1. Department of Neurology, the University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
2. Department of Neurosurgery, the University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
3. Department of Anesthesiology and Critical Care, the University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
4. Division of Laboratory Medicine, Department of Pathology, The University of Alabama at Birmingham, Birmingham, Alabama.
5. Department of Pathology, Keck School of Medicine of USC, Los Angeles, California.
6. Department of Acute, Chronic, and Continuing Care, The University of Alabama at Birmingham, Birmingham, Alabama.