1 Department of Neurology, Dong-A University Hospital, Busan, South Korea.
2 Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, 179, Gudeok-ro, Seo-gu, Busan, 602-739, South Korea.
3 Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea.
4 Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, 179, Gudeok-ro, Seo-gu, Busan, 602-739, South Korea. kdchoi@pusan.ac.kr.