1. Unit of Neurology, G.B. Morgagni-L. Pierantoni Hospital, 34 Via Carlo Forlanini, I-47121 Forlì, Italy, e-mail: albertoraggi@libero.it
2. Unit of Psychology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), I-94018 Troina, Italy
3. Unit of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), I-94018 Troina, Italy