Bell's palsy

Bell’s palsy is the most common diagnosis given to patients with acute facial palsy. Despite substantial effort to study its disease process, the management of Bell’s palsy remains controversial.

Although Bell’s palsy is a diagnosis of exclusion, it is the most common diagnosis given for acute facial palsy (> 60%). It causes peripheral facial neuropathy that tends to be unilateral and has a rapid onset. Its incidence is about 30 per 100,000. There is an equal male to female ration and a 3.3 times greater incidence in pregnant females. The left and right sides of the face are equally involved, and less than 1% of cases are bilateral. The recurrence rate is about 10% and can be ipsilateral or bilateral. Patients with diabetes have 4 - 5 times more risk of developing the disease. A family history is positive in about 10% of patients with Bell's palsy.

In 1982, Peitersen et al. published an article on the natural history of Bell’s palsy based on more than a thousand Danish patients. He found that Bell’s palsy occurred in every decade of life, with a mean age of between 40 and 44 years. It was less common before the age of 15 and after the age of 60 years. The prognosis for Bell's palsy is generally good with 85 % of patients recovering completely within one month. The remaining 15% progress to complete degeneration and will not usually show signs of recovery for three to six months. The longer the time needed for recovery, the greater the probability of sequelae. Patients with incomplete paralysis will recover with no sequelae 95% of the time. Based on this study, poor outcome of Bell’s palsy is associated with advanced age, late return of muscular function or beginning of remission, complete palsy, abnormal taste, stapedial reflex, and lacrimation.

Treatment options of Bell’s palsy range from observation, medical treatment, surgical decompression, to facial rehabilitation. The efficacies of oral prednisone and anti-viral agents have been studied extensively, yet there is no consensus among experts on ideal regimen and dosage.

Eye care is of utmost importance in facial nerve paralysis due to the risk of exposure keratitis. Artificial tears and lacrilube ointment should be prescribed. Taping of the eye lids during sleep may be helpful as well as the use of a moisture chamber. Patients should avoid contact lens, fans and dust, and should have eye protection when outside in the wind. Gold weight implant to the upper eyelid should be considered in patients with long-standing facial paralysis.

Source:
Dr. Kevin Ho UTMB Grand Round presentation: "Bell's palsy - to treat or not to treat". Feb 2007