[1] Univ Groningen, Dept Neurol, Univ Med Ctr Groningen, NL-9700 RB Groningen, Netherlands
[2] Tergooi Hosp, Dept Neurol, NL-1201 DA Hilversum, Netherlands
[3] Erasmus MC, Dept Neurol, NL-3000 CA Rotterdam, Netherlands
[4] Erasmus MC, Dept Paediat Neurol, NL-3000 CB Rotterdam, Netherlands
[5] Canisius Wilhelmina Hosp, Dept Neurol, NL-6500 GS Nijmegen, Netherlands
[6] Juliana Childrens Hosp, Dept Neurol, NL-2506 LP The Hague, Netherlands
[7] Westeinde Ziekenhuis, Dept Neurol, NL-2501 CK The Hague, Netherlands
[8] Med Ctr Rijnmond S, Dept Neurol, NL-3007 AC Rotterdam, Netherlands
[9] Univ Med Ctr Utrecht, Dept Paediat Neurol, Utrecht, Netherlands