Bell's palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or seventh cranial nerve.
Damage to this nerve causes weakness or paralysis of these muscles. Paralysis means that you cannot use the muscles at all.
Causes of Bell's palsy
Bell's palsy affects about 30,000 to 40,000 people a year in the United States.
It involves damage to the seventh cranial (facial) nerve. This nerve controls the movement of the muscles of the face.
Bell's palsy is thought to be due to swelling (inflammation) of this nerve in the area where it travels through the bones of the skull.
The cause is often not clear. A type of herpes infection called herpes zoster might be involved. Other conditions that may cause Bell's palsy include:
Having diabetes and being pregnant may increase the risk of Bell's palsy.
Bell's palsy Symptoms
Sometimes you may have a cold shortly before the symptoms of Bell's palsy begin.
Symptoms most often start suddenly, but may take 2 to 3 days to show up. They do not become more severe after that.
Symptoms are almost always on one side of the face only. They may range from mild to severe.
Many patients feel discomfort behind the ear before weakness is noticed. The face will feel stiff or pulled to one side, and may look different. Other symptoms can include:
- Difficulty closing one eye
- Difficulty eating and drinking; food falls out of one side of the mouth
- Drooling due to lack of control over the muscles of the face
- Drooping of the face, such as the eyelid or corner of the mouth
- Problems smiling, grimacing, or making facial expressions
- Twitching or weakness of the muscles in the face
Other symptoms that may occur:
- Dry eye, which may lead to eye sores or infections
- Dry mouth
- Loss of sense of taste
- Sound that is louder in one ear (hyperacusis)
- Twitching in face
Tests and Exams
Often, Bell's palsy can be diagnosed just by taking a health history and doing a complete physical exam.
Blood tests will be done to look for medical problems such as Lyme disease, which may cause Bell's palsy.
If your health care provider is worried that a brain tumor is causing your symptoms, you may need:
Sometimes, you will need a test to check the nerves that supply the muscles of your face:
Treatment of Bell's palsy
Often, no treatment is needed. Symptoms often begin to improve right away. However, it may take weeks or even months for the muscles to get stronger, and this may be frustrating.
Your health care provider may give you lubricating eye drops or eye ointments to keep the surface of the eye moist if you cannot close it completely. You may need to wear an eye patch while you sleep.
Sometimes medicines may be used, but it is not clear how much they help. If medicines are used, they should be started right away.
- Corticosteroids may reduce swelling around the facial nerve
- Medications can fight the virus that may be causing Bell's palsy
Surgery to relieve pressure on the nerve (decompression surgery) has not been shown to benefit most people with Bell's palsy.
If you have problems closing your eye, you need to protect it from injury. Ask your doctor for tips.
Most cases go away completely within a few weeks to months.
If you did not lose all of your nerve function and symptoms began to improve within 3 weeks, you are more likely to regain all or most of the strength in your facial muscles.
Sometimes, the following symptoms may still be present:
- Long-term changes in taste
- Spasms of muscles or eyelids
- Weakness that remains in facial muscles
The eye surface may become dry, leading to eye sores, infections, and vision loss.
When to Contact a Health Professional
Call your health care provider right away if your face droops or you have other symptoms of Bell's palsy. Your health care provider can rule out other, more serious conditions, such as stroke.
Prevention of Bell's palsy
There is no known way to prevent Bell's palsy.
Baugh RF, Basura GJ, Ishii LE, et al., American Academy of Otolaryngology -- Head and Neck Surgery. Clinical practice guideline: Bell's palsy. Otolaryngology - Head and Neck Surgery. 2013;149:S1-S27.
Gronseth GS, Paduga R. Evidence-based guideline update: Steroids and antivirals for Bell palsy. Neurology. 2012;79:1-5
McAllister K, Walker D, Donnan PT, Swan I. Surgical interventions for the early management of Bell's palsy. Cochrane Database Syst Rev. 2011 Feb 16;(2):CD007468.
|Review Date: 5/20/2014
Reviewed By: Joseph V. Campellone, M.D., Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.