1. Diagnostic Radiology Department, National Institutes of Health Clinical Center;
2. Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke;
3. Department of Neurological Surgery, Emory University, Atlanta, Georgia;
4. Head and Neck Surgery Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland;
5. Department of Otolaryngology–Head and Neck Surgery, Georgetown University Medical Center, Georgetown University, Washington, DC; and
6. Department of Neurological Surgery, The Ohio State University, Columbus, Ohio