1. From the Department of Neurology, Childrens National Medical Center, Washington, DC;
2. Division of Neuroradiology, Department of Diagnostic Imaging, Hasbro Children's Hospital and Rhode Island Hospital, and Department of Diagnostic Imaging, Brown University School of Medicine, Providence, Rhode Island; and the
3. Division of Pediatric Neurology, Departments of Pediatrics and Neurology, Hasbro Children's Hospital and Rhode Island Hospital, and Department of Pediatrics and Clinical Neurosciences, Brown University School of Medicine, Providence, Rhode Island.