Bell’s palsy occurs when a facial nerve becomes swollen or inflamed, causing paralysis or weakness on one side of the face. The onset of the paralysis is sudden, and the exact cause of the inflammation may be difficult to identify. Bell’s palsy is often linked to upper respiratory infections, viral infections such as those caused by infectious mononucleosis, herpes, mumps, HIV viruses, and bacterial infections such as Lyme disease. Facial weakness from Bell’s palsy can be associated with a more generalized peripheral neuropathy as well. People with diabetes are at a four times greater risk of developing Bell’s palsy. Women also have an increased risk of Bell’s palsy during the third trimester of pregnancy.
Bell’s palsy is named for Sir Charles Bell, a Scottish surgeon, who, in 1821, demonstrated that the facial nerve is a separate nerve. The facial nerve controls the muscles that move the eyebrows, eyes, and mouth. This same nerve controls the tear glands, the salivary glands, and the taste buds located toward the front of the tongue.
Although Bell’s palsy is emotionally distressing and physically uncomfortable, it usually is not dangerous. Most people completely recover.
Symptoms & Signs
(Not all symptoms and signs may be present.)
- Changes in the ability to taste food
- Distorted facial expression due to weakness or paralysis
- Drooping of the eyelid and corner of the mouth
- Dry eyes or excessive tearing in one eye
- Pain on the affected side of face behind ear
- Sensitivity to sound
- Sudden weakness or paralysis on one side of the face
- Tingling on the weak side of the face
Treatment & Therapy
(Not all treatments and therapies may be indicated.)
- Eye drops for affected eye
- Medications such as steroids to reduce inflammation of nerve and decrease pain
- Surgery (in rare cases to improve appearance)
- Treatment of underlying viral infection