Effects Of Cerebral Small Vessel Disease On Cerebral Blood Flow Perfusion And Cognitive Impairment In Alzheimer's Disease And Mild Cognitive Impairment Patients

Objective:To evaluate the manifestation of cerebral small vessel damaged and blood flow perfusion by Alzheimer's disease(AD).mild cognitive impairment(MCI)patients and control group,using MRI plain scan.susceptibility weighted imaging(SWI)and 3D arterial spin labeling(3D ASL).and to analyze the correlation between MRI findings and cognitive score,explore the effects of CSVD on blood perfusion and cognitive status.Materials and Methods;Twenty-four clinically confirmed cases of AD participated into this study(12 males and 12 females,mean age=73.08±8.39);Twenty-four cases of MCI(11 males and 13 females,mean age=70.08±8.5);Twenty-two volunteers whose age and gender matched with AD group were recruited as control(11 males,11 females,mean age=71.01 ±8.10).The clinical data of all the subjects were collected,and the MMSE table was also evaluated by neurologist.All subjects underwent conventional MRI scan?SWI and 3D ASL sequences(PLD=1.5s)in 3.0T scanner.Enlarged perivacular space(EPVS)?the number of cerebral microbleeds(CMBs)?the degree of white matter lesions(WML)and the number of lacunar infarction(LI)were recorded,meanwhile the CBF values were manually measured in the bilateral basal ganglia(BG)and centrum semiovale(CS)white matter.SPSS 17.0 statistic software was used for analysis,all data was shown as mean value and standard deviation,P?0.05 as deemed as statistically significant.The t test was used to compare the CBF values between groups.The Kruskal-Wallis test and Kolmogorov-Smirmov Z test were used to compare the ranked data.Correlation analysis using spearman correlation,the impact factors of EPVS scores were further analyzed by multivariate sequential regression analysis.Results:1.EPVS scores:In the BG,EPVS scores in AD group(2,08±0.77)was higher than that in MCI(1.29±0.46)and control group(1.09±0.29)(P<0.01),No difference was found between EPVS scores in MCI and control group(P>0.05);In the CS,EPVS scores in AD group(2.87±0.79)and MCI group(2.12±0.53)were significantly higher than that in control group(1.36±0.49)(P<0.01).2.CMBs:No statistical difference was found in the degree of cerebral microbleeds between the three group(P>0.05).3.WML:The per:iventricular hyperintense(PVH)and deep white matter hyperintense(DWMH)in the AD group significantly increased than in the control group(P<0.05),Compared to the MCI group,AD group showed up more severe degree in the PVH(P<0.01).4.LI:The incidence of LI in the AD group was 58.3%(14/24),29.2%(7/24)in the MCI group and 18.2%(4/22)in the control group(P<0.05),the incidence rate of infarction was higher in AD group than in control group((P<0.05).5.CBF value:In the BG,the CBF values of the AD group(39.51 ± 4.65)ml/(100g· min)and the MCI group(44.91 ±6.06)ml/(100g·min)were significantly lower than those in the control group(48.38±4.26)ml/(100g · min).The CBF values of the AD group?MCI group and the control group were increasing sequentially(18.31 ± 2.36?21.53±2.12?26.42± 2.22)ml/(100g · min)(P<0.05).6.Correlation analysis of EPVS:Homocysteine(Hcy)?total cholesterol(TC)?the PVH?DWMH?LI and CBF value showed the positive correlation with EPVS scores(P<0.05).7.The correlation of MRI manifestations and cognitive level:In all studied factors,course of disease?homocysteine?total cholesterol?EPVS scores?degree of WML?CBF value in BG and CS showed the negative correlation with MMSE score(P<0.05).Among them,there was a significant correlation between the BG EPVS scores and PVH with MMSE score(P<0.01).Conclusion:1.AD and MCI patients often combined with CSVD,and the phenomenon was more common and serious in AD patients.2.High homocysteine(Hcy),high total cholesterol,LI,hypoperfusion and WML were found to be influencing factors for EPVS,and the study verified a good consistent between EPVS and CBF in BG and CS of AD patients,and furthermore reflected of EPVS as the biomarker of cognitive status to a certain extent.3.Hyperlipidemia,high homocysteine(Hcy),long course of disease,blood flow perfusion,EPVS and WML were correlated with the cognitive function in AD patients and lead to exacerbations;EPVS scores and PVH can be used as imaging indicators of disease surveillance.