1. Veterans Administration Medical Center, Philadelphia, Pennsylvania.
2. Traumatic Brain Injury Laboratory, Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania.
3. Neurosurgical Intensive Care Unit, Department of Anesthesia and Critical Care Medicine, Ospedale Maggiore Policlinico IRCCS, Milano, Italy.
4. Department of Neurology and Neuroscience Research of the Children's Hospital of Philadelphia, Pennsylvania.
5. Department of Neurobiology and Anatomy, Drexel University, Philadelphia, Pennsylvania.
6. Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.