Q: When I saw my cousin two days ago, she was fine. But yesterday her face looked strange — half her mouth and one of her eyelids was drooping. I thought she was having a stroke, but her doctor says she has Bell's palsy. What can you tell me about this condition?
A: Bell's palsy is a disorder in which damage to the facial nerve causes partial or total paralysis of one side of the face. As in your cousin's case, it can cause startling changes on the affected side. These include a drooping mouth, a sagging eyebrow and a drooping eyelid that prevents the eye from closing properly.
The good news is that Bell's palsy is not nearly as serious as it looks. Its symptoms are usually temporary, but they can be very distressing for patients. Because the facial nerve controls muscles of the face, Bell's palsy not only affects appearance, but also the ability to speak, eat, sleep or taste food. Saliva may dribble from the corner of the mouth. Recovery can take weeks — even months. During that time, many people restrict their activities, and some become socially isolated.
Bell's palsy usually begins without warning and may develop rapidly, often overnight. It may be preceded by symptoms suggesting a viral illness, such as fatigue or a headache. The facial weakness generally peaks within 24 hours, rarely worsening after that.
Most scientists believe that Bell's palsy is triggered by a viral infection that causes inflammation of the facial nerve. This nerve starts in the brain and winds its way through the bones of the skull to the muscles of the face. It's made of thousands of nerve fibers that carry signals to and from the facial muscles as well as the saliva and tear glands. It also plays a role in taste.
The drooping mouth and other symptoms develop when the nerve swells and gets pinched when it travels through a narrow passageway in the skull beneath the ear. The affected eye may appear teary but remains mostly dry and irritated because it cannot blink or close completely. Drooling is another common symptom. Some people experience numbness or ear pain on the affected side. They may also become overly sensitive to sound.
Doctors aren't exactly sure what causes Bell's palsy. In the past, scientists focused on herpes simplex type 1 virus, the virus that causes cold sores. Other viral suspects include herpes zoster, which causes chickenpox and shingles, and the Epstein-Barr virus, which causes mononucleosis. As a result, doctors often prescribed an antiviral medication, as well as a corticosteroid to quell inflammation. But evidence has begun to cast doubt on this approach.
In a 2007 study, 551 Bell's palsy patients were randomly assigned to take either a corticosteroid, an antiviral drug, both medications or a placebo. After nine months, 94 percent of patients who took the corticosteroid had recovered fully. Patients who took the antiviral drug did no better than those who took placebo pills. The drug combination was no better than taking the corticosteroid alone.
A similar trial of 829 patients in 2008 confirmed these results. Patients who took a corticosteroid made a complete recovery much faster than those who did not. There was no difference in recovery times between patients who received an antiviral drug and those who did not.
In 2009, the Cochrane Collaboration, an organization that evaluates medical research, weighed in on the issue. The group determined that antivirals are less effective than steroid drugs and no more effective than a placebo in bringing about a complete recovery. It also questioned whether herpes simplex virus causes Bell's palsy.
Your cousin was smart to see her doctor right away. Early treatment (within three days) with a steroid increases the chances of a full recovery. A doctor can also rule out conditions that cause similar symptoms, such as Lyme disease, other bacterial infections and some types of tumors. Stroke can cause facial symptoms like Bell's palsy, but it typically also affects the limbs on that side of the body as well as the ability to speak.
Most people start to get better within a couple of weeks and return to normal after several months. During that time, your cousin needs to keep her affected eye moist. She can use eye drops while awake and a special ointment at night. She may also need to wear an eye patch or other protective eyewear.
Recovery takes time and patience. Your support can help your cousin strike a note of optimism as she makes slow but steady progress.