1. Department of Neurosurgery, Yokohama City University
2. Department of Second Department of Internal Medicine, Yokohama City University
3. Department of Neurosurgery, Kanagawa Prefectural Ashigarakami Hospital
4. Department of Neurosurgery, Yokosuka Kyosai Hospital
5. Department of Neurosurgery, Nishiarai Hospital
6. Department of Neurosurgery, Odawara City Hospital