1. Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan
2. Department of Healthcare Epidemiology, Graduate School of Medicine and Public Health, Kyoto University, Kyoto, Japan
3. Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
4. Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Kyoto, Japan
5. Department of Otolaryngology, Shiga General Hospital, Shiga, Japan
6. Department of Otolaryngology, Kyoto Teishin Hospital, Kyoto, Japan