Effects Of Diabetes On Motor Recovery After Cerebral Infarction

Objective: Combined with diffusion tensor imaging(DTI)and resting-state f MRI(rs-f MRI)techniques to observe the dynamic changes of white matter fiber tracts and resting-state functional connectivity between the primary motor cortex of the two hemispheres after cerebral infarction,which is a single subcortical infarction located in the middle cerebral artery.To investigate the remodeling characteristics of interhemispheric functional connectivity and white matter fiber bundles in diabetic patients after cerebral infarction and to examine their effects on motor function recovery over time.Methods: From January 2019 to October 2020,primary acute cerebral infarction patients who were admitted to the Department of Neurology in the First Affiliated Hospital of Guangxi Medical University were successively included.According to diabetes mellitus,the patients were divided into two groups: diabetic cerebral infarction group and common cerebral infarction group.Ten age-and sex-matched healthy subjects were included,and the healthy control group received an MRI examination.The baseline characteristics of cerebral infarction participants,including age,sex,lesion volume,lesion location,and vascular risk factors,were recorded.The severity of neurological impairment in the acute phase was assessed using the National Institutes of Health Cerebral Infraction Score(NIHSS).All patients underwent two magnetic resonance examinations(including conventional T1,T2,DTI,and rs-f MRI)within 7 days(T1,4±2.5 days)and week 6(T2,42±3 days)after the onset of infarction.Fugl-Meyer Assessment(FMA,Range: 0-100)and Barthel Index(BI,Range: 0-100)were used to evaluate motor function before each MRI examination.After preprocessing the original DTI image,we used a multiple-ROI approach based on existing anatomic knowledge about tract trajectories to reconstruct the tracts of interest(including the isthmus of corpus callosum,bilateral corticospinal tracts).Then,fractional anisotropy(FA),axial diffusivity(AD),and radial diffusivity(RD)were generated.After the original rs-f MRI image was preprocessed,the resting-state functional connection between the primary motor cortex of the two hemispheres(M1-M1FC)was calculated by the corresponding software.Two independent samples t-test or Mann-Whitney U test were used for comparison between the two groups.Repeated measure analysis of variance(rm-ANOVA)was used to determine the differences in imaging and clinical indicators at different time points in the group.In the diabetic group,Pearson correlation analysis was used to evaluate the correlation between white matter structure and M1-M1 FC,MRI parameters and motor function recovery.Pearson correlation analysis was used to evaluate the relationship between the percentage change of ipsilesional CST-FA,M1-M1 FC,and the percentage change of FMA in patients with cerebral infarction in the two groups from T1 to T2.Results: A total of 40 patients with acute cerebral infarction(17 females,23 males,age 62.9±11.4 years)were enrolled in the study.Among the 40 patients,there were 17 patients with diabetes and 23 patients with common cerebral infarction.The median duration of diabetes was 6.4 years.Overall,the majority of patients presented with mild to moderate cerebral infarction,with a median NIHSS score of 7(interquartile range 3-15)in the diabetic group and6(interquartile range 4-15)in the common group.The scores of FMA and BI in the 2 groups showed an increasing trend at 2-time points.The FA value of remaining ipsilesional CST in the diabetic group and the common group was lower than the healthy control group at the T1 time point.The difference was statistically significant.From T1 to T2,the FA of ipsilesional remaining CST in both groups showed an upward trend.There was no significant difference in the percentage change of remaining ipsilesional CST-FA between the two groups.At the T1 time point,FA in the corpus callosum(CC)isthmus of the diabetic cerebral infarction group was significantly lower than that of the common cerebral infarction group and healthy control group.From T1 to T2,FA in the isthmus of CC in the diabetic cerebral infarction group and the ordinary cerebral infarction group showed a downward trend,and the percentage of FA value in the isthmus of CC in the diabetic cerebral infarction group was lower than that in the ordinary cerebral infarction group.From T1 to T2,M1-M1 FC increased in both the diabetic and common cerebral infarction groups.The percentage change of M1-M1 FC in the diabetic group was 85.77%±17.63%,and that in the common cerebral infarction group was 106.01%±20.34%.The difference was statistically significant.Correlation analysis showed that: The decreased FA value in the isthmus of the corpus callosum at the T1 time point was negatively correlated with the course of the disease.In contrast,the increased RD value was positively correlated with the course of the disease,and the changes of FA and RD were not significantly correlated with the level of Hb A1 c.After cerebral infarction,with or without diabetes mellitus,the enhanced ipsilesional remaining CST-FA and the enhanced M1-M1 FC were positively correlated with increased motor function scores.A decrease of FA value in the corpus callosum in the diabetic group at the early stage was positively associated with decreased motor function recovery and decreased M1-M1 FC.Conclusion: The decrease of microstructural integrity of corpus callosum caused by diabetes may impair the remodeling of interhemispheric functional connectivity and the recovery of motor function after cerebral infarction.The degree of motor function recovery after cerebral infarction is related to the degree of remodeling of ipsilateral remaining corticospinal tract and functional connection between hemispheres.