferrin assays of pleural fluid are of significant diagnostic utility in suspected cases of CSF hydrothorax.

The mechanism of CSF hydrothorax in children without VP shunt catheter displacement remains less clear.

Migration of CSF from the peritoneal to the pleural cavity depends on two factors: Malabsorption of CSF in the peritoneal cavity and open communication between the peritoneal and the pleural cavities to enable intraperitoneal CSF to pass into the pleural cavity.[6] A theoretical risk factor is the limited peritoneal capacity to resorb CSF in children, resulting in CSF ascites and associated pleural effusion. Possible contributory factors also include history of abdominal infection, abdominal surgery, and formation of pseudocysts.[5] Another possibility is mechanical leakage of CSF from the shunt valve, the catheter, or between their connection, which is most likely suspected to be the case in our patient.

Conduits for intrathoracic catheter migration traditionally have been suggested to involve congenital diaphragmatic hiatuses, such as the anterior foramen of Morgagni and the posterior foramen of Bochdalek.[7] In children, these areas in the diaphragm are also easily eroded or can harbor microscopic communications undetectable by thoracoscopy or nuclear imaging studies.[9] Chronic inflammation can further facilitate transudation of CSF fluid via capillary and lymphatic channels in the diaphragm. A cyclic pressure gradient, created by negative S332

intrathoracic pressure during inspiration and positive abdominal pressure during expiration, is presumed to allow unidirectional flow of CSF.[3] In view of these mechanistic factors, a literature review of CSF hydrothorax in children without intrathoracic catheter migration was performed. A total of 11 pediatric cases of CSF hydrothorax without intrathoracic catheter migration were identified in the English literature [Table 1]. Age at VP shunt placement ranged from birth to 8 years. Interval time to CSF hydrothorax ranged from 1.5 months to 5 years. Clinical risk factors for poor abdominal re‑absorption of CSF were identified in two cases (18%), including one patient who had a prior abdominal surgery (Nissen fundoplication)[3] and another who previously had been diagnosed with necrotizing enterocolitis.[4] Interestingly, both resulted in shunt revision. By contrast, our patient underwent two prior shunt revisions in the absence of apparent abdominal risk factors.

Common presenting symptoms included ascites (N = 4) and inguinal hernia or hydrocele (N = 3). None of the patients with these symptoms had a history of shunt revision. It is widely accepted that very young children with poor abdominal re‑absorptive capacity are susceptible to development of hydrocele or inguinal hernia following placement of VP shunt. While relatively little is known whether these presenting abdominal symptoms have any relation to CSF hydrothorax development, ascites appeared to occur mutually independent from inguinal hernia or hydrocele [Table 1]. Consistent with this trend, findings in our patient included mild ascites but no inguinal hernia or hydrocele.

As reported in Table 1, diagnostic studies reported in the literature, in descending order of frequency, consisted of CSF culture, radionuclide shuntogram, beta‑2 transferrin, and beta‑trace protein. CSF culture was documented in eight cases (73%). Radionuclide shunt study was obtained in five cases (45%). Beta‑2 transferrin was sent in four cases (36%), all of which returned positive. One report utilized beta‑trace protein, which was positive.

Variability in diagnostic methods may be related to diagnostic preference or institutional availability of these tests as reflected by the wide geographic origin of the report series.[1] A chest tube was placed in 5 of 11 cases (45%) for management of pleural effusion. Laterality of VP shunt was right‑sided (82%), left‑sided (9%), and not reported (9%). Pleural effusion developed in the right lung (82%), left lung (9%), and bilateral lungs (9%).

