Byungseok Kim1, Taewon Kim2,3. 1. Department of Neurology, College of Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea. 2. Department of Neurology, College of Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea. kimtaewon@catholic.ac.kr. 3. Department of Neurology, Incheon St's Mary's Hospital, Catholic University of Korea, 665 Bupyeong-6-dong, Bupyeong-gu, Incheon, 403-720, South Korea. kimtaewon@catholic.ac.kr.