Abstract
Objective To analyze the microstructural changes of white matter fiber tracts in patients with cerebral small vessel disease(CSVD)based on diffusion tensor imaging(DTI)using automatic fiber quantification(AFQ)technology and to explore the relationship between these changes and gait disorders.Methods Patients with CSVD who visited the Department of Neurology of the Second Affiliated Hospital of Xuzhou Medical University from September 2024 to May 2025 were prospectively included.Clinical data were collected from all patients enrolled,including demographic data(age,gender,years of education,body mass index),cerebrovascular risk factors(hypertension,diabetes,history of stroke,hyperlipidemia,smoking history,drinking history),laboratory tests(cholesterol,triglycerides,high-density lipoprotein cholesterol,low-density lipoprotein cholesterol,lipoprotein a,fasting blood glucose,glycated hemoglobin,homocysteine,uric acid,creatinine),Montreal cognitive assessment scale visuospatial executive function score within 72 h after enrollment,periventricular white matter hyperintensity score,deep white matter hyperintensity score,lacunar infarction,microbleeds,enlarged perivascular spaces(＞10),brain atrophy,incidental diffusion-weighted imaging positivity,cortical microinfarction,and cortical surface iron deposition.Within 72 h after enrollment,gait analysis was performed on all patients using a wearable motion and gait quantification assessment system,and multiple gait parameters were obtained:basic spatiotemporal parameters(timed up and go test[TUG]time,gait speed,cadence,walking duration,sitting duration,standing duration,step length,stride length,stance phase,swing phase),walking balance parameters(step length variability,peak trunk[forward,backward,left,right]tilt angle),symmetry parameters(step length asymmetry),turning flexibility parameters(turning duration,peak angular velocity during turning,average angular velocity during turning),and coordination(relative mean phase difference,phase coordination index,left-right foot coordination).All enrolled patients completed the short physical performance battery(SPPB)within 72 h of enrollment.According to the SPPB score,all patients were divided into the normal gait group(SPPB score ≥ 10 points)and the gait disorder group(SPPB score＜10 points).3.0T MRI-DTI data were collected,and the whole brain streamlines were divided into 20 white matter tracts based on the Johns Hopkins University white matter tractography atlas and path points.Each tract was equally divided into 100 nodes,and AFQ technology was used to extract the fractional anisotropy(FA),mean diffusivity(MD),axial diffusivity(AD),and radial diffusivity(RD)values of each node of the 100 nodes of each white matter tract.The clinical data,gait parameters,and imaging data of the two groups of patients were compared.Partial correlation analysis was used to explore the correlation between each gait parameter and the average values of FA,MD,AD,and RD of all nodes of each white matter tract segment.To further control the influence of confounding factors,multiple linear regression analysis was performed with each gait parameter and SPPB scores as the dependent variable and the average values of FA,MD,AD,and RD of the white matter tract segments correlated with the gait parameters as the independent variables.All independent variables were subjected to multicollinearity tests.Variables with collinearity(with the tolerance less than 0.1,and the variance inflation factor[VIF]greater than 10)were excluded,the rest variables were analyzed with multiple linear regression to explore the relationship between the average values of FA,MD,AD,and RD of different segments of the white matter tracts and each gait parameter.Results A total of 60 patients with CSVD were included,including 31 males and 29 females,aged 45 to 80 years,with an average age of(64±11)years.Among them,31 patients had normal gait and 29 had gait disorders.(1)Compared with the gait disorder group,the normal gait group had a longer education duration and a lower body mass index(all P＜0.05),while there were no statistically significant differences in the other indicators between the two groups(all P＞0.05).Compared with the normal gait group,the gait disorder group had longer TUG time,walking duration,step length variability,and turning duration,and lower gait speed,step length,stride length,peak angular velocity during turning,and average angular velocity during turning(all P＜0.05).(2)The FA values of the anterior cingulate gyrus(nodes 10-20,30-35)in the gait disorder group were lower than those in the normal gait group(false discovery rate[FDR]corrected,P＜0.05);the MD values of the anterior part of the left inferior longitudinal fasciculus(nodes 1-43,53-56),the RD values of the anterior-middle part of the left cingulate gyrus(nodes 12-17,29-60),and the AD values of the anterior part of the left inferior longitudinal fasciculus(nodes 10-29)were higher in the gait disorder group than in the normal gait group(FDR corrected,P＜0.05).(3)The results of the partial correlation analysis showed that the average FA value of the anterior cingulate gyrus(nodes 10-20)was negatively correlated with turning duration(r=-0.330,P=0.027)and positively correlated with peak angular velocity during turning(r=0.301,P=0.045)and average angular velocity during turning(r=0.355,P=0.017);the average MD value of the anterior part of the left inferior longitudinal fasciculus(nodes 1-43)was negatively correlated with gait speed(r=-0.306,P=0.039),step length(r=-0.344,P=0.019),and stride length(r=-0.347,P=0.018);the average RD value of the anterior-middle part of the left cingulate gyrus(nodes 29-60)was positively correlated with TUG time(r=0.326,P=0.029),walking duration(r=0.383,P=0.009),and turning duration(r=0.512,P=0.001),and negatively correlated with gait speed(r=-0.304,P=0.042),average angular velocity during turning(r=-0.504,P=0.001),and peak angular velocity during turning(r=-0.466,P=0.001);the average AD value of the anterior part of the left inferior longitudinal fasciculus(nodes 10-29)was negatively correlated with gait speed(r=-0.354,P=0.016),step length(r=-0.337,P=0.022),stride length(r=-0.347,P=0.018),and average angular velocity during turning(r=-0.341,P=0.020),and positively correlated with walking duration(r=0.323,P=0.029)and sitting duration(r=0.383,P=0.009).There was no correlation between the remaining gait parameters and the average values of the fiber tract segment indicators(all P＞0.05).(4)No variables with collinearity were found by the collinearity test.The multiple linear regression model showed that,after controlling for confounding factors,the average MD value of the anterior part of the left inferior longitudinal fasciculus(node 1-43)was negatively correlated with step length(β=-0.380,P=0.008)and stride length(β=-0.431,P=0.002);the average AD value of the anterior part of the left inferior longitudinal fasciculus(node 10-29)was negatively correlated with average angular velocity during turning(β=-0.391,P=0.007).The average RD value of the left anterior midcingulate(nodes 29-60)was positively correlated with the TUG time(β=0.667,P=0.002),walking duration(β=0.387,P=0.007),and SPPB score(β=0.413,P=0.002),and negatively correlated with gait speed(β=-0.706,P=0.013)and peak turning angular velocity(β=-0.296,P=0.040).No correlation was found between the average values of FA,MD,AD,and RD of the rest segments of the white matter tracts with each gait parameter and SPPB score(all P＞0.05).Conclusion CSVD patients with gait disorder exhibited multi-segment white matter microstructural damage in the left anterior cingulum and left anterior inferior longitudinal fasciculus,which affected their gait function.关键词
脑小血管病/弥散张量成像/步态障碍,神经性/白质微结构/纤维束Key words
Cerebral small vessel disease/Diffusion tensor imaging/Gait disorders,neurologic/White matter microstructure/Fiber tracts
