Bell's palsy and herpes viruses: to (acyclo)vir or not to (acyclo)vir?

The majority of peripheral seventh cranial nerve palsy cases remain without an identified etiology and will eventually be diagnosed as idiopathic or B ell's palsy. Some features of this condition may be characteristic of a vir al infection. Indeed, several herpes viruses have been implicated as potent ial causative pathogens. Besides varicella-zoster virus, shown to cause Bel l's palsy under the Ramsay-Hunt syndrome, recent years have seen an increas ed interest and focus on the possible herpes simplex virus type 1 (HSV-1) e tiology in idiopathic facial paralysis. We review the clinical, biological and virological basis for the potential herpetic cause of Bell's palsy and the rational for antiviral therapy in this condition. (C) 1999 Elsevier Sci ence B.V. All rights reserved.