Information on the following diseases can be found in the Related Disorders section of this report:

• Glossopharyngeal Neuralgia
• Sphenopalatine Ganglion Neuralgia
• Post-herpetic Pain
• Multiple Sclerosis

The most significant symptom of trigeminal neuralgia is recurring episodes of intense, short-lived spasms of pain of the mouth, cheek, nose, and/or other facial areas. The pain is sometimes compared with a series of "electrical shocks" followed by a steady, dull ache. The pain often starts and stops quite rapidly. The pain may be triggered by tactile stimuli (e.g., brushing of the teeth, drinking of hot and/or cold drinks, chewing, etc.) and by extreme heat and/or cold. In most cases, painful symptoms are limited to one side of the face (unilateral). The skin on the affected side may become flushed and the eye may also tear. Individuals with trigeminal neuralgia may also experience excessive salivation. Many individuals have "trigger" points where light touch may produce a pain episode.

There are other disorders associated with facial pain that are similar to trigeminal neuralgia. However, this disorder is distinctive as to the extremely short duration of the pain (usually only a few seconds) and the location of the pain.

The symptoms may go into remission for as long as six months. However, the episodes typically recur.

The exact cause of trigeminal neuralgia is not fully understood. In most cases, the symptoms are due to compression of the trigeminal nerve by a blood vessel (vascular compression) resulting in damage to, or loss of, the myelin sheath from nerve fibers (demyelination). The myelin sheath is the fatty covering of nerve cells and fibers. Some researchers believe that, in some cases, damage to the myelin sheath results in increased electrical activity in the trigeminal nerve, which triggers the pain regions of the brain. In rare cases, compression of the trigeminal nerve is caused by the growth of a benign tumor (e.g., neuroma).

Toxic, nutritional, and infectious factors may also play a possible role in causing the disorder. In some cases, Trigeminal neuralgia may occur secondary to another disorder such as multiple sclerosis.

Many different factors can trigger a painful episode in individuals with trigeminal neuralgia including brushing ones teeth or putting on makeup.

In rare cases, trigeminal neuralgia has run in families. In some familial cases, researches believe the disorder is inherited as an autosomal dominant trait.

Trigeminal neuralgia affects females more often than males by a ration of 3:2. Although the exact incidence is unknown, approximately 10,000-15,000 new cases occur each year in the United States. The disorder most frequently affects people after the age of 60 years. However, cases have been reported in children and young adults.

Symptoms of the following disorders can be similar to those of trigeminal neuralgia. Comparisons may be useful for a differential diagnosis:

Glossopharyngeal neuralgia is a rare syndrome that, like trigeminal neuralgia, has symptoms of excruciating facial pain. In this disorder, however, pain tends to center around the throat, tonsils, the back of the tongue and the middle ear, originating usually at the base of the tongue. Glossopharyngeal neuralgia affects men more prevalently than women, and usually appears after age 40. In differential diagnosis, trigeminal neuralgia may be ruled out by tactile stimulation of the throat resulting in an attack, which can then be ameliorated by application of the drug tetracaine in glossopharyngeal neuralgia.

Sphenopalatine ganglion neuralgia is another related disorder. It may be caused by an infection in the accessory nasal sinus. This disorder can be identified by its symptomatic pain in the face, eye, upper jaw, root of the nose, teeth, ear, neck and shoulder. Prognosis for this disease is generally quite favorable. A neoplasm, tumor or another lesion impinging on the nerve can also result in symptoms like those associated with trigeminal neuralgia. Pain in these cases, however, is usually persistent and results in sensory impairment.

Post-herpetic pain, occurring after a herpes virus infection, also may cause facial pains. This is caused by neural impairment, yet it is identifiable as such by the history of the appearance of a herpetic rash usually located near the eyes.

Common dental problems such as cavities (caries) and gum disease may be mistaken for trigeminal neuralgia.

The outlook of individuals with trigeminal neuralgia is generally favorable, with both medical and surgical means of treatment. The anti-seizure (anticonvulsant) drug carbamazine (Tegretol) is often an effective treatment for the disorder. Administration of this drug should be accompanied by a monitoring of liver and hemapoietic (relating to formation of blood cells) functions. In some affected individuals, phenytoin (Dilantin) has been found to be an effective treatment.

