卒中后早期认知下降患者默认模式网络和执行控制网络改变的功能磁共振成像研究

Changes of DMN and ECN in patients with post-stroke early cognitive impairment based on functional magnetic resonance imaging

目的基于静息态功能磁共振成像(rs-fMRI)探讨卒中后早期认知下降患者大脑静息态脑网络功能连接变化。方法连续招募2021年5月至11月于海南医学院第一附属医院神经内科急性轻型缺血性卒中患者66例,所有患者均完成神经心理学评估,根据是否简易智能状态检查量表(MMSE)评分<26分分为认知下降组35例和认知正常组31例。完成rs-fMRI扫描,比较2组前默认网络(aDMN)、后默认网络(pDMN)和执行控制网络(ECN)的功能连接(FC)改变,采用族错误率(FWE)校正。结果认知下降组蒙特利尔认知评估量表评分、MMSE总分、执行、注意力、记忆力、定向力评分明显低于认知正常组,差异有统计学意义(P<0.01)。与认知正常组比较,认知下降组aDMN左侧额中回、背外侧额上回FC明显减弱(P=0.000,FWE校正),pDMN右侧豆状壳核、左侧角回、右侧后扣带回、左侧顶下缘角回、右侧顶下缘角回FC明显减弱(P<0.05,P<0.01,FWE校正),ECN右侧海马旁回和左侧舌回的FC明显增加,在左侧后扣带回、双侧额中回和背外侧额上回的FC明显减弱(P<0.01,FWE校正)。与认知正常组比较,认知下降组pDMN与ECN间的FC明显增强(0.755±0.338 vs 0.110±0.298,P=0.000)。认知下降组ECN左额中回、背外侧额上回的FC与注意力评分呈负相关(r=-0.363,P=0.045)。认知下降组aDMN左额中回、背外侧额上回的FC与执行功能评分呈正相关(r=0.481,P=0.006)。结论卒中后早期认知功能下降患者的默认模式网络和ECN发生变化,左侧额中回、背外侧额上回的FC改变与卒中后早期认知功能下降的发生有关。

Objective To investigate the changes of functional connectivity of resting-state networks in patients with post-stroke early cognitive impairment based on resting-state functional magnetic resonance imaging(rs-fMRI).Methods From May to November 2021,66 consecutive patients with acute minor ischemic stroke were recruited in our department.All of them completed neuropsychological evaluations.According to whether the Mini-Mental State Examination(MMSE)score<26,they were divided into cognitive decline group(35 cases)and cognitively normal group(31 cases).rs-fMRI scanning was performed to compare functional connectivity(FC)changes in the anterior and posterior default mode network(aDMN and pDMN)and executive control network(ECN),with FWE correction.Results The Montreal Cognitive Assessment Scale score,MMSE total score,and execution,attention,memory,and orientation scores were significantly lower in the cognitive decline group than the cognitively normal group(P<0.01).Compared with the cognitively normal group,the cognitive decline group had obviously decreased FC of the left middle frontal gyrus and superior frontal gyrus in the aDMN(P=0.000,FWE correction),and reduced FC of the right putamen,left angular gyrus,right posterior cingulate gyrus,left inferior parietal gyrus and right inferior parietal gyrus in the pDMN(P<0.05,P<0.01,FWE correction).Increased FC in the right parahippocampal gyrus and left lingual gyrus,and decreased FC in the left posterior cingulate gyrus and bilateral middle frontal gyrus and superior frontal gyrus in the ECN were observed in the cognitive decline group than the cognitively normal group(P<0.01,FWE correction).The FC between pDMN and ECN was notably enhanced in the cognitive decline group compared with the cognitively normal group(0.755±0.338 vs 0.110±0.298,P=0.000).The FC in the left middle frontal gyrus and superior frontal gyrus of the ECN were negatively correlated with attention scores in the cognitive decline group(r=-0.363,P=0.045),and the FC in the left middle frontal gyrus and superior frontal gyrus of the aDMN were also positively correlated with attention scores in the group(r=0.481,P=0.006).Conclusion There exist changes in DMN and ECN in patients with post-stroke early cognitive impairment.The FC changes in the left middle frontal gyrus and superior frontal gyrus are related to the occurrence of post-stroke early cognitive impairment.