Language Dysfunction After Subcortical Infarction:A TBSS Study

ObjectionCombining clinical observation with MRI diffusion tensor image(DTI),by using tract-based apatial statistics method(TBSS),we aimed to explore the language deficiency and symptom related tracts’ structure of patients with subcortical aphasia after cerebral infarction,and to find the.change of tracts in the acute stage of patients with subcortical aphasia and the subsequent natural recovery process.Materials and methodsWe designed a prospective observational study.The infarction patients are from the patients in the acute stage of subcortical infarction hospitalized in the Department of cerebrovascular disease of the southern theater general hospital from January 2018 to December 2019,and is divided into right subcortical infarction and left subcortical infarction,according to the lesion location.A group of health volunteers matched in age,years of education and risk factors of cerebrovascular disease was recruited.According to the inclusion criteria and exclusion criteria,29 patients with subcortical aphasia(9 on the right,20 on the left)and 26 healthy controls were enrolled.The language function,MRI and other related scales were evaluated once both in the acute stage(within 72 hours)and the chronic stage(90±7 days).The evaluation index of language function is Chinese version of Western Aphasia Battery.MR examination included T1 plain scan and DTI.TBSS data was processed and counted on FMRIB Software Library(FSL)by using virtual machine system,gender comparison was counted by Fisher exact probability,age comparison was counted by double sample t-test,education years was counted by nonparametric test,and Pearson correlation is used for average anisotropic fraction(FA)value of tracts with spss24,P value<0.05 is considered as statistically significant.Results1.Left subcortical infarction:The patients with left subcortical infarction were mainly fluent aphasia(14/20).The aphasia quotitent,spontaneous language fluency,comprehension,repetition and naming scores of the left subcortical infarction group were significantly lower than those of the healthy group in the acute stage,and the results were statistically different,while in the chronic stage,the only significant difference was the fluency score.Compared with the healthy control group,the average FA value of the left superior longitudinal fasciculus(SLF),the left inferior frontal occipital fasciculus(IFOF)and the forceps minor in the acute and chronic stage was lower in the left subcortical infarction group.Compared the average FA value of the whole brain of patient,the average FA value of the left SLF in the chronic stage was higher than that in the acute stage.In the left subcortical infarction group,the average FA of left SLF was positively correlated with the scores of aphasia quotitent,language fluency,comprehension,repetition and naming,and the average FA of left SLF was most correlated with the scores of language fluency;the average FA of left IFOF was positively correlated with the scores of aphasia quotitent,comprehension and naming,but not with the score of language fluency and repetition.2.Right subcortical infarction:The most of patients with right subcortical infarction were also mainly fluent aphasia(7/9).The scores of aphasia quotitent,spontaneous language fluency,understanding,retelling and naming in the right subcortical infarction group were lower than those in the healthy group in the acute stage,and there were statistical differences in the comparison results.In the chronic stage,the significant difference were the understanding and naming scores.Compared with the healthy group,the average FA value of the left IFOF and the forceps minor in the acute and chronic stage in the right subcortical infarction group was lower than that in the healthy group.Compared with the FA value of the whole brain,the average FA value of the right IFOF and the forceps major in the chronic stage was higher than that in the acute stage.In the right subcortical infarction group,the average FA of left IFOF was positively correlated with the score of comprehension and naming,but not with the score of language fluency and retelling.Conclusion1.Fluent aphasia is the main language dysfunction type of subcortical aphasia,while infarction occurred in the dominant hemisphere may also lead to partial nonfluent aphasia(30%).2.In the left subcortical aphasia group,the aphasia symptom was related to the destruction of the left SLF and the left IFOF.The recovery of aphasia symptom may due to the compensation of the left SLF.3.In the right subcortical aphasia group,the aphasia symptom was related to the destruction of the left IFOF.The recovery of aphasia symptom may due to the compensation of the right IFOF,probably atributted to the regulation of forceps major(1/3 of the posterior part of the corpus callosum).