关键词: 脑梗死, 胼胝体, 各向异性分数, 功能连接, 运动功能障碍

Abstract: Objective To explore the relationship between the changes of corpus callosum related structure and function and motor dysfunction in patients with cerebral infarction (CI). Methods 41 patients with cerebral infarction (CI) admitted to our hospital from March 2022 to September 2025 were selected as the study subjects and included in the CI group.Additionally,41 age- and gender-matched healthy subjects were selected and included in the control group.Diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rs-fMRI) were used to assess the fractional anisotropy (FA) values of the corpus callosum fibers and interhemispheric functional connectivity,and their correlation with FMA scores was analyzed. Results In the hemispheric interconnection group,29 out of 32 corticospinal nerve fiber bundles in the homologous brain regions of the hemispheres showed significantly reduced FA values in the mid-sagittal plane region (P＜0.05).Furthermore,the FA values of these 29 corticospinal fibers were significantly reduced and positively correlated with FMA scores (P＜0.05).The overall functional connectivity between hemispheres was significantly weakened,with 5 connections showing a significant correlation with FMA scores (P＜0.05).Among them,three involved homologous brain regions,which were primary motor cortex (r=0.503,P=0.018),ventral premotor area (r=0.594,P=0.004),inferior frontal gyrus (r=0.482,P=0.028); Two are functional connections of non homologous brain regions,which are the connections between the lateral orbital gyrus of the affected side and the orbital part of the inferior frontal gyrus of the contralateral side (r=0.487,P=0.027),and between the inferior parietal lobule of the affected side and the superior marginal gyrus of the contralateral side (r=0.524,P=0.015). Conclusion After unilateral CI,extensive microstructural damage appeared in the fiber bundles connecting the corpus callosum to the bilateral hemispheres,and the interhemispheric functional connectivity showed an overall weakening.These structural and functional impairments,especially the disruption of connections in sensorimotor related brain regions,are closely related to the severity of motor dysfunction in patients.Dysregulation of the bilateral hemispheric network mediated by the corpus callosum is an important mechanism of movement disorders after CI.

Key words: Cerebral infarction, Corpus callosum, Anisotropy fraction, Functional connectivity, Motor dysfunction