[1] Univ Penn, Sch Med, Dept Neurol, Philadelphia, PA 19104 USA
[2] Univ Penn, Sch Med, Dept Ophthalmol, Philadelphia, PA 19104 USA
[3] Johns Hopkins Univ, Sch Med, Dept Neurol, Baltimore, MD 21205 USA
[4] Hop Neurol, Lyon, France
[5] Inst Neurol, London WC1N 3BG, England
[6] Gen Teaching Hosp, Prague, Czech Republic
[7] St Vincents Univ Hosp, Dublin, Ireland
[8] Univ Basel Hosp, Basel, Switzerland
[9] Mt Sinai Sch Med, New York, NY USA
[10] St Michaels Hosp, Toronto, ON M5B 1W8, Canada
[11] Multiple Sclerosis Ctr Texas Neurol, Dallas, TX USA
[12] Vrije Univ Amsterdam, Med Ctr, Amsterdam, Netherlands
[13] Cleveland Clin Fdn, Mellen Ctr Multiple Sclerosis Res, Cleveland, OH 44195 USA
[14] MS Ctr Atlanta, Atlanta, GA USA
[15] Silesian Med Univ, Katowice, Poland
[16] SUNY Buffalo, Baird Multiple Sclerosis Ctr, Buffalo, NY 14260 USA
[17] Biogen Idec Inc, Cambridge, MA USA
[18] Multiple Sclerosis Ctr, Northbrook, IL USA