Trigeminal Neuralgia

Trigeminal neuralgia (tic douloureux) is an intense, stabbing pain in the face. The pain results from a problem with the nerve that connects parts of the face to the brain (the 5th cranial nerve, or trigeminal nerve).

Trigeminal neuralgia usually occurs in people over 50, particularly women.

Causes

The cause is often unknown. A common identifiable cause is a blood vessel (artery or vein) in an abnormal position. The blood vessel presses on the trigeminal nerve near the brain, where the nerve originates. Rarely, trigeminal neuralgia results from pressure due to a tumor or develops after an episode of shingles that affects the trigeminal nerve.

Symptoms and Diagnosis

Often, the pain is triggered by touching a particular spot (called a trigger point) on the face, lips, or tongue or by an activity such as brushing the teeth, shaving, talking, or chewing. But the pain may occur spontaneously.

Excruciating, stabbing pain occurs in repeated short, lightning-like bursts. Sometimes the disorder causes a dull, constant burning or aching, with occasional bursts of stabbing pain. The bursts of pain typically last seconds, but they may last up to 15 minutes. The pain may recur as often as 100 times a day. It can be incapacitating. Because the pain is intense, people tend to wince. Thus, the disorder is sometimes called a tic.

The pain is most often felt in the cheek next to the nose or in the jaw. But it can occur in any part of the forehead or lower face. Usually, only one side of the face is affected. When both sides are affected, they rarely hurt at the same time.

Doctors can usually diagnose trigeminal neuralgia based on its characteristic pain. Some tests may be done to determine what is causing the pain. For example, magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA) may be done to check for a blood vessel in an abnormal position or a tumor.

Treatment and Outlook

Usually, typical pain relievers (analgesics) do not help. Gabapentin, a drug used to prevent seizures (anticonvulsant), may help. If gabapentin is ineffective or has intolerable side effects, other anticonvulsants, such as carbamazepine, phenytoin, or valproate, may be prescribed. Baclofen (a drug used to reduce muscle spasms) or a tricyclic antidepressant may be used instead.

If the cause is a blood vessel in an abnormal position, surgery may be done. The blood vessel is separated from the nerve, and a small sponge is placed between them. This procedure usually relieves the pain for many years. If the cause is a tumor, the tumor can be surgically removed.

If drugs are ineffective and surgery to take pressure off the nerve is not possible, a test may be done to determine whether other treatments would help. For the test, an anesthetic is injected into the nerve to temporarily prevent the nerve from functioning. If the pain is relieved, a drug such as glycerol may be injected into the nerve through a needle inserted through the skin in the cheek. This treatment, called a nerve block, often provides relief for a few months to a few years. When discomfort in the face returns, another injection can be given. However, injections may become less effective as they are repeated.

Another option is cutting the nerve. The nerve can be cut surgically or with heat (applied by inserting a needle). This procedure relieves the pain permanently. But afterward, the face is likely to be numb.

See the figure Taking the Pressure off a Nerve.

Trigeminal neuralgia occurs in bouts or episodes. There may be long intervals without any episodes. How long these intervals will last cannot be predicted, and what makes the episodes stop and start is unknown.