1. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
2. Thyroid Cancer Center, National Cancer Center, Goyang, Korea.
3. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
4. Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
5. Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, Korea.