Cervical Spine Disorders Problems & Symptoms

Cervical Spine Disorders

Problems & Symptoms

by: Winston T. Capel, MD, MBA, FACS, FAANS Spinal Neurosurgery

Introduction

Cervical Spine Disorders are common in the population. The most common cervical spine problems/symptoms are:

1. Neck Pain

2. Radiculopathy (Arm Pain/numbness caused by nerve compression)

3. Myelopathy (Spinal cord compression by disc, ligament and bone)

All 3 problems can exist solitarily or in combination in the same patient.

Neck Pain

A common medical compliant but less frequent than low back pain. It is most commonly due to degeneration of the disc and facet joints. The disc in the cervical spine serves as a shock absorber and allows for motion; it is prone to early degeneration because of its high mobility and frequent motion cycles (head motion). The degeneration of the disc and arthritis of the facet joints is called Spondylosis. As the disc ages (degenerates) it undergoes programed biochemical changes that include weakening (reduced cross linkages of the collagen), reduced blood supply, reduced compacity to resist compression which leads to increased loading of the facet joints with resulting articular cartilage wear. A companion to degeneration is inflammation which leads to the biochemical stimulation of pain receptors. The inflammatory process will cycle randomly or in response to activity/position; in general, pain is proportional to the level of inflammation present. Risk factors for disc degeneration include: genetics, wear and tear, heavy labor, repetitive trauma and nicotine exposure.

Most commonly neck pain is intermittent and reoccurring but can be chronic and persistent in up to 10% of the population. All thought Spondylosis is by far the most common cause of neck pain, it can also be caused by: Trauma (fracture/dislocation, ligament injury), tumor and infection. With spondylosis (degenerative disc disease) symptoms are generally worse with prolonged fixed positions: driving, staring at computer monitors/TV or at night sleeping.

WORKUP

IMAGING:

• if there is a history of trauma or neurologic symptoms (modality: CT/plain x-ray)

TREATMENT:

• Range of motion and isometric exercises

• Treat inflammation: oral and topical anti-inflammatories

• Frequent change in position

• Heat

Radiculopathy

Radiculopathy is disease of the nerve root. Classic radiculopathy is characterized by descending arm pain with numbness in the distribution of the compressed nerve(s). In more extreme compression muscle weakness can occur. Radiculopathy can be caused by disc herniation and/or bone spurs compressing the nerve in the foramen (where the nerve exits the spine). Radiculopathy can be present without or without neck pain. The natural history is generally favorable with conservative (non-operative) care.

Workup

IMAGING:

• MRI if symptoms are persistent

• EMG/NCS: used when there is diagnostic uncertainty

• It can be clinically challenging to differentiate peripheral nerve entrapment (neuropathy) like carpal tunnel disease from radiculopathy (especially C6) and they can frequently coexist. In general peripheral nerve problems ascend and nerve root compression (radiculopathy) descend in symptomatology. An EMG/NCS can help differentiate peripheral nerve disease from nerve root compression. It can quantify advanced disease when axonal degeneration is identified.

TREATMENT:

• Traction: can be very helpful, 15 pound for 30 minutes twice daily. A home traction device is more cost effective and allows for consistent application of forces that can retract the disc herniation or bone spur away from the affected nerve reducing nerve inflammation and symptoms.

• Neuromodulating Drugs (Neurontin, Lyrica): this class of drugs is generally the most effective for nerve pain. Neurontin is commonly under dosed. Titration dosing is required for Neurontin due to the potential side effect of drowsiness or dizziness. It is generally well tolerated if titration is gradual. A common regimen is 300mg increased by one capsule/day until daily dose is 1800mg/day. These drugs are controlled substances because patients need significant supervision in the initiation and termination of their use. Lyrica can be started at a therapeutic dose without titration and increased as needed. Common starting dose for Lyrica is 75mg twice daily.

• Surgery: only for intractable symptoms after failed nonoperative care. Rarely a rapidly progressive neurologic deficits will accelerate the need for surgery. Surgical options include: anterior cervical discectomy and Fusion (ACDF) or total disc replacement (TDR). TDR is FDA approved for single level disease and is not covered by some 3rd party payers. It is possible to decompress the affected nerve posteriorly and avoid fusion (motion preservation) but this technique is used much less frequently than anterior approaches especially for disc herniations.

Myelopathy

Myelopathy is disease of the spinal cord. In cervical pathology the cord can be compressed by disc herniation, osteophytes (bone spurs) this is called spondylotic myelopathy. Often cord compression is caused by a combination of bone and disc. The ligament behind the vertebral body and disc (posterior longitudinal ligament can become calcified (ossification) creating an entity called Ossification of the Posterior longitudinal ligament (OPLL). Stenosis is the narrowing of the cord transmitting spinal canal no matter the tissue type causing the compression. Approximately 5% of the population are born with congenital stenosis of the canal; these patients are much more vulnerable to cord compression over their lifetime. The degenerative changes result in disc collapse, bone spur formation that reduces the diameter of the spinal canal.

The clinical presentation of cervical myelopathy can be acute but is most often slow and insidious. It is commonly missed on history and exam due to its slow progression. This delay in diagnosis can lead to major debilitation. The presenting symptoms most often include:

• Bilateral hand numbness that usually involves all 5 fingers, unlike radiculopathy which involves 2 or less fingers in the dermatomes of the affected nerve.

• Decreased fine motor coordination. Patients will often experience dropping things and/or change in hand writing.

• Ataxia: patients will start stumbling and falling which can be dangerous with a narrowed spinal canal (stenosis). Falls call lead to acute spinal cord injury due to the intolerability of the stenotic canal to extreme and sudden hyperextension.

A major component of the pathophysiology of stenosis is chronic low blood flow (hypoperfusion) to the spinal cord. This leads to cell loss (atrophy) of the cord. As the atrophy progresses so do symptoms. The central nervous system has very limited capacity to regenerate. When the diagnosis of myelopathy is made surgery is usually required and the goals of surgery are not necessarily to make the patient better but to keep them from getting worse. Surgery is very effective in halting progression of the disease. Surgery will require decompression: removing disc and bone. This will be followed by reconstruction: rebuilding the structures removed using materials like polymers or titanium that will provide structural support for removed structures and contain bone forming material leading to fusion. Fusion is where motion is arrested between vertebrae a tradeoff required in most cases. Fusion requires the use of metallic (titanium) fixation in the form of screws and a plate to stabilize the reconstruction until bone growth is complete (fusion). Once the fusion is complete all reconstructive elements and fixation are inert and it is living bone that is responsible for reconstruction and fusion. In some patients a decompression can be done by removing the lamina (laminectomy) and a reconstruction/fusion are not required.

In summary, the above cervical spinal disorders are the most commonly observed and most have a good prognosis with good opportunity for successful non-surgical care. Surgery can be very effective for failed non-surgical care.

Inside Medicine | Summer Issue 2021