| Backgrounds and Objectives: Cerebral white matter lesions is one of the main causes of cognitive dysfunction in the elderly.It is not only one of the main pathological types of vascular dementia,but also related to the mild cognitive impairment to the Alzheimer's disease.Epidemiological survey suggested that the proportion of WMLs in 60 year old and older patients was up to 30% detected by brain magnetic resonance imaging.The proportion further increased with age.Therefore,it is important to study the brain white matter lesions and its cognitive dysfunction.Pathological changes in white matter lesions include demyelination of white matter fibers and axonal degeneration.Low density lesion was observed in the bilateral cerebral hemisphere and the half oval area of the cerebral hemisphere in brain CT examination.Brain MRI are more sensitive to detecte white matter lesions with hyperintensity on T2 weighted phase and FLAIR imaging.White matter lesions include juxtaventricular WMLs(JVWMLs)?periventricular WMLs(PVWMLs)?deep WMLs(DWMLs)and juxtacortical WMLs(JCWMLs).The white matter around the lateral ventricles refers to the white matter of the 3-13 mm range of the wall of the lateral ventricles which located between brain parenchyma perforating artery and choroidal artery branches of arteries and are prone to suffer from ischemic injury.Previous studies suggest that WMLs lead to the decline of cognitive processing speed,executive function,episodic memory and attention.However,pathological change in WMLs was heterogeneity.Different individuals,lesion site,stages may exist significant differences.Due to the difference involving the neural network or cortical contact may lead to different aspects of cognitive impairment.The mechanisms that specific parts of WMLs with characteristics cognitive impairment are still not clear,which restricts the early diagnosis and clinical prevention and treatment of cognitive impairment caused by WMLs.This study is based on the hypothesis that cognitive impairment is caused by cerebral white matter lesions and cortical neural circuits dysfunction.Patients with periventricle posterior horn of white matter lesions(peripostcornu white matter lesions,PPWMLs)caused by ischemic was investigated to study the correlation between characteristics cognitive damage and function and structure change of brain.Object and method:Participants with early solitary peripostcornu white matter lesions were enrolled in the present study.We evaluate the cognitive scores with neuropsychological scale and individual cognition scale,found specific pattern of the regional cerebral cortex spontaneous activation status with Resting-state functional Magnetic Resonance Imaging(Rs-f MRI)in all the subjects.We also evaluate the changes of cortical structure with voxel-based morphology(VBM)technology,evaluate the possible factors which are associated with the cognitive impairments by multimodeanalysis.The relationships among cerebral cortex functional activation status,grey matter volume atrophy and cognitive impairments were analysised.Result:1.general information:Compared with the control group we found there was no significant difference between PPWMLs group in gender,age and education.(P?0.05)2.Neuropsychological test results :Compared with the control group,we found that the cognitive tests of patients with peripostcornu white matter lesions showed significant decline in the global cognitive test scores and visuo-spatial skills,memory,and verbal fluency.2.1 global cognitive functionThe results of mini-mental state examination(MMSE)indicated that the score of PPWMLs group was 25.69 + 2.75 and the score of CN group was 29 + 1.15.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)The results of Montreal cognitive assessment(Mo CA,Beijing version)indicated that the score of PPWMLs group was 20.46 ± 2.82 and the score of CN group was 27.08 ± 0.95.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)2.2 Executive functionThe results of Trail making test(TMT)(time)indicated that the score of PPWMLs group was 82.62 ± 40.51 and the score of CN group was 57.38 ± 27.96.The score of the PPWMLs group and CN group had no significant difference(P>0.05)The results of Trail making test(TMT)(wrong times)indicated that the score of PPWMLs group was 1.38 ±1.66 and the score of CN group was 0.15 ± 0.38.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)2.3 AttentionThe results of Symbol digit modalities test(SDMT)indicated that the score of PPWMLs group was 28.69 ±9.24 and the score of CN group was 37.00 ±15.40.The score of the PPWMLs group and CN group had no significant difference(P>0.05)The results of Digit span test(DST)(forward)indicated that the score of PPWMLs group was 8.77 ± 1.83 and the score of CN group was 11.23 ±1.79.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)The results of Digit span test(DST)(backward)indicated that the score of PPWMLs group was 4.38 ± 1.39 and the score of CN group was 7.00 ±1.96.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)2.4 MemoryThe results of Instantaneous memory(ITM)indicated that the score of PPWMLs group was 2.31 ± 0.75 and the score of CN group was 2.92 ± 0.28.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)The results of short-term memory(STM)(MMSE)indicated that the score of PPWMLs group was 1.92 ±0.95 and the score of CN group was 2.69±0.63.