AD与MCI患者注意功能障碍的功能磁共振对比研究

A comparative functional MRI study on the abnormal attention function of patients with AD and MCI

目的探究阿尔茨海默病(Alzheimer’s disease,AD)与轻度认知障碍(mild cognitive impairment,MCI)患者背侧与腹侧注意网络功能连接异常。方法对17例AD患者、16例MCI患者与16例正常老年被试者进行功能磁共振扫描,采用独立成分分析方法提取三组被试者背侧(dorsal attention network,DAN)与腹侧注意网络(ventral attention network,VAN)功能连接图像,应用单因素方差分析进行组间对比。结果 DAN内包括左侧额眼区与顶下沟区域以及扣带回后部等区域具有显著组间差异;而VAN内在额下回/额中回眶部以及背侧额中/下回等部位具有显著组间差异。对感兴趣区进行两两比较发现AD组表现出全局性注意网络衰退,而MCI组表现出选择性注意网络衰退,其中背侧出现连接降低,而腹侧连接无显著异常。结论 AD与MCI患者静息态注意网络功能连接的差异可能是注意行为能力差异的神经机制,反映了痴呆进展过程中神经退行变与神经代偿程度。

Objective To explore the abnormalities in the dorsal and ventral attention network of patients with AD and MCI. Methods Seventeen patients with AD, sixteen patients with MCI and sixteen normal aging participants underwent functional MRI scanning. After data preproeessing, independent component analysis was performed to extract the functional connectivity pattern of dorsal and ventral attention networks of three groups, and the between-group differences were calculated using one way analysis of variance. Results The dorsal attention network significantly differed in the left frontal eye fields, intraparietal sulcus area, as well as posterior cingulate cortex, while, the ventral attention network significantly differed in the right ventral and dorsal middle/ inferior frontal gyms. Post hoc comparisons on the regions of interest revealed totally impaired attentional networks for patients with AD, whereas, selectively impaired attention networks for patients with MCI, with impaired connectivity in the dorsal system, but preserved connectivity in the ventral system. Conclusion The differed functional connectivity in the attention networks of patients with AD and MCI may be the neural mechanisms of behavioral attention deficits, reflecting the deterioration progress and neural compensation degree in the process of dementia.