IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli, IS, Italy. Department of Biomedical Sciences, University of Sassari, Sassari, Italy. IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli, IS, Italy; Department of Human Neurosciences, Sapienza, University of Rome, Viale Dell' Università 30, 00185 Rome, Italy. Movement Disorders Center, Department of Neurology, University of Cagliari, SS 554 km 4.500, 09042 Cagliari, Italy. Department of Biomedical Sciences, University of Sassari, Viale S. Pietro, 43c, 07100 Sassari, Italy; Unit of Endocrinology, Nutritional and Metabolic Disorders, AOU Sassari, 07100 Sassari, Italy. IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli, IS, Italy; Department of Human Neurosciences, Sapienza, University of Rome, Viale Dell' Università 30, 00185 Rome, Italy. Electronic address: alfredo.berardelli@uniroma1.it.