1. Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts;
2. Department of Neurosurgery, Geisinger, Danville, Pennsylvania;
3. Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania;
4. Mayfield Clinic, TriHealth Neuroscience Institute, Good Samaritan Hospital, Cincinnati, Ohio;
5. Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah;
6. Department of Clinical Neurosciences, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada;
7. Department of Neurological Surgery, University of Washington, Seattle, Washington; and
8. Department of Neurological Surgery, Cooper University Health Care, Cooper Medical School of Rowan University, Camden, New Jersey