1. Unit of Neurosurgery, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy
2. Institute of Neurosurgery, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, Catholic University, 00168 Rome, Italy
3. Unit of Neurosurgery, Mater Olbia Hospital, 07026 Olbia, Italy
4. Unit of Radiology, Mater Olbia Hospital, 07026 Olbia, Italy