1. Department of Neurology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
2. Department of Neurology, Neuroscience Research Institute, Seoul National University Medical Research Council, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
3. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Neurology, Ajou University Medical Center, Ajou University College of Medicine, Suwon, Korea.
5. Department of Neurology, Konkuk University Hospital, Konkuk University College of Medicine, Seoul, Korea.