1. Department of Neurosurgery, Jikei University Kashiwa Hospital, Kashiwa, Chiba, Japan
2. Department of Emergency Medicine, Jikei University Kashiwa Hospital, Kashiwa, Chiba, Japan
3. Department of Neurology, Jikei University Kashiwa Hospital, Kashiwa, Chiba, Japan
4. Department of Neurosurgery, Jikei University School of Medicine, Tokyo, Japan