短暂性脑缺血发作患者静息状态下脑功能连接研究

目的利用功能磁共振成像（functional magnetic resonance imaging，fMRI），动态考察短暂性脑缺血发作（transient ischemic attack，TIA）患者在静息状态下功能连接的变化，探讨TIA患者工作记忆受损的神经机制。方法纳入首次发作右侧大脑半球前循环TIA的患者35例为研究对象（TIA组），以35例健康成人为对照（对照组）。在TIA发作1周和3个月时分别行脑部静息态功能磁共振成像（resting-state functional magnetic resonance imaging,rs-fMRI）扫描，以右侧下前额叶及其镜像区为感兴趣区，计算同全脑的功能连接状况，并与对照组进行比较。结果与对照组相比，TIA患者在发病后1周表现出包括左侧小脑、右侧颞上回和右侧岛叶在内的较广泛的颅内功能连接增强，以及右侧额中回功能连接降低；而在发病后3月，包括右侧颞上回、左侧岛叶以及双侧丘脑的功能连接则逐渐转变为整体降低。进一步的相关分析发现，TIA患者在发病后1周小脑和岛叶的功能连接值同执行2-back任务时的反应时间存在相关（r值分别为0.870 2和0.781 1）。结论尽管TIA的神经系统局灶体征可迅速恢复，但在工作记忆相关的脑区将存在较长一段时间的异常激活。

Altered Functional Connectivity in Patients with Transient Ischemic Attack by Resting-state Functional MRI

ObjectiveTo investigate longitudinal changes in functional connectivity during resting-state in patients with transient ischemic attack (TIA). Methods35 patients first suffering TIA in the right hemisphere were recruited, with 35 healthy volunteers were recruited as control. At 1 week and 3 months after TIA attack, functional magnetic resonance imaging (fMRI) scans were performed, then resting-state functional connectivity was assessed and compared with that of healthy subjects. Right inferior prefrontal cortex (iPFC) and its mirror region was used as region of interest (ROI) in this analysis. ResultsCompared with controls, higher functional connectivity with the left cerebellum, right superior temporal gyrus (STG) and insula, and lower functional connectivity with the right middle frontal gyrus (MFG) was demonstrated in patients at 1 week after TIA; while decreased functional connectivity in right STG, left insula and bilateral thalamus was shown in patients at 3 month after TIA. Correlation analysis found that functional connectivity of right iPFC with the cerebellum and insula was positively correlated with 2-back reaction time at 1 week after TIA. ConclusionAlthough the nervous system signs of TIA can be quickly recovered, abnormal activation of working memory-related brain regions will occur for a long time.