On call: Bell's palsy
Q. Last month I developed severe weakness on the whole left side of my face. My doctor diagnosed Bell's palsy and referred me to a neurologist. I recovered before I got to see her, so I didn't keep the appointment. Although my face is now back to normal, I'd like to know more about the condition. What can you tell me?
A. Although it sounds exotic, Bell's palsy isn't all that rare, occurring in one of every 4,000 adults per year. And while it sounds very serious, it's usually a mild condition that resolves almost completely in most people.
The problem is caused by the inflammation of the facial, or seventh, cranial nerve. It begins abruptly with a weakness on one side of the face that increases to its maximum over 1–2 days and then stabilizes. Many patients complain of pain behind the ear on the affected side of the face, and some experience abnormally acute hearing in that ear. A less common symptom is a diminished sense of taste on half the tongue. Because the eyelid muscles are weak, patients can't blink or close their eyes fully, so eye dryness and irritation can be troublesome. The weakness involves the entire face from head to chin, but it ranges in severity from mild weakness to a nearly complete paralysis. About 85% of patients recover completely, but improvement can be slow, taking several months. Facial weakness can sometimes persist, especially in patients with the most severe cases.