1. Interdepartmental Division of Critical Care, University of Toronto, Toronto, Ontario, Canada;
2. Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
3. Department of Neurology,
4. Department of Anesthesiology and Critical Care Medicine,
5. Department of Neurosurgery, and
6. Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
7. Department of Biomedical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland