两种类型轻度认知功能障碍患者的多模态核磁共振研究

发布时间：2018-07-10 09:42

本文选题：扩散张量成像 + 遗忘型轻度认知功能障碍　；参考：《吉林大学》2012年博士论文

【摘要】：轻度认知功能障碍（Mild Cognitive Impairment，MCI）是指出现轻度记忆或认知功能障碍，但不影响日常生活能力，是介于正常老化和早期痴呆之间的一种临床状态，被公认为老年痴呆早期干预治疗最合适的研究群体。依据损害的类型和数量的不同，将MCI分为遗忘型MCI和非遗忘型MCI。基于影像学特征、神经心理学、神经精神病学和行为学量表及病因学等因素，也可将MCI分为两型：神经退行性病变型MCI和血管型MCI。遗忘型MCI进展为AD，皮质下血管型轻度认知障碍进展为VaD的风险都非常高。我们应用多模态的核磁共振技术对两种发病率最高的轻度认知障碍患者进行研究明确其结构与功能的变化，为发现一种临床适用的生物学标记物，能够尽早识别和早期诊断MCI患者，并判断其进展为痴呆的可能。 1、轻度认知功能障碍患者脑白质变化的扩散张量成像研究目的：遗忘型轻度认知功能障碍患者具有很高的进展为阿尔茨海默病（Alzheimer’s disease，AD）的风险。尸检证据表明，两者的脑的病理学改变是非常相似的。磁共振扩散张量成像的发展，使研究人员在体的研究大脑微观结构成为可能。利用DTI技术，观察遗忘型轻度认知功能障碍白质结构完整性的变化，通过测量部分各向异性（FA）和平均扩散率（MD）的变化，明确：1)aMCI患者是否在相应的脑区出现FA显著减少；2）aMCI组是否在相应的脑区出现显著MD增加；3）aMCI脑结构的变化。方法：40例aMCI患者和28例正常对照组（NC）首先进行临床痴呆量表（CDR）和简易精神状态量表（MMSE）及MoCA等神经系统测定及神经心理学分析，然后作为被试者进行DTI扫描。应用基于体素的全脑空间统计法（TBSS）分析检测各向异性（FA）和平均扩散率（MD）数值的变化，并进行组内和组间比较。结果：正常对照组NC相比，aMCI患者的双侧额叶、顶叶、和颞叶、胼胝体、联合纤维、投射纤维、双侧放射冠、右丘脑后辐射和右矢状层FA显著的减少（p0.05）。同时，，在双侧的额叶、顶叶和颞叶、胼胝体、联合纤维和投射纤维MD也出现显著增加（p0.05）。结论：利用DTI技术检测额叶、顶叶、颞叶、胼胝体、扣带回脑白质完整性的变化，有助于早期诊断aMCI。 2、皮质下血管型MCI患者脑部结构和功能改变的核磁共振研究目的：皮质下血管型轻度认知障碍是皮质下血管型痴呆的前期可逆状态，与小血管性疾病有十分密切的关系，因此阐明此期的生物学特征有重要的临床诊断意义。方法：入组被试者共33人，其中svMCI患者组11人，正常对照组22人，首先进行临床痴呆量表（CDR）和简易精神状态量表(MMSE)及MoCA等神经系统测定及神经心理学分析，采用结构磁共振成像技术评估被试者大脑灰质体积的变化，采用静息态功能fMRI（resting-state functionalMRI，rs-fMRI）评估自发性低频波动的改变，然后计算分析每个被试脑部灰质体积和功能性低频波动的变化，使用基于体素的形态测量学进行多元回归分析比较组间差异。结果：与正常对照组相比，svMCI患者组脑部出现明显的灰质体积减少区域包括：额下回、顶叶下部、扣带前皮质、岛叶和颞上回区域（P0.05）；低频振幅波动（amplitude of low-frequencyfluctuations，ALFF）在以下区域明显降低：扣带后皮质、楔前叶、颞回顶叶下部（P0.05）。然而，ALFF在svMCI患者脑部的其他一些区域却有明显的增加：枕叶和小脑区域（P0.05）。上述ALFF的组间差别在调整了组间的结构差别之后仍然存在。结论：svMCI患者脑部多个脑区出现结构和功能的异常。svMCI患者大脑结构上的萎缩并不能解释大脑功能的异常。
[Abstract]:Mild Cognitive Impairment (MCI) refers to the occurrence of mild memory or cognitive dysfunction, but does not affect the daily living ability. It is a clinical state between normal aging and early dementia. It is recognized as the most suitable research group for the early intervention treatment of Alzheimer's disease. Similarly, MCI can be divided into amnestic MCI and non amnestic MCI. based on imaging features, neuropsychology, neuropsychiatry and behavioral scale and etiology, and MCI can be divided into two types: neurodegenerative MCI and vascular MCI. amnestic MCI are progressing to AD, and mild cognitive impairment of subcortical vascular type is the risk of VaD It is very high. We use multimodal magnetic resonance imaging (MRI) to study the changes in the structure and function of two patients with the highest incidence of mild cognitive impairment. In order to find a clinically applicable biological marker, we can identify and early diagnose MCI patients as early as possible, and judge the possibility of dementia.
1, diffusion tensor imaging study of white matter changes in patients with mild cognitive impairment
Objective: Patients with amnestic mild cognitive impairment have a high risk of progressing to Alzheimer's disease (Alzheimer 's disease, AD). Autopsy evidence shows that the pathological changes in the brain are very similar. The development of MR diffusion tensor imaging makes it possible to study the microstructures of the brain in the human body. Using D TI technique was used to observe the changes in the white matter structure integrity of amnestic mild cognitive impairment. By measuring the changes in partial anisotropy (FA) and average diffusivity (MD), it was clear: 1) whether aMCI patients had a significant decrease in FA in the corresponding brain region; 