Department of Human Neuroscience, Sapienza - University of Rome, Viale dell'Università 30, 00185, Rome, Italy.
Medicine Department, Neurology Unit, San Filippo Neri Hospital, Via Giovanni Martinotti, 20, 00135, Rome, RM, Italy.
Neuroradiology. 2020 Jun;62(6):693-704. doi: 10.1007/s00234-020-02393-0. Epub 2020 Mar 18.
In multiple sclerosis (MS), how brain functional changes relate to clinical conditions is still a matter of debate. The aim of this study was to investigate how functional connectivity (FC) reorganization at three different scales, ranging from local to whole brain, is related to tissue damage and disability.
One-hundred-nineteen patients with MS were clinically evaluated with the Expanded Disability Status Scale and the Multiple Sclerosis Functional Composite. Patients and 42 healthy controls underwent a multimodal 3 T MRI, including resting-state functional MRI.
We identified 16 resting-state networks via independent component analysis and measured within-network, between-network, and whole-brain (global efficiency and degree centrality) FC. Within-network FC was higher in patients than in controls in default mode, frontoparietal, and executive-control networks, and corresponded to low clinical impairment (default mode network versus Expanded Disability Status Scale r = - 0.31, p < 0.01; right frontoparietal network versus Paced Auditory Serial Addition Test r = 0.33, p < 0.01). All measures of between-network and whole-brain FC, except default mode network global efficiency, were lower in patients than in controls, and corresponded to high disability (i.e., basal ganglia global efficiency versus Timed 25-Foot Walk r = - 0.25, p < 0.03; default mode global efficiency versus Expanded Disability Status Scale r = - 0.44, p < 0.001). Altered measures of within-network, between-network, and whole-brain FC were combined in functional indices that were linearly related to disease duration, Paced Auditory Serial Addition Test and lesion load and non-linearly related to Expanded Disability Status Scale.
We suggest that the combined evaluation of functional alterations occurring at different levels, from local to whole brain, could exhaustively describe neuroplastic changes in MS, while increased within-network FC likely represents adaptive compensatory processes, decreased between-network and whole-brain FC likely represent loss of functional network integration consequent to structural disruption.
在多发性硬化症（MS）中，大脑功能变化与临床状况的关系仍存在争议。本研究旨在探讨三个不同尺度的功能连接（FC）重组，从局部到全脑，与组织损伤和残疾的关系。
119 名 MS 患者接受扩展残疾状况量表和多发性硬化症功能综合评估。患者和 42 名健康对照者接受了 3T 多模态 MRI 检查，包括静息态功能 MRI。
通过独立成分分析我们识别出 16 个静息态网络，并测量了网络内、网络间以及全脑（全局效率和节点度）FC。与对照组相比，患者默认模式、额顶叶和执行控制网络的网络内 FC 更高，与临床损伤程度较低相关（默认模式网络与扩展残疾状况量表 r= -0.31，p<0.01；右额顶叶网络与听觉连续加法测试 r=0.33，p<0.01）。除默认模式网络全局效率外，患者的所有网络间和全脑 FC 测量值均低于对照组，与残疾程度较高相关（即基底节全局效率与定时 25 英尺步行 r= -0.25，p<0.03；默认模式全局效率与扩展残疾状况量表 r= -0.44，p<0.001）。网络内、网络间和全脑 FC 的改变指标组合成与疾病持续时间、听觉连续加法测试和病变负荷呈线性相关、与扩展残疾状况量表呈非线性相关的功能指数。
我们认为，从局部到全脑，对不同水平的功能改变进行综合评估，可以详尽地描述 MS 中的神经可塑性变化，而网络内 FC 的增加可能代表适应性补偿过程，网络间和全脑 FC 的减少可能代表结构破坏导致的功能网络整合丧失。
