中文摘要：

目的通过对患者大脑中动脉血管反应性（CVR）与椎动脉CVR的比较，评估颅内外大动脉无狭窄但发生后循环梗死（PCI）患者CVR，探讨前后循环血流动力学变化在预测PCI发生中的作用。方法选择PCI患者27例（PCI组），选择同期健康体检者25例（对照组）。采用经颅多普勒超声结合CO2 吸入试验检测所有入选患者的大脑申动脉cVR和椎动脉CVR。结果与对照组比较，PCI组左侧和右侧大脑中动脉CVR明显下降[（25．96±15．90）％vs（34．63±8．60）％，（26．40±14．54）％vs（34．49±9．08）％，P〈0．05]；PCI组椎动脉CVR较对照组有下降，但差异无统计学意义（P〉0．05）。多变量线性回归分析显示，糖尿病是大脑中动脉CVR受损的独立危险因素（β=0．116，P=0．035）。结论大脑中动脉CVR下降，而非椎动脉CVR下降，可作为颅内外大动脉无狭窄患者发生PCI预测指标。对于颅内外大动脉无明显狭窄的患者，糖尿病是大脑中动脉CVR降低的独立危险因素。

英文摘要：

Objective To assess the cerebrovascular reactivity （CVR） in patients with posterior cir- culation infarction（PCI） but without intra- and extracranial conducting artery stenosis. Methods Twenty-seven PCI patients served as a PCI group and 25 subjects undergoing physical examina- tion served as a control group in this study. The CVR in middle cerebral artery （MCA） and verte- bral artery （VA） was detected by transcranial Doppler uhrasonography combined with CO2 inha- lation test. Results The CVR in left and right MCA was significantly lower in PCI group than in control group （25.96±15.90）%vs（34.63±8.60）%,（26.40±14.54）%vs（34.49±9.08）%,P〈0.05）. No significant difference was found in CVR between the two groups although it was higher in PCI group than in control group （P 〉 0. 05）. Multivariate linear regression analysis showed that diabetes was the independent risk factor for CVR in MCA （β=-0. 116 ,P=0. 035）. Conclusion Reduced CVR in MCA rather than CVR in VA can be used as an independent predic- tor of PCI. Diabetes is an independent risk factor for reduced CRV in MCA of patients without in- tra- and extracranial conducting artery stenosis.