The U.S. Food and Drug Administration (FDA) has approved the drug carbamazepine extended release capsules (Carbatrol) has been approved for the treatment of trigeminal neuralgia. Carbatrol is manufactured by Shire Pharmaceuticals.

Additionally, Tegnetol X-R (carbamazepine extended release tablets) produced by Novartis may be used.

In terms of surgical treatments, the most widely used is the Jannetta procedure, which involves the removal of vascular structures pressing on the trigeminal ganglion (microvascular decompression). In another possible treatment, a percutaneous needle makes electrolytic lesions of the trigeminal ganglion. Radiofrequency rhizotomy, a procedure in which a needle is inserted into the ganglion of the nerve through the cheek and the nerved is burned. In a procedure called percutaneous glycerol rhizotomy, a needle is inserted through the cheek and a chemical is placed around the nerve.

In cases of pain that do not respond to therapy (intractable pain), the 5th nerve fibers near the trigeminal ganglion may be surgically sectioned. Other treatment is symptomatic and supportive.

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com

TEXTBOOKS
Jannetta PJ. Trigeminal Neuralgia. In: NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. Philadelphia, PA. 2003:595

Trigeminal Neuralgia: Treatment by Microvascular Decompression: PJ Jannetta; In: Neurosurgery; Wilkins et al., eds.: McGraw-Hill (1984).

FROM THE INTENET
McKusick VA, ed. Online Mendelian Inheritance in Man (OMIM). Baltimore. MD: The Johns Hopkins University; Entry No:190400; Last Update:6/7/95.

National Institute of Neurological Disorders and Stoke. Trigeminal Neuralgia Information Page. May 5, 2001. Available at: http://www.ninds.nih.gov/health_and_medical/disorders/trigemin_doc.htm

REVIEW ARTICLES
Sindrup SH, Jensen TS. Pharmacotherapy of trigeminal neuralgia. Clin J Pain. 2002;18:22-27.

Fleetwood IG, et al. Familial trigeminal neuralgia. Case report and review of the literature. J Neurosurg. 2001;95:513-17.

Love S, Coakham HB. Trigeminal neuralgia: pathology and pathogenesis. Brain. 2001;124:2347-60.

Tenser RB. Trigeminal neuralgia: mechanisms of treatment. Neurology. 1998;51:17-19.

JOURNAL ARTICLES
Sandoval-Balanzario MA, et al. Surgical treatment for trigeminal neuralgia. Gac Med Mex. 2004;140:405-10.

Cheuk AV, et al. Gamma knife surgery for trigeminal neuralgia: outcome, imanging, and brainstem correlates. Int J Radiat Oncol Biol Phys. 2004;60:537-64.

Rozen TD, Trigeminal neuralgia and glossopharyngeal neuralgia. Neurol Clin. 2004;22:1850-206.

Kao MC. Gamma knife surgery for trigeminal neuralgia. J Neurosurg. 2002;96:160-61.

Rozen TD. Antiepileptic drugs in the management of cluster headache and trigeminal neuralgia. Headache. 2001;41:25-33.

Young RF, et al. Gamma knife radiosurgery for treatment of trigeminal neuralgia. Idiopathic and tumor related. Neurology. 1997;48:608-14.

Maciewicz R, et al. Trigeminal neuralgia: gamma radiosurgery may provide new options for treatment. Neurology. 1997 1997;48:565-66.

Lunardi G, et al. Clinical effectiveness of lamotrigine and plasma levels in essential and symptomatic trigeminal neuralgia. Neurology. 1997 1997;48:1714-17.

Fields HL. Treatment of trigeminal neuralgia. N Eng J Med. 1996;334:1125-26.

Barker FG 2nd, et al. The long-term outcome of microvascular decompression for trigeminal neuralgia. N Eng J Med. 1996;334:1077-83.

Barker FG 2nd, et al. Microvascular decompression for hemifacial spasm. J Neurosurg. 1995;82:201-10.