1. Department of Neurosurgery, Tazuke Kofukai Medical Research Institute and Kitano Hospital, Osaka, Osaka, Japan
2. Department of Neurology, Kyoto University, Kyoto, Kyoto, Japan
3. Department of Neurosurgery, Japanese Red Cross Fukui Hospital, Fukui, Fukui, Japan
4. Department of Neurology, Saiseikai-Nakatsu Hospital, Osaka, Osaka, Japan
5. Department of Radiology, Tazuke Kofukai Medical Research Institute and Kitano Hospital, Osaka, Osaka, Japan