Trigeminal neuralgia, also known as tic douloureux, is a painful disorder of a nerve in the face called the trigeminal nerve or fifth cranial nerve. There are two trigeminal nerves, one on each side of the face. These nerves are responsible for detecting touch, pain, temperature and pressure sensations in areas of the face between the jaw and forehead.
People who have trigeminal neuralgia usually have episodes of sudden, intense, "stabbing" or "shocklike" facial pain. This pain can occur almost anywhere between the jaw and forehead, including inside the mouth. However, it usually is limited to one side of the face.
In some cases, the cause of trigeminal neuralgia is unknown. In many people, however, something seems to be irritating the trigeminal nerve, usually in the area of the nerve's origin deep within the skull. In most cases, the irritation is believed to be caused by an abnormal blood vessel pressing on the nerve. Less often, the nerve is being irritated by a tumor in the brain or nerves. Sometimes, the problem is related to a rare type of stroke. In addition, up to 8% of patients who have multiple sclerosis (MS) eventually develop trigeminal neuralgia as a result of MS-related nerve damage.
New cases of trigeminal neuralgia affect 4 to 5 of every 100,000 people in the United States each year. It affects women slightly more often than men, possibly because the disease is most common in older people and women live longer. The first episode of facial pain usually occurs when the patient is 50 to 70 years old. Although infants, children and young adults may develop this disorder, it is rare in people younger than age 40.