1. Department of Clinical and Experimental Medicine, Otolaryngology Unit, University-Hospital of Parma, Parma, Italy
2. Gruppo Otologico Piacenza, Rome, Italy
3. University of Chieti, Chieti, Italy
4. Department of Neurosurgery, Military Hospital of Tunis, University of Tunis El Manar, Tunis, Tunisia
5. Department of Otolaryngology, Hôpital Universitaire Nord, Marseille, France