Dear Doctor: Our dad’s left eye and the side of his face started to droop suddenly, and it seemed like he’d had a stroke. The doctor says it’s actually Bell’s palsy. What is that?
Dear Reader: We can imagine the concern — and subsequent relief — when the signs that suggested your father had suffered a stroke turned out to be Bell’s palsy. Although the two are quite different, there is some crossover in symptoms. Add in the fact that, unlike stroke, Bell’s palsy isn’t that well-known, and it’s easy to understand the confusion.
Bell’s palsy is a type of temporary facial paralysis that arises from damage to the facial nerve. For fellow science nerds, this is the seventh cranial nerve, which animates the muscles we use to make facial expressions like smiling, raising our eyebrows, frowning and winking. It’s also involved in the sense of taste, the functioning of the salivary and tear glands, and the muscles of a small bone in the middle ear.
Although the exact cause for Bell’s palsy isn’t known, it occurs when something causes the nerve to become swollen, inflamed or compressed. Illness, injury and a family history of the disorder may also play a role.
As happened with your dad, the symptoms of Bell’s palsy can appear quite suddenly. In other cases, the paralysis may take a few days to develop. The onset of facial drooping, which usually occurs on only one side of the face, can indeed seem like the effects of a stroke. So can the ensuing weakness, numbness or twitching. Other possible symptoms of Bell’s palsy include headache, mild fever, ringing in the ears, pain behind the ear or near the jaw of the affected side, drooling and changes to taste and hearing. Once the symptoms begin, there is no known way to stop them.
About 40,000 people in the United States develop Bell’s palsy each year. It affects men and women at equal rates, and it is most common between ages 15 and 60. People living with diabetes and those recovering from a respiratory ailment such as a cold or the flu appear to be at greater risk. With no diagnostic tests currently available, Bell’s palsy is identified via a physical exam and the process of elimination. The symptoms are localized and specific, though, so it’s not a difficult diagnosis.
Mild cases don’t require treatment and begin to resolve on their own, often within two or three weeks of the onset of symptoms. In most people, facial nerve function returns to normal within three to six months.
It’s possible — but quite rare — for the symptoms to become permanent. Also possible but rare are recurrences of the disorder. In more serious cases, steroids such as prednisone can be effective in reducing inflammation and swelling. If infection is present, it will also be addressed. Since the facial paralysis can affect the eyelid and tear ducts, it’s important to take steps to protect the affected eye from debris, and to keep it lubricated.
Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health.