OBJECTIVE To investigate if changes in brain network function and connectivity contribute to the abnormalities in visual event related potentials (ERP) in relapsing-remitting multiple sclerosis (RRMS), and explore their relation to a decrease in cognitive performance. METHODS We evaluated 72 patients with RRMS and 89 healthy control subjects in a cross-sectional study. Visual ERP were generated using illusory and non-illusory stimuli and recorded using 21 EEG scalp electrodes. The measured activity was modelled using Dynamic Causal Modelling. The model network consisted of 4 symmetric nodes including the primary visual cortex (V1/V2) and the Lateral Occipital Complex. Patients and controls were tested with a neuropsychological test battery consisting of 18 cognitive tests covering six cognitive domains. RESULTS We found reduced cortical connectivity in bottom-up and interhemispheric connections to the right lateral occipital complex in patients (p < 0.001). Furthermore, interhemispherical connections were related to cognitive dysfunction in several domains (attention, executive function, visual perception and organization, processing speed and global cognition) for patients (p < 0.05). No relation was seen between cortical network connectivity and cognitive function in the healthy control subjects. CONCLUSION Changes in the functional connectivity to higher cortical regions provide a neurobiological explanation for the changes of the visual ERP in RRMS. SIGNIFICANCE This study suggests that changes in connectivity to higher cortical regions partly explain visual network dysfunction in RRMS where a lower interhemispheric connectivity may contribute to impaired cognitive function.

中文翻译：

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复发缓解型多发性硬化视觉网络功能障碍的机制及其与认知的关系

目的 研究脑网络功能和连通性的变化是否会导致复发缓解型多发性硬化症（RRMS）的视觉事件相关电位（ERP）异常，并探讨其与认知能力下降的关系。方法 我们在横断面研究中评估了 72 名 RRMS 患者和 89 名健康对照受试者。使用幻觉和非幻觉刺激生成视觉 ERP，并使用 21 个 EEG 头皮电极记录。使用动态因果建模对测量的活动进行建模。模型网络由 4 个对称节点组成，包括初级视觉皮层 (V1/V2) 和外侧枕骨复合体。患者和对照组使用神经心理学测试组进行测试，该组由 18 项认知测试组成，涵盖六个认知领域。结果 我们发现患者与右侧枕骨复合体的自下而上和半球间连接的皮质连接性降低（p < 0.001）。此外，半球间的联系与患者在多个领域（注意力、执行功能、视觉感知和组织、处理速度和全局认知）的认知功能障碍有关（p < 0.05）。健康对照受试者的皮层网络连接与认知功能之间没有关系。结论与更高皮质区域的功能连接的变化为 RRMS 中视觉 ERP 的变化提供了神经生物学解释。