الملخص
Objectives:To investigate the predictive effect of regional homogeneity (ReHo) from resting-state functional magnetic resonance imaging (rs-fMRI) in acute phase on memory function of chronic phage in ischemic stroke patients and the effects of residual learning (REL) on the predictive performance of machine learning models.Methods:From June 2019 to June 2021, rs-fMRI data of one-week after stroke (acute phase) were collected from 35 first-time ischemic stroke patients, and their memory scores were assessed by the Rey auditory verbal learning test (RAVLT) at 6 months after stroke (chronic phase). Using ReHo from rs-fMRI data in acute phase of ischemic stroke patients, the support vector regression (SVR) and the REL-based SVR (REL-SVR) were constructed to predict the patients’ memory scores at 6 months after stroke, and the performance of the two models was compared using Pearson correlation coefficient.Results:Based on the ReHo from acute phase, the correlation coefficient between the predicted values and the true scores from the SVR model was r=0.524, P=0.001, while the correlation coefficient obtained by the REL-SVR model was r=0.671, P<0.001. Brain regions with relatively higher weights such as Temporal_Pole_Mid_R (weight value: 1.03), Temporal_Mid_R(weight value: 1.03), Temporal_Inf_R (weight value: 1.03), Occipital_Mid_R (weight value: 0.57), Frontal_Mid_L (weight value: 0.32), Frontal_Sup_Medial_L (weight value: 0.53), SupraMarginal_L (weight value: 1.54), Calcarine_L (weight value: 0.65), Lingual_L (weight value: 0.58), Cuneus_L (weight value: 0.65), Precuneus_L (weight value: 0.83), cerebellum(weight value>1.0) made larger contributions to the prediction model. Conclusions:ReHo in the acute-phase can effectively predict memory in the chronic phase of ischemic stroke patients. Furthermore, REL can improve the performance of the traditional SVR model and achieve higher predictive accuracy.
الملخص
Objective:To investigate the changes in gray matter volume (GMV) and abnormalities in structural covariant network (SCN) patterns in patients with chronic pontine infarction (PI).Methods:Patients with unilateral chronic PI (case group) with the first onset admitted to the First Affiliated Hospital of Zhengzhou University and Tianjin Medical University General Hospital from October 2014 to June 2021 were prospectively included. At the same time, healthy subjects matched with age, gender and education years (normal control group) were included. High-resolution three-dimensional T 1 structural MRI images and behavioral scores of the subjects were collected. The voxel-based morphometry and two-sample t test were used to explore the differences in GMV between the groups. Using GMV differential brain regions as seed points, SCN was constructed to explore the abnormality of structural covariant patterns in patients with PI. Spearman rank correlation analysis was used to analyze the correlation between GMV in differential brain regions and behavioral scores. Results:A total of 60 patients with PI were enrolled, including 33 left PI and 27 right PI, while 34 healthy controls were also enrolled. Compared with the normal control group, the GMV in bilateral posterior cerebellar lobe decreased significantly in the left PI group, and the GMV in left anterior and posterior cerebellar lobes and the right posterior cerebellar lobe decreased significantly in the right PI group (Gaussian random field correction with voxel level P<0.001 and cluster level P<0.05, cluster voxel >20), and there was a significant correlation between GMV values in the left anterior and posterior cerebellar lobes and the right posterior cerebellar lobe and the motor function score ( P<0.05). In addition, compared with the normal control group, the right PI group had broader covariate brain regions and a significant increase in the number of structural connections between covariate brain regions (family-wise error correction with voxel level P<0.05, cluster voxel >20). Conclusions:The GMV in bilateral posterior cerebellar lobe decreases significantly in patients with chronic PI, and were secondary to broader covariate brain regions and structural connections. This may be the neural mechanism of impaired behavioral function in patients with PI.
الملخص
Objective@#To explore the influence of the location of the infarction lesion on the resting-state functional connectivity (rsFC) of the motor execution network.@*Methods@#A total of 144 patients with infarction of the motor pathway were involved in the study, including 97 patients with capsule stroke (CS) and 47 patients with pontine stroke (PS).50 age-matched healthy subjects were enrolled.After acquiring the structural images and the resting-state functional MRI data of all the subjects by 3.0-Tesla MR scanner, the functional connectivity was calculated in different regions of interest and the differences of the rsFC within the motor execution network among patients with different infarction location were compared.@*Results@#Left CS patients exhibited increased rsFC in L_PMd (MNI x, y, z: -22, -13, 57) -R_M1 (MNI x, y, z: 38, -22, 56) (F=3.951, P=0.022), the increased rsFC than healthy controls (P=0.031); Left CS patients exhibited increased rsFC in R_PMv (MNI x, y, z: 53, 0, 25)-L_SPL (MNI x, y, z: -22, -64, 54) than healthy controls (F=4.017, P=0.021), left CS patients exhibited decreased rsFC in R_PCG (MNI x, y, z: 37, -34, 53) -R_PMv (MNI x, y, z: 53, 0, 25) than healthy controls(F=-3.788, P=0.025). Right CS patients exhibited increased rsFC than healthy controls in R_PMd(MNI x, y, z: 28, -10, 54)-L_M1(MNI x, y, z: -38, -22, 56) (F=4.438, P=0.014), right CS patients exhibited increased rsFC than healthy controls in R_PMv(MNI x, y, z: 53, 0, 25)-R_PCG(MNI x, y, z: 37, -34, 53)(F=4.830, P=0.010), right CS patients exhibited decreased rsFC in L_M1(MNI x, y, z: -38, -22, 56)-L_SMA(MNI x, y, z: -5, -4, 57) than healthy controls (F=-5.102, P=0.007). And the left PS patients showed increased rsFC than healthy controls in R_DN -L_SMA (F=4.939, P=0.009), left PS patients exhibited increased rsFC than healthy controls in L_DN-R_SMA (F=3.431, P=0.036), left PS patients exhibited reduced rsFC than healthy controls in R_AICb -R_PMd (F=-4.114, P=0.019). Right PS patients showed increased rsFC compared with healthy controls in L_DN-R_M1(F=3.075, P=0.049), and increased rsFC compared with healthy controls in L_AICb-R_SCb (F=3.725, P=0.027).@*Conclusion@#The infarction location poses influence on the FC alteration of the motor network after stroke.