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Objective:To investigate the cognitive-related networks of patients with different cognitive impairment related to white matter lesions (WMLs), and explore the correlation between the altered functional connectivity and the executive function.Methods:Patients with white matter lesions in Beijing Tiantan Hospital from January 2016 to December 2020 were selected , who were divided into WML-non-dementia vascular cognitive impairment (WML-VCIND) group( n=19)and WML-vascular dementia (VaD) group( n=19). At the same time, 24 normal control group (NC) with no cognitive impairment with age, gender and education level matched were enrolled. The Stroop B, Stroop C, trail making test(TMT-B) and verbal fluency test (VFT) were used to evaluate the executive function of all subjects. The ICA method was used to identity four cognitive-related RSNs: frontoparietal network (FPN), salience network (SN), default network (DMN), and dorsal attention network (DAN). Using SPSS 20.0 software, the functional connectivity (FC) of the regions of interest of the selected RSNs among the three groups were compared by analysis of covariance, and correlation between the altered FCs and executive function scores were explored by Spearman correlation analysis. Results:(1) The FC of the medial prefrontal cortex (MPFC)-left inferior parietal lobe (IPL.L) in the VaD group(0.267±0.320) was significantly lower than that in the NC group (0.520±0.253)( P=0.005). The FC of MPFC-posterior cingulate (PCC) was significantly lower in the VaD group(0.655±0.284) than that in the VCIND group(0.810±0.232) ( P=0.017). The FC of MPFC-left insula and MPFC-left dorsolateral prefrontal cortex (DLPFC.L)was significantly higher in the VaD group(0.411±0.277, 0.545±0.311)than that in the VCIND group(0.239±0.308, 0.353±0.270)( P=0.044, 0.028). The FC of the left superior parietal lobe (SPL.L)-right dorsolateral prefrontal cortex (DLPFC.R) in the VCIND group(0.488±0.157) was significantly higher than that in the NC group(0.301±0.257) ( P=0.010). The FC of MPFC-left insula and MPFC-DLPFC.L was higher in NC group than that in VaD group ( P=0.020, 0.037). (2) The FC of MPFC-PCC was negatively correlated with Stroop C score ( r=-0.279, P=0.036), and TMT-B score ( r=-0.313, P=0.018). The FC of MPFC-IPL.L was negatively correlated with Stroop B score ( r=-0.311, P=0.018), Stroop C score( r=-0.308, P=0.020) and TMT-B score ( r=-0.367, P=0.005), while positively correlated with VFT score ( r=0.357, P=0.006). The FC of SPL.L-DLPFC.R was positively correlated with the Stroop B score ( r=0.305, P=0.021). Conclusion:There are certain differences in the functional connectivity between brain areas within the cognitive related brain networks, and the differences in FC between different brain areas are correlated with executive function scores. The changes of the FC may indicate possibly decline in executive function, which can explain the mechanism of cognitive declines.
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Objective:To analyze the characteristic of nerve tracts in different stages of cognitive impairment caused by white matter hypertensities, applying diffusion tensor imaging-peak width of skeletonized mean diffusivity as evaluation indicator.Methods:Demographic characteristics and vascular risk factors of all subjects were recorded.Screened out 50 subjects without WMH and whose MoCA scale was more than or equal 26 points as normal control group.Then, we assessed 85 patients with WMH using the MoCA scale and clinical dementia assessment. Of 85 patients, 45 cases were divided into the normal cognition group, 23 cases were assigned into non-dementia vascular cognitive impairment group, and 17 cases into the vascular dementia group.The diffusion tensor imaging-peak width of skeletonized mean diffusivity marking method was used to compare the integrity of white matter fibers in WMH patients with varying degrees of cognitive impairment and normal control group.Results:The difference of PSMD among the four groups was statistically significant(CN group: 3.558±0.157, VCIND group: 4.128±0.222, VaD group: 5.469±0.000, NC group: 2.612±0.105, F=42.479, P<0.05). PSMD in WMH groups were higher than that in NC group (all P<0.05). There was no significant difference between WMH-VCIND group and WMH-CN group ( P=0.067). The PSMD of WMH-VAD group was higher than that of WMH-CN group and WMH-VCIND group (both P<0.05). Conclusion:PSMD can accurately detect white matter fiber damage caused by WMH.The degree of WMH combined cognitive decline was not completely consistent with the degree of PSMD increase.Compared with the cases with normal WMH cognition, PSMD was not significantly increased when WMH was combined with VCIND, while PSMD was significantly increased when WMH was combined with VaD.DTI-PSMD value as imaging marker can provide objective basis for clinical diagnosis of WMH-VaD.
