OBJECTIVES:

To determine whether reactivation of herpes simplex virus (HSV) type 1 or varicella-zoster virus (VZV) is the main cause of Bell's palsy and whether antiviral drugs bring about recovery from Bell's palsy.

STUDY DESIGN:

Randomized, multicenter, controlled study.

METHODS:

One hundred fifty patients with Bell's palsy were enrolled in this study. The patients were randomly assigned to a prednisolone group or a prednisolone-valacyclovir group, in whom virologic examinations for HSV-1 and VZV were performed by simple randomization scheme in sealed envelopes. The recovery rates among various groups were analyzed using the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS:

Reactivation of HSV-1, VZV, and both viruses was detected in 15.3%, 14.7%, and 4.0% of patients, respectively. There was no significant difference in recovery rates between the prednisolone group and the prednisolone-valacyclovir group, although recovery in the patients with HSV-1 reactivation tended to be higher in the prednisolone-valacyclovir group than in the prednisolone group. There was a significant difference in recovery among age groups and between individuals with complete and incomplete paralysis.

CONCLUSIONS:

Reactivation of HSV-1 or VZV was observed in 34% of the patients with Bell's palsy. The effect of combination therapy with prednisolone and valacyclovir on recovery was not significantly higher than that with prednisolone alone.