Incidence, Symptoms, and Causes Bell's palsy is a paralysis of the facial muscle, usually only on one side of the face. Approximately one person of every 4000 contracts the disease in any given year. It is more common among diabetics with high blood pressure and among pregnant women in the last third of their pregnancy. The facial nerve passes through a narrow channel of bone in the face, so when the nerve swells due to inflammation, the result may be nerve compression and degeneration. The resulting lack of nerve function mainly prevents facial movement, but salivation, tear production, and facial sensation may also be reduced.
Younger patients have a better recovery rate than older ones.
Traditionally, Bell's palsy was defined as facial paralysis of unknown cause, but that definition has become controversial. These stresses include menstruation, dental extraction, coldness, or exposure to other infectious agents, particularly upper respiratory tract infection-and these same stresses are associated with Bell's palsy. The evidence has become strong that Bell's palsy is usually the only manifestation of a herpes reactivation. In addition to the risk of permanent nerve damage, Bell's palsy patients can experience serious eye damage. Artificial tears, ophthalmic ointments, and protective goggles may be required, under the guidance of a physician.