1. Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota
2. Neurosurgery Department, Brigham and Women's Hospital, Boston, Massachusetts
3. Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
4. Vanderbuilt Medical School, Nashville, Tennessee
5. David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
6. Albert Einstein College of Medicine, Bronx, New York