[1] Univ Turin, Dept Psychol, Turin, Italy
[2] Citta Salute & Sci Torino Hosp, CPO Piemonte, Unit Clin Epidemiol, Turin, Italy
[3] Fdn IRCCS Ist Neurol Carlo Besta, Unit Neuroepidemiol, Milan, Italy
[4] Italian Multiple Sclerosis Fdn FISM, Sci Res Area, Genoa, Italy
[5] Fdn FARO, Turin, Italy
[6] Fdn IRCCS Ist Neurol Carlo Besta, Dept Neuroimmunol & Neuromuscular Dis, Multiple Sclerosis Ctr, Milan, Italy
[7] Fdn IRCCS S Lucia, Multiple Sclerosis Unit, Rome, Italy
[8] Univ Catania, Dept Med & Surg Sci & Adv Technol, GF Ingrassia, Catania, Italy
[9] Univ Catania, Multiple Sclerosis Ctr, Catania, Italy