Bell Palsy Overview and Clinical Manifestations

Study Notes

Bell Palsy Overview

Acute-onset peripheral facial nerve palsy with no associated cranial nerve neuropathies or brainstem dysfunction.
Incidence rates: approximately 3 in 100,000 (children), increasing to 10 in 100,000 (teens), and 25 in 100,000 (adults).
Only 1% of cases exhibit bilateral involvement clinically, though many show abnormal electrophysiological findings on the unaffected side.
Commonly appears about 2 weeks post-viral infection.
Reactivation of herpes simplex or varicella-zoster virus is a likely cause.

Clinical Manifestations

Pain behind the ear may precede sudden weakness.
Facial weakness affects both upper and lower portions; drooping of the mouth is noted.
Inability to close the eye on the affected side increases the risk of exposure keratitis.
Approximately 50% of patients may lose taste sensation on the anterior two-thirds of the tongue on the affected side.
Lacrimation usually remains intact; facial numbness and paresthesias are uncommon but may indicate trigeminal nerve involvement.

Investigations

Typical cases of Bell palsy do not require imaging.
MRI may be necessary for children under 2 years or when atypical signs or chronic/recurrent weakness are present to exclude structural lesions.
Viral studies and serology often yield noncontributory results.
A complete blood count should be performed to rule out leukemia in younger patients or those with atypical manifestations.
Lyme antibody testing is recommended for children in endemic areas.
Neurophysiologic examination is crucial for patients not recovering in a few weeks to assess nerve damage and expected recovery timeline.
Chronic facial nerve conditions should be evaluated for other underlying causes like hypertension, diabetes, tumors, or acute traumatic injuries.

Treatment

Pediatric Bell palsy typically resolves well without treatment; corticosteroids' efficacy has not been established.
Oral prednisone is recommended (1 mg/kg/day for 5-7 days) starting within the first three days after symptom onset for pediatric cases.
Adult treatment often combines oral steroids with antivirals like valacyclovir or famciclovir.
Corneal protection with methylcellulose eye drops or lubricants is especially crucial during nighttime.

Prognosis

Most children achieve complete spontaneous recovery within weeks.
Certain factors may complicate recovery but are generally rare.

Description

This quiz covers the essential aspects of Bell Palsy, including its incidence rates, clinical symptoms, and underlying causes. Learn about the typical manifestations and complications associated with this condition, as well as the potential role of viral infections in its onset.