1. Surgical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
2. Department of Experimental Neurology, Charité University Medicine, Berlin, Germany
3. Department of Neurosurgery, University Hospital Geneva, Geneva, Switzerland
4. Department of Neurosurgery, Santa Barbara Cottage Hospital, Santa Barbara, California
5. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan
6. Department of Neurosurgery, University of Virginia, Charlottesville, Virginia