Background. Fatigue is one of the most distressing symptoms among persons with multiple sclerosis (PwMS). The experience of fatigue is inherently interoceptive, yet no study to date has explicitly investigated the insular cortex (IC) as a primary goal in the experience of fatigue in PwMS. In addition, it is unknown how brain regions such as IC play a role in state or trait fatigue. Objective. Assess the involvement of the IC in trait fatigue and state fatigue in PwMS with and without clinical fatigue. Methods. Trait and state fatigue, cognitive status, and structural MRI were assessed in 27 PwMS. PwMS were stratified into nonclinical fatigue (nF-MS, ) () and clinical fatigue (F-MS, ) (). Voxel-based morphometry analysis (VBM) for the whole sample () and for the two groups was performed. Anatomical covariance analysis (ACA) analysis was conducted by selecting different volumes included in the corticostriatal network (CoStN) and analyzing interhemispheric correlations between those volumes to explore the state of the CoStN in both groups. Results. In the VBM analysis, when considering the whole sample of PwMS, higher levels of trait fatigue were negatively associated with grey matter (GM) volume in the left dorsal anterior insula (dAI) (; ; ). When comparing nF-MS versus F-MS, significant differences were found in the left dAI, where the F-MS group showed less GM volume in the left dAI. In the ACA analysis, the F-MS group showed fewer significant interhemispheric correlations in comparison with the Low-FSS group. Conclusions. The present results provide support to the interoceptive component of self-reported fatigue and suggest that changes in the relationship between the different anatomical regions involved in the CoStN are present even in nonclinical trait fatigue. Those changes might be responsible for the experience of trait fatigue in PwMS. Future studies with larger samples and multimodal MRI acquisitions should be considered to fully understand the changes in the CoStN and the specific role of the IC in trait fatigue.

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解剖协方差分析：与多发性硬化症的临床特征疲劳相关的相关网络中断的检测：一项初步研究

背景。疲劳是多发性硬化症（PwMS）患者中最令人困扰的症状之一。疲劳经历本质上是互感的，但迄今为止，尚无任何研究明确地将岛状皮质（IC）作为PwMS疲劳经历的主要目标。另外，还不清楚诸如IC之类的大脑区域如何在状态或特质疲劳中发挥作用。目标。评估有无临床疲劳的PwMS中IC与特质疲劳和状态疲劳的关系。方法。在27个PwMS中评估了特质和状态疲劳，认知状态以及结构MRI。PwMS分为非临床疲劳（nF-MS，）（）和临床疲劳（F-MS，）（）。整个样品的基于体素的形态分析（VBM）（），并进行了两组。解剖协方差分析（ACA）分析是通过选择皮层神经网络（CoStN）中包含的不同体积并分析这些体积之间的半球间相关性来探索两组中CoStN的状态。结果。在VBM分析中，当考虑整个PwMS样本时，较高水平的性格疲劳与左背前绝缘（dAI）中的灰质（GM）量负相关（; ; ）。比较nF-MS与F-MS时，在左dAI中发现了显着差异，其中F-MS组在左dAI中显示出较少的GM体积。在ACA分析中，与Low-FSS组相比，F-MS组显示出明显的半球间相关性。结论。本研究结果为自我报告的疲劳的感受性成分提供了支持，并表明即使在非临床性状疲劳中，CoStN涉及的不同解剖区域之间的关系也会出现变化。这些变化可能是造成PwMS中特质疲劳的原因。应该考虑使用更大的样本和多模式MRI采集进行进一步研究，以充分了解CoStN的变化以及IC在性状疲劳中的特定作用。