额叶癫痫功能磁共振成像初步研究

发布时间：2018-07-16 21:01

【摘要】：第一部分：额叶癫痫的静息态fMRI低频振幅研究目的常规结构MRI阴性的额叶癫痫(frontal lobe epilepsy, FLE)占额叶癫痫的主要组成部分,对该部分FLE患者癫痫异常活动的检测是临床诊断的重点。本研究通过低频振幅(Amplitude of low-frequency fluctuation, ALFF)分析的静息态fMRI方法观察结构MRI阴性FLE发作间期脑活动的改变模式,探讨该方法在癫痫活动检测中的应用价值。方法本研究纳入46例常规结构MRI阴性的FLE患者作为实验组及46例性别、年龄无差异的健康志愿者作为对照组,在3T MR扫描仪下进行发作间期脑静息态功能数据采集,采用ALFF方法对数据进行分析,通过两样本t检验,观察FLE患者相对正常对照组ALFF活动的改变情况。并采用基于体素的相关算法观察FLE患者ALFF改变与癫痫发病病程的相关关系。结果相比正常对照组,FLE患者ALFF增加区域呈对称性分布,以双内侧额叶、前扣带回、丘脑、岛叶、基底节区为主(P0.05),ALFF降低脑区位于双侧颞下回、左侧顶上回及眶部额上回。相关分析发现,FLE发病病程与内侧前额叶、前扣带回、双侧壳核与岛叶ALFF值呈正相关,与扣带回后部及双侧角回ALFF值呈负相关。结论在FLE患者中,除额叶脑区外,还有基底节区、岛叶、丘脑等区域脑功能活动改变。基于ALFF分析的静息态fMRI可作为一种可靠的影像工具对常规结构MRI阴性的FLE异常脑活动进行检测。第二部分：额叶癫痫局部脑活动及脑网络连接改变的静息态fMRI研究目的癫痫表现为局部神经活动同步性异常增高,同时还是一种脑网络异常疾病。本研究联合采用基于静息态局域一致性(regional homogeneity, ReHo)及功能连接(functional connectivity, FC)分析的fMRI方法,观察FLE患者脑局域活动同步性的异常及癫痫脑网络长距离活动同步性的异常。方法纳入受试者同前。采用ReHo观察FLE患者局域脑活动同步性改变的脑区,再采用基于种子点的功能连接技术,对FLE脑局域活动异常脑区间的功能网络的改变进行观察。并将反映局域及网络连接的影像指标与疾病病程进行相关。结果结果显示,相比正常对照组,FLE组ReHo值升高区域于前、中扣带回、双侧岛叶、丘脑及右侧基底节,ReHo值降低区域位于左侧额上回、左侧颞中回、颞下回及小脑(P0.01)。相关分析显示FLE患者前、中扣带回ReHo值与FLE患者的发病病程长短呈正相关(P0.01)。FC分析显示,额叶癫痫患者相较正常对照组表现为全脑范围的功能连接下降,包括左内侧额上回与右额上回,左额中回与右颞下回,左侧直回与左侧顶叶,左侧壳核与左侧颞下回,左侧颞下回与右侧岛叶,左侧直回与右侧颞下回及双侧小脑半球的脑区之间功能连接减低(P0.01)。相关性分析结果显示,FLE患者左侧直回与右侧颞下回之间、双侧小脑半球间功能连接减低与FLE发病病程呈相关性(P0.05)。结论FLE患者较正常人不仅存在局域一致性的异常,还存在全脑多脑区之间长距离功能网络连接减低,包括额叶内部的功能连接及额叶与外部脑区如颞叶、顶叶、及小脑等多个脑区功能连接减低。部分功能连接减低程度与发病病程长短相关,可能因为癫痫活动及癫痫长期影响导致其脑区功能及脑区间连接的损害。
[Abstract]:The first part: the resting state fMRI low frequency amplitude study of frontal lobe epilepsy purpose conventional structure MRI negative frontal lobe epilepsy (frontal lobe epilepsy, FLE) is the main component of frontal lobe epilepsy. The detection of abnormal epileptic activity in this part of FLE patients is the focal point of clinical diagnosis. This study is carried out through low frequency amplitude (Amplitude of low-frequency flu). Ctuation, ALFF) analysis of the resting state fMRI method to observe the change pattern of brain activity in the interval of MRI negative FLE, and explore the application value of this method in the detection of epileptic activity. Methods this study included 46 normal MRI negative FLE patients as experimental group and 46 sex, age free healthy volunteers as the control group. The interictal resting state function data were collected under the 3T MR scanner. The data were analyzed by the ALFF method. The changes of ALFF activity in the FLE patients compared with the normal control group were observed by two sample t test. The correlation between the ALFF changes of FLE patients and the course of epilepsy was observed by the correlation algorithm based on voxel. Compared with the normal control group, the area of ALFF increase in FLE patients was symmetrical distribution, with the double medial frontal lobe, the anterior cingulate gyrus, the thalamus, the insula, and the basal ganglia (P0.05), and the ALFF decreased the brain area in the bilateral inferior temporal gyrus, the left apical upper gyrus and the orbital frontal gyrus. The correlation analysis found that the course of the FLE onset and the medial prefrontal cortex, the anterior cingulate gyrus, bilateral putamen and insula ALFF. The values were positively correlated with the ALFF values of the posterior cingulate gyrus and bilateral angular gyrus. Conclusion in the FLE patients, the brain