[1] Leiden Univ, Inst Psychol Hlth Med & Neuropsychol Unit, POB 9555, NL-2300 RB Leiden, Netherlands
[2] Univ Humanist Studies, Utrecht, Netherlands
[3] Natl Multiple Sclerosis Fdn, Rotterdam, Netherlands
[4] Elisabeth TweeSteden Hosp, Dept Neurol, Tilburg, Netherlands
[5] MS4 Res Inst, Nijmegen, Netherlands
[6] Univ Groningen, Univ Med Ctr Groningen, Dept Community & Occupat Med, Groningen, Netherlands
[7] Univ Groningen, Univ Med Ctr Groningen, Ctr Rehabil, Haren, Netherlands
[8] Tilburg Univ, Tranzo Sci Ctr Care & Welf, Dept Social & Behav Sci, Tilburg, Netherlands
[9] North West Univ South Africa, Optentia, Vanderbijlspark, South Africa
[10] Med Ctr Leeuwarden, Dept Neurol, Leeuwarden, Netherlands
[11] Jeroen Bosch Hosp, Dept Neurol, sHertogenbosch, Netherlands
[12] St Antonius Hosp, Dept Neurol, Nieuwegein, Netherlands
[13] Groene Hart Hosp, Dept Neurol, Gouda, Netherlands
[14] Upendo MS Clin, Boxtel, Netherlands
[15] Alrijne Hosp Leiden, Dept Neurol, Leiden, Netherlands
[16] Zuyderland Med Ctr, Dept Neurol, Sittard Geleen, Netherlands
[17] Canisius Wilhelmina Hosp, Dept Neurol, Nijmegen, Netherlands
[18] Radboud Univ Nijmegen, Donders Inst Brain Cognit & Behav, Dept Human Genet, Med Ctr, Nijmegen, Netherlands
[19] Leiden Univ, Dept Neurol, Med Ctr, Leiden, Netherlands