Steroid use shows promise in treating Bell's palsy
By the faculty of Harvard Medical School for The Harvard Medical School Adviser

Q: A colleague of mine recently developed a droopy eyelid and a dry eye, but only on one side of his face. His doctor diagnosed him with Bell's palsy. What is that, exactly?

A: Palsy is a medical term for muscle weakness. Sir Charles Bell was the 19th-century Scottish physician who first described the anatomy and function of the facial nerve. Bell's palsy is a weakness of the muscles on one side of the face caused by inflammation of the facial nerve on that side. The nerve becomes inflamed and swollen and stops functioning properly (see illustration).

About 40,000 Americans come down with Bell's palsy each year. Teenagers, 20- somethings and people over age 60 seem to be most vulnerable. Bell's palsy is somewhat more likely to occur during pregnancy, especially in the last three months. People with diabetes are four to five times more likely to get Bell's palsy and are more likely to experience a recurrence of the problem. About 8 percent of patients report that a close relative also has had Bell's palsy, but it's unclear whether the condition has a genetic basis.

In most cases, the nerve inflammation is probably caused by a viral infection -- most commonly, the same virus that causes cold sores, the herpes simplex type 1 virus. This virus often lurks in the nervous system after an initial infection but remains "asleep," causing no trouble most of the time. For unknown reasons, the virus "wakes up" and causes inflammation, perhaps because the immune system temporarily lets down its guard in response to stress or even a minor cold.

The early symptoms include an odd sensation in part of the face and pain in or around the ear. The affected ear may also become abnormally sensitive to loud noises. Within a day or two, a person with Bell's palsy may have trouble closing his or her mouth and eye on one side of the face. The eyes may tear more or less than usual. Some people also lose their sense of taste on the same side of the tongue as the palsy.

Doctors diagnose Bell's palsy by testing the weakness in the muscles of the face, paying special attention to how well the person can close both eyes and hold them closed. Having the person smile or whistle reveals possible differences on the sides of the face.

Most patients' symptoms peak at 48 hours, start to improve by two weeks and have resolved within six months. In some cases, though, the symptoms do not resolve completely, and there is some permanent facial weakness.

Injured nerves outside the brain and spinal cord have a remarkable ability to heal, which is why people can recover from mild cases of Bell's palsy without any medication. But an important 2007 study confirmed that early antiinflammatory treatment with prednisolone (a corticosteroid similar to the prednisone that most American doctors prescribe) improves the chances of complete healing. However, the research did not find any benefit for an anti-herpes virus drug that has also been commonly prescribed.

When Bell's palsy affects the eye, the cornea can become dry and possibly get scratched. So people with this symptom should wear glasses to protect their eye from wind and dust. They should also use artificial tears during the day and lubricate the eye at night with a sterile eye ointment.

Although the symptoms of Bell's palsy are frightening, there's a good chance that the nerve will be able to work properly again. Eighty-five percent of people with Bell's palsy recover completely within a few months. Children almost always recover completely.

Taste returns before facial strength. If taste returns within five to seven days after symptoms began, it's more likely you will recover completely. It's also more likely you will recover completely if your facial muscles were not fully paralyzed at the most severe point of the illness.

Bell's palsy often affects the muscles of the forehead, eyelids and cheeks more than the mouth. It sounds serious, but its bark is worse than its bite.

Copyright 2007 the President and Fellows of Harvard Developed by Harvard Health Publications (www.health.harvard.ed u). Distributed by UFS. Submit questions to harvard_ adviser@hms.harva rd.edu.