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Objective:To explore abnormal microstructural changes of white matter in patients with white matter lesions(WML) using diffusion tensor imaging(DTI), and to determine the association of such abnormalities of DTI parameters with executive function.Methods:Totally 34 patients with WML were recruited from the department of Neurology, Beijing Tiantan Hospital, Capital Medical University from March 2012 to May 2019.All patients with WML were scored with Hamilton depression scale (HAMD) and Hamilton anxiety scale (HAMA), and assessed with Montreal cognitive assessment (MoCA) and clinical dementia rating(CDR). They were divided into WML-cognitive normal group, WML-vascular cognitive impairment-non dementia group and WML-Dementia group.The Stroop color and word test (SCWT), trail making test-A (TMTA), digit symbol test and verbal fluency test were carried out to evaluate executive function.In addition, the healthy elderly without WML lesions were selected as the control group after they were examined by MRI, and all brains of the subjects went through DTI with Siemens 3.0 T MR.The data were collected and analyzed by voxel based analysis (VBA). The anisotropy and mean diffusion coefficient of DTI in the region of interest (ROI) and other regions in the brain were studied in the four groups, and their correlation with scores of executive function in WML patients was analyzed.Results:(1)In these executive function test, there were significant differences between the patients with cognitive impairment (WML-VAD group, WML-VCIND group) and normal cognition group(WML-CN group, NC group), such as SCWT(B)(65.54±6.24 vs 43.67±0.95, 76.75±2.13 vs 43.67±0. 95, 65.54±6.24 vs 43.66±1.81, 76.75±2.13 vs 43.66±1.81), SCWT(C)(88.58±6.76 vs 61.63±1.31, 96.37±1.47 vs 61 63±1.31, 88.58±6.76 vs 66.31±8.19, 96.37±1.47 vs 66.31±8.19), TMTA(40.47±2.76 vs 30.92±0.47, 44.24±1.43 vs 30.92±0.47, 44.24±1.43 vs 31.99±2.07, 40.47±2.76 vs 31.99±2.07), TMTB(88.66±6.55 vs 80.34±0.61, 96.70±1.72 vs 80.34±0.61, 88.66±6.55 vs 83.10±5.91, 96.70±1.72 vs 83. 10±5.91), Digit Symbol Test(39.25±5.63 vs 47.00±2.55, 31.27±3.93 vs 47.00±2.5, 39.25±5.63 vs 48.86±4.34, 31.27±3.93 vs 48.86±4.34) and Verbal Fluency Test(8.94±1.00 vs 11.71±0.47, 6.64±0.81 vs 11.71±0.47, 8.94±1.00 vs 10.86±0.69, 6.64±0.81 vs 10.86±0.69) scores ( P<0.05); In the patients with cognitive impairment, there were significant differences between WML-VAD group and WML-VCIND group, such as SCWT(B), SCWT(C), TMTA, TMTB, digit symbol test and verbal fluency test scores ( P<0.05); There were significant differences between WML-CN patients and NC group in the scores of SCWT (C), verbal fluency test( P<0.05). (2)FA values in the genu of corpus callosum and the inferior longitudinal fasciculus were negatively correlated with the time of SCWT (B), SCWT (C) and the TMTA( r=-0.436--0.471), but positively correlated with the scores of digit symbol test and verbal fluency test( r=0.428-0.573). MD values in the genu of corpus callosum, the superior/inferior longitudinal fasciculus and the inferior fronto-occipital fasciculus were positively correlated with the time of SCWT (B), SCWT (C) and TMTA( r=0.432~0.609), but negatively correlated with the scores of digit symbol test and verbal fluency test( r=-0.424--0.630, all P<0.003125 after emendation). Conclusion:The executive function of patients with WML-Dementia decreases significantly.The more serious the damage of white matter microstructure, the more serious the damage of executive of function.
