1. Center for Surgical Trials and Outcomes Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.
2. International Center for Spinal Cord Injury, Hugo W. Moser Research Institute at Kennedy Krieger Institute, Baltimore, Maryland.
3. Center for Surgery and Public Health, Harvard Medical School and Harvard School of Public Health, Brigham and Women's Hospital, Boston, Massachusetts.
4. Department of Neurology, Johns Hopkins Hospital, Baltimore, Maryland.
5. International Neurorehabilitation Institute, Lutherville, Maryland.
6. Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.