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