1 Department of Neurology, Bundang Jesaeng General Hospital, Daejin Medical Center, Kwandong University College of Medicine, Seongnam, South Korea
2 Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
3 Department of Neurology, Hallym University College of Medicine, Anyang, South Korea
4 Department of Occupational and Environmental Medicine, Sacred Heart Hospital, Hallym University College of Medicine, Anyang, South Korea
5 Department of Neurology, College of Medicine, Chungnam National University, Daejeon, South Korea