1. Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA;
2. Department of Neurology, Division of Neurocritical Care and Emergency Neurology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
3. Department of Neurology, Division of Neurocritical Care, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
4. Departments of Pathology and Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA