Chang-Hee Kim1, Kwang-Dong Choi2. 1. Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University Medical Center, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea. 2. Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, 179, Gudeok-ro, Seo-gu, Busan, 602-739, South Korea. kdchoi@pusan.ac.kr.