1. Department of Neurosurgery, International University of Health and Welfare, School of Medicine, Narita Hospital, Narita,
2. Department of Neurology, International University of Health and Welfare, School of Medicine, Narita Hospital, Narita,
3. Department of Neurosurgery, Imari Arita Kyoritsu Hospital, Arita, Japan
4. Department of Neurosurgery, Shiroishi Kyoritsu Hospital, Shiroishi, Japan.