1. Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia and Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
2. Department of Neurology, Children's Hospital Boston and Massachusetts General Hospital, Boston, Massachusetts
3. Department of Neurology, Cleveland Clinic, Cleveland, Ohio
4. National Multiple Sclerosis Society, New York, New York
5. Department of Pediatrics, Children's Memorial Hospital, Chicago, Illinois,