1. Division of Neurotology, Department of Otorhinolaryngology, Complexo Hospitalario Universitario, Santiago de Compostela, Spain
2. Department of Dermatology and Otorhinolaryngology, University of Santiago de Compostela, Spain
3. Department of Otorhinolaryngology, University Hospital Lucus Augusti, Lugo, Spain
4. Department of Otorhinolaryngology, Complexo Hospitalario Universitario, Santiago de Compostela, Spain
5. Clinical Epidemiology Unit, Complexo Hospitalario Universitario, Instituto de Investigación Sanitaria de Santiago (IDIS), Santiago de Compostela, Spain