1. Department of Neurological Surgery, University of California, San Francisco, California;
2. Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois;
3. Prince of Wales Clinical School, University of New South Wales, Randwick, and Department of Neurology, St. Vincent’s Hospital, Darlinghurst, New South Wales, Australia; and
4. Department of Anesthesia & Perioperative Care, University of California, San Francisco, California