1. Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
2. Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
3. Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
4. Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan