失眠相关神经通路结构连接异常的磁共振研究进展

Advances in Magnetic Resonance Imaging (MRI) Research on Structural Connectivity Abnormalities in Neural Pathways Associated with Insomnia

摘要: 失眠是一种常见的睡眠障碍，其发病机制与大脑多个神经通路的功能及结构连接异常密切相关，其中又以边缘系统–皮质–基底神经节通路和前额叶–纹状体通路的异常最为突出。而结构连接作为神经通路的解剖学基础，其异常可能是功能改变和临床症状产生的根源。既往研究已证实，失眠患者在上述神经通路的重要组成脑区存在明显结构异常。边缘系统–皮质–基底神经节通路中的眶额叶、海马和丘脑等关键脑区的结构变化可能通过影响情绪调节和觉醒控制导致失眠。前额叶–纹状体通路中的尾状核、壳核和伏隔核能够通过调控多巴胺和腺苷等神经递质维持睡眠–觉醒周期的平衡，其结构改变会打破这一平衡，进而引发失眠。因此，本文聚焦于结构连接层面，综述并深入探讨边缘系统–皮质–基底神经节通路和前额叶–纹状体通路中多脑区的结构异常，导致睡眠–觉醒调节障碍，最终诱发失眠的具体机制。

Abstract: Insomnia is a prevalent sleep disorder whose pathogenesis is closely associated with aberrant functional and structural connectivity across multiple neural pathways in the brain, with the most prominent alterations observed in the limbic-cortical-basal ganglia circuit and the prefrontal-striatal pathway. As the anatomical substrate of neural pathways, abnormal structural connectivity is considered to underlie functional alterations and the emergence of clinical symptoms. Accumulating neuroimaging evidence has demonstrated marked structural abnormalities in the key constituent regions of these two pathways among patients with insomnia. Structural changes in core nodes of the limbic-cortical-basal ganglia circuit, including the orbitofrontal cortex, hippocampus, and thalamus, may contribute to insomnia by impairing emotional regulation and arousal control. Within the prefrontal-striatal pathway, the caudate nucleus, putamen, and nucleus accumbens maintain the homeostasis of the sleep-wake cycle via regulating neurotransmitters such as dopamine and adenosine; structural alterations in these regions can disrupt this balance and precipitate the onset of insomnia. Accordingly, this review focuses on the dimension of structural connectivity, systematically summarizes and elaborates the mechanisms by which structural abnormalities across multiple brain regions in the two aforementioned pathways induce sleep-wake dysregulation and ultimately lead to the development of insomnia.