Youngje Heo1, Taewon Kim2. 1. Department of Neurology, College of Medicine, Incheon St Mary's Hospital, The Catholic University of Korea, 56 Dongsuro, Incheon, 21431, South Korea. 2. Department of Neurology, College of Medicine, Incheon St Mary's Hospital, The Catholic University of Korea, 56 Dongsuro, Incheon, 21431, South Korea. kimtaewon@catholic.ac.kr.