脑卒中运动功能障碍的局部一致性fMRI研究

目的:运用静息态功能性磁共振成像探究不同程度运动功能障碍脑卒中的脑局部一致性(regional homogeneity,ReHo)变化。方法:对单侧皮质下脑卒中患者(其中轻度和重度运动功能障碍患者各13例)和13例健康志愿者分别进行静息态功能磁共振成像检查。分别计算三组被试的全脑ReHo值,运用双样本t检验得到组间的差异脑区,进一步将差异脑区的ReHo值与临床上肢运动功能评分及手腕运动功能评分作相关性分析。结果:与健康对照组比较,轻度组病灶同侧皮质下的尾状核和丘脑的ReHo显著减小,辅助运动区及病灶对侧颞下回、梭状回及小脑的ReHo显著增高。重度组病灶同侧的初级运动皮质、扣带前回、颞下回、脑岛、枕中回及丘脑的ReHo显著减小,病灶对侧额上回、颞下回及小脑的ReHo显著增高。患者子组比较,重度组病灶同侧枕中回和病灶对侧颞上回的ReHo均显著低于轻度组,其中枕中回的ReHo值与上肢和"手+腕"FMA(Fugl-Meyer Assessment)评分显示正相关(分别为r=0.647,r=0.682,P<0.001),颞上回的ReHo值亦与上肢和"手+腕"FMA评分显示正相关(分别为r=0.646,r=0.718,P<0.001)。结论:单侧皮质下脑卒中运动功能障碍静息态神经功能活动异常与运动功能严重程度密切相关,主要涉及邻近病灶的皮质下组织和远离病灶的脑皮质。其中一些脑区的ReHo值与患者运动功能评分存在相关性,或许说明ReHo分析可以作为评估卒中患者运动功能障碍的一个重要影像学指标。

Brain regional homogeneity alterations at resting state in the patients with motor deficits after stroke

Objective:To investigate abnormal regional homogeneity in stroke patients with different severity of motor deficit.Method:The unilateral subcortical stroke survivors(n=13,mild motor deficits,n=13,severe motor deficits,respectively)relative to healthy participants(n=13)were enrolled.The Kendall’s coefficients of concordance of the whole brain of each group was calculated.Two-sample t-test was performed to compare the differences in brain regions between the two groups,and we further investigated the relationship between the motor deficits and ReHo of these areas.Result:Compared with healthy controls,the ReHo in the ipsilesional caudate nucleus and thalamus decreased significantly,while the ReHo in the supplementary motor area and the contralesional inferior temporal gyrus,fusiform gyrus and cerebellum increased significantly in the mild stroke group.In the severe stroke group,the ReHo in the ipsilesional primary motor area,anterior cingulate gyrus,inferior temporal gyrus,insula,occipital middle gyrus and thalamus decreased significantly,but the ReHo in the contralesional superior frontal gyrus,inferior temporal gyrus and cerebellum increased significantly.Further comparison was made between the two subgroups of stroke.In the severe stroke survivors,the ReHo in the ipsilesional occipital gyrus and contralesional superior temporal gyrus were significantly lower than those in the mild motor stroke survivors,with their ReHo values positively correlated with the FMA scores(both the upper extremity section and the hand+wrist section of the Fugl-Meyer Scale).Conclusion:The abnormal resting brain function activity of unilateral subcortical stroke motor dysfunction mainly involved the subcortical tissue adjacent to the lesion and the cerebral cortex far away from the lesion,which was closely related to the severity of motor dysfunction.ReHo in specific brain regions was significantly correlated with patients’motor function scores,indicating that ReHo method may be used as an important reference for the assessment of motor dysfunction in stroke patients.