Facial nerve disorders and diseases [electronic resource] : diagnosis and management / [edited by] Orlando Guntinas-Lichius, MD, Professor and Chairman, Department of Otorhinolaryngology and Facial Nerve Center, Jena University Hospital, Jena, Germany, Barry M. Schaitkin, MD, Professor, Facial Nerve Center, Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA