静息态全脑体素水平功能连接分析对脑小血管病相关轻度认知障碍患者认知水平的预测作用

Predictive effect of resting state whole brain voxel level functional connectivity analysis on cognitive level of patients with mild cognitive impairment associated with cerebral small vessel disease

目的通过体素水平静息态功能MRI(resting state functional MRI,rs-fMRI)序列探索脑小血管病相关轻度认知障碍(mild cognitive impairment associated with cerebral small vessel disease,CSVD-MCI)患者早期认知障碍的机制,并分析其与临床神经心理学指标的相关性。材料与方法筛选临床及常规MRI检查符合CSVD-MCI诊断标准的受试者21例,并挑选与其年龄、性别及受教育年限相匹配的健康对照(health control,HC)20例,所有被试都接受rs-fMRI检查,计算全脑度中心度(degree centrality,DC)值,将两组DC值差异显著团块的峰值蒙特利尔神经病学研究所(Montreal Neurological Institute,MNI)坐标作为种子点,与全脑其他体素进行功能连接(functional connection,FC)分析,两组脑功能存在差异脑区的DC及FC值与蒙特利尔认知评估量表(Montreal Cognitive Assessment,MoCA)评分进行相关性分析,并进一步分析CSVD总负荷评分与MoCA评分,以及CSVD总负荷评分与各认知域评分的相关性。结果与HC组相比,CSVD-MCI组左侧内侧额上回/左侧前扣带回、左侧角回/左侧缘上回、右侧内侧额上回/右侧额中回、左侧小脑及右侧小脑DC值减低,左侧前扣带回与左侧颞中下回、双侧楔前叶、双侧中扣带回FC值减低。白质高信号评分、CSVD总负荷评分与MoCA评分呈显著负相关(r_(s)=−0.461,P=0.036;r_(s)=−0.458,P=0.037);CSVD总负荷评分与视空间和执行功能评分呈负相关(r_(s)=−0.473,P=0.030),与其他认知域评分无显著相关性。CSVD-MCI组左侧前扣带回-右侧楔前叶FC值与MoCA评分呈显著正相关(r=0.565,P=0.018)。结论常规MRI可以显示CSVD特征性影像学病灶,rs-fMRI序列可以早期发现DC及FC减低脑区,CSVD评分及DC、FC值与临床神经心理学评分呈明显相关,可作为CSVD-MCI患者的潜在影像学标志物,揭示其认知功能减退的潜在机制。

Objective:The resting state functional MRI(rs-fMRI)sequence at the voxel level was used to explore the mechanism of early cognitive impairment in patients with mild cognitive impairment associated with cerebral small vessel disease(CSVD-MCI)and analyze its correlation with clinical neuropsychology indicators.Materials and Methods:Twenty-one subjects who met the diagnostic criteria of CSVD-MCI by routine MRI were screened,and 20 healthy control(HC)subjects matched with their age,gender and years of education were selected.All subjects received rs-fMRI,and calculated the value of degree centrality(DC),the peak Montreal Neurological Institute(MNI)coordinates of the two groups with significantly different DC values were used as seed points for functional connectivity(FC)analysis with other voxels in the whole brain,correlation analysis was performed between DC and FC values and Montreal Cognitive Assessment(MoCA)scores in brain regions with differences in brain function between the two groups,to further analyze the correlation between CSVD total load score and MoCA score,and CSVD total load score and each cognitive domain score.Results:Compared with the HC group,the left medial superior frontal gyrus/left anterior cingulate gyrus,left angular gyrus/left supramarginal gyrus,right medial superior frontal gyrus/right middle frontal gyrus,left cerebellum and right cerebellum DC values of the CSVD-MCI group were reduced,and the FC values of the left anterior cingulate gyrus,left middle inferior temporal gyrus,bilateral precuneus,and bilateral middle cingulate gyrus were reduced.There was a significant negative correlation between white matter high signal score,CSVD total load score,and MoCA score(r_(s)=−0.461,P=0.036;r_(s)=−0.458,P=0.037);the total load score of CSVD was negatively correlated with visual space and executive function scores(r_(s)=−0.473,P=0.030),but not significantly correlated with other cognitive domain scores.In the CSVD-MCI group,the FC value of left anterior cingulate cortex and right precuneus was significantly positively correlated with MoCA score(r=0.565,P=0.018).Conclusions:Conventional MRI can display characteristic imaging lesions of CSVD,while rs-fMRI sequence can early detect reduced DC and FC in brain regions.The CSVD score and DC,FC are significantly correlated with clinical neuropsychological scores,and can serve as potential imaging markers for CSVD-MCI patients,revealing the potential mechanism of cognitive decline.