1. Department of Neurosurgery, University of Utah, Salt Lake City, Utah.
2. Department of Brain and Spinal Cord Injury Center (BASIC), University of California, San Francisco, San Francisco, California.
3. Department of Neurosurgery, University of California, San Francisco, San Francisco, California.
4. Department of Emergency Medicine, University of California, San Francisco, San Francisco, California.
5. Department of Radiology, University of California, San Francisco, San Francisco, California.
6. Department of Anaesthesia, University of California, San Francisco, San Francisco, California.