Attenuation of cortical activity triggering descending pain inhibition in chronic low back pain patients: a functional magnetic resonance imaging study
Attenuation of cortical activity triggering descending pain inhibition in chronic low back pain patients: a functional magnetic resonance imaging study
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DOI：
10.1007/s00540-017-2343-1
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发表时间：
2017-08-01
影响因子：
2.8
通讯作者：
Konno, Shin-ichi
中科院分区：
文献类型：
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作者：
Matsuo, Yohei;Kurata, Jiro;Konno, Shin-ichi
相当一部分慢性下腰痛(CLBP)患者缺乏解剖异常，抵抗常规治疗干预，其症状往往伴有心理和社会因素。据报道，这类患者在神经成像研究中显示出大脑解剖和功能的异常。在这里，我们通过功能磁共振成像(FMRI)检测慢性腰痛患者和健康对照组对模拟下腰痛刺激的大脑反应的差异，并通过心理物理问卷调查他们的行为相关性。11名慢性下腰痛患者和13名健康受试者参加了这项研究。使用麦吉尔疼痛问卷简表对持续性疼痛进行心理物理评估后，在3Tesla磁共振扫描仪上进行全脑功能磁共振成像，同时在左侧腰背部接受3块30-S机械疼痛刺激，中间放置30-S，然后进行三维解剖成像。使用多受试者一般线性模型分析与疼痛相关的血氧水平依赖(BOLD)信号变化的功能图像。在激活的簇处检测个体BOLD信号幅度与心理物理变量的相关性。两个cLBP和5个HS组的数据集因缺乏或人为数据或年龄不匹配而被排除在分析之外。HS组显示右侧岛叶皮质、右侧背外侧前额叶皮质(DLPFC)、左侧扣带前皮质(ACC)和左侧楔前叶与LBP相关的激活；而在顶叶和枕叶皮质，包括双侧顶上皮质，LBP相关的大片区域失活。另一方面，cLBP组在这些皮质区域没有表现出任何明显的激活，但在双侧顶上皮质和部分运动前区域显示出类似的失活。Hs>；cLBP对比显示cLBP组ACC和DLPFC的活性显著降低，这与较高的MPQ得分呈负相关。cLBP患者在ACC和DLPFC对疼痛的反应性减弱，这两个已知的皮质区域介导了疼痛的情感成分和自上而下的调制。目前的结果可能与慢性下腰痛患者下行疼痛抑制系统功能障碍有关，这可能在疼痛的慢性化过程中起作用。
A considerable portion of chronic low back pain (cLBP) patients lack anatomical abnormality, resist conventional therapeutic interventions, and their symptoms are often complicated with psychological and social factors. Such patients have been reported to show cerebral abnormalities both in anatomy and function by neuroimaging studies. Here we examined differences in cerebral reactivity to a simulated low back pain stimulus between cLBP patients and healthy controls by functional magnetic resonance imaging (fMRI), and their behavioral correlates from a psychophysical questionnaire.Eleven cLBP patients and 13 healthy subjects (HS) were enrolled in this study. After psychophysical evaluation on-going pain with McGill Pain Questionnaire Short Form (MPQ), they underwent whole-brain fMRI in a 3-Tesla MRI scanner while receiving three blocks of 30-s mechanical pain stimuli at the left low back with a 30-s rest in between, followed by a three-dimensional anatomical imaging. Functional images were analyzed with a multi-subject general linear model for blood oxygenation level-dependent (BOLD) signal changes associated with pain. Individual BOLD signal amplitudes at activated clusters were examined for correlation with psychophysical variables. Two in the cLBP and five data sets in the HS groups were excluded from analysis because of deficient or artifactual data or mismatch in age.The HS group showed LBP-related activation at the right insular cortex, right dorsolateral prefrontal cortex (DLPFC), left anterior cingulate cortex (ACC), and left precuneus; and deactivation in a large area over the parietal and occipital cortices, including the bilateral superior parietal cortex. On the other hand, the cLBP group did not show any significant activation at those cortical areas, but showed similar deactivation at the bilateral superior parietal cortex and part of the premotor area. An HS > cLBP contrast revealed significantly less activity at the ACC and DLPFC in the cLBP group, which was negatively correlated with higher MPQ scores.The cLBP patients showed attenuated reactivity to pain at the ACC and DLPFC, known cortical areas mediating affective component, and top-down modulation, of pain. The present results might be associated with possible dysfunction of the descending pain inhibitory system in patients with chronic low back pain, which might possibly play a role in chronification of pain.