Bell's Palsy

What is Bell's palsy?

Bell's palsy is a paralysis or weakness of the muscles on one side of your face. Damage to the facial nerve that controls muscles on one side of the face causes that side of your face to droop . The nerve damage may also affect your sense of taste and how you make tears and saliva. This condition comes on suddenly, often overnight, and usually gets better on its own within a few weeks.

Bell's palsy is not the result of a stroke or a transient ischemic attack (TIA). While stroke and TIA can cause facial paralysis, there is no link between Bell's palsy and either of these conditions. Palsy simply means weakness or paralysis.

What causes Bell's palsy?

The cause of Bell's palsy is not clear. Experts believe some cases may be linked to the herpes virus that causes cold sores.¹

In most cases of Bell's palsy, the nerve that controls muscles on either side of the face is damaged by inflammation.

Many health problems can cause weakness or paralysis of the face. If a specific reason cannot be found for the weakness, the condition is called Bell's palsy.

What are the symptoms?

The main symptom of Bell's palsy is a sudden weakness or paralysis in one side of your face that causes it to droop. This may make it hard for you to close your eye on that side of your face.

Other symptoms include:

• Drooling.
• Eye problems, such as excessive tearing or a dry eye.
• Loss of ability to taste.
• Pain in or behind your ear.
• Numbness in the affected side of your face.
• Increased sensitivity to sound.

How is Bell's palsy diagnosed?

Your doctor may diagnose Bell's palsy by asking you questions, such as about how your symptoms developed. He or she will also give you a physical and neurological exam to check facial nerve function and rule out more serious causes of facial paralysis.

How is it treated?

Most people who have Bell's palsy recover on their own within a few weeks to a couple of months.² However, a small number of people may have permanent weakness of the muscles on the affected side of the face.

Your doctor may prescribe antiviral drugs, such as acyclovir, if he or she believes that Bell's palsy is caused by a virus. If your doctor suspects that Bell's palsy is caused by inflammation from another disease, you may be given corticosteroids, such as prednisone, to reduce the inflammation. However, there is no clear evidence that corticosteroids or antiviral medicines are effective treatments for Bell's palsy.^{3, 4}

Frequently Asked Questions

The main symptom of Bell's palsy is weakness or paralysis of the muscles on one side of the face. The affected side of the face looks flat and expressionless or droopy . Other symptoms include:

• A dry eye on the affected side because you are unable to blink.
• Tearing in the affected eye.
• Pain behind the ear on the affected side of the face, which may occur a day or two before the paralysis begins.
• Increased sensitivity to sounds.
• Drooling because you may not be able to close your mouth completely.
• A dry mouth and problems swallowing because you make less saliva.
• A decreased ability to taste, especially at the tip of your tongue.

The paralysis is likely to become worse for the first couple of days, then gradually get better. In most cases, all symptoms are gone within 2 months.

A number of other conditions, such as stroke or Lyme disease, can also cause facial weakness and paralysis.

Bell's palsy is usually diagnosed from a medical history, a physical exam, and a neurological exam that checks facial nerve function and rules out more serious causes of facial paralysis.

Your doctor will decide whether you could have Bell's palsy by asking you questions about your medical history, such as:

• What are your symptoms? When did you first notice them? Have you ever had them before?
• Have you recently had a head injury?
• Do you have pain or loss of feeling in your face or head area?
• Have you had any other problems, such as dizziness, hearing loss, changes in your ability to taste, or weakness in any other part of your body?
• Have you recently had a cold, the flu, or a respiratory illness?

During a neurological exam, your doctor will evaluate your muscle weakness. You may be asked to:

• Lift your eyebrows and then lower them.
• Close your eyes tightly and then open them.
• Smile or show your teeth.

Bell's palsy may be diagnosed when you have:

• Weakness and paralysis that develop suddenly and affect the muscles on one side of your face.
• No signs of any other disease or injury that might explain the weakness and paralysis.

Weakness that occurs on one side of your face should be checked by a doctor right away to rule out more serious conditions. Early detection and treatment of Bell's palsy may help prevent permanent nerve damage.

Your doctor may order additional tests to look for other possible causes of your facial weakness and paralysis. These tests include:

• Blood tests, to rule out diseases such as Lyme disease, HIV, or syphilis.
• Hearing tests, to determine whether your hearing or the muscles in your middle ear are affected.
• A CT scan or MRI, to check for a brain tumor or stroke.
• A lumbar puncture, to check for signs of infection or bleeding.

Bell's palsy usually goes away without treatment, especially if you can still partly move the muscles on the affected side of your face. Almost all people who can still move their facial muscles to some degree recover completely without needing any medication or other treatment.²

Your chances for a full recovery are better if your symptoms start to improve on their own within 3 weeks.² About 2 out 3 of people who get Bell's palsy recover completely.⁵ The remainder have ongoing weakness that ranges from partial to complete paralysis, which may never completely disappear. Some go on to develop involuntary facial movements, such as twitching lips, tearing eyes, or spasms of the face or eyelids.

