Seonkyung Lee1, Yu Jin Koo1, Hyo-Jung Kim2, Ji-Soo Kim3,4. 1. Dizziness Center, Clinical Neuroscience Center, Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-707, South Korea. 2. Research Administration Team, Seoul National University Bundang Hospital, Seongnam, South Korea. 3. Dizziness Center, Clinical Neuroscience Center, Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-707, South Korea. jisookim@snu.ac.kr. 4. Department of Neurology, Seoul National University College of Medicine, Seoul, South Korea. jisookim@snu.ac.kr.