1. Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon;
2. Department of Neurosurgery, Duke University, Durham, North Carolina;
3. Department of Neurosurgery, Westchester Medical Center, Valhalla, New York;
4. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan;
5. Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York;
6. Department of Neurosurgery, University at Buffalo, Buffalo, New York;
7. Department of Neurosurgery, Wake Forest University, Winston-Salem, North Carolina; and
8. Department of Neurological Surgery, Vanderbilt University, Nashville, Tennessee