[1] Univ Bergen, Dept Clin Med, Bergen, Norway
[2] Haukeland Hosp, Dept Neurol, Bergen, Norway
[3] Hellenic Pasteur Inst, Dept Neurobiol, Athens, Greece
[4] Tzartos NeuroDiagnost, Athens, Greece
[5] IRCCS, Fdn Policlin A Gemelli, Ist Neurol, Rome, Italy
[6] Univ Cattolica Sacro Cuore, Rome, Italy
[7] Univ Oxford, Hosp Trust, Nuffield Dept Clin Neurosci, Oxford, England
[8] Univ Virginia, Dept Neurol, Charlottesville, VA USA
[9] Leiden Univ, Dept Neurol, Med Ctr, Leiden, Netherlands