1. Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Department of Neurosurgery, Konkuk University Chungju Hospital, Chungju, Korea.
3. Department of Pathology, Ewha Womans University School of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
5. Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.