【作者】 许飞；

【导师】 高晴；

【作者基本信息】 电子科技大学 ， 概率论与数理统计， 2015， 硕士

【摘要】 大脑是迄今为止人们所认识的最为精细,最为复杂的系统,它是由一些在解剖上相互连接、功能上既相互影响又相互独立的脑区组成。功能分离指大脑特定的脑区或者说神经核负责各自不同的特定功能,而功能整合则是指人的行为实现需要不同脑区共同协作完成的。脑网络研究是当前神经科学领域的研究热点之一,能够从系统水平上研究脑区间的连接机制,揭示大脑的内在组织模式。目前已经广泛的应用到许多的人脑研究方面,尤其是精神疾病方面的研究。近年来,脑成像技术尤其是磁共振成像技术(magnetic resonance imaging,MRI)的出现和快速发展为获取大脑的各种数据提供了影像学工具,基于图论的复杂网络分析则为脑网络的研究提供了强有力的技术手段。本文主要以功能磁共振成像(functional magnetic resonance imaging,fMRI)获取的静息态数据为载体,以大尺度脑功能连接网络分析方法为手段,结合图论分析方法探测大脑的内在组织特性,并进一步将其应用于临床脑疾病中,从系统水平层面探测脑疾病的内在病理生理机制。本文的主要研究工作包括如下几个部分:1、利用局部一致性(Regional Homogeneity,ReHo)方法来研究无先兆偏头痛患者(MWoA)的功能磁共振图像在局部的脑区跟正常被试(HC)的差异。并运用相关分析来探测这些有差异的脑区跟MWoA病程的关系。我们的研究结果表明,MWoA的ReHo值在小脑,额叶,颞叶,神经基底节等部分区域出现了较HC降低的情况。这些区域都是跟大脑疼痛相关的脑区,跟人的疼痛相关的认知和情感功能有密切的相关。所以我们认为伴随着疼痛的不断刺激和疾病的进行,MWoA相应的认知情感功能会受到一定程度的损害。另外我们通过相关分析发现MWoA的左侧壳核的ReHo值与病程呈负相关关系。由于壳核是神经基底节的重要组成部分,而基底节在偏头痛疾病中是一个重要的网络节点,所以我们认为这可能与MWoA对长期的疼痛刺激的生理响应有关。该研究从静息态角度提高了我们对无先兆偏头痛病理生理机制的了解。2、运用一种超快的数据驱动方法-功能连接密度(functional connectivity density,FCD),在全脑的体素水平上比较MWoA跟HC的长程和短程功能连接密度的差异。我们的研究结果表明,MWoA的短程功能连接密度在左侧前额叶皮层,边缘系统(双边海马),旁边缘系统(双边脑岛,右侧杏仁核和扣带回前部),皮层下区域(双边壳核,尾状核)都比HC降低。MWoA的长程功能连接密度在右侧颞下回降低。这些有异常的区域都集中在大脑的疼痛矩阵。这些结果表明连续的疼痛刺激可能影响了疼痛矩阵的功能。这些脑区主要涉及疼痛过程的认知和情感过程,表明女性偏头痛患者有不稳定的认知-情感系统。另外,我们发现MWoA左侧额中回,左侧额中回眶部,左侧额下回三角部,左侧的壳核和尾状核都跟MWoA的病程呈现负相关关系。这表明随着疾病的进行,这些脑区的功能网络也在改变,并且FCD值可以作为一个生物学指标来衡量MWoA的疾病程度。更多还原

【Abstract】 The human brain is so far considered to the most complex, most delicate object in the universe, which is organized into parallel, interacting systems of anatomically connected areas. The functional segregation refers that the specific region or neural cluster of brain takes charge the specific function; while the functional integration refers that everal activity of human being needs the cooperation of some different brain regions. Nowadays, brain network research is one of the hot topics in the field of neuroscience, which can investigate the connection mechanism between brain regions on the level of system, and further reveal the underlying organization of the brain. The network analysis techonology has been applied to lots of brain research, especially to the research of brain mental and nervous disorder. In recent years, the invention and rapid development of brain imaging technologies, especially magnetic resonance imaging(MRI), provide imaging tool to acquire various brain data; while complex network analysis based on graph theory provides a valuable technical means for brain network research. The current work dedicated to investigating the underlying topological organization of the brain on the large-scale brain network level, by means of functional magnetic resonance imaging(fMRI), and graph theoretical analysis, and further detect the pathophysiological mechanism of clinical brain diseases from the system level. The main works and contributions of this dissertation are as follows:1. Using Regional Homogeneity(ReHo) analysis method to measure the brain regional of significantly different between MWoA and HC. And using the correlation analysis to detect the relationship between these are significantly different areas of the brain with duration of disease. Our results showed that the ReHo value of MWoA in the cerebellum, frontal lobe, temporal lobe, basal ganglia area appeared more decrease than HC. These areas are located in the pain matrix of brain, which are closely related to cognitive and emotional functions of people. So we suggested that with the constant stimulus of pain and increase duration of disease, MWoA corresponding cognitive emotion function will be affected. In addition, we found that ReHo values of left putamen had a significant negative correlations with duration of disease. The putamen is an important part of the basal ganglia, and basal ganglia is an important network nodes of migraine disease. So we think this may be related to the physiological response of MWoA on long-term pain stimulus. The study from the network level of resting state improved our understanding of migraine without aura pathophysiological mechanisms.2. Using functional connectivity density(FCD) mapping, an ultrafast and voxel-wise data-driven approach, to measure short- and long-range FCD in MWoA patients. We found the long-range FCD value in right inferior temporal gyrus reduced significantly in MWoA group compared to HC group. The abnormal short-range FCD values in regions of left PFC, limbic system(the bilateral hippocampus), paralimbic system(the bilateral insula, right amygdala and ACC), subcortical(the bilateral putamen, caudate) comparing to HC were found. These regions covered the great majority of the pain matrix, which was closely related to headache. These results indicate that constant pain stimulation may affect the function of the pain matrix. These brain areas mainly relates to process of cognitive and emotional of pain, which suggested that female migraine patients have an instability system of cognitive and emotional. In addition, we further found short-range FCD in left frontal cortex including left middle frontal gyrus(orbital part), left middle frontal gyrus and left inferior frontal gyrus(triangular part), and left basal ganglia(BG) including putamen and caudate were significantly negatively correlated with duration of disease, indicating that the functional networks of these regions changed as the disease progressed. And FCD values can be used as a biological indicator to measure the degree of disease of MWo A.更多还原