1. From the Departments of Pediatrics (E.I.P., R.L., A.G., T.L., P.J.O., W.B.D., M.B., A.P., I.N.), Neurology (A.M.), Psychiatry & Behavioral Sciences (J.R.W., B.A.M.), and Radiology (D.N.), University of Minnesota Medical School, Minneapolis; Biostatistical Design and Analysis Center (R.S.), Clinical and Translational Science Institute, University of Minnesota, Minneapolis; and Independent Neuroradiologist-Consultant (D.L.), Minneapolis, MN.