1. Department of Neurology, Ewha Womans University Seoul Hospital, Ewha Womans University College of Medicine, Seoul, Korea.
2. Department of Neurology, Ewha Womans University Mokdong Hospital, Ewha Womans University College of Medicine, Seoul, Korea.
3. Division of Psychiatry, Division of Mental Health Care of Older People, University College London, London, UK.
4. Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
5. Clinical Trial Center, Mokdong Hospital, Ewha Womans University College of Medicine, Seoul, Korea.
6. Department of Neurology, Eulji University School of Medicine, Daejeon, Korea.
7. Department of Neurology, Dong-A University College of Medicine, Busan, Korea.
8. Department of Neurology, Pusan National University School of Medicine, Busan, Korea.
9. Department of Neurology, Konyang University Hospital, College of Medicine, Konyang University, Daejeon, Korea.
10. Department of Neurology, Kangwon National University Hospital, Kangwon National University College of Medicine, Chuncheon, Korea.
11. Department of Neurology, Yonsei University Wonju College of Medicine, Wonju, Korea.
12. Department of Neurology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.