There are over 7,000 nerve fibers that protrude from the cranial nerve of the face, and damage to any of these nerve fibers can lead to weakness and paralysis. Bell's palsy affects approximately 23 out of every 100,000 people, mostly those over the age of 40. According to the Mayo Clinic, the exact cause of Bell's palsy is unknown, but it is suspected that it may be viral. The herpes virus has been linked to Bell's palsy, along with the Epstein Barr virus that causes mononucleosis and the herpes zoster virus that is responsible for chickenpox.
Bell's palsy is also referred to as "acute idiopathic neuropathy" of the face. The condition occurs when the nerves of the face become damaged. In most cases, Bell's palsy only affects one side of the face, but in rare circumstances it may affect both sides. According to the National Institute of Neurological Disorders and Stroke, the symptoms of Bell's palsy come on quickly and can cause major facial abnormalities. Symptoms of Bell's palsy can be severe or mild, and can have a drastic effect on the symmetry of the eyes and mouth. The Bell's palsy condition is usually only temporary, lasting just a few weeks or several months.
Bell's palsy results in the swelling of nerves in the face; therefore, corticosteroids are often used to reduce the inflammation. The U.S. National Library of Medicine reports that when combined with antiviral medications, corticosteroids can be even more effective in treating Bell's palsy. However, corticosteroids can only be used for short periods, ideally only one to two weeks.
Antiviral medications are especially designed to combat viruses that cause infection. According to the Bell's Palsy Information Site, antiviral medications attack the viruses that cause Bell's palsy and hinder their ability to multiply. If a virus cannot multiply, it cannot survive. Therefore, the symptoms of the virus will last for a shorter duration if antiviral medications are administered to a Bell's palsy patient immediately following diagnosis.
Facial retraining is a type of physical therapy that is sometimes used to restore symmetry and strength to the muscles of the face. Aetna explains that facial retraining involves a series of facial exercises that are performed by the patient in combination with EMG training. EMG stands for "electromyography," a type of therapy that utilizes electrical currents to stimulate muscles.
It is common for Bell's palsy to affect the eyes. Muscle weakness in the eyes due to damaged facial nerves can make the eyelids unable to open and close. This can cause a condition known as "dry eye." The moisture content of the eye is completely dependent on the eye's ability to blink. It is the blinking that allows the eye fluid to coat the eye and support the drainage process. When the muscles that control this process are compromised, the result is a dry, burning sensation in the eye. According to Merck, saline eye drops are often used to maintain moisture and relieve the symptoms of dry eye.