| Objective: By using the rest-stating effective connectivity(rs EC),the differences in the motor recovery mechanisms between stroke patients with different subcortical lesions were explored.This study is related to the following two aspects.The first,we aimed to investigate rs EC changes among the primary motor cortex(M1),supplementary motor area(SMA)and cerebellum(Ce),and their clinical correlations in subcortical stroke patients.Another aim of this study was to investigate whether different sites of subcortical stroke may have differences in functional connectivity within the motor execution network.Subjects and Methods: Based on the rigorous inclusion and exclusion standards,we selected 114 chronic stroke patients collected from three domestic first-class hospitals,including 79 patients with capsular stroke(CS),35 patients with pontine stroke(PS).At the same time,50 healthy controls(HC)matched with their age and gender,were selected as the normal control group.All of the subjects were conduct neurobehavioral scales and then functional and structural images were acquired using a 3.0 T scanner.Then according to the Fugl-Meyer Assessment(FMA),patients who were obtain less than 100 scores are classified as partial recovery(PR)group.Two-way analysis of covariance(ANCOVA)was used to investigate the main and interaction effects of the lesion-sides and groups on rs EC while with age,sex and scans as the nuisance variables.The altered rs EC were correlated with motor scores.In addition,divide the above patients into left CS,left PS,right CS and right PS.Then according to the definition of motor execution network,we superimposed the probability maps of lesions in patients with chronic subcortical stroke,and then removed the intersections(basal ganglia and thalamic regions).We got 8 regions of interest(ROIs)in the left hemisphere and 9 ROIs in the right hemispere,they constitute the motor execution network.Namely,the M1,AICb,DN,PMd,PCG,SCb,SPL,SMA,PMv in the right hemisphere and the M1,AICb,DN,PMd,SCb,SPL,SMA and PMv in the left hemisphere.The general linear model was used to compare left CS,left PS ang HC group differences,right CS,right PS ang HC group differences in the resting-state functional connectivity(rs FC)between these ROIs.Results: 1.Although no significant lesion-side effects and lesion-side × group interactions,several rs EC showed significant group effects.Both CS and PS patients showed reduced rs EC from the ipsilesional to the contralesional M1 and increased rs EC from the contralesional M1 to the ipsilesional M1 and the cerebellum than controls.2.CS patients had increased rs EC from the contralesional SMA to the ipsilesional M1 than PS patients and controls.The rs EC from the contralesional to the ipsilesional cerebellum was increased only in PS patients.3.These rs EC changes were correlated with motor scores in the PR patients.4.Compared to controls,the increased rs FC in the motor execution network were connectivity of the left PMd-right M1 and the right PMv-left SPL in the left CS group,those of the right PMd-left M1 and the right PMv-right PCG in the right CS group,those of the right DN-left SMA and the left DN-right SMA in the left PS group,and those of the left DN-right M1 and the left AICb-right SCb in the right PS group.5.Compared to controls,the reduced rs FC in the motor execution network were the right PCG-right PMv connectivity in the left CS group,the left M1-left SMA connectivity in the right CS group,and the right AICb-right PMd connectivity in the left PS group.Conclusions:1.Both the CS and PS patients with subcortical stroke affected the effectivity connectivity of the M1,suggesting it may be an important target for the recovery of motor function after stroke.2.There were correlations between motor function and rs EC changes in patients with PR,suggesting that these positive correlation from the contralateral M1 to ipsilateral M1 and contralateral SMA to ipsilateral M1,the negative correlation from ipsilateral M1 to contralateral M1 may be one of the neural bases accounting for the recovery of motor function in stroke patients.3.Stroke patients with CS and PS had their own unique connectivity changes in motor execution network. |
