功能磁共振成像评价肝性脑病患者大脑基线活动的改变

目的 采用fMRI技术观察肝性脑病(HE)患者大脑基线活动改变。方法 对24例HE患者行静息态fMRI扫描,获取低频振幅(ALFF),其中临床症状明显的肝性脑病(OHE组)及临床症状隐匿的轻微型肝性脑病(MHE组)各12例。另选12名健康志愿者作为对照组。并进行统计学分析。结果 3组ALFF差异有统计学意义(P均<0.05)的脑区主要集中于额叶、顶叶及颞叶。与对照组比较,OHE组ALFF升高的脑区包括右侧小脑后叶、左侧小脑前叶、左侧海马旁回及左侧额下回/岛叶皮质,MHE组ALFF升高的脑区包括右侧缘上回/颞上回;OHE组ALFF减低的脑区包括双侧内侧前额叶皮质、双侧后扣带回/左侧楔叶、右侧中央后回/中央前回、左侧中央旁小叶及左侧辅助运动区,MHE组ALFF减低的脑区包括左侧距状裂皮质、双侧后扣带回/右侧楔前叶、左侧中央后回、双侧中央旁小叶及双侧辅助运动区(P均<0.05)。与MHE组比较,OHE组ALFF减低的脑区包括左侧前扣带回、双侧内侧前额叶皮质、双侧后扣带回、右侧角回/枕上回及右侧额中回(P均<0.05)。OHE组及MHE组双侧后扣带回ALFF均与血氨水平呈负相关(P均<0.05)。结论 OHE及MHE患者均存在静息态下脑功能异常。

fMRI evaluation of alterations of baseline brain activity in patients with hepatic encephalopathy

Objective To investigate the changes of baseline brain activity in patients with hepatic encephalopathy (HE) using fMRI. Methods A total of 24 HE patients underwent resting-state fMRI scan, including 12 cases with previous overt HE (OHE group) and 12 cases with minimal HE (MHE group). The amplitude of low-frequency fluctuation (ALFF) data was obtained. Moreover, 12 healthy volunteers were enrolled as control group. And the statistical analysis was done. Results The areas with statistical differences of ALFF among the 3 groups (all P<0.05) mainly included the frontal lobe, parietal lobe and temporal lobe. Compared with control group, increasing ALFF values of right post cerebellum lobe, left front cerebellum lobe, left parahippocampal gyrus and left inferior frontal gyrus/insular cortex were found in OHE group, as well as those of right supramarginal gyrus/superior temporal gyrus were found in MHE group (all P<0.05); decreasing ALFF of bilateral medial prefrontal cortex, bilateral posterior cingulate cortex/left precuneus, right postcentral gyrus/precentral gyrus, left paracentral lobule and left supplementary motor area in OHE group and of left calcarine cortex, bilateral posterior cingulate cortex/right precuneus, left postcentral gyrus, bilateral paracentral lobule and bilateral supplementary motor area in MHE group (all P<0.05). Compared with MHE group, ALFF of OHE group decreased in left anterior cingulate cortex, bilateral medial prefrontal cortex, bilateral posterior cingulate cortex, right angular gyrus/superior occipital gyrus and right middle frontal gyrus (all P<0.05). ALFF in bilateral posterior cingulate cortex negatively correlated with blood ammonia level in OHE and MHE groups (both P<0.05). Conclusion Both of OHE and MHE patients exist brain dysfunction under resting-state.