1. Department of Otolaryngology, Hennepin County Medical Center, University of Minnesota, Minneapolis, Minnesota.
2. Twin Star Medical, Minneapolis, Minnesota.
3. Cardiovascular Research, V.A. Medical Center, University of California–Los Angeles San Francisco, California.
4. Chief, Division of Neurosurgery, Department of Surgery, Hennepin County Medical Center, University of Minnesota, Minneapolis, Minnesota.
5. Department of Neurosurgery, University of Minnesota, Minneapolis, Minnesota.