Woojun Kim1, Jae Young An2. 1. Department of Neurology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. 2. Department of Neurology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, 93-6, Ji-dong, Paldal-gu, Suwon, 442-723, Gyeonggi-do, Korea. nrjyan@gmail.com.