1. Department of Neurology; Korea University College of Medicine; Seoul, #73, Inchon-ro Seongbuk-gu Seoul 136-705 South Korea
2. Department of Rehabilitation Medicine; Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea; Seoul South Korea
3. Department of Rehabilitation Medicine; Korea University College of Medicine; Seoul South Korea
4. Department of Neurology; Seoul National University Bundang Hospital, Seoul National University, College of Medicine; Seoul South Korea