1. Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
2. The Pediatric Demyelinating Disease Program, Program in Neuroscience & Mental Health, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada M5G 1X8
3. Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA