1. Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy;
2. Otolaryngology-Head and Neck Surgery Department, University Hospital of Verona, Italy;
3. Neurosurgery Department, New Civil Hospital SantAgostino-Estense, Baggiovara (MO), Italy;
4. Otolaryngology-Head and Neck Surgery Department, Inselspital, University Hospital and University of Bern, Switzerland