1. Department of Neurosurgery, Bellaria Hospital, Azienda Unita Santiaria Locale Città di Bologna, Bologna, Italy
2. Ear, Nose, and Throat Department, Azienda Unita Santiaria Locale Sant'Orsola-Malpighi, University of Bologna, Bologna, Italy
3. Ear, Nose, and Throat Department, Azienda Unita Santiaria Locale Città di Bologna, Budrio, Italy