1. Departments of Neurosurgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
2. Departments of Division of Neurosurgery, Saiseikai Kumamoto Hospital, Kumamoto, Japan
3. Departments of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
4. Department of Neurosurgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan