Module 8.5 - Bell's Palsy

Question 1

What is and what causes Bell’s Palsy?

Answer 1

Sudden onset of temporary unilateral facial paralysis or weakness caused by inflammation of the 7th cranial nerve, usually following a viral infection.

Question 2

What are the predisposing factors of Bell’s Palsy?

Answer 2

A. Idiopathic

B. Involves CN VII near the stylomastoid foramen

C. Affects individuals across the lifespan without gender preference

D. Affects 25 in 100,000 persons in the U.S. annually

E. Clinical appearance correlates with viral infection, stress or fatigue

F. Familial tendency

G. Increased incidence in the following:

HTN, DM, Viral infection (herpes simplex, zoster, Epstein-Barr virus, adenovirus, influenza B and cytomegalovirus)

H. May be related to cold exposure

I. Symptoms vary from person to person

J. Lyme disease (increased incidence of reoccurrence)

Question 3

What are the subjective/physical exam findings associated with bell’s palsy?

Answer 3

A. Unilateral facial paralysis

• 1. Affects the eyebrows, eyelid and/or mouth
• 2. Mimics stroke, but only facial muscle involvement is noted on exam
• 3. Corneal reflex (blink test) is abnormal in 100% of cases

B. Drooping eyelid and corner of mouth

C. Drooling- a result of mouth paralysis

D. Impairment of taste

E. Excessive tearing in one eye or dryness in one eye due to inability to close eyelid.

F. Pain or discomfort around the jaw and behind the ear

G. Ringing in one or both ears

H. Headache

I. Hypersensitivity to sound on the affected side

J. Impaired speech

K. Dizziness

Question 4

What laboratory/diagnostic tests are used to diagnose bell’s palsy?

Answer 4

A. Nonspecific, diagnosis is one of exclusion

B. A lumbar puncture is typically not indicated

C. Consider test to confirm or exclude other diagnosis, such as:

• 1. CT, MRI (r/o tumor)
• 2. Lyme titer (if history of tick exposure)
• 3. Audiogram to rule out cranial nerve VIII involvement (not associated with Bell’s Palsy)

Question 5

How do you manage Bell’s Palsey?

Answer 5

A. Eye care - including keeping the eye moist (artificial tears), and protecting the eye from debris or injury (eye patches)

B. Consider referral to physical therapy - for exercise and stimulation to reduce risk of contractures of the paralyzed muscles.

C. Steroids - indicated to decrease inflammation around cranial nerve VII

1. In the early stages of illness (before day 10 of onset).
2. Tapers regimen of methylprednisolone (medrol dosepak).
3. Antiviral drugs, such as acyclovir or valacyclovir – may stop the progression of the infection if a virus is the cause.

D. Patient education - explain to the patient that the disorder is usually self-limiting and that most cases begin to resolve in 4-6 weeks with complete resolution within 6 months.

Question 6

What are 3 complications of Bell’s Palsy?

Answer 6

A. Post paralytic facial spasms – usually occurs as tonic contraction of one side of the face

B. Co-contracting muscles – synkinesis (involuntary muscle movements accompanying voluntary movement); example: voluntary smiling induces involuntary contraction of the eye muscles causing the eye to squint when smiling. This is secondary to incomplete or aberrant regeneration of damaged nerve fibers.

C. Corneal exposure – can lead to corneal thinning and perforation especially in the setting diminished corneal sensation, and corneal ulceration.