功能磁共振成像观察颈动脉/大脑中动脉狭窄或闭塞患者的图片工作记忆

目的 探讨左侧颈内动脉/大脑中动脉狭窄或闭塞患者与正常人图片工作记忆的激活脑区差异及其记忆障碍的脑加工机制。方法 对患者组12例左侧颈动脉/大脑中动脉狭窄或闭塞患者 (其中左侧颈内动脉狭窄4例,左侧颈内动脉闭塞2例,左侧大脑中动脉狭窄5例,左侧大脑中动脉闭塞1例)及24名健康志愿者(对照组)进行图片工作记忆任务的功能磁共振成像,采用AFNI软件进行分析。结果 左侧颈内动脉/大脑中动脉狭窄和闭塞患者的反应时间显著延长(P<0.05),正确率显著降低(P<0.05)。患者组图片工作记忆的编码期、保持期、提取期的脑激活显著少于对照组,其中提取期最为明显。结论 左侧颈动脉狭窄/闭塞患者图片工作记忆任务的脑激活区存在损害,功能磁共振成像研究能为早期诊断认知障碍提供影像学依据。

Functional MRI observation of picture working memory in patients with carotid artery/middle cerebral artery stenosis or occlusion

Objective To explore the difference of picture working memory between the patients with left internal carotid artery (ICA)/middle cerebral artery (MCA) stenosis or occlusion and healthy subjects with functional magnetic resonance imaging (fMRI). Methods fMRI were acquired in 12 patients with left ICA/MCA stenosis or occlusion (4 with ICA stenosis, 2 with ICA occlusion, 5 with MCA stenosis, 1 with MCA occlusion) and 24 healthy subjects when they received picture working memory experiment. AFNI was used to process fMRI data and localize functional areas of brain. Results The patient group showed longer reaction time and lower correct ratio (P<0.05) compared with those of the control group. The patients demonstrated fewer activated brain regions during three phase (encoding, maintain and retrieval phase) of picture task. It was the most prominent during retrieval phase in patients. Conclusion This study revealed the deficits of picture working memory in patients with left ICA/MCA stenosis or occlusion. These findings will play important roles for the early diagnosis of cognitive impairment.