Marcello Mario Mascia1, Giovanni Defazio2,3. 1. Department of Medical Sciences and Public Health, Institute of Neurology, University Hospital D. Casula, Monserrato, Cagliari, Italy. marcello.mas@tiscali.it. 2. Department of Medical Sciences and Public Health, Institute of Neurology, University Hospital D. Casula, Monserrato, Cagliari, Italy. 3. Department of Medical Sciences and Public Health, Institute of Neurology, University of Cagliari, Cagliari, Italy.