1. College of Medicine, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH 44272, USA
2. Department of Medicine, Summa Health System, Akron, OH 44303, USA
3. Johns Hopkins School of Public Health, Baltimore, MD 21205, USA
4. Department of Physical Medicine and Rehabilitation, Rush University Medical Center, Chicago, IL 60612, USA
5. Department of Neurosurgery, George Washington University, Washington, DC 20037, USA
6. Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA