Division of Pediatric Neurology, Department of Pediatrics, Boston Medical Center, Boston, Massachusetts. Electronic address: rachel.hirschberger@childrens.harvard.edu. Division of Pediatric Neurology, Department of Pediatrics, Boston Medical Center, Boston, Massachusetts. University of North Carolina, Chapel Hill, North Carolina. Department of Psychology and Neuroanatomy, Boston University, Boston, Massachusetts. Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts. Division of Pediatric Neurology, Department of Neurology, Johns Hopkins Hospital, Baltimore, Maryland. Department of Radiology, Boston Medical Center, Boston University, Boston, Massachusetts. Departments of Psychiatry and Pediatrics, UMASS Medical School/ University of Massachusetts Memorial Health Care, Worcester, Massachusetts. National Institute of Neurological Disorders and Stroke, Bethesda, Maryland. Department of Epidemiology and Biostatistics and Pediatrics and Human Development, Michigan State University, East Lansing, Michigan.