1. From the Department of Neurosurgery (K.U., S.Y.)
2. Department of Clinical Epidemiology (K.U., T. Morimoto), Hyogo College of Medicine, Japan
3. Department of Neurosurgery, Goshi Hospital, Amagasaki, Japan (N.H., Y.O.)
4. Department of Neurosurgery, Amagasaki Chuo Hospital, Japan (T. Matsumoto, R.T.)
5. Department of Neurosurgery, Yoshida Hospital Cerebrovascular Research Institute, Kobe, Japan (I.Y.)
6. Department of Internal Medicine, Hirosaki Stroke and Rehabilitation Center, Japan (S.S.)
7. Department of Neurosurgery, Seisho Hospital, Odawara, Japan (M.T.)
8. Department of Neurosurgery, Disaster Medical Center, National Hospital Organization, Tachikawa, Japan (K.S.)
9. Department of Neurosurgery, Araki Neurosurgical Hospital, Hiroshima, Japan (H.A.).