1. Department of Neurology, Shandong University of Qilu Hospital, Jinan, Shandong 250012, P.R. China
2. Department of Critical Medicine, The Third People's Hospital of Heze, Heze, Shandong 274000, P.R. China
3. Department of Geriatrics, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250011, P.R. China