颞叶癫痫情景记忆损伤中海马网络功能重塑的动态磁共振成像研究

Epilepsy is a common chronic nervous system disease. The characteristics of memory disorder in patients with temporal lobe epilepsy (TLE) is episodic memory impairment, which is more harmful than the seizure itself. Episodic memory impairment in TLE maybe caused by the plasticity of the complex neural networks. However, the mechanism remains unclear.To observe the functional alterations of the hippocampal network is an important approach to study the mechanism of episodic memory impairment in TLE. Recent studies suggest that the hippocampal network is composed of anterior and posterior hippocampal networks by distinct pathways, which play different roles in episodic memory. Our previous study indicates that the selective plasticity of anterior and posterior hippocampal networks may be an important cause of episodic memory impairment. On this basis, the current project will test the hypothesis with multimodal neuroimaging techniques from different dimensions, and build a dynamic imaging model of episodic memory impairment in TLE, which may provide imaging evidence for clinical treatment strategies.

癫痫是一种常见的慢性神经系统疾病。颞叶癫痫记忆障碍的特征表现是情景记忆损伤，其危害大于癫痫发作本身。颞叶癫痫情景记忆损伤可能是由复杂的神经网络重塑所致，但其机制尚不清楚。观察海马网络功能变化是研究颞叶癫痫情景记忆损伤机制的重要手段。近来的研究成果表明，海马网络是由不同传导通路的前海马网络与后海马网络组成，它们在情景记忆中发挥不同的作用。申请人前期的研究结果提示，颞叶癫痫中前后海马网络选择性重塑可能是情景记忆损伤的重要原因。本项目在此基础上，将应用多模态神经影像学技术从不同维度验证该假说，并构建颞叶癫痫情景记忆损伤的动态影像学模型，为临床处理策略提供影像学证据。

目前颞叶癫痫共患记忆障碍的研究存在局限性，一个重要原因是忽视了海马复杂的结构与功能特性，导致研究结果的一致性并不高。我们基于前后海马网络的新框架研究颞叶癫痫共患记忆障碍的脑网络机制，其结果表明健康人的前后海马网络在语言记忆和非语言记忆中发挥功能整合和分离的作用，这是颞叶癫痫出现不同表现形式的记忆障碍的重要原因。相比海马局部结构的变化，前后海马网络的结构与功能变化在颞叶癫痫共患记忆障碍中可能扮演了更为重要的作用。后海马网络的动态模块化功能异常重构及相关通路的白质微结构损伤是记忆损伤的基础。这些结果能够为临床治疗颞叶癫痫共患记忆障碍提供理论依据，有望为临床精准治疗颞叶癫痫提供新的治疗策略。