1. Department of Neurosurgery, Osaka National Hospital, National Hospital Organization, Osaka, Osaka, Japan
2. Department of Neurosurgery, Osaka University, Graduate School of Medicine, Suita, Osaka, Japan
3. Department of Dermatology, Osaka National Hospital, National Hospital Organization, Osaka, Osaka, Japan
4. Department of Central Laboratory and Surgical Pathology, Osaka National Hospital, National Hospital Organization, Osaka, Osaka, Japan