[1] Karolinska Inst, Dept Clin Neurosci, R54, S-14186 Huddinge, Sweden
[2] Karolinska Univ Hosp, Dept Neurol, Stockholm, Sweden
[3] Univ Helsinki, Res Programs Unit, Mol Neurol, Helsinki, Finland
[4] Univ Oulu, Res Unit Clin Neurosci, Neurol, Oulu, Finland
[5] Tampere Univ Hosp, Dept Neurol, Tampere, Finland
[6] Univ Tampere, Fac Med & Life Sci, Tampere, Finland
[7] Univ Hosp North Norway, Dept Neurol, Tromso, Norway
[8] Sorlandet Hosp, Dept Neurol, Kristiansand, Norway
[9] Oslo Univ Hosp, Dept Neurol, Oslo, Norway
[10] Univ Oslo, Fac Med, Oslo, Norway
[11] Aarhus Univ Hosp, Dept Neurol, Aarhus, Denmark