If your doctor thinks that your Bell's palsy is caused by a virus, you may be given antiviral drugs, such as acyclovir. However, there is no clear evidence that antiviral drugs are an effective treatment for Bell's palsy.³

If your doctor thinks that your Bell's palsy is caused by inflammation from another disease, you may be given corticosteroids, such as prednisone, to reduce the inflammation. However, no benefits from this treatment have been proven.⁴

If Bell's palsy affects your ability to close the affected eye, proper eye care, including keeping the eye moist, is essential to prevent eye damage. Try the following to help protect your eye:

• Use your finger to close and open your eyelid. Doing this frequently will help keep the eye moist.
• Use "artificial tears," which are eyedrops that contain methylcellulose, to keep your eye moist during the day. Talk to your doctor about how often to use the eyedrops.
• Apply special ointment or wear an eye patch at night to protect your eye and keep it moist. You may need to apply ointment and then tape your eyelid shut at night.
• Wear glasses or goggles to keep dust and other foreign matter out of the eye.

If your eye starts to hurt or is damaged, you may need to see an eye doctor (ophthalmologist).

If your condition does not improve as expected, your doctor may order additional tests, such as an MRI or a blood culture, to rule out other possible causes for your facial paralysis.

Some people develop involuntary facial movements months after being diagnosed with Bell's palsy. This condition may be treated with injections of botulinum toxin to temporarily paralyze the facial muscles.

Treating permanent facial paralysis

If you develop permanent facial paralysis, you may benefit from surgery or physical therapy.

Your doctor may recommend surgery if you have had Bell's palsy for 6 to 12 months without improvement. Surgeries that may improve your appearance and partially restore muscle function include:

• Grafting another nerve to the facial nerve. In many cases, the nerve that controls tongue sensitivity is attached to the facial nerve. Damage to this nerve causes a loss of sensation on half of the tongue. However, some people who have had Bell's palsy for a long time may find this preferable to having the muscles on one side of their face completely paralyzed.
• Transferring normal muscle tissue to the affected area, usually the lips.

Who to see for Bell's palsy

Health professionals who can diagnose and treat Bell's palsy include:

• Family medicine physicians.
• Internists.
• Neurologists.
• Physician assistants.
• Nurse practitioners.

If your eyes, mouth, or tongue are affected by Bell's palsy, you can take steps prevent future complications.

Eye care

Dry eyes can lead to serious problems with vision. Blinking keeps the eye moist and protects it from dust and other foreign matter. When you can't blink, your eye may become dry, and sores may develop on the clear covering of the eye (cornea). Sores on the cornea that are not treated can cause blindness. If you are unable to close your eye fully or blink because of Bell's palsy, try the following to help protect your eye:

• Use your finger to close and open your eyelid. Doing this frequently will help keep the eye moist.
• Use "artificial tears," which are eyedrops that contain methylcellulose, to keep your eye moist during the day. Talk to your doctor about how often to use the eyedrops.
• Apply special ointment or wear an eye patch at night to protect your eye and keep it moist. You may need to apply ointment and then tape your eyelid shut at night.
• Wear glasses or goggles to keep dust and other foreign matter out of the eye.

Call your doctor if you have Bell's palsy and develop any eye symptoms such as redness, itching, pain, or new vision problems.

Mouth care

When you have no feeling and little saliva on one side of your tongue, food particles may get stuck in that part of your mouth, leading to gum disease or tooth decay. Brushing and flossing your teeth frequently and carefully can help prevent these problems.

You can prevent swallowing problems by eating slowly and thoroughly chewing your food. Eating soft, smooth foods, such as yogurt, may also help.

As the nerve in your face begins to function again, doing simple exercises, such as tightening and relaxing your facial muscles, may make those muscles stronger and help you recover more quickly. Massaging your forehead, cheeks, and lips with oil or cream may also help.

Organizations

• Ear Infections
• Lyme Disease
• Shingles
• Stroke

Citations

1. Holland NJ, Weiner GM (2004). Recent developments in Bell's palsy. BMJ, 329: 553–557.

2. Salinas R (2004). Bell's palsy. Clinical Evidence (8): 1774–1777.

3. Allen D, Dunn L (2005). Acyclovir or valacyclovir for Bell's palsy (idiopathic facial paralysis). Cochrane Database of Systematic Reviews (1). Oxford: Update Software.

4. Salinas RA, et al. (2005). Corticosteroids for Bell's palsy (idiopatic facial paralysis). Cochrane Database of Systematic Reviews (1). Oxford: Update Software.

5. Solomon D (2003). Bell's palsy and other VII lesions. In RW Evans, ed., Saunders Manual of Neurologic Practice, chap. 6, pp. 348–352. Philadelphia: Saunders.

Other Works Consulted

• Gooch CL, et al. (2005). Cranial and peripheral nerve lesions. In LP Rowland, ed., Merritt's Neurology, 11th ed., pp. 523–543. Philadelphia: Lippincott Williams and Wilkins.

• Victor M, Ropper AH (2001). Diseases of the cranial nerves. In Adams and Victor's Principles of Neurology, 7th ed., pp. 1446–1463. New York: McGraw Hill.

Author:	Merrill Hayden	Last Updated August 9, 2005
Medical Review:	Patrice Burgess, MD - Family Medicine Barrie J. Hurwitz, MD - Neurology
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