Rodríguez-Nieto Geraldine, Seer Caroline, Adab Hamed Zivari, Jimenez-Marin Antonio, Chalavi Sima, Rasooli Amirhossein, Cortés Jesús M, Sunaert Stefan, Swinnen Stephan P
Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium.
KU Leuven Brain Institute (LBI), KU Leuven, Leuven, Belgium.
Front Aging Neurosci. 2025 Jul 8;17:1593868. doi: 10.3389/fnagi.2025.1593868. eCollection 2025.
Older age is associated with alterations in executive functioning (EF). Age-related alterations in the integrity of structural brain networks may contribute to EF decline, with potential consequences for independent living. Graph theory provides powerful metrics to examine the brain's structural connectome, but few studies have investigated the relationship of EF and structural brain networks, as described by graph-theoretical measures, in older adults. We aimed to investigate the mediatory role of network characteristics for the relationship between age and EF in older adults.
Eighty-four older adults completed a battery of EF tasks to allow for the extraction of a latent Common-EF factor. White-matter tractograms were generated from diffusion neuroimaging using anatomically-constrained tractography (ACT) and spherical-deconvolution informed filtering of tractograms (SIFT2).
From the resulting networks, global efficiency (reflecting integration) as well as local efficiency (reflecting segregation) were calculated. Older age was associated with worse EF and decreased global and local efficiency. Both global and local efficiency were positively correlated with EF. Local efficiency mediated the negative correlation of age and EF, whereas no such relationship was found for global efficiency. Further regional efficiency analyses identified the nodes that contributed to the mediation effect of local efficiency.
These results shed light on the shared variability among the integrity of structural brain networks and EF at older age. A causal role of a reduced segregation in structural brain networks to support EF in older adults remains to be determined but would bear promising potential for preserving EF during aging.
老年与执行功能（EF）的改变有关。大脑结构网络完整性的年龄相关改变可能导致EF下降，对独立生活产生潜在影响。图论提供了强大的指标来研究大脑的结构连接组，但很少有研究调查老年人中EF与结构大脑网络（如图论测量所描述）之间的关系。我们旨在研究网络特征在老年人年龄与EF关系中的中介作用。
84名老年人完成了一系列EF任务，以提取潜在的共同EF因素。使用解剖约束纤维束成像（ACT）和基于球形反卷积的纤维束滤波（SIFT2）从扩散神经成像中生成白质纤维束图。
从生成的网络中，计算了全局效率（反映整合）和局部效率（反映分离）。年龄较大与较差的EF以及降低的全局和局部效率相关。全局和局部效率均与EF呈正相关。局部效率介导了年龄与EF的负相关，而全局效率未发现这种关系。进一步的区域效率分析确定了对局部效率中介效应有贡献的节点。
这些结果揭示了老年时大脑结构网络完整性与EF之间的共同变异性。大脑结构网络中分离减少对支持老年人EF的因果作用仍有待确定，但在衰老过程中保持EF方面具有潜在的前景。
