[1] Aristotle Univ Thessaloniki, Sch Psychol, Lab Cognit Neurosci, Thessaloniki 54124, Greece
[2] Aristotle Univ Thessaloniki, AHEPA Univ Hosp, Multiple Sclerosis Ctr, Dept Neurol 2, Thessaloniki 54621, Greece
[3] Univ Cyprus, Med Sch, CY-1678 Nicosia, Cyprus
[4] Univ Hosp, Dept Neurol, Inselspital, CH-3010 Bern, Switzerland
[5] Univ Hosp Patras, Dept Neurol & Psychiat, Neuropsychol Sect, Patras 26504, Greece
[6] Univ Patras, Med Sch, Patras 26504, Greece
[7] Univ Ioannina, Sch Hlth Sci, Dept Speech & Language Therapy, Ioannina 45100, Greece
[8] Univ Thessaly, Univ Hosp Larissa, Dept Neurol, Larisa 41334, Greece