Do either corticosteroids or antiviral agents reduce the risk of long-term facial paresis in patients with new-onset Bell's palsy?

Background: The cause of Bell's palsy remains uncertain, although accumulating evidence suggests a viral etiology. To date, treatment to minimize long-term deficits from this disorder typically includes anti-inflammatory or antiviral medication.

Clinical Question: Do corticosteroids or antiviral agents, either alone or in combination, reduce the risk of long-term facial paresis in patients with new-onset Bell's palsy?

Evidence Review: Three multicenter, randomized, controlled trials enrolled over 1,500 adult patients with paroxysmal, unilateral paresis of cranial nerve VII and treated them with varying regimens and combinations of prednisolone, antiviral agents, and placebo, and evaluated complete recovery up to 12 months later.

Results: The two larger, most recent trials incorporated similar factorial designs to allow for comparisons between steroids, antivirals, both combined, and placebo, and assessed recovery using validated measures of facial nerve function. In the larger, blinded trial, the numbers needed to treat to achieve complete recovery for patients in the prednisolone and acyclovir groups at 9 months were 7.8 (95% confidence interval [CI] 5.9-13.7) and 18.7 (95% CI 9.5-infinity), respectively. The number needed to treat to achieve complete recovery for patients in the valacyclovir plus prednisolone group vs. the prednisolone alone group in the second trial was 14.8 (95% CI 9.1-744.8).

Conclusions: Current evidence suggests that prednisolone, an inexpensive and readily available medication, is effective for this common condition, but there was no statistically significant difference observed with acyclovir. Valacyclovir provides minimal added benefit to prednisolone alone.