1. Department of Neurology and Neuroscience, The New York Presbyterian-Weill Cornell Medical College, New York, New York
2. Department of Neurosurgery, Virginia Commonwealth University Medical Center, Richmond, Virginia
3. Neurosurgical Department, Medical School Hannover, Hannover, Germany
4. Division of Neurosurgery, University of California at Los Angeles Medical Center, Los Angeles, California
5. Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts