1. Unit of Neurology , G.B. Morgagni – L. Pierantoni Hospital , Via Carlo Forlanini 34 , 47121 Forlì , Italy
2. Department of Surgery and Medical-Surgical Specialties , University of Catania , Via Santa Sofia 78 , 95123 Catania , Italy
3. Department of Neurology IC , Oasi Research Institute-IRCCS , Via Conte Ruggero 73 , 94018 Troina , Italy