[1] Kings Coll Hosp London, Dept Neurol, London, England
[2] Aarhus Univ, Aarhus, Denmark
[3] Univ Toronto, Univ Hlth Network, Ellen & Martin Prosserman Ctr Neuromuscular Dis, Toronto, ON, Canada
[4] Univ Belgrade, Univ Clin Ctr Serbia, Neurol Clin, Fac Med, Belgrade, Serbia
[5] Med Univ Lublin, Dept Neurol, Lublin, Poland
[6] Univ Clin Ctr Nis, Neurol Clin, Nish, Serbia
[7] Takeda Dev Ctr Amer Inc, Cambridge, MA USA