While most VP shunts and resultant hydrothorax were right‑sided, laterality of VP shunt did not overlap with concomitant hydrothorax when it occurred in the left.[2] There was one case of right‑sided VP shunt resulting in bilateral involvement of the lungs.[4]

SNI: Pediatric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgical Neurology International

Table 1: Series of CSF hydrothorax in children without intrathoracic catheter migration Series

Origin

Globl and Kaufman (1978)[5] Philadelphia, PA, USA [4] Faillace and Garrison (1998) Jacksonville, FL, USA Hadzikaric et al. (2002)[6] Al‑Khobar, Saudi Arabia Adeolu et al. (2006)[1] Osun state, Nigeria Born et al. (2008)[2] Bonn, Germany Smith and Cohen (2009)[10] Toronto, Canada Chuen‑im et al. (2011)[3] St. Louis, MO, USA Kocaogullar et al. (2011)[7] Konya, Turkey Patel et al. (2011)[9] Little Rock, AR, USA Ulus et al. (2012)[12] Samsun, Turkey O’Halloran et al. (2013)[8] Dublin, Ireland

Prior Prior Ascites Inguinal CSF Beta‑2 Radionuclide Chest Laterality Laterality shunt abdominal hernia or culture transferrin shuntogram tube of VP of pleural revision surgery hydrocele shunt effusion No

No

Yes

No

Sterile NR

No

No

Right

Right

Yes

No

No

No

Sterile NR

Yes

No

Right

Bilateral

No

No

No

Yes

Sterile NR

No

Yes

Right

Left

No

No

No

No

NR

No

No

Right

Right

No No Yes

No No Yes

Yes Yes No

No No No

Sterile NR* Sterile Positive Sterile Positive

No No Yes

No Yes Yes

Left Right NR

Right Right Right

No No

No No

No No

Yes Yes

NR NR Sterile Positive

Yes Yes

Yes No

Right Right

Right Right

No No

No No

No Yes

No No

NR Positive Sterile NR

Yes No

Yes No

Right Right

Right Right

NR

*Beta‑trace protein. †Abbreviation NR (Not Reported)

Final surgical treatment modalities ranged from ventriculo‑atrial (VA) shunt placement (73%), reposition of peritoneal catheter (18%), and endoscopic choroid plexus coagulation (9%). Of eight patients in whom VA shunt was eventually placed, the catheter was externalized prior to VA shunt placement in two cases, and the peritoneal catheter was repositioned prior to VA shunt placement in one case. Externalization of a distal catheter may guide subsequent strategy for treatment, whether it is conversion to a VA shunt or replacement of the distal VP shunt catheter. Ventriculo‑pleural shunt was attempted in one patient but subsequently had to be revised to a VA shunt.

Further follow‑up data may be useful for determination of long‑term efficacy of various surgical revision modalities.

CONCLUSION CSF hydrothorax is a rare but important complication of VP shunt placement in children without evidence of shunt migration or malfunction. Postulated mechanisms include limited peritoneal capacity to resorb CSF in children and microscopic communications present in congenital diaphragmatic hiatuses. In suspected cases, beta‑2 transferrin assay and radionuclide tracer shunt series are useful diagnostic studies. CSF culture is commonly obtained to exclude infection. Thoracocentesis of pleural fluid or chest tube placement facilitates management of persistent pleural effusion. Externalization of the distal shunt catheter may resolve the hydrothorax and may guide subsequent treatment strategy.

REFERENCES 1.

Adeolu AA, Komolafe EO, Abiodun AA, Adetiloye VA. Symptomatic pleural effusion without intrathoracic migration of ventriculoperitoneal shunt catheter. Childs Nerv Syst 2006;22:186‑8.

2. Born M, Reichling S, Schirrmeister J. Pleural effusion: Beta‑trace protein in diagnosing ventriculoperitoneal shunt complications. J Child Neurol 2008;23:810‑2.

3. Chuen‑im P, Smyth MD, Segura B, Ferkol T, Rivera‑Spoljaric K. Recurrent pleural effusion without intrathoracic migration of ventriculoperitoneal shunt catheter: A case report. Pediatr Pulmonol 2012;47:91‑5.

