What Is It? Bell's palsy is a weakness of the muscles on one side of the face caused by inflammation, swelling and abnormal function of the facial nerve.
There are two facial nerves, one for the right side of the face and one for the left. Each facial nerve has several branches. The main branch controls most of the muscles on one side of the face, including the muscles that control facial expression and the muscles that close and open the eyes and the lips. Other smaller branches go to the tongue and ear.
Bell's palsy occurs in both men and women, in all age groups, and at all times of the year. The alteration in nerve function usually is related to inflammation, often from a viral infection. Two types of herpes viruses, the one that causes fever blisters and the chickenpox virus, are believed to be likely causes. Less common causes of Bell's palsy are Lyme disease and brain tumors.
Symptoms In most cases, symptoms of Bell's palsy begin gradually and become most severe in 48 hours. Early symptoms include altered sensation in a part of the face, pain in or around the ear, increased or decreased hearing and impaired taste. As the condition progresses, you may develop difficulty smiling and closing your lips and eye on one side of your face. You may not be able to hold food in your mouth. Your eyes may become dry, or unusually wet.
Diagnosis Your doctor usually will be able to diagnose Bell's palsy based on a physical examination. He or she will test for weakness in the muscles of your face, paying special attention to your ability to close both eyes and hold them closed. He or she may ask you to smile or whistle to look for a difference on the two sides of your face. Your doctor will ask whether you are having any other symptoms of numbness, weakness or difficulty with walking. These symptoms are not associated with Bell's palsy.
If there are no other symptoms and the abnormal findings are only in your face, then your doctor can diagnose Bell's palsy without further testing. Your doctor may order a blood sugar test if you have not had one recently. If you live in an area where there is Lyme disease, your doctor may order a blood test for Lyme antibody. If the problem continues or if you have other symptoms, your doctor may order a complete neurological evaluation and magnetic resonance imaging (MRI) of the brain.
Expected Duration Most symptoms go away within weeks to months.
Prevention There is no way to prevent Bell's palsy.
Treatment Although the symptoms of Bell's palsy are frightening, the outlook is good for recovering nerve function, especially when treatment is started within 48 hours of when symptoms begin. If the symptoms are mild, you may not need treatment at all. Most commonly, people with Bell's palsy are prescribed prednisone, a corticosteroid, to reduce the inflammation and swelling in the nerve and decrease pain. Many physicians prescribe a combination of prednisone and an antiviral drug, because Bell's palsy often is caused by a herpesvirus. The medication usually is taken for 10 to 14 days, but sometimes as long as 21 days.
If Bell's palsy is affecting your ability to close your eyes, your corneas can become dry, which can lead to corneal abrasion. To prevent this, you must protect your eye from wind and dust by wearing glasses or an eye patch. You will need to keep your eyes moist by using artificial tears frequently during the day and lubricating the eye at night with a sterile eye ointment.
For people who have had Bell's palsy for at least one year, and who still have severe impairment of facial function, surgery may be considered. Although surgical results vary, most people experience some degree of improvement.
When To Call a Professional Call your doctor immediately at the first sign of decreased strength in your face, difficulty eating or drinking, or a droopy eyelid. Also call your doctor if you experience sudden ear pain, especially if you see blisters around your ear or inside your ear canal.
If you have been diagnosed with Bell's palsy, call your doctor immediately if you develop a painful or irritated eye or any symptoms of arm and leg weakness, double vision, dizziness, trouble swallowing or progressive headache. Also contact your doctor promptly if symptoms get worse.
Prognosis Eighty-five percent of patients with Bell's palsy recover completely within a few months, and children almost always recover completely. People usually recover their sense of taste before recovering facial strength. Recovering your sense of taste is a good sign if it occurs within the first five to seven days after symptoms begin. Another good sign is incomplete paralysis of the face at the most severe point of illness.
Many factors have been associated with a poorer prognosis, including a high degree of impairment, a longer time passing before symptoms improve, advanced age and severe pain.
Additional Info National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Phone: (800) 352-9424
