1. Department of Neurology, Chung-Ang University Gwangmyeong Hospital, Gwangmyeong, Gyeonggi-do, Korea
2. Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
3. Department of Neurology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
4. Department of Neurology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju, Gangwon-do, Korea