1. Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Neurology, Seoul Hospital, Ewha Womans University College of Medicine, Seoul, Korea.
3. Department of Radiology, Haeundae Paik Hospital, Inje Unversity College of Medicine, Busan, Korea.
4. Department of Neurology, Haeundae Paik Hospital, Inje Unversity College of Medicine, Busan, Korea.