1. Division of Neurosurgery, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, Tottori, Japan
2. Department of Otolaryngology/Head and Neck Surgery, Fukuyama Medical Center, Fukuyama, Hiroshima, Japan
3. Department of Neurosurgery, Matsue Seikyo General Hospital, Matsue, Shimane, Japan
4. Division of Molecular Pathology, Department of Pathology, Faculty of Medicine, Tottori University, Yonago, Tottori, Japan