Practice Parameter: Bell’s Palsy

Abstract & Commentary

Source: Grogan PM, Gronseth GS. Neurology. 2001;56: 830-836.

Various treatment options exist for Bell’s palsy, some undeniably useful, some unequivocally pointless. Artificial tears, lubricating ophthalmic ointment, and eyelid taping prevent corneal drying. Massage and facial nerve electrical stimulation provide psychological support, but little else. Within this spectrum, wither steroids, acyclovir, and facial nerve surgical decompression?

A special article by the Quality Standards Subcommittee of the American Academy of Neurology addresses this question. A MEDLINE search of the National Library of Medicine’s database from 1966 to June 2000, and review of the references of these articles to identify other relevant reports on Bell’s palsy, uncovered 230 articles examining steroids (only 9 were prospective), 92 addressing acyclovir (3 prospective), and 104 discussing surgical decompression (4 prospective). None were adequately powered class I studies, defined as a randomized, controlled trial with 1) clearly defined primary outcomes and exclusion and inclusion criteria; 2) equivalent baseline characteristics among treatment arms; and 3) satisfactory accounting of dropouts and crossovers. Results of class I and II (3 of 4 above criteria) were pooled where possible.

No definite benefit could be established for steroids, acyclovir, or surgical decompression. Probable benefit from steroids, with acyclovir possibly effective when combined with prednisone, was suggested by the available evidence. No recommendation could be made regarding surgical decompression. Bell’s palsy remains a disease in search of a proven effective therapy.

Comment by Michael Rubin, MD

Herpes simplex virus (HSV) type 1 is reportedly the major cause of Bell’s palsy,1 but HSV type 6 may also be a common culprit. Using polymerase chain reaction (PCR), type 6 HSV DNA was detected in the tear fluid of 35% of patients (7 of 20) with Bell’s palsy.2 Varicella zoster virus (VZV) reactivation (Ramsay Hunt syndrome), which may appear without skin lesions and mimic Bell’s palsy, was found in 10% (2 of 20). VZV is more resistant to acyclovir, and may be responsible for some treatment failures. If suspected, higher doses of acyclovir are recommended.

Transmastoid decompression may benefit severe Bell’s palsy. Among 101 adults with significant denervation following prednisone therapy for Bell’s palsy, defined as > 95% amplitude drop in compound muscle action potential on facial motor nerve stimulation, 58 underwent decompression and 43 were followed conservatively. Two months following surgery, the operated group demonstrated a significantly better House-Brackmann grade than the nonsurgical group.3 Further studies are warranted, however, before recommendation of this procedure is justified.

References

1. Morrow MJ. Curr Treat Options Neurol. 2000;2: 407-416.

2. Pitkaranta A, et al. J Clin Microbiol. 2000;38: 2753-2755.

3. Yanagihara N, et al. Otolaryngol Head Neck Surg. 2001;124:282-286.

Dr. Rubin is Associate Professor of Clinical Neurology, New York Presbyterian Hospital-Cornell Campus, New York, NY.