Bells Palsy

What Is It?

Bell's palsy is a weakness of the muscles on one side of the face caused by problems with a facial nerve. The nerve becomes inflamed and swollen and stops functioning properly.

There are two facial nerves, one for the right side of the face and one for the left. Each 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.

The nerve inflammation of Bell's palsy usually is caused by a viral infection. The most common associated viral infection is herpes simplex, the same herpes virus that causes cold sores (fever blisters). A variant of Bell's palsy, called Ramsay-Hunt syndrome, is caused by the herpes zoster virus, the virus that causes chickenpox and shingles. People with diabetes are more likely to develop Bell’s palsy. A less common cause of Bell's palsy is Lyme disease.

Symptoms

In most cases, symptoms of Bell's palsy begin gradually and peak in 48 hours. Early symptoms include changed sensation in a portion of the face, pain in or around the ear, increased or decreased hearing and impaired taste. As the condition progresses, a person typically has trouble closing his or her mouth and eye on one side of the face, and may complain of being unable to hold food in the mouth. The eyes also may tear more or less than usual.