1. From the Department of Clinical Neurosciences (N.C., M.W.K.), University of Calgary, Canada; Department of Neurology (J.M.), Rijnstate Hospital, Arnhem, The Netherlands; Multiple Sclerosis Center (P.R., J.D.B.), Swedish Neuroscience Institute, Seattle, WA; Department of Neurology (B.M.J.U., E.M.M.S.), MS Center Amsterdam, Amsterdam University Medical Centers, Amsterdam, The Netherlands; Department of Biostatistics (G.R.C.), University of Alabama at Birmingham; Department of Community Health Sciences...