1. From the Division of Neurogenetics (A.J., C.S., N.J.A.), Department of Neurology, NYU Grossman School of Medicine; Lincoln Memorial University DeBusk College of Osteopathic Medicine (A.J.), Harrogate, TN; Multiple Sclerosis Comprehensive Care Center (V.P.A., I.K.), Department of Neurology; and Division of Neuroradiology (M.J.B.), Department of Radiology, NYU Grossman School of Medicine, New York,.