1. Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah;
2. Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota;
3. Department of Neurosurgery, Carolina Neurosurgery and Spine Associates and Neuroscience Institute, Carolinas Health Care System, Charlotte, North Carolina;
4. Department of Neurosurgery, University of California, San Francisco, California;
5. Department of Neurosurgery, Duke University, Durham, North Carolina;
6. Department of Neurosurgery, Weill Cornell Medical College, New York, New York;
7. Department of Neurosurgery, University of Tennessee and Semmes Murphey Clinic, Memphis, Tennessee;
8. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan;
9. Saint Luke’s Neurological and Spine Surgery, Kansas City, Missouri;
10. Department of Neurosurgery, University of North Carolina, Chapel Hill, North Carolina;
11. Atlantic Neurosurgical Specialists, Morristown, New Jersey;
12. Department of Neurosurgery, University of Virginia Health System, Charlottesville, Virginia;
13. Department of Neurosurgery, Indiana University; Goodman Campbell Brain and Spine, Indianapolis, Indiana;
14. Department of Neurosurgery, University of Miami, Florida; and
15. Barrow Brain and Spine, Phoenix, Arizona