1. Department of Neurological Surgery, University of Utah, Salt Lake City, Utah;
2. Department of Neurological Surgery, University of California, San Francisco, California;
3. Department of Neurological Surgery, Weill Cornell Medical College, New York, New York;
4. Atlantic Neurosurgical Specialists, Morristown, New Jersey;
5. Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota;
6. Norton Leatherman Spine Center, Louisville, Kentucky;
7. Department of Neurosurgery, University of Tennessee, Memphis, Tennessee;
8. Geisinger Health System, Danville, Pennsylvania;
9. Goodman Campbell Brain and Spine, Indianapolis, Indiana;
10. Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia;
11. Departments of Neurological Surgery and Orthopedic Surgery, Duke University, Durham, North Carolina;
12. Atlanta Brain and Spine, Atlanta, Georgia;
13. Department of Neurologic Surgery, University of Miami, Florida;
14. Department of Neurologic Surgery, University of Michigan, Ann Arbor, Michigan; and
15. Neuroscience Institute, Carolinas Healthcare System and Carolina Neurosurgery & Spine Associates, Charlotte, North Carolina