2) whether the aMCI group had a significant MD increase in the corresponding brain region; 3) the change of the aMCI brain structure. Methods: 40 aMCI patients and 28 normal control groups (NC) were first performed the clinical dementia scale (CDR), the simple mental state scale (MMSE) and MoCA, and the neuropsychological analysis, and then performed DTI scan as the subjects. The total brain spatial statistics (TBSS) was used to detect the anisotropy (FA) and the average diffusion. Results: the rate (MD) values were changed in group and between groups. Results: compared with the normal control group NC, the bilateral frontal, parietal, temporal, corpus callosum, combined fibers, projective fibers, bilateral radiated crowns, right colliculus and right sagittal FA decreased significantly in aMCI patients (P0.05). At the same time, bilateral frontal, parietal and temporal lobes, corpus callosum, combined MD also increased significantly (P0.05). Conclusion: the changes in the white matter integrity of the frontal, parietal, temporal, corpus callosum and cingulate gyrus were detected by DTI technique, which was helpful to the early diagnosis of aMCI..
2, changes in brain structure and function in patients with subcortical vascular MCI: a magnetic resonance imaging study
Objective: the mild cognitive impairment of subcortical vascular type is the prophase reversible state of subcortical vascular dementia and has a close relationship with the small vascular diseases. Therefore, it is important to clarify the biological characteristics of this period. Methods: 33 people were enrolled in the group, including 11 svMCI patients and 22 normal controls, first carried out. The clinical dementia scale (CDR), the simple mental state scale (MMSE) and MoCA were measured and the neuropsychological analysis was used to evaluate the changes in the volume of gray matter in the subjects of the subjects by structural magnetic resonance imaging (fMRI). The changes of spontaneous low frequency fluctuations were evaluated by resting state function fMRI (resting-state functionalMRI, rs-fMRI), and then the scores were calculated. The changes in the gray matter volume and functional low frequency fluctuation of the brain were analyzed in each group. The difference between the groups was compared with the morphometry based on voxel based morphometry. Results: compared with the normal control group, there was a significant reduction in the gray matter volume in the brain of the svMCI patients: the lower frontal gyrus, the lower parietal lobe, the anterior cingulate cortex, the insula, and the temporomidi. The upper gyrus (P0.05); low frequency amplitude fluctuation (amplitude of low-frequencyfluctuations, ALFF) significantly decreased in the following regions: the posterior cingulate cortex, the anterior lobe of the wedge, and the lower temporal parietal lobe (P0.05). However, the ALFF in some other regions of the brain of the svMCI patients was significantly increased: the occipital lobe and the cerebellar region (P0.05). The differences between the above-mentioned ALFF groups After adjusting the structural differences between the groups, conclusion: the atrophy of the brain structure in patients with abnormal.SvMCI in svMCI patients with multiple brain areas and functions does not explain the abnormalities of the brain function.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R749.1

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