[1] Gansu Prov Matern & Child Care Hosp, Dept Neurosurg, Lanzhou 730050, Gansu, Peoples R China
[2] Shanghai Xuhui Cent Hosp, Dept Rehabil Med, Shanghai 200030, Peoples R China
[3] Univ Hong Kong, Sch Publ Hlth, Pokfulam, Hong Kong 999077, Peoples R China
[4] Univ Leeds, Sch Biomed Sci, Woodhouse, Leeds LS2 9JT, England
[5] Gansu Univ Chinese Med, Clin Med Coll 1, Lanzhou 730000, Gansu, Peoples R China