1. College of Clinical Medicine, North China University of Science and Technology, Tangshan, Hebei 063000, P.R. China
2. College of Nursing and Rehabilitation, North China University of Science and Technology, Tangshan, Hebei 063000, P.R. China
3. Department of Neurosurgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, Hebei 063000, P.R. China