目的:认知缺陷在颞叶癫痫(TLE)患者中很常见。这里,我们旨在研究与TLE患者不同认知状态相关的功能网络的模块化架构,以及丘脑在模块化网络中的作用.
方法:对53例TLE患者和37例匹配的健康对照者进行静息状态功能磁共振成像扫描。所有患者均接受蒙特利尔认知评估测验,并据此分为认知正常的TLE患者(TLE-CN,n=35)和TLE患者认知障碍(TLE-CI,n=18)组。计算和比较了功能网络的模块化特性,包括全局模块化Q,模块化偏析指数,结膜内连接,和模块间连接。在分析每个丘脑细分的模块化属性(参与系数和模块内度z得分)以评估丘脑对模块化功能网络的贡献之前,通过应用“赢家通吃”策略来生成与模块化网络相对应的丘脑细分。然后进一步探讨了网络属性与认知表现之间的关系。
结果:TLE-CN和TLE-CI患者均显示出较低的整体模块化,以及腹侧注意力网络和默认模式网络的较低模块化隔离指数值。然而,不同的认知状态存在不同的模内和模间连接模式。此外,TLE-CN和TLE-CI患者均表现出功能性丘脑细分的异常模块化特性,TLE-CI患者表现出更广泛的异常。TLE-CI患者的认知表现与功能网络的模块化特性无关,而与功能性丘脑细分的模块化特性无关。
结论:丘脑在模块化网络中起着重要作用,并可能代表TLE认知损害的关键神经机制。
Cognitive deficit is common in patients with temporal lobe epilepsy (TLE). Here, we aimed to investigate the modular architecture of functional networks associated with distinct cognitive states in TLE patients together with the role of the thalamus in modular networks.
Resting-state functional magnetic resonance imaging scans were acquired from 53 TLE patients and 37 matched healthy controls. All patients received the Montreal Cognitive Assessment test and accordingly were divided into TLE patients with normal cognition (TLE-CN, n = 35) and TLE patients with cognitive impairment (TLE-CI, n = 18) groups. The modular properties of functional networks were calculated and compared including global modularity Q, modular segregation index, intramodular connections, and intermodular connections. Thalamic subdivisions corresponding to the modular networks were generated by applying a \'winner-take-all\' strategy before analyzing the modular properties (participation coefficient and within-module degree z-score) of each thalamic subdivision to assess the contribution of the thalamus to modular functional networks. Relationships between network properties and cognitive performance were then further explored.
Both TLE-CN and TLE-CI patients showed lower global modularity, as well as lower modular segregation index values for the ventral attention network and the default mode network. However, different patterns of intramodular and intermodular connections existed for different cognitive states. In addition, both TLE-CN and TLE-CI patients exhibited anomalous modular properties of functional thalamic subdivisions, with TLE-CI patients presenting a broader range of abnormalities. Cognitive performance in TLE-CI patients was not related to the modular properties of functional network but rather to the modular properties of functional thalamic subdivisions.
The thalamus plays a prominent role in modular networks and potentially represents a key neural mechanism underlying cognitive impairment in TLE.