1. Department of Neurosurgery, University of Virginia Health Sciences Center, Charlottesville, Virginia
2. Department of Neurosurgery, Wake Forest University School of Medicine, Winston-Salem, North Carolina
3. Department of Neurosurgery, Ospedale Bellaria, Bologna, Italy
4. Department of Neurosurgery and Toshiba Stroke Research Center, State University of New York, Buffalo, New York