The exact cause of Bell's palsy is unknown, but most researchers believe that the most likely cause is a viral infection (herpes simplex or herpes zoster virus) that causes swelling and inflammation of the facial nerve. Although research has found that the herpes simplex 1 virus (the virus that causes cold sores) is present, in many cases a direct link to the virus has not been proven.

Herpes zoster, the virus that causes shingles and chickenpox, hides in your nerve roots. Many experts believe this virus is responsible for some cases of Bell's palsy, but this theory is still disputed.

Some people are more prone to Bell's palsy than others. Your risk is higher if you have one of these conditions:

• a common cold or some other upper respiratory ailment
• cold sores
• diabetes
• influenza
• pregnancy (particularly the third trimester)

Bell's palsy usually appears suddenly, often overnight. The primary symptom is weakness and paralysis on one side of the face. You may find that you can't make the same expressions as usual. Typically, you'll be unable to fully close one eye. Other possible symptoms include:

• altered sense of taste
• facial pain, pain in or behind the ear (in fewer than 50% of cases)
• no tears in one eye
• sensitivity to noise on the affected side

There's none of the confusion, language difficulty, or crushing headache that's commonly seen in stroke victims. You may have some trouble talking, but it's purely muscular, whereas stroke victims have difficulty finding the words they need.

Usually, the symptoms appear at once. Occasionally, they worsen over a few days. Steady, progressive paralysis over several weeks is not a sign of Bell's palsy.

The most serious complication seen in Bell's palsy is permanent mild facial paralysis. This is found in a minority of cases. Overall, about 80% recover completely over weeks to months, and most of the rest improve.

Another complication is increased risk of stroke. Stroke prevention and follow-up is recommended.

Some people don't recover completely. This is more likely in people who are older than 60 or who are experiencing weakness or paralysis on both sides of the face.

People who don't recover completely may be left with one or more of the following symptoms:

• abnormal blink
• asymmetrical smile
• buccinator paralysis (food caught in cheek of paralyzed side)
• corneal damage
• drooling of liquids from corner of paralyzed mouth
• dry eye
• excessive perspiration
• frozen muscle in the nostril area
• hyperacusis (perceiving sounds as unusually loud)
• impaired taste
• impaired speech
• synkinesis (involuntary movement associated with a voluntary movement)

Bell's palsy is diagnosed based on its symptoms and physical signs. There are a huge number of conditions, including head injury, that can cause facial paralysis, but few have the same pattern as Bell's palsy. Additional tests such as CAT scans or MRI scans are usually not necessary.

Bell's palsy must be differentiated from Lyme disease, Guillain-Barré syndrome, sarcoidosis, parotid tumor, and stroke. Lymphoma can also in rare instances be a cause of facial paralysis.

Often no medication at all is prescribed, but everyone with Bell's palsy needs special protection for his or her open eye. It will usually remain open for at least a week, and may not be producing tears. Eyedrops, eyepatches, and special lotions at night are used. These almost always prevent long-term damage to the surface of the eye (cornea).

Some specialists give the anti-viral medication acyclovir* if they suspect herpes simplex I. Corticosteroids, such as prednisone, are commonly prescribed to reduce swelling around the nerve. These are usually taken for about 7 to 10 days. There is little evidence, however, to suggest they speed or improve recovery.

In the past, a surgical technique called decompression of the seventh nerve was sometimes used. It's less common now, as many experts believe inflammation and not compression of the nerve is the root of the problem.

There is no known way of preventing Bell's palsy.

All material copyright MediResource Inc. 1996 – 2020. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/condition/getcondition/Bells-Palsy