1. Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford, California
2. Department of Neurology and Neurosciences, Texas Scottish Rite Hospital for Children, Dallas, Texas
3. Department of Pediatrics, Rehabilitation Institute of Chicago, Chicago, Illinois
4. Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland
5. Department of Child Neurology, University of Rochester Medical Center, Rochester, New York