1. 1Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon;
2. 2Wallace Trials Center, Greenwich Hospital, Greenwich, Connecticut;
3. 3Department of Neurosurgery, Lahey Clinic Medical Center, Burlington, Massachusetts;
4. 4Department of Neurosurgery, Penn State Hershey Neuroscience Institute, Hershey, Pennsylvania;
5. 5Department of Neurological Surgery, George Washington University, Washington, DC;
6. 6Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee;
7. 7Carolina Neurosurgery and Spine Associates; and
8. 8Department of Neurological Surgery, Carolinas Medical Center, Charlotte, North Carolina