基于格兰杰因果的功能性消化不良大脑异常研究

发布时间：2018-07-17 05:05

【摘要】：功能性胃肠病是指出现了腹胀、腹痛、腹泻和便秘等消化系统症状但又没有生化或结构异常的一组疾病。在世界范围内都有着很高的发病率，基于欧美人口的调查显示，欧美人群中功能性胃肠病的患病率为21%-41%，在我国也有10%-12%的社区人口患有功能性胃肠病。随着对功能性胃肠病研究的深入，人们发现脑肠轴互动的异常对功能性胃肠病的发生及发展起到了非常重要的作用。作为功能性胃肠病的主要分支之一，功能性消化不良在功能性胃肠病的临床诊断中占有非常大的比例。通过正离子断层扫描技术，研究人员发现功能性消化不良患者静息态的大脑活动以及中枢神经系统的胃肠刺激加工方面存在异常。另外研究人员通过使用功能磁共振成像技术同样发现功能性消化不良患者静息态的大脑活动以及一些脑区之间的功能连接存在异常。此外，有研究表明，人类的大脑是由一系列空间独立但功能相关的静息态功能网络组成，这些功能网络协同完成人类的正常行为。然而关于功能性消化不良患者静息态功能网络的研究还很少，因此，本研究主要结合核磁共振成像技术、独立成分分析以及格兰杰因果分析方法对静息态功能网络进行初步的研究，研究的主要结果和创新点如下： 1，功能性消化不良患者大脑显著网络相关的因果连接模式出现异常。本研究通过独立成分分析以及条件格兰杰因果分析对功能性消化不良患者大脑显著网络相关的静息态功能网络的因果连接模式进行研究。我们发现功能性消化不良患者大脑的显著网络对默认网络以及中心执行网络的因果调节作用减弱。并且脑岛对于默认网络以及中心执行网络的因果调节作用被前扣带替代。该研究表明功能性消化不良患者大脑静息态功能网络之间的调节作用异常是脑岛以及前扣带回皮层的异常导致的。 2，功能性消化不良患者大脑默认网络存在异常。本研究通过独立成分分析以及双样本t检验对功能性消化不良患者大脑的默认网络进行研究。发现患者的前扣带回皮层、腹内侧前额叶皮层、背外侧前额叶皮层、感觉运动皮层、颞极、旁海马回、下顶叶以及眶额叶皮层的活动存在异常。其中旁海马区域的活动与功能性消化不良患者的病情严重程度呈显著的反相关关系。另外通过条件格兰杰因果分析我们发现功能性消化不良患者的旁海马区域明显孤立，，并且前扣带与这些异常区域之间的有效连接减弱。本研究首次对功能性消化不良患者的默认网络进行研究，并为功能性消化不良患者中枢神经异常提供影像学证据。
[Abstract]:Functional gastrointestinal disease refers to a group of diseases with abdominal distension, abdominal pain, diarrhea, constipation and other digestive system symptoms without biochemical or structural abnormalities. There is a high incidence rate in the world. Based on the survey of European and American population, the prevalence rate of functional gastrointestinal disease in European and American population is 21% -41%. In our country, 10% -12% of the community population also have functional gastrointestinal disease. With the development of functional gastrointestinal disease, it has been found that abnormal interaction between brain and intestinal axis plays an important role in the occurrence and development of functional gastrointestinal disease. As one of the main branches of functional gastrointestinal disease, functional dyspepsia occupies a large proportion in the clinical diagnosis of functional gastrointestinal disease. Using positive ion tomography, the researchers found abnormalities in resting brain activity in patients with functional dyspepsia and in the processing of gastrointestinal stimuli in the central nervous system. In addition, functional magnetic resonance imaging (fMRI) techniques were also used to detect resting brain activity and functional connections in some brain regions in patients with functional dyspepsia. In addition, studies have shown that the human brain is composed of a series of spatially independent but functionally related resting functional networks, which cooperate to accomplish normal human behavior. However, there is little research on resting functional network in patients with functional dyspepsia. Independent component Analysis (ICA) and Granger causality Analysis (Granger causality Analysis) are used to study the resting functional network. The main findings and innovations are as follows: 1. The causal connection patterns associated with significant network in functional dyspepsia patients are abnormal. In this study, independent component analysis and conditional Granger causality analysis were used to study the causal connection patterns of resting functional networks associated with significant brain network in patients with functional dyspepsia. We found that the significant network of the brain in patients with functional dyspepsia weakens the causal regulation of the default and central executive networks. And the causal adjustment of the island to the default network and the central executive network is replaced by the anterior cingulate band. This study shows that the abnormal regulation between resting functional networks in patients with functional dyspepsia is due to the abnormalities of the cerebral islets and the cortex of anterior cingulate gyrus. 2. The default network of brain in patients with functional dyspepsia is abnormal. The default network of the brain in patients with functional dyspepsia was studied by independent component analysis and two-sample t-test. Abnormal activities were found in the anterior cingulate cortex ventromedial prefrontal cortex dorsolateral prefrontal cortex sensory motor cortex temporal pole paracarpal gyrus inferior parietal lobe and orbital frontal cortex. The activity of parahippocampal region was inversely correlated with the severity of the disease in patients with functional dyspepsia. In addition, by conditional Granger causality analysis, we found that the parahippocampal region in patients with functional dyspepsia was significantly isolated, and the effective connection between the anterior cingulate band and these abnormal regions was weakened. In this study, the default network of patients with functional dyspepsia was studied for the first time, and the imaging evidence was provided for the abnormality of central nervous system in patients with functional dyspepsia.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R57

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