Center for Chronic Pain and Drug Abuse, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
Pain. 2021 May 1;162(5):1457-1467. doi: 10.1097/j.pain.0000000000002143.
Sex differences in the quality and prevalence of chronic pain are manifold, with women generally presenting higher incidence and severity. Uncovering chronic pain-related sex differences inform neural mechanisms and may lead to novel treatment routes. In a multicenter morphological study (total n = 374), we investigated whether the shape of subcortical regions would reflect sex differences in back pain. Given the hormone-dependent functions of the hippocampus, and its role in the transition to chronic pain, this region constituted our primary candidate. We found that the anterior part of the left hippocampus (alHP) presented outer deformation in women with chronic back pain (CBP), identified in CBP in the United States (n = 77 women vs n = 78 men) and validated in a Chinese data set (n = 29 women vs n = 58 men with CBP, in contrast to n = 53 female and n = 43 male healthy controls). Next, we examined this region in subacute back pain who persisted with back pain a year later (SBPp; n = 18 women vs n = 18 men) and in a subgroup with persistent back pain for 3 years. Weeks after onset of back pain, there was no deformation within alHP, but at 1 and 3 years women exhibited a trend for outer deformation. The alHP partly overlapped with the subiculum and entorhinal cortex, whose functional connectivity, in healthy subjects, was associated with emotional and episodic memory related terms (Neurosynth, reverse inference). These findings suggest that in women the alHP undergoes anatomical changes with pain persistence, highlighting sexually dimorphic involvement of emotional and episodic memory-related circuitry with chronic pain.
性别在慢性疼痛的质量和流行率方面存在多种差异，女性通常表现出更高的发生率和严重程度。揭示与慢性疼痛相关的性别差异可以帮助我们了解神经机制，并可能为新的治疗方法提供线索。在一项多中心形态学研究（总 n = 374）中，我们研究了皮质下区域的形状是否反映了腰痛的性别差异。鉴于海马体的激素依赖性功能及其在慢性疼痛转变中的作用，该区域是我们的主要候选区域。我们发现，慢性腰痛（CBP）女性的左侧海马体前部（alHP）存在外部变形，这在美国的 CBP 患者中得到了确认（n = 77 名女性与 n = 78 名男性），在中国的数据集中得到了验证（n = 29 名患有 CBP 的女性与 n = 58 名男性，与 n = 53 名健康女性和 n = 43 名健康男性相比）。接下来，我们在亚急性腰痛患者中检查了这个区域，这些患者在一年后仍有腰痛（SBPp；n = 18 名女性与 n = 18 名男性），并在持续腰痛 3 年的亚组中进行了检查。腰痛发作后数周内，alHP 内没有变形，但在 1 年和 3 年时，女性出现了外部变形的趋势。alHP 部分与下托和内嗅皮层重叠，在健康受试者中，其功能连接与情绪和情景记忆相关术语有关（神经合成，反向推理）。这些发现表明，在女性中，alHP 在疼痛持续存在时会发生解剖结构变化，突出了与慢性疼痛相关的情绪和情景记忆回路的性别差异。
