1. Department of Radiology, The Johns Hopkins Hospital, Baltimore, MD, USA
2. Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, MD, USA
3. The Johns Hopkins School of Medicine, Baltimore, MD, USA
4. University of Wisconsin Department of Orthopedics and Rehabilitation, Madison, WI, USA
5. Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA
6. Department of Neurological Surgery, Cleveland Clinic, Cleveland, OH, USA
7. University of Southern California, Los Angeles, CA, USA
8. Department of Medicine, The Johns Hopkins Hospital, Baltimore, MD, USA
9. University of Miami Miller School of Medicine, Miami, FL, USA