1. Division of Otolaryngology, Head and Neck Surgery, Department of Sensory and Motor Organs, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8504, Japan
2. Division of Neurosurgery, Department of Brain and Neurosciences, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8504, Japan
3. Division of Gastroenterology and Nephrology, Department of Multidisciplinary Internal Medicine, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8504, Japan
4. Division of Otolaryngology, Tottori Red Cross Hospital, Tottori 680-8517, Japan