1. Department of Neuroscience/Neurosurgery, University of Turin, Novara, Italy
2. Department of Neurosurgery, Hospital Santa Corona Pietra Ligure, Pietra Ligure, Italy
3. Department of Neurosurgery, University of Turin, Turin, Italy
4. Department of Neurosurgery, AOU Maggiore della Carità, Novara, Italy
5. Department of Neuroscience/Neurosurgery, University of Turin, Torino, Piemonte, Italy