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Objective To explore abnormal microstmctural changes of white matter in patients with white matter lesions using diffusion tensor imaging(DTI),and to determine the association of such abnormalities of DTI parameters with cognitive function.Methods The objects who have already confirmed with WML were collected from March 2012 to February 2018 through magnetic resonance imaging (MRI) scan from the neurology department of Beijing Tiantan Hospital.Use The hamilton depression scale(HAMD) and the hamilton anxiety scale (HAMA) to eliminate anxiety and depression,and divided into WML-CN group,WML-VCIND group and WML-VAD group with Mini-mental state examination (MMSE),Montreal Cognitive Assessment (MOCA)and clinical dementia rating(CDR).In addition,select the healthy elderly people without WML by MRI scan as the normal control group.All of the subjects were detected with the superconduct magnetic resonance imaging system (German SIEMENS 3.0T) for the DTI scanning.Original images were processed with VBA.Then explore the changes of FA and MD of DTI in whole brain and regions of interest in NC group,WML-CN group,WML-VCIND group and WWML-VAD group,and its correlation with the severity of cognitive impairment in patients with WML.Results The damage degree of the fiber microstructure of brain white matter was significantly correlated with the total grade point of MoCA (P＜0.01).In figure FA,the variance analysis of F test results showed that the significant brain areas were the splenium of the corpus callosum,the genu of corpus callosum,bilateral posterior internal capsule,retrolenticular part of internal capsule,anterior thalamic radiation,partial inferior longitudinal fasciculus and inferior fronto-occipital fasciculus,cingulate,external capsule,upper and posterior part of the radiation crowns,partial superior longitudinal fasciculus,etc.(P＜0.05 after FWE correction based on TFCE method).In Figure MD,the variance analysis of F test results showed that the statistically significant brain areas mainly included the left external capsule and hook,partial genu and splenium of corpus callosum,Bilateral,bilateral inferior fronto-occipital fasciculus,inferior longitudinal fasciculus,anterior thalamic radiation,retrolenticular part of internal capsule,cingulate,etc (P＜ 0.05 after FWE conection based on TFCE).Conclusion No matter whether cognitive impairment exists in patient with WML or not,all DTI parameters are different from those of normal people.The integrity of white matter fiber has been damaged with different degrees.The more severe the cognitive impairment in the external manifestations of patients with WML,the greater the damage to the intrinsic white matter microstructure.
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@#Objective To detect the effective connectivity of resting- state functional magnetic resonance imaging (fMRI) in normal adults. Methods 36 normal adults were performed resting-state fMRI scanning, and 5 brain netwokes were included as regions of interests. Independent component (ICA) was used to evaluate the effective connectivity, and multivariate Granger causality analysis (mGCA) was used to analyze the casuality between the networks. All preprocessing steps were carried out using Statistical Parametric Mapping 5.0 software. Results 5 classic resting brain networks including default mode network (DMN), memory network (MeN), motor network (MoN), auditory network (AN) and executive control network (ECN) were aquired. The mGCA presented significant casuality between DMN and other 4 networks, MeN and ECN, AN and MoN, ECN and AN. Conclusion There are specific brain effective connectivity of resting-state fMRI in normal adults, and there is significant causal link between these networks.
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Objective To study the default mode network (DMN) of mild cognitive impairment (MCI) related to leukoaraiosis (LA) with resting-state functional magnetic resonance imaging (rs-fMRI). Methods 31 LA patients (Clinical Dementia Rating of 0.5) and 27 nor-mal controls (Clinical Dementia Rating of 0, and matched in age, gender and lever of education) were scanned with the rs-fMRI. The data was analyzed with SPM5 software, using independent component analysis. The differences between the both groups were compared with two-sample t-test. Results The DMN during resting-state of normal controls was posterior cingulate cortex/precuneus, bilateral medial fron-tal cortex, bilateral middle temporal gyrus, bilateral inferior parietal gyrus, angular gyrus, bilateral hippocampus. The DMN of MCI group was consistent with the normal controls, but the activation decreased in anterior cingulate cortex/left medial frontal lobe, right parahippcam-pus/uncus, right inferior temporal gyrus, left deep frontal white matter/head of caudate nucleus;and increased in the left caudate nucleus/an-terior cingulate cortex, left frontal lobe, and left superior temporal gyrus/inferior parietal gyrus. Conclusion Activation of resting-state func-tional network is disorder in LA, which may relate to cognitive impairment.