1. From the Departments of Neurology, Psychiatry and Radiology, Boston Children’s Hospital, and Department of Neurology, Harvard Medical School, Boston, MA (M.J.R.); Division of Neurology, Department of Pediatrics, Hospital for Sick Children Toronto, Ontario, Canada (G.d.V.); The Children’s Hospital of Philadelphia, Departments of Neurology and Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia (R.N.I.); Department of Neurology, Alberta Children's Hospital Research...