1. Department of Neurology, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
2. Department of Neurology, Seoul Medical Center, Seoul, Korea.
3. Department of Neurology, Bundang Clinical Neuroscience Institute, Seoul National University Bundang Hospital, Seongnam, Korea.
4. Department of Neurology, Daegu Catholic University School of Medicine, Daegu, Korea.
5. Department of Neurology, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea.
6. Department of Neurology, Chungnam National University Hospital, Chungnam National University School of Medicine, Chungnam, Korea.
7. Sleep Disorders Center, Department of Neurology, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan, Korea.
8. Department of Neurology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.