Department of Physical Therapy & Rehabilitation Sciences, University of Kansas Medical Center, Kansas City, KS 66160, USA.
Brain Sci. 2012 Sep 1;2(3):319-31. doi: 10.3390/brainsci2030319.
The involvement of the primary motor cortex (M1) in chronic low back pain (LBP) is a relatively new concept. Decreased M1 excitability and an analgesic effect after M1 stimulation have been recently reported. However, the neurochemical changes underlying these functional M1 changes are unknown. The current study investigated whether neurochemicals specific to neurons and glial cells in both right and left M1 are altered. N-Acetylaspartate (NAA) and myo-inositol (mI) were measured with proton magnetic resonance spectroscopy in 19 subjects with chronic LBP and 14 healthy controls. We also examined correlations among neurochemicals within and between M1 and relationships between neurochemical concentrations and clinical features of pain. Right M1 NAA was lower in subjects with LBP compared to controls (p = 0.008). Left M1 NAA and mI were not significantly different between LBP and control groups. Correlations between neurochemical concentrations across M1s were different between groups (p = 0.008). There were no significant correlations between M1 neurochemicals and pain characteristics. These findings provide preliminary evidence of neuronal depression and altered neuronalglial interactions across M1 in chronic LBP.
初级运动皮层（M1）在慢性下腰痛（LBP）中的参与是一个相对较新的概念。最近有报道称，M1 兴奋性降低和 M1 刺激后的镇痛作用。然而，这些功能 M1 变化背后的神经化学变化尚不清楚。本研究旨在探讨左右 M1 中神经元和神经胶质细胞的特定神经化学物质是否发生改变。19 名慢性 LBP 患者和 14 名健康对照者进行了质子磁共振波谱检查，以测量 N-乙酰天门冬氨酸（NAA）和肌醇（mI）。我们还检查了 M1 内和 M1 之间神经化学物质之间的相关性，以及神经化学物质浓度与疼痛临床特征之间的关系。与对照组相比，LBP 患者的右侧 M1 NAA 降低（p=0.008）。LBP 组和对照组左侧 M1 NAA 和 mI 无显著差异。M1 之间神经化学物质的相关性在组间存在差异（p=0.008）。M1 神经化学物质与疼痛特征之间无显著相关性。这些发现为慢性 LBP 中 M1 跨区神经元抑制和神经元-神经胶质相互作用改变提供了初步证据。
