1. 1Carolina Neurosurgery & Spine Associates;
2. 2Department of Neurological Surgery, Carolinas Medical Center, Charlotte, North Carolina;
3. 3Department of Neurological Surgery, Columbia University College of Physicians and Surgeons, New York, New York;
4. 4Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon;
5. 5Wallace Trials Center, Greenwich Hospital, Greenwich, Connecticut;
6. 6Department of Neurosurgery, Lahey Clinic Medical Center, Burlington, Massachusetts; and
7. 7Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee