[1] Univ Nijmegen, Dept Clin Neurophysiol, Med Ctr, Nijmegen, Netherlands
[2] Univ Nijmegen, Neuromuscular Ctr Nijmegen, Med Ctr, Neurol Inst, Nijmegen, Netherlands
[3] Canisius Wilhelmina Hosp, Dept Neurol, Nijmegen, Netherlands
[4] Univ Rotterdam, Med Ctr, Dept Immunol, Erasmus MC, Rotterdam, Netherlands