Diaz Monica M, Harris Matthew G, Koble Jacqueline M, Copperthite Keely, Jimenez Jordan, Dayan Eran
University of North Carolina at Chapel Hill School of Medicine.
Res Sq. 2025 Aug 27:rs.3.rs-7303216. doi: 10.21203/rs.3.rs-7303216/v1.
Neurocognitive impairment (NCI) is a common comorbidity among aging people with HIV (PWH), despite effective antiretroviral therapy (ART). Processing speed is often the earliest affected cognitive domain and may be linked to disrupted functional brain network organization. This study investigated whether the balance of segregation and integration in large-scale functional networks is associated with processing speed in middle-aged and older PWH.
In a prospective, cross-sectional study, 26 virologically suppressed PWH aged ≥ 50 years underwent neuropsychological testing and resting-state functional MRI (rs-fMRI). Functional brain networks were constructed using a 300-node cortico-subcortical parcellation. System segregation index and node-level participation coefficient (PC) were calculated to quantify the global and local balance between integration and segregation, respectively. Associations with age-adjusted Wechsler Adult Intelligence Scale (WAIS-III) Symbol Search (WAISsys) T-scores were assessed using regression and correlational analyses.
Higher system segregation within associative networks was significantly associated with better WAISsys T-scores (β = 0.544, p = 0.004), whereas segregation in sensorimotor networks was not. The majority of nodal PC values were negatively correlated with WAISsys T-scores, indicating that lower processing speed was associated with less segregated and more integrated connectivity. Nodes showing the strongest negative associations with WAISsys T-scores were disproportionately located in the default mode and frontoparietal networks.
In middle-aged and older PWH, greater segregation within associative networks is linked to better processing speed. Disruptions in network segregation and modularity, especially in cognitive control systems, may be associated with processing speed deficits despite viral suppression. These findings highlight the importance of functional brain network topology and organization as a potential biomarker for cognitive aging in HIV.
尽管有有效的抗逆转录病毒疗法（ART），神经认知障碍（NCI）仍是老年HIV感染者（PWH）中常见的合并症。处理速度通常是最早受到影响的认知领域，可能与功能性脑网络组织紊乱有关。本研究调查了大规模功能网络中分离与整合的平衡是否与中老年PWH的处理速度相关。
在一项前瞻性横断面研究中，26名年龄≥50岁、病毒学抑制的PWH接受了神经心理学测试和静息态功能磁共振成像（rs-fMRI）。使用300节点的皮质-皮质下分区构建功能性脑网络。计算系统分离指数和节点水平参与系数（PC），分别量化整合与分离之间的全局和局部平衡。使用回归和相关分析评估与年龄调整后的韦氏成人智力量表（WAIS-III）符号搜索（WAISsys）T分数的关联。
联想网络中较高的系统分离与较好的WAISsys T分数显著相关（β = 0.544，p = 0.004），而感觉运动网络中的分离则不然。大多数节点PC值与WAISsys T分数呈负相关，表明较低的处理速度与较少的分离和较多的整合连接性相关。与WAISsys T分数显示最强负相关的节点不成比例地位于默认模式和额顶网络中。
在中老年PWH中，联想网络内更大的分离与更好的处理速度相关。网络分离和模块化的破坏，尤其是在认知控制系统中，可能与病毒抑制后处理速度缺陷有关。这些发现突出了功能性脑网络拓扑结构和组织作为HIV认知老化潜在生物标志物的重要性。
