Department of Medical Imaging, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Department of Medical Imaging, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Neuroscience. 2022 Feb 1;482:18-29. doi: 10.1016/j.neuroscience.2021.12.003. Epub 2021 Dec 8.
Chronic nonspecific low back pain (cNLBP) is a leading contributor to disease burden worldwide that is difficult to treat due to its nonspecific aetiology and complexity. The amygdala is a complex of structurally and functionally heterogeneous nuclei that serve as a key neural substrate for the interactions between pain and negative affective states. However, whether the functions of amygdalar subcomponents are differentially altered in cNLBP remains unknown. Little attention has focused on effective connectivity of the amygdala with the cortex in cNLBP. In this study, thirty-three patients with cNLBP and 33 healthy controls (HCs) were included. Resting-state functional connectivity (rsFC) and effective connectivity of the amygdala and its subregions were examined. Our results showed that the patient group exhibited significantly greater rsFC between the left amygdala and left dorsal medial prefrontal cortex (mPFC), which was negatively correlated with pain intensity ratings. Subregional analyses suggested a difference located at the superficial nuclei of the amygdala. Dynamic causal modelling revealed significantly lower effective connectivity from the left amygdala to the dorsal mPFC in patients with cNLBP than in HCs. Both groups exhibited stronger effective connectivity from the left amygdala to the right amygdala. In summary, these findings not only suggested altered rsFC of the amygdala-mPFC pathway in cNLBP but also implicated an abnormal direction of information processing between the amygdala and mPFC in these patients. Our results further highlight the involvement of the amygdala in the neuropathology of cNLBP.
慢性非特异性下腰痛（cNLBP）是全球导致疾病负担的主要原因之一，由于其非特异性病因和复杂性，难以治疗。杏仁核是一个结构和功能上异质的核团复合体，是疼痛和负性情绪状态之间相互作用的关键神经基础。然而，cNLBP 患者杏仁核亚区的功能是否存在差异尚不清楚。很少有人关注 cNLBP 患者杏仁核与皮质之间的有效连接。在这项研究中，纳入了 33 名 cNLBP 患者和 33 名健康对照者（HCs）。研究了杏仁核及其亚区的静息态功能连接（rsFC）和有效连接。我们的研究结果显示，与 HCs 相比，患者组左侧杏仁核与左侧背内侧前额叶皮质（dmPFC）之间的 rsFC 显著增加，且与疼痛强度评分呈负相关。亚区分析提示差异位于杏仁核的浅层核。动态因果建模显示，与 HCs 相比，cNLBP 患者左侧杏仁核到 dmPFC 的有效连接显著降低。两组均表现出更强的左侧杏仁核到右侧杏仁核的有效连接。总之，这些发现不仅表明 cNLBP 患者杏仁核- dmPFC 通路的 rsFC 发生改变，还提示这些患者杏仁核和 dmPFC 之间的信息处理方向异常。我们的研究结果进一步强调了杏仁核在 cNLBP 神经病理学中的作用。
