1. Division of Palliative Medicine, Department of Medicine, MedStar Washington Hospital Center, Washington, DC, USA.
2. Department of Medicine, Georgetown University School of Medicine, Washington, DC, USA.
3. Department of Critical Care and Preanesthesia, MedStar Washington Hospital Center, Washington, DC, USA.
4. Department of Neurosurgery, MedStar Washington Hospital Center, Washington, DC, USA.
5. Department of Critical Care Medicine, MedStar Washington Hospital Center, Washington, DC, USA.
6. Department of Neurology, Georgetown University School of Medicine, Washington, DC, USA.