1. Department of Neurology, Uijeongbu Eulji Medical Center, Eulji University School of Medicine, Uijeongbu, Republic of Korea
2. Department of Neurology, Seoul Medical Center, Seoul, Republic of Korea
3. Department of Neurology, Seoul Metropolitan Seobuk Hospital, Seoul, Republic of Korea
4. Department of Neurology, Daegu Catholic University School of Medicine, Daegu, Republic of Korea
5. Department of Neurology, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Republic of Korea
6. Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
7. Department of Neurology, Chungnam National University Hospital, Chungnam National University School of Medicine, Chungnam, Republic of Korea
8. Sleep Disorders Center, Department of Neurology, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan, Republic of Korea
9. Department of Neurology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
10. Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea