1. Department of Neurosurgery, Graduate School of Medical Sciences, Kumamoto University; Kumamoto, Japan
2. Department of Cerebrovascular Disease and Acute Coronary Syndrome, Graduate School of Medical Sciences, Kumamoto University; Kumamoto, Japan
3. Department of Neurology, Graduate School of Medical Sciences, Kumamoto University; Kumamoto, Japan
4. Department of Neurosurgery, Graduate School of Medical Sciences, Kanazawa University; Kanazawa, Japan