1. Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of Medicine Gainesville Florida
2. Department of NeurologyUniversity of Florida College of Medicine Gainesville Florida
3. Department of PediatricsUniversity of Ottawa and Children's Hospital of Eastern Ontario Ottawa Ontario Canada
4. Department of PediatricsNorthwestern University Feinberg School of Medicine and Lurie Children's Hospital Chicago Illinois
5. National Institute of Neurological Disorders and Stroke Bethesda Maryland
6. Functional and Applied Biomechanics Section, Rehabilitation MedicineNational Institutes of Health Clinical Center Bethesda Maryland
7. Inova Neuroscience and Spine Institute, Inova Fairfax Hospital Falls Church Virginia
8. Centre de Référence Maladies Neuromusculaires, Service de Neurologie, Réanimation et Réeducation Pédiatriques, Hôpital Raymond Poincaré Garches France