Spatial working memory dysfunction in minimal hepatic encephalopathy: An ethology and BOLD-fMRI study
Spatial working memory dysfunction in minimal hepatic encephalopathy: An ethology and BOLD-fMRI study
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DOI：
10.1016/j.brainres.2012.01.036
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发表时间：
2012-03-22
期刊：
影响因子：
2.9
通讯作者：
Ma, Shu-hua
中科院分区：
文献类型：
--
作者：
Liao, Ling-min;Zhou, Li-xue;Ma, Shu-hua
术语“轻度肝性脑病”（MHE）是指没有可识别的临床症状，但在神经心理和神经生理测试中表现异常的个体群体。研究表明，MHE患者有认知障碍，影响他们的日常生活，应该得到治疗。本研究通过行为测试和BOLD-fMRI探讨MHE患者空间工作记忆障碍的神经基础。正常对照12例，肝硬化无MHE患者12例，MHE患者12例。MHE组的记忆商（韦氏记忆量表-中文修订：WMS-CR）低于正常对照组和肝硬化无MHE组，且主要涉及短期记忆和瞬态记忆。MHE组的反应准确率低于对照组和肝硬化合并无MHE组，平均反应时间延长。fMRI数据强调了一个由双侧前额叶皮质（PFC）、双侧运动前区（PreMA）、辅助运动区（SMA）和双侧顶叶区（PA）组成的神经网络，该神经网络在n-back任务中被激活。正常对照组BOLD-fMRI反应的负荷效应出现在所有感兴趣区域（ROI），但仅出现在PreMA和PA， MHE组PFC或SMA的负荷效应不随n-back负荷而变化。正常对照组的所有roi的激活强度都高于MHE组，特别是在2背负荷时。综上所述，MHE患者存在空间工作记忆功能衰退，双侧PFC、PMA、SMA和PA的损伤通常导致空间工作记忆功能障碍。PFC损伤可能是空间工作记忆损伤的神经基础。(C) 2012 Elsevier B.V.版权所有
The term "minimal hepatic encephalopathy" (MHE) refers to a population of individuals who have no recognizable clinical symptoms but perform abnormally on neuropsychological and neurophysiological tests. Research shows that MHE patients have impairments in cognition affecting their daily lives that should be treated. This study explored the neural basis of spatial working memory impairment in MHE patients using behavioral test and BOLD-fMRI. Twelve normal controls, twelve cirrhosis patients without MHE and twelve MHE patients took part. The memory quotient of the MHE group (Wechsler Memory Scale-Chinese revised: WMS-CR) was lower than the normal control group and the cirrhosis-without-MHE group, and primarily concerned short-term memory and transient memory. Performance accuracy was lower for the MHE group than the control group and the cirrhosis-without-MHE group, and mean reaction time was prolonged. The fMRI data highlighted a neural network consisting of: bilateral prefrontal cortex (PFC), bilateral premotor area (PreMA), supplementary motor area (SMA) and bilateral parietal areas (PA), which was activated in the n-back task. The load effect of BOLD-fMRI response appeared in all regions of interest (ROI) for the normal control group, but only appeared in PreMA and PA, and did not vary with n-back load in PFC or SMA for the MHE group. Activation intensities for all ROIs were higher for the normal control group than the MHE group, especially in 2-back load. In conclusion, these results demonstrate that MHE patients have debilitated spatial working memory, and that impairments of bilateral PFC, PMA, SMA, and PA commonly lead to spatial working memory dysfunction. Furthermore, PFC impairment may form the neural basis of spatial working memory impairment. (C) 2012 Elsevier B.V. All rights reserved.