1. Department of Neurology, Seoul National University, College of Medicine, Boramae Hospital, Seoul, Korea.
2. Department of Neurology, Seoul National University, College of Medicine, Seoul National University Hospital, Seoul, Korea.
3. Department of Neurology and Clinical Epidemiology, College of Medicine, Soonchunhyang University, Cheonan, Korea.
4. Department of Psychiatry, Seoul National University, College of Medicine, Boramae Hospital, Seoul, Korea.
5. Department of Internal Medicine, College of Medicine, Soonchunhyang University, Cheonan, Korea.