What is Bell's palsy?
Bell's palsy is a weakness (paralysis) that affects the muscles of the face. It is due to a problem with the facial nerve. It usually affects one side of the face, but rarely both sides are affected. Bell's palsy is named after the doctor who first described it. Bell's palsy is a weakness (partial or total) of the facial nerve. The facial nerve is the nerve that controls
expression on each side of the face, tearing, taste, and even hearing to some extent.
Bell's palsy has been described as a diagnosis of exclusion because several other disorders present similar symptoms. Facial palsies have been linked to conditions such as Lyme disease, ear infection, meningitis, syphilis, German measles (rubella), mumps, chickenpox (varicella), and infection with Epstein-Barr virus (e.g., infectious mononucleosis). True Bell's palsy is an idiopathic facial palsy, meaning the root cause cannot be identified. Although Bell's palsy is not life-threatening, it can present symptoms similar to truly serious conditions, such as a stroke, ruptured aneurysm, or tumors.
Every year, approximately 40,000-65,000 Americans are stricken with Bell's palsy. Worldwide, there is an annual incidence of 20-30 cases per 100,000 individuals. An individual can be affected at any age, but young and middle-aged adults are the most likely to be affected. It is unusual to see Bell's palsy in people less than 10 years old. Bell's palsy can affect either side of the face, and neither gender seems to be at a greater risk. Pregnant women and individuals with diabetes, influenza, a cold, or an upper respiratory infection seem to be at a greater risk. Although it cannot be considered a serious condition from a health standpoint, it can cause extreme stress, embarrassment, and inconvenience for those affected.
In the large majority of cases (80-85%), the facial weakness or paralysis is temporary. However, individuals who experience complete paralysis seem to have a poorer recovery rate with only 60% returning to normal. Approximately 4-6% of all Bell's palsy cases result in permanent facial deformity, and another 10-15% experience permanent problems with spasms, twitching, or contracted muscles. Between 2% and 7.3% of individuals who have experienced Bell's palsy will have a recurrence. On average, the first recurrence happens 9.8 years after the first episode; the second, 6.7 years later. One recurrence is very infrequent, and a second is extremely rare.