1. Institute of Neurosurgery, Fondazione Policlinico Universitario A. Gemelli IRCCS, Catholic University, Rome, Italy
2. Department of Neurosurgery, Mater Olbia Hospital, Olbia, Italy
3. Neurosurgery Unit, Department of Neuroscience, Santa Maria della Misericordia, University Hospital, Italy, Udine
4. Division of Neurosurgery, Department of Neurosciences, Policlinico "G.Rodolico" University Hospital, Catania, Italy
5. Department of Neuro-Pathology, Fondazione Policlinico Universitario Agostino Gemelli IRCSS, Catholic University of Rome, Rome, Italy
6. Institute of Orthopedics, Fondazione Policlinico Universitario Agostino Gemelli IRCSS, Catholic University of Rome, Rome, Italy
7. Unit of Orthopedics, Mater Olbia Hospital, Olbia, Italy
8. Unit of Neurosurgery, Fondazione Policlinico San Matteo Pavia IRCCS, Pavia, Italy