1. Department of Neurology, Daejeon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
2. Department of Neurology, Chungbuk National University Hospital, Cheongju, Korea.
3. Department of Medicine, Division of Clinical Pharmacology and the Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, TN, USA.
4. College of Medicine and Medical Research Information Center (MedRIC), Chungbuk National University, Cheongju, Korea.