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)The results of short-term memory(STM)(Mo CA)indicated that the score of PPWMLs group was 1.92 ± 1.66 and the score of CN group was 4.08 ± 1.18.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)2.5 Visuo-spatial skillsThe results of clock drawing test(CDT)indicated that the score of PPWMLs group was 2.31 ± 0.75 and the score of CN group was 2.92 ± 0.28.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)2.6 Verbal fluencyThe results of verbal fluency test(VFT)indicated that the score of PPWMLs group was 9.85 ± 2.19 and the score of CN group was 13.31 ± 4.15.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)2.7 Other itemsThe results of Activities of Daily Living Scale(ADL)indicated that the score of PPWMLs group was 20.00± 0.00 and the score of CN group was 20.00± 0.00.The score of the PPWMLs group and CN group had no significant difference(P>0.05)The results of Neuropsychiatric Inventory(NPI)indicated that the score of PPWMLs group and the score of CN group were 0.All of them had no psychiatric symptom.The results of Hamilton depression scale,(HAMD)indicated that the score of PPWMLs group was 1.00 ± 1.14 and the score of CN group was 1.15 ± 1.34.The score of the PPWMLs group and CN group had no significant difference(P>0.05).All of them had no depression.The results of Informant Questionaire on Cognitive Decline in the Elderly(IQCODE)indicated that the score of PPWMLs group was 3.30 ± 0.36 and the score of CN group was 3.05 ± 0.61.The score of PPWMLs group was significantly lower than that of CN group(P<0.05)3.The result of Rs-fMRI(resting-state functional magnetic resonance imaging,Rs-fMRI):3.1 Compared with NC group,the ALFF of bilateral half leaflets bilateral inferior semi-lunar lobule(bilateral ISLL),bilateral inferior temporal gyrus(bilateral ITG),right hippocampus(right Hip)and the left putamen(left PUT)are significantly reduced in PPWMLs group.3.2 Compared with NC group,the ALFF of back of bilateral middle frontal gyrus(bilateral MFG)in bilateral frontal,bilateral calcarine fissure and surrounding cortex(bilateral CAL),bilateral posterior cingulated cortex(bilateral PCC),bilateral superior temporal gyrus(bilateral STG)and right middle temporal gyrus(right MTG)are significantly increased in PPWMLs group.3.3 Partial correlation analysis showed that the ALFF value of back on the left inferior temporal gyrus(ITG)was positively correlated with the digit span score(r = 0.744,P = 0.022),and the superior temporal gyrus(STG)was positively correlated with the TMT score(r = 0.828,P = 0.006)in PPWMLs group.4.The results of gray matter volume change:4.1 Compared with NC group,the gray matter volume(GMV)in the left anterior cerebellum lobe(Left Cerebellum Anterior Lobe),bilateral orbital partin superior frontal gyrus(Bilateral ORBsup),bilateral calcarine fissure and surrounding cortex(bilateral CAL),bilateral anterior cingulated cortex(bilateral ACC),bilateral middle temporal gyrus(bilateral MTG),right putamen(Right PUT)are significantly increased in PPWMLs group.(P <0.05)4.2 The gray matter volume(GMV)in bilateral fusiform gyrus(bilateral FFG)was significantly decreased in PPWMLs group.(P <0.05)4.3 The GMV values in left anterior cerebellum lobe(Left Cerebellum Anterior Lobe)was positively correlated with Digit Span Test scores in PPWMLs group.(r = 0.0.58,P = 0.03)Conclusion:1.Compared with the control group,early solitary PPWMLs caused mild cognitive impairment which was mainly in visuo-spatial construction ability,memory and language fluency.2.The ALFF value of bilateral half leaflets,bilateral inferior temporal gyrus,right hippocampus,the left putamen region were significantly reduced in the PPWMLs group,indicating that the above activity weakened brain function may be related with the cognitive impairment.The ALFF value of bilateral middle frontal gyrus,bilateral calcarine fissure and surrounding cortex,bilateral posterior cingulated gyrus,the bilateral superior temporal gyrus were significantly higher in the PPWMLs group,indicating that the function of above activity were compensatory increased.The ALFF value of left tempora was positively correlated with the digit span score in the PPWMLs group,suggesting that the aforementioned parts involved in attention and executive function.3.The volume of the left lobe,bilateral orbital partin superior frontal gyrus,bilateral calcarine fissure and surrounding cortex,bilateral anterior cingulate gyrus,bilateral middle temporal gyrus and the right putamen in the PPWMLs group were higher than that of control group,indicating that the cognitive impairments were not due to structural abnormalities caused by the aforementioned parts.The gray matter volume of PMV in bilateral fusiform gyrus(bilateral FFG)was significantly decreased in PPWMLs group,suggesting that cognitive dysfunction may be related with the shrink of relevant parts.The GMV values in left anterior cerebellum lobe(Left Cerebellum Anterior Lobe)was positively correlated with Digit Span Test scores in PPWMLs group,suggesting that parts of the foregoing may be involved in memory,attention and other aspects of cognitive activity. |
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