functional activities in the basal ganglia, the insula, and the thalamus were changed except for the frontal lobes. The resting state fMRI based on ALFF analysis could be used as a reliable imaging tool to detect the abnormal FLE brain activity of the normal structure MRI negative FLE. The second part: the resting state fMRI study of local brain activity and brain network connection in frontal lobe epilepsy, the purpose of the study was to show that epilepsy showed abnormal increased synchronization of local nerve activity, and a brain network abnormal disease. This study combined regional homogeneity (ReHo) and functional connectivity based on resting state (functional con). Nectivity, FC) analysis of the fMRI method to observe the abnormal synchronization of brain local activity in FLE patients and the abnormal synchronization of long distance activity of epileptic brain network. Methods the subjects were included in the same before. The brain region of the local brain activity synchronism in FLE patients was observed by ReHo, and the function connection technique based on seed subpoints was used to observe the local regional activity of FLE. The changes in the functional network of the normal brain region were observed and the imaging indexes of the local and network connections were correlated with the course of disease. The results showed that compared with the normal control group, the ReHo value of the FLE group increased in the anterior cingulate gyrus, the bilateral insula, the thalamus and the right basal ganglia, and the ReHo value decreased in the left upper frontal gyrus, and the left temporal region. Middle gyrus, infratemporal gyrus and cerebellum (P0.01). Correlation analysis showed that the ReHo value of cingulate gyrus in FLE patients was positively correlated with the duration of the onset of FLE (P0.01).FC analysis showed that the frontal lobe epileptic patients compared with the normal control group showed the functional connection decrease in the whole brain range, including the upper left medial frontal gyrus and the right frontal gyrus, the left middle frontal gyrus and the right infratemporal. The left parietal gyrus and left parietal lobe, left putamen and left temporal gyrus, left inferior temporal gyrus and right Island lobe, left lateral direct gyrus and right lateral temporal gyrus and bilateral cerebellar hemispheres were reduced (P0.01). Correlation analysis showed that the bilateral cerebellar hemispherical functional connections were decreased between the left side of the left and right lateral temporal gyrus in FLE patients. Conclusion there is a correlation with the pathogenesis of FLE (P0.05). Conclusion there is not only an abnormal local concordance in FLE patients, but also the reduction of long distance functional network connections between the whole brain regions, including functional connections in the frontal lobes and the functional connections of the frontal lobe and the external brain areas such as the temporal lobe, the parietal lobe, and the cerebellum. The degree of reduction is related to the duration of the disease. It may be due to the long-term effects of epileptic activity and epilepsy on the brain function and the damage of the brain regions.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R445.2;R742.1

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