[1] Univ Groningen, Univ Med Ctr Groningen, Dept Neurol, NL-9700 RB Groningen, Netherlands
[2] Univ Amsterdam, Acad Med Ctr, Dept Neurol, NL-1105 AZ Amsterdam, Netherlands
[3] Haga Ziekenhuis Teaching Hosp, Dept Neurol, NL-2545 CH The Hague, Netherlands
[4] Univ Amsterdam, Dept Paediat, Acad Med Ctr, NL-1105 AZ Amsterdam, Netherlands
[5] Radboud Univ Nijmegen, Dept Neurol, Med Ctr, NL-6525 GA Nijmegen, Netherlands
[6] Univ Groningen, Univ Med Ctr Groningen, Dept Genet, NL-9700 RB Groningen, Netherlands