基于多模态磁共振轻度创伤性脑损伤后认知障碍神经机制的纵向研究

Persistent cognitive impairment is a common complication in mild traumatic brain injury (mTBI), seriously affecting the quality of patients’ life. At present, the neural mechanism is still unclear. Previous studies have found brain structural, functional and cerebral blood flow changes using single modal MRI. However, the longitudinal pattern and dependency relationship in brain structural, functional and cerebral blood flow changes remain unclear. Our previous study found structural changes in cognitive impairment after mTBI using diffusion kurtosis imaging (DKI) sequence. Therefore, we further hypothesize that there is dynamic brain structural, functional and cerebral blood flow changes underlying the occurrence of cognitive impairment after mTBI, and the early MRI changes could be used to assess the occurrence of persistent cognitive impairment after mTBI. In this project, a large sample of mTBI patients with cognitive impairment will be recruited, who will have neurocognitive tests and muti-modal MRI examinations including structural, DKI, arterial spin labeling and resting-state functional MRI sequences at multiple time points from acute period to chronic period. We will investigate the evolving law and the dependency relationship of brain structural, functional, and cerebral blood flow changes in cognitive impairment after mTBI and investigate the value of early MRI changes in assessing the occurrence of persistent cognitive impairment after mTBI. This project will deepen our knowledge of the neural mechanism of cognitive impairment after mTBI and provide possible neuroimaging biomarker for early diagnosis and treatment.

轻度创伤性脑损伤（mTBI）后可发生持续认知障碍，严重影响患者生活质量，其神经影像学机制尚未完全明确。既往单模态磁共振研究表明mTBI后存在脑结构、功能、血流改变，但是mTBI后认知障碍脑结构、功能、血流动态演变规律及相互关系尚不完全清楚。本项目组前期应用DKI序列研究发现mTBI后认知障碍存在脑结构改变基础。因此， 本项目进一步提出科学假说： mTBI后认知障碍存在脑结构、功能、血流改变基础并存在失代偿改变，磁共振早期影像指标可用于评估持续认知障碍的发生。本项目拟招募大样本mTBI认知障碍患者，进行多时间点认知功能测试及多模态MRI扫描，包括结构像、DKI、ASL及静息态fMRI序列。从脑结构、功能、血流角度探索mTBI后认知障碍脑改变的演变规律，并分析早期影像指标评估持续认知障碍的价值。本研究将进一步加深对mTBI后认知障碍脑改变认识，为mTBI后认知障碍早期诊治提供重要的影像标记。

轻度创伤性脑损伤（mTBI）后发生的认知障碍，严重影响患者生活质量。既往单模态磁共振研究表明mTBI后存在脑结构、功能、血流改变，但是mTBI后认知障碍脑结构、功能、血流相互关系尚不完全清楚。本项目通过招募大样本mTBI认知障碍患者，进行认知功能测试及多模态MRI扫描，包括结构像、DKI、ASL及静息态fMRI序列。本项目研究表明mTBI组与对照组相比脑灰质及皮质下脑核团体积没有差异，mTBI组ReHo值及ALFF有显著增高区域。mTBI患者广泛白质纤维束和皮质下核团MK值降低与认知障碍存在相关。针对丘脑研究表明，mTBI后丘脑MK值减低，CBF减低，ODI值升高，且与认知障碍发生存在相关性。此外本研究表明mTBI患者ALPS参数减低，PSMD参数增高，PSMD参数与认知功能存在相关性，ALPS参数部分介导PSMD与认知功能的关系。通过对国际公开数据库的研究表明TBI病史退伍军人CSO-EPVS增多并且与认知障碍相关，CSF P-tau部分介导CSO-EPVS与认知障碍的关系。这些研究对于进一步加深对mTBI后认知障碍脑改变认识，为mTBI后认知障碍早期诊治提供了重要的影像标记。