Laboratorio de Neurociencia Social y Neuromodulación, Centro de Investigación en Complejidad Social (neuroCICS), Facultad de Gobierno, Universidad del Desarrollo, Santiago de Chile, Chile.
Departamento de Neurología, Hospital Clínico de la Pontificia Universidad Católica de Chile, Santiago de Chile, Chile.
Sci Rep. 2020 Jun 9;10(1):9310. doi: 10.1038/s41598-020-66279-0.
Working Memory (WM) impairment is the most common cognitive deficit of patients with Multiple Sclerosis (MS). However, evidence of its neurobiological mechanisms is scarce. Here we recorded electroencephalographic activity of twenty patients with relapsing-remitting MS and minimal cognitive deficit, and 20 healthy control (HC) subjects while they solved a WM task. In spite of similar performance, the HC group demonstrated both a correlation between temporoparietal theta activity and memory load, and a correlation between medial frontal theta activity and successful memory performances. MS patients did not show theses correlations leading significant differences between groups. Moreover, cortical connectivity analyses using granger causality and phase-amplitude coupling between theta and gamma revealed that HC group, but not MS group, presented a load-modulated progression of the frontal-to-parietal connectivity. This connectivity correlated with working memory capacity in MS groups. This early alterations in the oscillatory dynamics underlaying working memory could be useful for plan therapeutic interventions.
工作记忆（WM）损伤是多发性硬化症（MS）患者最常见的认知缺陷。然而，其神经生物学机制的证据还很缺乏。在这里，我们记录了 20 名缓解-复发型 MS 且认知缺陷最小的患者和 20 名健康对照（HC）受试者在解决 WM 任务时的脑电图活动。尽管表现相似，但 HC 组表现出颞顶叶θ活动与记忆负荷之间的相关性，以及内侧额叶θ活动与成功记忆表现之间的相关性。MS 患者则没有显示出这些相关性，导致组间存在显著差异。此外，使用格兰杰因果关系和θ和γ之间的相位-幅度耦合进行皮质连通性分析表明，HC 组而非 MS 组表现出额叶到顶叶连通性的负荷调制进展。这种连通性与 MS 组的工作记忆容量相关。工作记忆下的这种早期振荡动力学变化可能对计划治疗干预有用。
