[1] UCL Inst Neurol, London, England
[2] Univ Copenhagen, Danish Multiple Sclerosis Ctr, Rigshosp, Copenhagen, Denmark
[3] Heinrich Heine Univ, Med Fac, Dept Neurol, Dusseldorf, Germany
[4] McGill Univ, Montreal Neurol Inst, Montreal, PQ, Canada
[5] Univ Ottawa, Ottawa Hosp, Res Inst, Ottawa, ON, Canada
[6] Piedmont HealthCare, Mooresville, NC USA
[7] Icahn Sch Med Mt Sinai, New York, NY 10029 USA
[8] MS Ctr Northeastern New York, Latham, NY USA
[9] Biogen, Cambridge, MA USA