[1] St Vincents Univ Hosp, Dublin 4, Ireland
[2] McGill Univ, Montreal Neurol Inst & Hosp, Montreal, PQ, Canada
[3] Cleveland Clin, Mellen Ctr Multiple Sclerosis Treatment & Res, Cleveland, OH 44106 USA
[4] Ruhr Univ Bochum, St Josef Hosp, Bochum, Germany
[5] Queen Mary Univ London, Blizard Inst, Barts & London Sch Med & Dent, London, England
[6] Virginia Mason Med Ctr, Seattle, WA 98101 USA
[7] Biogen Idec Inc, Weston, MA USA