1. School of Medicine, Oregon Health & Science University, Portland, Oregon;
2. University of Florida College of Medicine, Gainesville, Florida;
3. School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York;
4. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan;
5. Chicago Medical School, Rosalind Franklin University of Medicine and Science, Chicago, Illinois;
6. School of Medicine, University of California, Irvine, California;
7. Department of Neurosurgery, Barrow Neurological Institute, Phoenix, Arizona; and
8. Department of Neurosurgery, Indiana University, Indianapolis, Indiana