Correlation of memory impairment and cerebral perfusion in patients with vertebral-basilar artery stenosis

Objective To evaluate the correlation between cerebral blood flow perfusion and memory impairment in patients with severe stenosis of vertebral basilar artery(VBA). Methods 62 cases of patients with VBA stenosis diagnosed by digital subtraction angiography(DSA) in Beijing Tiantan Hospital from September 2016 to March 2017 were enrolled.Mental State Examination (MMSE), Clinical Memory Scale(CMS) test and CT perfusion(CTP) was performed.All patients were divided into memory normal group(n=24, including 1 excellent case, 6 above normal cases, and 14 normal cases) and memory impairment group(n=38, including 18 below normal cases, 12 periphery cases, 8 impaired cases) according to CMS.The ratios of side-to-side period were compared between bilateral mesial temporal lobe and anterior circulation area.The relative time to peak (rTTP), relative mean transit time(rMTT), relative cerebral blood flow(rCBF) and relative cerebral blood volume(rCBV) were calculate. Results The incidence of CTP decompensation in the medial temporal lobe was higher than that in the patients with memory impairment(P<0.05). The difference of rTTP and rMTT value between the two groups in the bilateral medial temporal lobes was statistically significant(rTTP: (1.131±0.037), (1.437±0.139), t=10.520, P<0.05); rMTT: (1.081±0.059), (1.281±0.174), t=5.423, P<0.05). Conclusion The patients with VBA severe stenosis are more likely to get memory impairment due to cerebral hypoperfusion. Key words: Vertebra-basilar artery stenosis; CT perfusion; Memory impairment