1. Department of Neurosurgery, University of Pennsylvania, and Veterans Administration Medical Center, Philadelphia, Pennsylvania, U.S.A.
2. Neurosurgical Intensive Care Unit, Department of Anesthesia and Critical Care Medicine, Ospedale Maggiore Policlinico IRCCS, Milan, Italy
3. Department of Trauma Surgery, Johann Wolfgang Goethe-University, Frankfurt, Germany
4. Department of Surgery, University of Cologne, Köln, Germany
5. Department of Pathology and Laboratory Medicine, University of Pennsylvania, and Veterans Administration Medical Center, Philadelphia, Pennsylvania, U.S.A.
6. Department of Neuropathology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, U.K.