Chronic pain is common in young people and can have a major life impact. Despite the burden of chronic pain, mechanisms underlying chronic pain development and persistence are still poorly understood. Specifically, white matter (WM) connectivity has remained largely unexplored in pediatric chronic pain. Using diffusion-weighted imaging, this study examined WM microstructure in adolescents (age M = 15.8 years, SD = 2.8 years) with chronic pain (n = 44) compared with healthy controls (n = 24). Neurite orientation dispersion and density imaging modeling was applied, and voxel-based whole-white-matter analyses were used to obtain an overview of potential alterations in youth with chronic pain and tract-specific profile analyses to evaluate microstructural profiles of tracts of interest more closely. Our main findings are that (1) youth with chronic pain showed widespread elevated orientation dispersion compared with controls in several tracts, indicative of less coherence; (2) signs of neurite density tract-profile alterations were observed in several tracts of interest, with mainly higher density levels in patients; and (3) several WM microstructural alterations were associated with pain catastrophizing in the patient group. Implicated tracts include both those connecting cortical and limbic structures (uncinate fasciculus, cingulum, anterior thalamic radiation), which were associated with pain catastrophizing, as well as sensorimotor tracts (corticospinal tract). By identifying alterations in the biologically informative WM microstructural metrics orientation dispersion and neurite density, our findings provide important and novel mechanistic insights for understanding the pathophysiology underlying chronic pain. Taken together, the data support alterations in fiber organization as a meaningful characteristic, contributing process to the chronic pain state.

中文翻译：

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使用神经突定向分散和密度成像探测患有慢性疼痛的青少年白质微结构及其与灾难化的关系。

慢性疼痛在年轻人中很常见，会对生活产生重大影响。尽管存在慢性疼痛的负担，但慢性疼痛发生和持续的机制仍然知之甚少。具体而言，在儿科慢性疼痛中，白质（WM）连接性在很大程度上尚未得到探索。本研究使用弥散加权成像检查了患有慢性疼痛的青少年（年龄 M = 15.8 岁，SD = 2.8 岁）（n = 44）与健康对照组（n = 24）的 WM 微观结构。应用神经突定向分散和密度成像模型，并使用基于体素的全白质分析来概述患有慢性疼痛的青少年的潜在变化，并使用束特异性轮廓分析来更仔细地评估感兴趣束的微观结构轮廓。我们的主要发现是：（1）患有慢性疼痛的青少年与对照组相比，在多个神经束中表现出普遍较高的方向分散性，表明一致性较差； (2) 在几个感兴趣的神经束中观察到神经突密度束轮廓改变的迹象，主要是患者的密度水平较高； (3) 一些 WM 微观结构的改变与患者组的疼痛灾难性相关。涉及的束包括连接皮质和边缘结构的束（钩束、扣带回、丘脑前辐射），这些束与疼痛灾难性相关，以及感觉运动束（皮质脊髓束）。通过识别生物信息 WM 微观结构指标方向分散度和神经突密度的变化，我们的研究结果为理解慢性疼痛背后的病理生理学提供了重要且新颖的机制见解。总的来说，这些数据支持纤维组织的改变是一种有意义的特征，有助于慢性疼痛状态的发生。