McMaster University

McMaster University

Faculty of
Health Sciences

Combination treatment provides additional benefit for Bell Palsy

Published: September 3, 2009
Gordon Guyatt
Dr. Gordon Guyatt, a professor of medicine and clinical epidemiology and biostatistics

Nearly one in six people diagnosed with a facial paralysis of unknown cause called Bell Palsy, will experience persistent weakness, permanent facial contractions or involuntary movement of the facial muscles.

Treatment of the condition with corticosteroids is associated with better recovery, and the combination of corticosteroids and antiviral agents may give additional benefit, according to a systematic review and meta-analysis of previously published studies by researchers from McMaster University and other Canadian institutions.

The study, to be published in the September 2 issue of the Journal of the American Medical Association (JAMA), involved several McMaster researchers, including corresponding author Dr. Gordon Guyatt, a professor of medicine and clinical epidemiology and biostatistics.

"High-quality evidence suggests that corticosteroids alone reduce the risk of unsatisfactory recovery by nine per cent," said Guyatt, a member of CLARITY (Clinical Advances through Research and Information Translation) at McMaster. "Corticosteroid therapy combined with antiviral agents reduced the risk of unsatisfactory recovery compared with antiviral agents alone."

The research team conducted a search of the medical literature for randomized controlled trials comparing treatment with either corticosteroids or antiviral agents with a control measuring unsatisfactory facial recovery (four months or more), unsatisfactory short-term recovery (six weeks to less than four months), synkinesis (involuntary movement of facial muscles) and autonomic dysfunction, or adverse effects. Unsatisfactory recovery was defined as failing to achieve complete or near-normal recovery.

The authors identified 854 studies, of which 18 were eligible for inclusion for evaluation. The 18 studies included 2,786 patients and were conducted in 12 countries and five continents.

The authors found a possible incremental benefit of antiviral agents in addition to corticosteroids, with an absolute risk reduction of five per cent compared with corticosteroids alone. The effect, however, was not definitive and did not quite reach statistical significance.

The authors concluded that further primary studies are needed to definitively establish – or refute — an incremental benefit of combined therapy compared with corticosteroid therapy alone.

Bell Palsy is an acute weakness or paralysis of the facial nerve and has an annual incidence of 20 to 30 per 100,000 of the population. A herpes infection likely causes the disorder. DNA samples from patients have yielded herpes simplex virus type 1 (HSV-1). Varicella zoster virus (VZV) reactivation is also associated with Bell Palsy.

While 71 per cent of untreated Bell Palsy patients recover completely and 84 percent will have complete or near normal recovery, the remainder will have persistent moderate to severe weakness, facial contracture or involuntary movement.

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