[1] NINDS, Neuroimmunol Branch, NIH, Bethesda, MD 20892 USA
[2] Yale Univ, Sch Med, Dept Epidemiol & Publ Hlth & Immunobiol, New Haven, CT 06520 USA
[3] Natl Multiple Sclerosis Soc, New York, NY 10017 USA
[4] Harvard Univ, Brigham & Womens Hosp, Ctr Neurol Dis, Inst Med, Boston, MA 02115 USA