无明显肝性脑病肝硬化患者静息态脑功能磁共振成像研究

Stady of resting-state brain activity in patients with HBV-related cirrhosis without overt hepatic encephalopathy

目的采用静息态功能磁共振成像技术(Rs-f MRI)探究无明显肝性脑病(OHE)的乙型肝炎病毒相关性肝硬化(HBV-RC)患者区域脑活动异常,并探讨其与认知障碍之间的关系。方法采用局部一致性(Re Ho)方法,比较32例无明显肝性脑病的乙型肝炎病毒相关性肝硬化患者与32例匹配良好的健康志愿者之间的静息态功能磁共振成像(Rs-f MRI)信号的局部一致性。采用肝性脑病心理测量积分(PHES)试验,对所有患者进行认知测定,分析局部一致性(Re Ho)的变异与肝性脑病心理测量评分(PHES)之间的关系。结果与健康对照组比较,肝硬化组前额叶皮层局部一致性(Re Ho)值升高,而在视觉相关皮层(如左舌回、颞中回和右中枕回)、运动相关皮层(如双侧中央前回和中央旁小叶)和双侧楔前叶局部一致性(Re Ho)值显著降低。相关性分析提示肝硬化患者左舌回(r=0.352;P=0.048)、右枕中回(r=0.453;P=0.009)以及双侧中央前回(左:r=0.436;P=0.013;右:r=0.582;P<0.001)、中央旁小叶(r=0.485;P=0.005)和楔前叶(r=0.468;P=0.007)平均Re Ho值与PHES值之间呈现正相关性。结论采用局部一致性(Re Ho)分析的静息态功能磁共振可作为一种无创性检查方法,用于揭示有关肝硬化患者认知改变的病理生理学机制信息。

Objective To investigate regional activity abnormalities in patients with hepatitis B virus- related cirrhosis （HBV-RC） without OHE using resting-state functional MRI （Rs-fMRI）, and to investigate the relationship between regional activity abnormalities and cognition impairment. Methods A newly reported regional homogeneity （ReHo） approach was used to compare the local synchronization of Rs-fMRI signals in 32 patients with HBV-RC without OHE and 32 well-matched healthy controls. Cognition was measured in all patients using psychometric hepatic encephalopathy score （PHES） tests, and the relationship between ReHo variation and PHES was evaluated. Results comparing to healthy controls, the cirrhosis group showed high ReHo in the prefrontal cortex, and widespread low ReHo in visual association areas （left lingual gyrus, middle temporal gyrus and right middle occipital gyrus）, motor association areas （bilateral precentral gyms and paracentral lobule） and the bilateral precuneus. Correlation analysis of the mean ReHo values in different brain areas and PHES in cirrhotic patients revealed a significant positive correlation in the left lingual gyms （r = 0.352; P = 0.048）, right middle occipital gyms （r = 0.453; P = 0.009） and bilateral precentral gyms （left： r = 0.436, P = 0.013; right： r = 0.582, P 〈 0.001）, paracentral lobule （r = 0.485; P = 0.005） and precuneus （r = 0.468; P = 0.007）. Conclusions Our results provide information on the pathophysiological mechanisms underlying cognitive alterations in cirrhotic patients and demonstrate the feasibility of using Rs-fMRI with ReHo analysis as a noninvasive modality to detect the progression of cognitive changes in cirrhotic patients.