1. Department of Neurological Surgery, University of Louisville, Louisville, Kentucky
2. School of Medicine, Georgetown University, Washington, DC
3. Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky
4. Department of Health Management and Systems Science, University of Louisville, Louisville, Kentucky
5. Division of Physical Medicine and Rehabilitation, University of Louisville, Louisville, Kentucky
6. Department of Physiology, University of Louisville, Louisville, Kentucky