1. Department of Biomedicine Neurosciences and Advanced Diagnostic, University of Palermo, School of Medicine, Palermo, Sicily, Italy,
2. Department of Neurosurgery, ARNAS Garibaldi, P.O. Garibaldi Nesima, Via Palermo, 636, Catania, Italy,
3. Division of Neurosurgery, Villa Sofia Hospital, Palermo, Sicily, Italy.