Etiopathogenesis of Bell's idiopathic peripheral facial palsy

Introduction. Bell's facial palsy is a common condition with an incidence varying between 11.5 and 40.2 cases per 100,000 persons per year. However, some aspects of its etiopathogenesis are still not clear. Development. Over the years four theories have been suggested to explain the disorder: vascular, immuno logical, compressive and viral. The vascular theory (the oldest) has been ruled out by various studies. Subsequently, the immunological and compressive theories were described almost simultaneously. The former established the mechanisms generating a neural inflammatory response, and the second the morphological basis which made the nerve sensitive to these mechanisms. Both theories suggested, amongst other agents, a virus as the agent triggering the process. Recently a virus of the herpes simplex family has been identified as the cause of the disease. Conclusion. At present there is broad general agreement that Bell's facial palsy is caused by reactivation ofa latent infected with human herpes simplex virus, localized to the facial nerve.