1. Chicago Medical School, Rosalind Franklin University, North Chicago, IL 60064, USA
2. School of Osteopathic Medicine, Campbell University, Lillington, NC 27546, USA
3. Faculty of Medicine and Health Sciences, An-Najah National University, Nablus P.O. Box 7, West Bank, Palestine
4. Central Michigan College of Medicine, Mount Pleasant, MI 48858, USA
5. Lake Erie College of Osteopathic Medicine, Erie, PA 16509, USA
6. School of Medicine, Tulane University, New Orleans, LA 70112, USA
7. Department of Neurology, Henry Ford Hospital, Detroit, MI 48202, USA
8. Department of Neurosurgery, Lenox Hill Hospital, New York, NY 10075, USA