1. International University of Health and Welfare;
2. Neuroscience Center, Fukuoka Sanno Hospital, Fukuoka;
3. Department of Neurosurgery, Tokyo Medical University, Tokyo;
4. Medical Research and Education Center, Aizawa Hospital, Matsumoto, Japan;
5. Lillian S. Wells Department of Neurosurgery, University of Florida, Gainesville; and
6. Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida