轻微型肝性脑病患者空间工作记忆的fMRI研究  

The fMRI Study of Working Memory in Patients with Minimal Hepatic Encephalopathy

作　　者：廖玲敏[1] 马树华 尹晶晶[1] 乐洪波[1] 周力学[3] 

机构地区：[1]汕头大学医学院第一附属医院放射科,广东汕头515041 [2]汕头潮南民生医院放射科,515144 [3]中山大学孙逸仙纪念医院妇产超声科,510060

出　　处：《临床放射学杂志》2011年第11期1576-1581,共6页Journal of Clinical Radiology

基　　金：国家自然科学基金(81072905);广东省自然科学基金(10151503102000015);广东省自然科学基金(S2011010005019);广东省科技计划项目(2009B030801323);广东省科技计划项目(2010B031600023);广东省中医药管理局课题(2010058);广东省中医药管理局课题(20111053);汕头市科技局课题(汕府科[2008]85号)资助

摘　　要：目的采用行为学和血氧依赖水平功能磁共振成像(BOLD-fMRI)方法探讨轻微型肝性脑病患者空间工作记忆损伤的脑神经机制。资料与方法从符合肝硬化诊断的40例患者中筛选出轻微型肝性脑病患者12例与正常对照者12名进行n-back任务负载下的脑fMRI扫描,以AFNI软件对fMRI数据进行定位定量分析。结果 (1)轻微型肝性脑病患者在三种任务负载下的正确率明显低于正常对照组,平均反应时间亦明显延长,两组差异具有显著性(P<0.001)。(2)fMRI结果发现,在n-back任务负载下,两组被试共同激活的脑区包括双侧前额叶(PFC),前运动区(PreMA),辅助运动区(SMA)及双侧顶叶(PA),且以右侧大脑半球优势为主。对这些感兴趣区进行定量分析发现,正常对照组这些脑区均表现出了和记忆负载相关的负载效应,而轻微型肝性脑病组只在双侧前运动区及双侧顶叶发现了这种负载效应。组间比较发现,在n-back任务负载下轻微型肝性脑病患者大部分工作记忆相关脑区的激活强度均比正常对照组小。结论轻微型肝性脑病患者存在空间工作记忆损伤,双侧前额叶、前运动区、辅助运动区及双侧顶叶功能减弱是空间工作记忆损伤的机制之一。Objective To explore the neural basis of spatial working memory impairment in mild hepatic encephalopathy using ethology and BOLD.Materials and Methods 12 patients with mild hepatic encephalopathy and 12 normal controls were matched for brain fMRI scanning of n back task.AFNI software was used to analyze fMRI data.Results（1） In the n back task,the accuracy of patients with mild hepatic encephalopathy was lower than that of the control group and the average response time was also significantly prolonged,which had significant differences（P0.001）.（2）fMRI study showed that the neural network of bilateral prefrontal cortex（PFC）,bilateral premotor area（PreMA）,supplementary motor area（SMA） and bilateral parietal area（PA） were activated in n back task.Quantitative analysis of regions of interests found that all of working memory related brain regions had memory load related load effect in the control group,but only PreMA and PA showed the load effect in patients with mild hepatic encephalopathy.（3） Intergroup analysis showed the activation intensity of working memory related brain regions of patients with mild hepatic encephalopathy were lower than that of the control group in three different memory loads.Conclusion Patients with mild hepatic encephalopathy have impairment in spatial working memory,and the weakened function of bilateral PFC,PreMA,SMA,and bilateral PA may be one of the neural mechanisms.

关 键 词：轻微型肝性脑病 工作记忆 N-BACK 行为学 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学] R747.9[医药卫生—诊断学]