What is Bell’s palsy? It is a disease of unknown cause, characterized by paralysis of muscles of the face. The condition is thought to be related to the body’s immune system. Most infections have been traced to the herpes simplex virus. Other viruses have also been implicated, such as varicella zoster ,cytomegalovirus, HIV, epstein barr, influenza and Lyme disease. The paralysis of muscles commonly occurs in those who are pregnant or have diabetes, the flu or other respiratory ailments.
Bell’s palsy develops suddenly, causing paralysis of muscles on one side of the face. The paralyzing effect continues for a few hours to two days. An episode of Bell’s Palsy is usually painless but, sometimes it is preceded by aching pain in the ear or jaw. People suffering from Bell’s palsy may feel weakening or numbness on one side of the face. The face may droop to one side. Smiling and eating usually become difficult on the affected side. Drinks and food may fall out of the affected side of the mouth. Dribbling of saliva may be another problem. Patients may become oversensitive to sound and lose their sense of taste on the front part of the tongue or on the affected side.
The viruses mentioned in the introduction above can cause an infection of the face. After the infection subsides, the virus may not be eliminated from the body. It becomes latent and resides in the roots of the nerve. Even many months or years after the infection, the virus may become active again. The reactivation of the virus is usually caused when the body’s immunity drops very low, due to long or debilitating diseases or deficiencies. When the virus becomes active again, it can cause inflammation of the facial nerve, at the point where the nerve leaves the skull to supply parts of the face. This inflammation results in weakness or paralysis of the muscles and abnormalities in function of parts of the face supplied by this nerve.
Nerves supply sensation and function to different parts of the body. The head and neck contain 12 pair of cranial nerves. The facial nerve is the 7th cranial nerve and supplies function to the muscles of facial expression, provides sensation of taste to the front of the tongue, supplies function to major salivary glands and branches to a muscle in the middle ear. Thus, when the nerve is inflamed, all of these areas can be affected.
Treatment and Prognosis
Some patients recover from Bell’s palsy without treatment, while others develop severe after-effects, despite treatment. The treatment of choice includes anti-inflammatory drugs and steroids. Antiviral medication may help protect the nerve from damage, if a virus is the cause. If the patient is unable to close his or her eye on the affected side, it should be covered with a pad or goggles. Facial massage may help prevent permanent deformity of the affected muscles. In chronic cases, the nerve may be surgically corrected.