1. Department of Neurosurgery, Kentucky College of Osteopathic Medicine, University of Pikeville, Pikeville, Kentucky, United States.
2. Department of Neurological Surgery, University of California, Irvine, California, United States.
3. Department of Neurosurgery, College of Osteopathic Medicine, Kansas City University, Kansas City, Missouri, United States.
4. Department of Neurosurgery, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, United States.
5. Department of Neurosurgery, University of Colorado School of Medicine, Aurora, Colorado, United States.
6. Department of Neurosurgery, Neurology, Radiology and Neuroscience, University of Kentucky, Lexington, Kentucky, United States.