1. Department of Neurosurgery, University of Cincinnati, Cincinnati, OH, USA
2. Department of Neurology and Rehabilitation Medicine, University of Cincinnati, Cincinnati, OH, USA
3. Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
4. Department of Neurology, San Francisco Veterans Administration Medical Center, San Francisco, CA, USA
5. Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
6. Brain and Spinal Injury Center, San Francisco General Hospital, San Francisco, CA, USA
7. Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, USA
8. Department of Radiology, University of California, San Francisco, San Francisco, CA, USA
9. Department of Neurological Surgery, Virginia Commonwealth University, Richmond, VA, USA
10. Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA