大脑中动脉供血区急性缺血性脑卒中患者的脑血管储备能力

Cerebrovascular reserve capacity of acute ischemic stroke patients in middle cerebral artery territory

目的评估大脑中动脉(MCA)供血区急性缺血性脑卒中患者脑血管储备(CVR)能力,分析CVR与神经功能改善的相关性。方法 50例MCA供血区急性缺血性脑卒中患者,在吸入5%二氧化碳(CO2)前后,分别进行CT灌注成像(CTPI)检查。在基底节区、放射冠区及半卵圆中心层面选择感兴趣区(ROI),测量ROI血流动力学指标如相对脑血流量(rCBF)、脑血容量(CBV)、平均通过时间(MTT)及达峰时间(TTP);以健侧为正常对照,分析患侧MCA供血区的血流动力学指标变化;计算CVR,分析患侧CVR与美国国立卫生研究院脑中量表(NIHSS)评分减分值的相关性。结果基础态下,与健侧相比,受试者患侧rCBF显著降低(P<0.01),CBV略增高(P<0.05),MTT与TTP均明显延长(P<0.01)。5%CO2激发后,根据患侧rCBF的变化,将CVR分为3型:激发后rCBF增高(28例)、rCBF变化不明显(8例)、rCBF降低(14例)。患侧CVR与第14 d的NIHSS评分减分值呈等级正相关(r=0.58,P<0.05)。结论 MCA供血区急性缺血性脑卒中患者存在脑灌注异常,CVR与神经功能改善呈正相关。

Objective To evaluate the cerebrovascular reserve（CVR） capacity of acute ischemic stroke patients in middle cerebral artery（MCA） territory, and to analyze the correlation between CVR and neurological function improvement. Methods CT perfusion imaging（CTPI） was performed in 50 patients with acute ischemic stroke in MCA territory before and after 5% CO_2 inhalation. The regions of interest（ROI） were selected in basal ganglia, corona radiata and semiovale center. The hemodynamics parameters, such as regional cerebral blood flow（rCBF）, cerebral volume（CBV）, mean transit time（MTT） and time to peak（TTP）, were measured in ROI. Based on the contralateral normal controls, the changes of hemodynamics parameters of affected MCA territory were analyzed. The CVR of each MCA territory was calculated, and the association between the CVR on the affected side with the NIHSS score subtraction was investigated. Results Before the CO_2 inhalation test, the lower mean rCBF（P〈0.01）, the slightly higher CBV（P〈0.05）, and the significantly prolonged MTT and TTP（P〈0.01） on the affected side were found. After the CO_2 inhalation test, according to the change of rCBF in the affected side, CVR was categorized into three types： increased rCBF（28 cases）, no obvious change in rCBF（8 cases） and decreased rCBF（14 cases）. There was a positive correlation between CVR on the affected side and NIHSS score subtraction on the 14 th day（r=0.58, P〈0.05）. Conclusions In the affected side of ischemic stroke patients, the changes of cerebral perfusion in middle cerebral artery（MCA） territory can be found, and the CVR can be positively correlated with neurological function improvement.