Bell's Palsy
Incidence
- 20 to 30 cases per 100,000 people per
year
- 60 to 75 per- cent of all cases of unilateral
facial paralysis
- sexes are affected equally
- median age at
onset is 40 years, but the disease may occur at any age
Outcomes
- Takes 3 days for maximal symptoms
- Up to 30% may have some residual symptoms at 6 months
- 7-12% of patients have a recurrence
Other causes of acquired peripheral facial weakness (much less
common)
- diabetes mellitus
- hypertension
- HIV
- Lyme disease
- Ramsay
Hunt syndrome
(facial palsy with zoster oticus caused by varicella–zoster virus - may
be more severe with a higher likelihood of permanent sequelae and
multiple cranial nerve involvement)
- sarcoidosis
- Sjögren’s syndrome
- parotid-nerve tumors
- eclampsia
- amyloidosis
Other patterns of facial palsy
- Recurrent facial palsy
- Ipsilateral - concern for schwannoma of facial nerve or nearby neoplasm compressing (parotid gland, temporal bone)
- Alternating - usually benign and may occur in up to 14% of patients with Bell's Palsy
- Bilateral facial palsy
- Neurological (Guillain-Barre), neoplasm (lymphoma)
- Infectious (Lyme), autoimmune and granulomataous diseases (Sarcoid)
Forehead sparing
- A peripheral lesion should have upper and lower facial weakness
- A central lesion should have only lower facial weakness
- May be accompanied by numbness - etiology unclear as Facial nerve (7th nerve) is motor
Treatment
- Artificial tears to lubricate the cornea and may need
to have the eye taped shut to prevent drying and infection
- Valacyclovir (1 g twice daily for
seven days) or famciclovir (750 mg three times daily) or acyclovir (800 mg five times daily) and oral
prednisone (1 mg per kilogram per day for seven days)
-
80 to 100 percent regain excellent function