1. Stroke Center, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan 450000, P.R. China
2. Department of Gastroenterology, Chinese PLA General Hospital, Beijing 100853, P.R. China
3. Department of Neurosurgery, Fuzhou General Hospital, Fuzhou, Fujian 350025, P.R. China