1. aDivision of Pediatric Neurology, Department of Neurology, Washington University School of Medicine, St Louis, Missouri
2. bDivision of Developmental Paediatrics, Department of Paediatrics, Holland Bloorview Kids Rehabilitation Hospital, University of Toronto, Toronto, Ontario, Canada
3. cDivision of Neurology, Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Children’s Mercy Kansas City, Kansas City, Missouri
4. dBarrow Neurologic Institute, Phoenix Children's Hospital, Departments of Child Health, Cellular and Molecular Medicine, Genetics, and Neurology, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona
5. ePittsford, New York
6. fH. Ben Taub Department of Physical Medicine and Rehabilitation and Departments of Neurosurgery and Pediatrics, Baylor College of Medicine, Houston, Texas
7. gDepartment of Epidemiology, Epidemiology Data Center, University of Pittsburgh, Pittsburgh, Pennsylvania