1. Department of Neurosurgery, Cannizzaro Hospital, Catania, Italy
2. Department of Neurosurgery, Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi, Catania, Sicilia, Italy
3. Department of Neurosurgery, Paracelsus Medical Private University, Salzburg, Austria
4. Department of Neurosurgery, Azienda Ospedaliera Cannizzaro, Catania, Sicilia, Italy
5. Department of Neurosurgery, National Specialist Hospital Garibaldi, Catania, Sicilia, Italy