ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
Objective To study the effect of white matter lesions location on cognitive function by comparing the correlation between the anatomical location of white matter lesions and cognitive function in leukoaraisosis(LA)patients. Methods A total of 75 LA patients with different degrees of white matter le-sion were randomly recruited.The modified Scheltens scale,Manolio scale and Fazekas scale were utilized to assess the severity of white matter lesions(WMLs)by two physicians.Montreal cognitive assessment (MoCA)was used to evaluate the cognitive function.The correlation between WMLs location and cognitive function was analyzed by spearman rank correlation analysis.The t-test was used to test the differences of periventricular white matter lesions with cognitive impairment(PWMLs-CI)and periventricular white matter lesions with cognitive normal(PWMLs-CN)in each goup. Results For Fazekas scale,PWMLs were signifi-cantly correlated with the decrease scores of MoCA score(r=-0.388,P=0.007),visuospatial and executive (r=-0.466,P=0.000),delayed recall(r=-0.461,P=0.001),abstraction(r=-0.355,P=0.011)and ori-entation(r=-0.337,P=0.016)(P<0.05).For Scheltens scale,PWMLs was negatively correlated with MoCA score(r=-0.390,P=0.003),visuospatial and executive(r=-0.464,P=0.000),delayed recall(r=0.484, P=0.000),attention(r=-0.375,P=0.008)and orientation(r=-0.342,P=0.013)(P<0.05),but not in deep white matter lesions(DWMLs)(P>0.05).Compared with PWMLs-CN,executive function(42.13 ± 0.89),attention(16.36±1.24)and visuospatial(2.25±0.31)in PWMLs-CI had statistical significance(P<0.05). Conclusion White matter lesions location affect cognitive function,PWMLs are more closely related to cognitive impairement,characterized by executive function,attention and visuospatial aspects.
ABSTRACT
Objective To explore the effect of leukoaraiosis (LA) on the efficiency of the brain function network and to analyze the features of the "small world" network with graph theory method.Methods This study involved 34 LA patients from the Department of Neurology,Beijing Tiantan hospital,Capital Medical University from January 2014 to September 2015 and 23 age-and sex-matched healthy controls(NC group).All participants underwent the neurocognitive tests including M MSE,MoCA and clinical dementia rating(CDR).The subjects were divided into LA with cognitive normal group (CN) (n=11) and LA patients with vascular cognitive impairment-non dementia group(VCIND) (n=23).Functional MRI (fMRI) was employed at resting state.And then,the functional network establishment and small-world network metrics (characteristic clustering coefficient and path length) were computed using graph analytical methods.Results In the range of 0.05 ≤ Kcost ≤ 0.5,the functional networks fitted the definition of small-worldness in LA (CN),LA(VCIND) and NC groups(δ＞1).The Lambda of group LA(CN) and LA (VCIND) were smaller than that of NC group at each threshold,and more closing to 1.The gamma of group LA(CN) were higher than that of NC group at each threshold.While the gamma of group LA(VCIND)were lower than that of NC group at each threshold.The sigma of group LA(CN) were higher than that of NC group at each threshold.Conclusion The LA patients exhibit abnormal small-world network properties.And compared with HCs,small world properties in LA (CN) patients have been increased,while that in LA (VCIND) patients have been reduced,which manifested that the altered topological properties may be responsible for cognitive dysfunction in LA patients.
ABSTRACT
Leukoaraiosis (LA) has important clinical significance;however, the neurobiological mechanism was still unclear. In this pa-per, we reviewed literatures about the clinical symptoms, pathology and imaging of LA in order to improve the understanding of the patho-logic mechanism, recognize the reversible pathological change in the earliest stage, which can help to prevent dementia.
ABSTRACT
Objective Estimating the determined result bias of two kinds of Cholesterol reagents,in order to research Comparability of results between different reagent method.Methods According to the file of NCCLS EP9-A of America,take 8 clinical serum samples every day,which conclude high、middle and low result samples,analyze each samples twice a day for 5 days,recorded results,analyzed the statistics.,to evaluate the bias estimation of two kinds reagents.According to contrast results,calibration for antomation system(c.f.a.s)taking two kinds calibration cost and using mixed human serum as calibration article,perform the same procedure described above but add 10 samples everyday.which conclude high、middle and low result samples,then statistics analysis was performed.Results The bias rate of two kinds reagents was 5.3%,the difference was statistically significant(P 0.05).Conclusions When changed regent or c.f.a.s in a clinical serum sample comparison experiment,for Cholesterol reagents from different company,c.f.a.s cannot take single calibration values,and cannot emendate the values of calibration serum only by the reply result from a single external quality assessment.Taking the mixed human serum calibrated by reference method as calibration values,which values can correct the determined bias caused by different regent.
ABSTRACT
The cardiotonic activity of MD, a domestic product of AR-L115, BS, was tested and verified in isolated guinea pig atria, compared with that of isopreraline (ISO). The electrically paced left atria was used to determine their positive inotropic action, while the spontaneously beating right atria was used to determine their positive chrono-tropic action. The results demonstrate: (1) MD showed a strong positive inotropic action comparable to ISO. (2) MD also showed some positive chronotropic action, although this is much weaker than that of ISO. (3) The single dose of MD showed that the positive inotropic action developed quite slowly and strengthened gradually for a long time, while the action of ISO developed so steeply that its peak effect can reached within a few minutes. (4) Propranolol can definitely block both inotropic and chronotropic actions of ISO but scarcely those of MD. This suggests that MD is not a ?1-receptor agonist.The experimental results described above are similar to those reports abroad.