1. Department of Neurosurgery, Chiba University
2. Department of Neurosurgery, Chiba Cancer Center
3. Department of Neurosurgery, Naruto Hospital
4. Second Department of Internal Medicine, Chiba University
5. Department of Pediatrics, Chiba University
6. Department of Neurosurgery, Kawatetsu Chiba Hospital6
7. Department of Neurosurgery, Kimitsu Chuo Hospital
8. Department of Neurosurgery, Matsudo Municipal Hospital8