fMRI结合神经症状评分评价运动疗法对大鼠局灶性脑缺血模型的疗效

摘要

目的 采用功能磁共振成像(fMRI)结合神经症状评分综合评价运动疗法对大鼠脑卒模型的疗效.方法 造模成功后的大鼠局灶性脑缺血MCAO模型40只随机分为模型组、运动组,每组各20只,分别于第1、10、20、30天采用神经症状评分综合评价观察大鼠恢复情况,采用fMRI检测正常大鼠及运动组第3、30天大鼠脑梗死部位.结果 30d后两组大鼠神经症状的综合行为学评分均较第1天均有明显改善,但运动组大鼠神经症状的综合行为学评价得分显著高于模型组,大鼠神经症状改善速度显著优于模型组(P-0.05).正常大鼠T1WI T2WI无异常,磁共振扩散张量白质纤维束示踪成像(DTT)显示双侧神经纤维束对称无中断.运动组大鼠第3天TIWI右侧半球可见条状低信号影,T2WI显示右侧大脑半球大片状高信号影,纤维束较左侧明显少,右侧明显中断,第30天T1WI、T2WI显示右侧大脑半球可见大片软化灶,右侧纤维束明显较对侧少,而且中断.血氧水平依赖性功能性磁共振成像(BOLD-fMRI)发现不同组别的大鼠及同一大鼠前后对照,激活点出现部位差异很大,可重复性差.结论 脑卒中后运动疗法可引起正常中枢神经系统明显的可塑性改变,增加脑损伤大鼠完整半球运动皮质的可塑性变化,加速大鼠脑卒中模型的康复速度和程度;DTT可准确检测大鼠脑卒中后神经纤维束的病理改变,BOLD-fMRI不适用于检测大鼠全麻状态下被动运动的激活部位.%Objective To evaluate the effect on the stoke model of rat by functional magnetic resonance imaging; evaluation (fMRI) combined with the nervous' symptom score. Method After successfully modeled, 40 MACO model rats were randomly divided into model group and exercise group, 20 animals were assigned in each group. The recovery of the rats was synthetically evaluated by the nervous symptom score on Day1, 10, 20, 30. The cerebral infraction position in both groups was detected by fMRI on Day3, 30. Result The score in both groups on Day30 was significantly higher than the Day1. But the score in exercise group's was significantly higher than the model group (P＜0.05).The T1WI, T2WI were normal, and diffusion ensor ractograph (DTT) showed bilateral nerve fiber bundle was symmetrical without interruption in normal rats. On Day 3, the exercise group, the T1WI showed low signal strip shadow and the T2WI showed large flake of high signal shadow in right cerebral hemisphere, the fiber bundle in right hemisphere was significantly decreased and broke off compared with the left hemisphere. On Day 30, T1WI, T2WI showed large areas of malacia in right hemisphere,the fiber bundle was obviously fewer than the opposite side and have been broken off. The blood oxygenation level dependent-functional magnetic resonance imaging (BOLD-fMRI) discovered the activated spot appeared in very different position and had poor reproducibility in different group rats and beforeafter study in the same rat. Conclusion The exercise therapy method could significantly improve the nervous symptom of stroke model rats. DTT could accurately detect the pathologic change of the nerve fiber bundle after the rats have been stroked. BOLD-fMRI was not appropriate to detect the rat's allokinetic activation position under anesthesia state.