1. Harvard Medical School, Boston, Massachusetts, USA;
2. Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA;
3. Division of Neurocritical Care, Massachusetts General Hospital, Boston, Massachusetts, USA;
4. Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, USA;
5. Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA