1. Department of Neurosurgery, Ehime University Graduate School of Medicine, Toon, Japan
2. Department of Neurosurgery, Ehime Prefectural Central Hospital, Matsuyama, Japan
3. Department of Pediatric Neurosurgery, Takatsuki General Hospital, Takatsuki, Japan
4. Department of Pediatrics, Ehime University Graduate School of Medicine, Toon, Japan.