Encyclopedia - Bell's Palsy

What causes Bell's Palsy?
What are the symptoms?
How is it treated?

Bell's Palsy is a form of paralysis or weakness on one side of the face characterized by abnormal facial movement, twitching, or other symptoms that typically resolve on their own. Because Bell's Palsy affects the facial nerve, careful attention must be paid to the eye muscle.

What causes Bell's Palsy?

Bell's Palsy can result from infection, injury, or tumors. However, in most cases, the causes of Bell's Palsy remain unknown. It often occurs as a result of the viral-induced swelling of the facial nerve. The facial nerve is made up of nerve fibers that transmit impulses to allow people to hear, smile, cry, wink, etc. When half or more of the fibers are impaired or blocked, changes occur in the signals to the facial controls, resulting in muscle spasms, twitching, drooping, drooling and more.

What are the symptoms?

Patients with Bell's Palsy often first experience:

• a sudden paralysis
• loss of control or weakness on one side of the face
• distorted mouth expressions, smiles, frowns, drooling, speech impairment
• pain behind the ear
• changes in taste, salivation
• lack of tearing

To diagnose Bell's Palsy, physicians will conduct tests to examine how the patients lift their eyebrows and lower them, how they smile and show their teeth, and how they close and open their eyelids. With severe Bell's Palsy, a patient's eye will not close completely.

In addition, other common tests include a hearing test, a balance test, CT scans, and MRIs. These and other laboratory tests help identify and rule out certain causes of facial paralysis. An electrical test stimulates the facial nerve to assess damage. The results of these tests determine the best course of treatment.

How is it treated?

Eye care is of great importance. Eyes require a constant flow of tears to stay healthy and visually acute. Tears lubricate the eyes by blinking. In the case of Bell's Palsy, the ability to blink is reduced or temporarily lost, causing excessive drying, erosion, or the formation of ulcers.

Often, physicians will advise the nighttime application of an eye patch, with or without an eye ointment, to keep the eye lubricated and protected from scratches, dust, or debris. During the day, patients are given eye drops to keep the eyes moist. Patients are also advised to carefully raise and lower the eyelid manually, taking care not to injure the eye.

Eighty-six percent of Bell's Palsy patients generally experience complete recovery, depending on the extent of nerve damage. Factors that place patients at risk are:

• more than 55 years of age
• hypertension
• changes in tearing
• facial nerve weakness or other facial nerve damage
• pain other than ear pain

Although Bell's Palsy is unsettling and disturbing, it is not dangerous if nerve damage is prevented. It is important to note, however, that full recovery occurs gradually, usually between four and six months and almost always within one year.