语言相关白质纤维在卒中后失语症中的弥散张量成像研究

发布时间：2018-12-12 03:16

【摘要】：目的:卒中后失语在脑卒中患者中占有较高的比例,对患者的整体康复和社会功能造成了不可忽视的影响。本研究旨在描述卒中后失语患者中白质结构的变化特征,发掘潜在的与特定语言功能相关的纤维以量化语言损伤程度,丰富现有的语言加工模型。方法:本研究收集了 14例卒中后失语患者,均于住院期间完成了汉语失语症量表评估和磁共振弥散张量序列的扫描。同时募集健康对照组11例,两组之间性别和年龄匹配。结果:全脑体素分析发现白质完整性的差异峰值位于左侧外囊。基于白质骨架的空间统计发现患者组双侧侧外囊、胼胝体等处的各向异性分数显著降低,而径向扩散率的减少则局限于左侧外囊。进一步的纤维追踪技术发现,左侧下纵束、钩束、下额枕束等多条语言相关纤维束在失语症患者中均显著受累(P0.05);其中患者左侧外囊所在的下额枕束的平均FA值较对照组的下降程度最大(0.324±0.023 vs.0.478±0.013;P0.0001),且与理解、复述、命名、失语商等多项语言指标显著相关(P0.01)。但患者组语言量表分数与其结构网络的全局效率、小世界属性等图论指标均无显著相关(P0.05)。结论:在亚急性期卒中后失语患者中,左半球语言相关纤维的髓鞘和轴索均受累,其中左侧下额枕束与多项语言功能之间存在密切关联,提示可能是影响失语症语言功能严重程度的关键纤维。病灶对侧半球的髓鞘亦发生了完整度的改变、但轴索尚未发生不可逆的改变,提示亚急性期失语症患者中可能已存在非优势半球的可塑性动员过程,肯定了白质纤维在语言加工模型及病理生理过程中的重要意义。
[Abstract]:Objective: aphasia after stroke occupies a high proportion in stroke patients and has a significant impact on the overall rehabilitation and social function of stroke patients. The purpose of this study was to describe the characteristics of white matter structure in aphasia patients after stroke, to explore potential fibers related to specific language function to quantify the degree of language damage and to enrich the existing language processing models. Methods: 14 patients with post-stroke aphasia were examined by Chinese aphasia scale and magnetic resonance diffusion-Zhang Liang sequence. At the same time, 11 healthy control group were recruited, gender and age matching between the two groups. Results: the differential peak of white matter integrity was found in the left external capsule by whole brain voxel analysis. The spatial statistics based on white matter skeleton showed that the anisotropy fraction of bilateral external bursa and corpus callosum were significantly decreased, while the reduction of radial diffusivity was limited to the left external capsule in the patient group. Further fiber tracing techniques showed that the left lower longitudinal bundle, hook bundle, and inferior frontal occipital bundle were significantly involved in aphasia (P0.05). The average FA value of the inferior frontal occipital bundle in the left external capsule was the largest (0.324 卤0.023 vs.0.478 卤0.013) compared with the control group. P0.0001), and it was significantly related to several language indexes, such as understanding, retelling, naming and aphasia quotient (P0.01). But there was no significant correlation between the score of patient group language scale and the global efficiency of the network, small-world attributes and other graph indicators (P0.05). Conclusion: in patients with subacute post-stroke aphasia, the myelin sheath and axonal cord of the left hemispheric language-related fibers are involved, and there is a close relationship between the left subfrontal occipital bundle and multiple language functions. The results suggest that it may be a key fiber affecting the severity of language function in aphasia. The integrity of myelin sheath in the contralateral hemisphere of the lesion was also changed, but no irreversible change had occurred in the axonal cord, suggesting that there might be a non-dominant hemispheric plasticity mobilization process in patients with subacute aphasia. The importance of white matter fiber in language processing model and pathophysiology was confirmed.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R445.2;R743.3

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