低级别肝性脑病静息态低频振幅变化研究

目的探讨低级别肝性脑病静息态下脑低频振幅变化及其意义。方法研究对象共59例,分三组：正常对照,单纯肝硬化组与低级别肝性脑组。组内ALFF强度检验使用单样本t检验。两组间ALFF差别使用双样本t检验。三组间ALFF比较使用单因素方差分析。结果组内t检验显示扣带回后部、楔前叶、额叶前内侧和顶下小叶等脑DMN相关区域内ALFF明显增高。与对照组相比,低级别HE组ALFF在楔叶、楔前叶、视觉皮层等脑叶显著减低;增高区域主要位于皮层和皮层下区。与单纯肝硬化组相比,低级别肝性脑病组ALFF在楔叶、楔前叶、视觉皮层、小脑左后叶显著减低;扣带回前部、双侧额上回,双侧额中回ALFF增高。单纯肝硬化组合对照组间没有差异。结论在低阶级肝性脑病患者中存在ALFF的异常变化,这些神经元活动异常可能是低级别HE患者神经病理机制的基础。

Abnormal baseline brain activity in low-grade hepatic encephalopathy

Objective To estimate abnormal baseline brain activity in low-grade hepatic encephalopathy.Methods We conducted a resting-state fMRI in 19 healthy controls,18 cirrhotic patients without HE,and 22 cirrhotic patients with low-grade HE.The amplitude of low-frequency fluctuations（ALFF）of fMRI signal was computed to measure the spontaneous neuronal activity.Results Several regions showing significant ALFF differences among three groups were the precuneus,occipital lobe,left frontal lobe and anterior/middle cingulate cortex,and left cerebellum posterior lobe.Compared to controls or patients without HE,patients with low-grade HE showed decreased ALFF in the precuneus and adjacent cuneus,visual cortex,and left cerebellum posterior lobe.Compared to controls,patients with low-grade HE showed higher ALFF in both cortical and subcortical regions,including the right middle cingulate gyrus,and left anterior/middle cingulate gyrus,inferior frontal gyrus,insula lobe,parahippocampal gyrus,middle temporal gyrus and lentiform nucleus;compared to patients without HE,patients with low-grade HE showed higher ALFF in the left medial frontal gyrus and anterior cingulate gyrus,bilateral superior frontal gyrus,and right middle frontal gyrus.Conclusion These results suggested the existence of aberrant brain activity at the baseline state in low-grade HE,which may be implicated in the neurological pathophysiology underlying HE.