Bell’s Palsy

– Unilateral facial paralysis with sudden loss of the ability to use the muscles that control expression on one side of the face.

Causes and Incidence

The cause is unknown but is thought to be related to a virus or immune disorder. Most individuals are 20 to 60 years of age, and men and women are affected equally.

Disease Process

Cranial nerve VII (facial nerve) is compressed at the temporal bone pathway by edema produced by an unknown cause. As a result, the muscles controlling expression on one side of the face are paralyzed.

Symptoms

Facial weakness, numbness and heaviness, pain behind the ear, followed by inability to work facial muscles on one side. The extent of the symptoms depends on the severity of compression; symptoms can include inability to wrinkle the forehead, upward rolling of the eyeball, inability to close the eyelid, and unilateral lack of smile or frown expression. Taste, lacrimation, and salivation may also be affected.

Potential Complications

Facial contractures, corneal ulceration, and synkinesia are possible complications. Paralysis may be transient or permanent. Any return of function usually occurs in 1 to 6 months.

Diagnostic Tests

Diagnosis is based on clinical examination and history of onset.

Treatments

Surgery
Hypoglossal: facial nerve anastomosis to restore partial facial function if none has returned by 6-12 months.

Drugs
Methylcellulose drops for affected eye; analgesics as required for pain.

General
Patching of affected eye; stimulation of faradic nerve and physical therapy to prevent facial contracture.