1. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
2. Liver Cirrhosis Clinical Research Center, Seoul, Korea.
3. Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.
4. Brain Korea 21 Project of Medical Science, Seoul, Korea.
5. Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.