1. Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Department of Neurology, Ajou University School of Medicine, Suwon, Korea.
3. Department of Neurology, Konkuk University School of Medicine, Seoul, Korea.
4. Department of Neurology, Yeungnam University School of Medicine, Daegu, Korea.
5. Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
6. Department of Neurology, Chung-Ang University School of Medicine, Seoul, Korea.