1. Department of Neurosurgery, Clinical Neuroscience Center, University of Utah, Salt Lake City, Utah;
2. Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado;
3. Department of Neurosurgery, Emory University, Atlanta, Georgia;
4. Morehouse School of Medicine, Atlanta, Georgia;
5. Department of Endovascular Surgical Neuroradiology/Neuroendovascular Surgery, University of Texas Southwestern Medical School, Dallas, Texas;
6. Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin;
7. Department of Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania;
8. Department of Neurosurgery, Cooper Medical School of Rowan University, Camden, New Jersey;
9. Department of Neurosurgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania;
10. Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, Iowa;
11. Department of Neurological Surgery, University of Washington, Harborview Medical Center, Seattle, Washington;
12. Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania;
13. Department of Neurosurgery, North Shore University Health System, Arlington Heights, Illinois;
14. Department of Surgery, University of Texas Rio Grande Valley School of Medicine, Edinburg, Texas; and
15. Department of Neurosurgery, University of Texas Health Science Center at San Antonio, Texas