Abstract：
The current study aims to characterize brain morphology of pain as reported by small fiber neuropathy (SFN) patients with or without a gain-of-function variant involving the SCN9A gene and compare these with findings in healthy controls without pain. The Neuropathic Pain Scale was used in patients with idiopathic SFN (N = 20) and SCN9A-associated SFN (N = 12) to capture pain phenotype. T1-weighted, structural magnetic resonance imaging (MRI) data were collected in patients and healthy controls (N = 21) to 1) compare cortical thickness and subcortical volumes and 2) quantify the association between severity, quality, and duration of pain with morphological properties. SCN9A-associated SFN patients showed significant (P < .017, Bonferroni corrected) higher cortical thickness in sensorimotor regions, compared to idiopathic SFN patients, while lower cortical thickness was found in more functionally diverse regions (eg, posterior cingulate cortex). SFN patient groups combined demonstrated a significant (Spearman\'s ρ = .44-.55, P = .005-.049) correlation among itch sensations (Neuropathic Pain Scale-7) and thickness of the left precentral gyrus, and midcingulate cortices. Significant associations were found between thalamic volumes and duration of pain (left: ρ = -.37, P = .043; right: ρ = -.40, P = .025). No associations were found between morphological properties and other pain qualities. In conclusion, in SCN9A-associated SFN, profound morphological alterations anchored within the pain matrix are present. The association between itch sensations of pain and sensorimotor and midcingulate structures provides a novel basis for further examining neurobiological underpinnings of itch in SFN. PERSPECTIVE: Cortical thickness and subcortical volume alterations in SFN patients were found in pain hubs, more profound in SCN9A-associated neuropathy, and correlated with itch and durations of pain. These findings contribute to our understanding of the pathophysiological pathways underlying chronic neuropathic pain and symptoms of itch in SFN.
摘要：
当前的研究旨在表征有或没有涉及SCN9A基因的功能获得变异的小纤维神经病（SFN）患者报告的疼痛的大脑形态，并将其与没有疼痛的健康对照中的发现进行比较。在患有特发性SFN（N=20）和SCN9A相关SFN（N=12）的患者中使用神经性疼痛量表来捕获疼痛表型。T1加权，在患者和健康对照（N=21）中收集了结构磁共振成像（MRI）数据，以1）比较皮质厚度和皮质下体积，以及2）量化严重程度之间的关联，质量,和具有形态学特性的疼痛持续时间。SCN9A相关的SFN患者在感觉运动区域显示出显着（P<.017，Bonferroni校正）较高的皮质厚度，与特发性SFN患者相比，而在功能更多样化的区域发现较低的皮质厚度(例如，后扣带皮质）。SFN患者组合并显示瘙痒感觉（神经性疼痛量表-7）与左中央前回厚度之间存在显着相关性（Spearman'sρ=.44-.55，P=.005-.049），和中扣带回皮质。丘脑体积与疼痛持续时间之间存在显着相关性（左：ρ=-.37，P=.043；右：ρ=-.40，P=.025）。在形态学特性和其他疼痛特性之间没有发现关联。总之,在SCN9A关联的SFN中，在疼痛矩阵中锚定的深刻的形态学改变是存在的。疼痛的瘙痒感觉与感觉运动和中扣带结构之间的关联为进一步检查SFN中瘙痒的神经生物学基础提供了新的基础。透视：在疼痛中心发现SFN患者的皮质厚度和皮质下体积改变，在SCN9A相关的神经病中更深刻，并与瘙痒和疼痛持续时间相关。这些发现有助于我们了解SFN中慢性神经性疼痛和瘙痒症状的病理生理途径。
