What is Bell's palsy?

Bell's palsy is a weakness or paralysis of the facial nerve. This nerve controls movement of the muscles of expression on each side of the face. When the nerve is weak or paralyzed, the affected side of the face droops and your child may have trouble closing the eye on that side.

How does it occur?

Something causes the nerve to swell or lose the covering that "insulates" the nerve. When this happens, it can no longer transmit impulses to the facial muscles. The muscles become weak or paralyzed and muscle control is lost. Bell's palsy often occurs a few weeks after having a viral infection. Therefore, some doctors think the cause may be related to something the immune system does because of fighting the infection. Other evidence suggests that at least some of the cases of Bell's palsy are caused by an actual viral infection.

What are the symptoms?

The first symptom may be an ache behind the ear on the affected side of the face. This is followed by weakness or paralysis in the facial muscles on that side. The paralysis usually starts in the lower part of the face. Other possible symptoms are tearing of the eye, decreased taste, a change in hearing, and trouble drinking or chewing. The severity of Bell's palsy can vary from a mild weakness to complete paralysis.

Symptoms may develop within a few hours to over a couple of days. The faster the symptoms happen, the more severe the weakness or paralysis is likely to be.

How is it diagnosed?

Your child's health care provider will ask about the symptoms and examine your child. The provider will need to rule out other possible causes of the symptoms, such as an injury, stroke, illness, or tumor.

Usually an ear, nose, throat, and neurological exam will rule out other possible medical problems. Your child may also have a hearing test or brain scan. Electrical testing on the facial nerve may be done to see how much the nerve is damaged.

How is it treated?

Because the eye on the affected side does not close completely, it's very important to protect it from problems such as dust and drying out. This is done by either patching the eye, using artificial tears (eyedrops), or both.

Because the cause of Bell's palsy is not well understood, the treatments are not well studied. Antiviral and steroid medicines are widely used but their effects are still not known. If steroids do help, the benefit is probably fairly small. The risk of harm is also probably small. For pain or discomfort, moist heat can help. Surgery is rarely needed to relieve pressure on the nerve. It is usually done only when the paralysis is severe and nerve tests show poor function.

How long will the effects last?

Recovery from Bell's palsy is variable and sometimes very slow. For many children with mild cases of Bell's palsy, weakness will last between 10 days and 6 weeks. For severe cases, it can take up to 7 months to improve. In about 1 in 10 cases, recovery is never complete.

The degree of weakness is important in predicting if nerve function will return completely or not. Children who have complete paralysis, that is no movement of the facial muscles at all, are more likely to not have full return of muscle movement. Children who have at least some muscle movement can usually expect a complete recovery.

Can my child get Bell's palsy again?

Bell's palsy rarely occurs twice in the same person. If someone has facial paralysis more than once, another problem may be causing it.