1. Sleep Disorders Center, Department of Neurology, Soonchunhyang University College of Medicine, Cheonan Hospital, Cheonan, Korea.
2. Department of Neurology, Dankook University College of Medicine, Dankook University Hospital, Cheonan, Korea.
3. Department of Preventive Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
4. Department of Neurology, Seoul National University Boramae Hospital, Seoul, Korea.
5. Department of Neurology, Chungnam National University College of Medicine, Daejeon, Korea.
6. Department of Neurology, Kyung Hee University College of Medicine, Seoul, Korea.
7. Department of Neurology, Neuroscience Center, Samsung Medical Center, Samsung Biomedical Research Institute, Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul, Korea.