4. Faillace WJ, Garrison RD. Hydrothorax after ventriculoperitoneal shunt placement in a premature infant: An iatrogenic postoperative complication.

Case report. J Neurosurg 1998;88:594‑7.

5. Glöbl HJ, Kaufmann HJ. Shunts and complications. Prog Pediatr Radiol 1978;6:231‑71.

6. Hadzikaric N, Nasser M, Mashani A, Ammar A. CSF hydrothorax‑VP shunt complication without displacement of a peritoneal catheter. Childs Nerv Syst 2002;18:179‑82.

7. Kocaogullar Y, Guney O, Kaya B, Erdi F. CSF hydrothorax after ventriculoperitoneal shunt without catheter migration:A case report. Neurol Sci 2011;32:949‑52.

8. O’Halloran PJ, Kaliaperumal C, Caird J. Chemotherapy‑induced cerebrospinal fluid malabsorption in a shunted child: Case report and review of the literature. BMJ Case Rep 2013;2013:pii: bcr2012008255.

9. Patel AP, Dorantes‑Argandar A, Raja AI. Cerebrospinal fluid hydrothorax without ventriculoperitoneal shunt migration in an infant. Pediatr Neurosurg 2011;47:74‑7.

10. Smith JC, Cohen E. Beta‑2‑transferrin to detect cerebrospinal fluid pleural effusion: A case report. J Med Case Rep 2009;3:6495.

11. Taub E, Lavyne MH. Thoracic complications of ventriculoperitoneal shunts: Case report and review of the literature. Neurosurgery 1994;34:181‑3.

12. Ulus A, Kuruoglu E, Ozdemir SM, Yapici O, Sensoy G, Yarar E, et al. CSF hydrothorax: Neither migration of peritoneal catheter into the chest nor ascites. Case report and review of the literature. Childs Nerv Syst 2012;28:1843‑8.

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Trigeminal neuralgia associated with Chiari 1 malformation: symptom resolution following craniocervical decompression and duroplasty: Case report and review of the literature Thorbjorn Loch‑Wilkinson, Chrisovalantis Tsimiklis1, Stephen Santoreneos1 Departments of Neurosurgery, Gold Coast University Hospital, 1 Hospital Boulevard, Southport, Queensland 4125, 1Neurosurgery, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia 5000, Australia E‑mail: *Thorbjorn Loch-Wilkinson - tloc0431@gmail.com; Chrisovalantis Tsimiklis - ctsimiklis29@gmail.com; Stephen Santoreneos - ssantore@bigpond.net.au *Corresponding author Received: 14 February 15 Accepted: 02 March 15 Published: 23 July 15 This article may be cited as: Loch-Wilkinson T, Tsimiklis C, Santoreneos S. Trigeminal neuralgia associated with Chiari 1 malformation: symptom resolution following craniocervical decompression and duroplasty: Case report and review of the literature. Surg Neurol Int 2015;6:S327-9. http://surgicalneurologyint.com/surgicalint_articles/Trigeminal-neuralgia-associated-with-Chiari-1-malformation:-symptom-resolution-following-craniocervical-decompressionand-duroplasty:-Case-report-and-review-of-the-literature/ Copyright: © 2015 Loch‑Wilkinson T. This is an open‑access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Background: Trigeminal neuralgia (TN) may rarely be the presenting or only symptom of Chiari 1 malformation (CM). Isolated case reports have described resolution of TN following craniocervical decompression where TN is present in association with CM. Case Report: This report discusses an unusual case of pure TN associated with CM that was successfully treated with craniocervical decompression and duroplasty and reviews the limited literature on the subject.

Conclusion: TN may be the sole presenting symptom of CM and can be successfully managed with craniocervical decompression. Clinicians should be aware of the association of TN with CM and consider surgical management.

Access this article online Website: www.surgicalneurologyint.com DOI: 10.4103/2152-7806.161407 Quick Response Code:

Key Words: Chiari malformation, craniocervical decompression, duroplasty, trigeminal neuralgia INTRODUCTION Trigeminal neuralgia (TN) may rarely be the presenting or only symptom of Chiari 1 malformation (CM). Isolated case reports have described resolution of TN following craniocervical decompression where TN is present in association with CM. This report discusses an unusual case of this nature that was successfully treated with craniocervical decompression and duroplasty and reviews the limited literature on the subject.

CASE REPORT A 39‑year‑old female presented with severe right sided facial pain of sudden onset. Her pain was so severe that

she was admitted to a rural hospital for pain management.

Her facial pain did not respond to oral medications including high dose carbamazepine, pregabalin, nonsteroidal antiinflammatory drugs (NSAIDS) and opiates. The patient was transferred to a tertiary hospital and investigation with magnetic resonance imaging (MRI) demonstrated a CM with tonsillar descent to the C1 level and very mildly increased T2 signal in the upper cervical cord [Figure 1]. There was no evidence of vascular conflict.

The patient proceeded to have a craniocervical decompression and duroplasty 8 weeks after first presentation of symptoms. At surgery tight arachnoid bands constricting the cerebellar tonsils were noted and the posterior aspect of the medulla S327

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Figure 1: Preoperative T2WI MRI Brain demonstrating Chiari 1 malformation with subtle upper cervical cord signal change. The patient had severe and refractory right sided trigeminal neuralgia as the sole presenting symptom

had a gliotic and tented appearance consistent with chronic compression. Division of the arachnoid bands was performed and diathermy of the cerebellar tonsils without subpial aspiration. Native pericranium was used for duraplasty. There were no surgical complications.

Following surgery the patient had immediate relief of facial pain and remains asymptomatic 1 year postsurgery with a satisfactory MRI appearance [Figure 2].

CONCLUSIONS TN associated with CM is limited to a very small number of case reports. A 2008 case report with a literature review found only 19 cases in the English language literature,[8] although in correspondence following this review several authors describe additional unpublished cases.

A small number of cases in the non‑English language literature can also be found.[1,4,7,14] Pure TN is particularly uncommon as a presentation of CM and is limited to isolated case reports.[2,7,9,10,13] Presentations of TN with CM may include bilateral symptoms or be secondary to hydrocephalus.[5,11,12,14] Postulated mechanisms of generation of TN due to Chiari malformation include (i) vascular compression at the nerve root entry zone, which could be affected by hydrocephalus or anatomic factors related to the Chiari malformation, such as a small posterior fossa; (ii) demyelination; (iii) microischaemic changes; and (iv) direct brainstem compression.[8] The spinal tract of the trigeminal nucleus has been implicated due to its dorsal location and poor myelination which potentially renders it vulnerable.[6,12] Case reports describe a range of successful treatments in cases of TN associated with Chiari malformation including medical treatment with carbamazepine[7] and craniocervical S328

Figure 2:T2WI MRI scan one year postcraniocervical decompression and duroplasty.The patient remains asymptomatic

decompression[3,10,12] as with this case. A bilateral TN case with associated CM was successfully treated with bilateral microvascular decompression (MVD),[15] however, it is argued by some authors that retrosigmoid craniotomy for MVD may improve symptoms by indirectly decompressing the foramen magnum.[6] Cases with associated hydrocephalus have been treated successfully with endoscopic third ventriculostomy[11] and ventricular shunt procedures.[5] Than et al., in 2011,[12] reviewed treatments for the 20 known cases described in the English literature at that time and found 15 of the 20 patients had been treated with craniocervical decompression with a reported 73% resolution of pain symptoms.

This case report contributes to the very limited number of case reports of Chiari malformation with pure TN, and those successfully treated with craniocervical decompression and duroplasty. Neurologists and neurosurgeons should consider this diagnosis in presentations of TN with concurrent CM and consider surgical treatment.

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