1. 1Carolina Neurosurgery and Spine Associates;
2. 2Department of Neurological Surgery, Carolinas Medical Center, Charlotte, North Carolina;
3. 3Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee;
4. 4Department of Orthopaedics, University of Louisville School of Medicine, Louisville, Kentucky;
5. 5Heart Health Strategies, Washington, DC;
6. 6Department of Neurological Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin; and
7. 7Columbia University College of Physicians and Surgeons, New York, New York