Trigeminal neuralgia

Definition

Trigeminal neuralgia is a disorder of the trigeminal nerve (the fifth cranial nerve) that causes episodes of sharp, stabbing pain in the cheek, lips, gums, or chin on one side of the face.

Description

The trigeminal nerve, which is divided into three branches, is responsible for chewing, for producing saliva and tears, and for sending facial sensations to the brain. When this nerve breaks down for some reason, it can trigger brief but agonizing sizzles of pain on one side of the face.

This condition is unusual in those under age 50 and more often occurs after 70. Women are three times more likely to have the condition than are men. When trigeminal neuralgia does occur in younger people, it is often associated with multiple sclerosis.

The pain, while brief, is so severe that the sufferer often can't do anything else while the attack lasts. People with this pain often wince or twitch, which is where trigeminal neuralgia gets its French nickname tic douloureux, meaning "painful twitch."

Causes & symptoms

The origin of trigeminal neuralgia is not certain, but scientists believe it may be caused by degeneration, pressure, or irritation of the trigeminal nerve. Some doctors believe the pain may be triggered by pressure from a nearby abnormally-formed artery lying too close to the nerve.

Any part of the three branches of the trigeminal nerve may be affected. Neuralgia of the first branch leads to pain around the eyes and over the forehead; the second branch causes pain in the upper lip, nose and cheek; the third branch causes pain on the side of the tongue and lower lip.

The first episodes are usually fairly mild and brief, and it may be minutes, hours, or weeks before the next attack. However, attacks tend to occur in clumps that may last for weeks at a time. As the sufferer ages, the episodes become more frequent and painful, until the person begins to live in constant fear of the next one.

The momentary bursts of pain usually begin from the same spot on the face each time. The pain can be triggered by touching the area, washing, shaving, eating, drinking, or even talking. Even a cool breeze across the face can set off an attack. Pain is more severe at the ends of the affected nerve, especially over the lip, chin, nostrils, or teeth.

Diagnosis

Diagnosis is usually made by eliminating other problems that could cause similar pain in teeth, jaw, head, or sinuses. Because patients with the condition tend to avoid trigger points, avoiding chewing, shaving, touching or washing their faces can be a clue to diagnosis of trigeminal neuralgia.

Treatment

It is not easy to treat trigeminal neuralgia. Pain can be suppressed by a range of medicines, including the anti-epilepsy medicines carbamazepine (Tegretol) or phenytoin (Dilantin). These drugs slow down the nerve signals at certain nerve terminals, which eases the pain. However, these drugs cause a wide range of side effects, including nausea, dizziness, drowsiness, liver problems, and skin allergies. Some people develop resistance to the drugs or they can't tolerate the high dosage needed to control the discomfort. If the medicines are stopped, the pain usually returns.

If drug treatment fails, surgical treatment to block pain signals from the nerve may be effective. Radio-frequency waves, gamma rays, or glycerol injections can deaden the nerve (and hence the pain). An operation that frees the nerve from whatever is compressing it (blood vessel or tumor) can permanently relieve pain, but this major neurosurgical procedure carries its own risks and complications. Alternatively, a new procedure seeks to place a cushioning sponge between the nerve and a pulsating artery wrapping around it to soothe the irritated nerve.

Prognosis

Although the pain is momentarily incapacitating, it's not life-threatening. As the person ages, the attacks can be expected to occur more and more frequently.

Prevention

While the condition itself can't be prevented, there are a number of things patients can do to avoid triggering attacks:

• Wash with cotton pads and warm water over the face.
• Rinse the mouth with water after eating, if toothbrushing triggers pain.
• Eat and drink food and beverages at room temperature.
• Chew on the unaffected side.
• Eat soft foods, if eating is becoming a problem.

Key Terms

Multiple sclerosis

A progressive disease of the central nervous system in which the coverings of nerves in the brain and spinal cord are destroyed.

Further Reading

For Your Information

Books

• Greenberg, David, Michael Aminoff, and Roger Simon. Clinical Neurology. Norwalk, CT: Appleton & Lange, 1993.

  Organizations

• Chronic Pain Outreach. 822 Wycliff Ct., Manassas, VA 22110. (703) 368-7357.
• National Chronic Pain Outreach Association, Inc. 4922 Hampden Lane, Bethesda, MD 20814. (301) 652-4948.
• National Institute of Neurological Disorders and Stroke. National Institutes of Health, 31 Center Drive, MSC 2540, Bldg. 31, Rm. 8A06, Bethesda, MD 20892. (800) 352-9424. http://www.ninds.nih.gov.
• Trigeminal Neuralgia Association. PO Box 785, Barnegat Light, NJ 08006. (609) 361-1014.

Gale Encyclopedia of Medicine. Gale Research, 1999.