Centro para la Investigación de Enfermedades Neuroinmunológicas (M.F.F., J.C.), FLENI, Buenos Aires, Argentina; Servicio de Neuroinmunología y Enfermedades Desmielinizantes (J.C.), Departamento de Neurología, FLENI, Buenos Aires, Argentina; Department of Neurology (M.J.A.), University of Florida, Gainesville; Mellen Center (A.R.-G.), Cleveland Clinic, Cleveland; Department of Neurology (D.G.), Charleston Area Medical Center, WV; Northern Michigan Neurology (D.D.), Traverse City; Division of Neurology (Y.H.-M.), Ann & Robert H. Lurie Children's Hospital of Chicago; MS Comprehensive Care Center (N.J.K.), Keck School of Medicine of University of Southern California, Los Angeles; Lake Norman Neurology (D.J.), Piedmont HealthCare, Mooresville, NC; The Marriage and Family Institute (M.B.), Saint Louis, MO; Department of Neurology (G.G.), Kansas University Medical Center, Kansas City; Neurology Division (D.M.), Department of Pediatrics, Loma Linda University Health Care, CA; American Academy of Neurology (E.L., J.C., T.G.), Minneapolis, MN; US Centers for Disease Control and Prevention (J.S.), Atlanta, GA; Department of Neurology (P.N.), Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA.