弥散张量成像观察电针对缺血性脑卒中大鼠运动皮层-纹状体神经传导束的影响

摘要

目的 运用小动物磁共振弥散张量成像(DTI),探讨电针曲池、足三里穴对大脑中动脉闭塞致缺血性脑卒中模型大鼠缺血侧运动皮层-纹状体神经传导束完整性的影响.方法 36只成年雄性Sprague-Dawley大鼠随机分为假手术组、模型组和电针组,每组12只,后两组线栓法制备缺血2 h再灌注模型.术后24 h,电针组电针患侧曲池、足三里穴,每天1次,连续14 d.改良神经功能缺损评分(mNSS)评价大鼠神经功能缺损情况;转棒测试观察大鼠运动功能;小动物磁共振成像系统行T2加权成像(T2WI)、DTI扫描,测量脑梗死体积,运动皮层、纹状体区神经传导束相对各向异性分数(rFA)和相对神经纤维数.结果 模型组和电针组大鼠较假手术组mNSS评分显著增加;干预7 d、14 d后,电针组评分较模型组降低(P<0.05);转棒测试电针组较模型组转棒上停留时间延长(P<0.05).T2WI成像显示,电针组较模型组脑梗死体积减少(P<0.05);DTI成像发现,电针组较模型组大鼠缺血侧运动皮层、纹状体rFA增加,运动皮层相对纤维束数增多(P<0.05).结论 电针曲池、足三里穴可改善缺血性脑卒中大鼠运动功能,与促进缺血侧运动皮层-纹状体神经传导束损伤的修复相关.%Objective To explore the effect of electroacupuncture at Quchi (LI11) and Zusanli (ST36) acupoints on motor behaviors, the axonal integrity and nerve bundle of motor cortex and striatum in rat model of ischemic stroke induced by middle cerebral artery occlusion (MCAO) using diffusion tensor imaging (DTI). Methods Thirty-six adult male Sprague-Dawley rats were randomly assigned to sham opera-tion group (sham group), ischemia control group (model group) and electroacupuncture treatment group (EA group) with twelve rats in each group. The later two groups were occluded their middle cerebral arteries for two hours. Twenty-four hours after modeling, EA group re-ceived electroacupuncture at Quchi (LI11) and Zusanli (ST36) acupoints on the paralyzed limb, once a day, for 14 days. They were assessed with modified Neurological Severity Scores (mNSS) and Rota-rod test, and scanned with small animal magnetic resonance imaging system for T2-weighted image (T2WI) and DTI, the infarct size, related fractional anisotropy (rFA) and related number of tracks of motor cortex and striatum were recorded. Results Compared with the sham group, the score of mNSS increased in the model group and EA group after model-ing, and was lower in EA group than in the model group seven days and 14 days after intervention (P<0.05). Rota-rod test showed that the retention time was significantly longer in EA group than in the model group (P<0.05). T2WI showed that the infarct size was smaller in EA group than in the model group (P<0.05). DTI showed that rFA in motor cortex and striatum was higher in EA group than in the model group (P<0.05), as well as the related number of tracks (P<0.05) in motor cortex. Conclusion Electroacupuncture at Quchi and Zusanli acupoints could improve the motor function in rats with ischemic stroke, which may be related to the recovery of nerve bundle of motor cortex and stri-atum in ischemic side.