School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK.
Chronic Pain and Fatigue Research Center, University of Michigan, Ann Arbor, MI, USA.
Rheumatology (Oxford). 2019 Oct 1;58(10):1822-1830. doi: 10.1093/rheumatology/kez132.
Fatigue is a major burden among patients with RA, yet is poorly understood. We sought to conduct the first imaging study to investigate the neurobiological correlates of fatigue in RA and to improve upon the methodological limitations of previous neuroimaging studies that have investigated this symptom in other populations.
Chronically fatigued RA patients were clinically characterized before undertaking a combined functional and structural mode MRI brain scan. The functional sequences were acquired during a fatigue-evoking task, then network-to-whole-brain analyses were undertaken. The structural analyses employed voxel-based morphometry in order to quantify regional grey matter volume. The scan was repeated 6 months later to test reproducibility.
Fifty-four participants attended both scans [n = 41 female; baseline mean (s.d.) age 54.94 (11.41) years]. A number of significant functional and structural neural imaging correlates of fatigue were identified. Notably, patients who reported higher levels of fatigue demonstrated higher levels of functional connectivity between the Dorsal Attention Network and medial prefrontal gyri, a finding that was reproduced in the repeat scans. Structurally, greater putamen grey matter volumes significantly correlated with greater levels of fatigue.
Fatigue in RA is associated with functional and structural MRI changes in the brain. The newly identified and reproduced neural imaging correlates provide a basis for future targeting and stratification of this key patient priority.
疲劳是类风湿关节炎（RA）患者的主要负担，但尚未被充分理解。我们旨在进行首次影像学研究，以调查 RA 患者疲劳的神经生物学相关性，并改进之前在其他人群中研究这一症状的神经影像学研究的方法学局限性。
在进行联合功能和结构磁共振成像（MRI）脑扫描之前，对慢性疲劳的 RA 患者进行临床特征描述。功能序列在疲劳诱发任务期间采集，然后进行网络到全脑分析。结构分析采用基于体素的形态测量学来量化区域灰质体积。扫描在 6 个月后重复进行，以测试可重复性。
54 名参与者参加了两次扫描[n=41 名女性；基线平均（标准差）年龄 54.94（11.41）岁]。确定了一些与疲劳相关的显著的功能和结构神经影像学相关性。值得注意的是，报告疲劳程度较高的患者表现出背侧注意网络和内侧前额叶回之间的功能连接性较高，这一发现在重复扫描中得到了重现。结构上，纹状体灰质体积越大，与疲劳程度越高显著相关。
RA 中的疲劳与大脑的功能和结构 MRI 变化有关。新发现的和可重复的神经影像学相关性为这一关键患者重点提供了靶向和分层的基础。
