TRIGEMINAL NEURALGIA
ARTICLE ABSTRACT A variety of pathologic conditions can cause orofacial pain. Establishing the etiology of the pain is key to providing appropriate treatment. Trigeminal neuralgia (TN) is a relatively uncommon condition and can present a diagnostic challenge to even the experienced dental practitioner. The authors discuss two cases of TN that exhibited intraoral trigger points, which initially resulted in confusion regarding the establishment of a correct diagnosis and treatment.
KEY WORDS:
trigeminal neuralgia,
tic douloureax
Trigeminal Neuralgia with Intraoral Trigger Points: Report of Two Cases Jude A. Fabiano, DDS1*; Andrew J. Fabiano, MD2; Patrick L. Anders, DDS3; Terrence J. Thines, DDS, MS4 Associate Professor and AEGD Program Director, Dept. of Restorative Dentistry, School of Dental Medicine, University at Buffalo, Buffalo, New York; 2Resident, Neurosurgery Residency Program, School of Medicine and Biomedical Sciences, University at Buffalo; 3Associate Professor, Dept. of Oral Diagnostic Sciences, School of Dental Medicine, University at Buffalo; 4Associate Professor and GPR Program Director, Dept. of Oral Diagnostic Sciences, School of Dental Medicine, University at Buffalo; *Corresponding author: jaf1@buffalo.edu Spec Care Dentist 25(4): [pagex-pagexx], 2005 1
Introduction The International Association for the Study of Pain defines “neuralgia” or “neuropathic pain” as pain “initiated or caused by a primary lesion or dysfunction in the nervous system.”1 Further, the group describes trigeminal neuralgia (TN) as unilateral facial pain, characterized by brief electric shock-like (lancinating) pain limited to the distribution of one or more of the three divisions of the trigeminal nerve (see Figure 1). The pain of TN is commonly evoked by trivial stimuli including washing, shaving, smoking, talking and brushing the teeth, but also may occur spontaneously. The pain is abrupt in onset and termination, and may remit for varying periods.2 The intensity of the pain is such that individuals with a severe, uncontrolled neuralgia have become suicidal.3 Although it is unilateral, the same nerve on both sides of the face may be affected independently in an individual. Formerly known as tic douloureax, TN affects the fifth cranial nerve, which transmits sensory impulses (touch, pressure, pain and temperature) from the orofacial region to the brain. It is the most common facial neuralgia, affecting
Figure 1: Dermatomes of the three divisions of the trigeminal nerve.
206 S p e c C a r e D e n t i s t 2 5 ( 4 ) 2 0 0 5
4.3 per 100,000 people, with women being slightly more affected than men by a 3:2 ratio.4 Although it occurs more often in the sixth decade of life, TN has been reported in infants and children.4,5 Two categories of TN exist: idiopathic and symptomatic. Idiopathic TN is characterized by unilateral facial pain that corresponds to the distribution of the fifth cranial nerve, a “trigger point” that, when stimulated, will evoke pain and an unremarkable clinical neurological examination.6 Symptomatic TN is diagnosed when the neurological examination reveals an organic cause or when additional cranial nerves are involved.6 The identification of a “trigger point” is paramount in establishing the presence of TN. A non-painful stimulus such as a light touch, facial movement or draft of air to a specific, ipsilateral area innervated by the trigeminal nerve may provoke or trigger” the pain.2,6 Additional stimuli that may initiate an attack include chewing, applying make-up and swallowing.