Lund Iréne, Lundeberg Thomas
Karolinska Institutet, Stockholm, Sweden.
Acupunct Med. 2006 Mar;24(1):13-5. doi: 10.1136/aim.24.1.13.
Most controlled trials of acupuncture have used minimal, superficial, sham, or 'placebo' acupuncture. It has recently been demonstrated that light touch of the skin stimulates mechanoreceptors coupled to slow conducting unmyelinated (C) afferents resulting in activity in the insular region, but not in the somatosensory cortex. Activity in these C tactile afferents has been suggested to induce a 'limbic touch' response resulting in emotional and hormonal reactions. It is likely that, in many acupuncture studies, control procedures that are meant to be inert are in fact activating these C tactile afferents and consequently result in the alleviation of the affective component of pain. This could explain why control interventions are equally effective as acupuncture in alleviating pain conditions that are predominantly associated with affective components such as migraine or low back pain, but not those with a more pronounced sensory component, such as osteoarthritis of the knee or lateral epicondylalgia.
大多数针灸对照试验使用的是微量、浅刺、假针刺或“安慰剂”针刺。最近有研究表明，皮肤的轻触会刺激与传导速度慢的无髓鞘（C）传入神经相连的机械感受器，从而导致脑岛区域活动，但体感皮层无活动。有人认为，这些C触觉传入神经的活动会引发“边缘性触觉”反应，从而导致情绪和激素反应。在许多针灸研究中，本应无活性的对照程序实际上可能激活了这些C触觉传入神经，从而减轻了疼痛的情感成分。这可以解释为什么对照干预在缓解主要与情感成分相关的疼痛状况（如偏头痛或腰痛）方面与针灸同样有效，但在缓解具有更明显感觉成分的疼痛状况（如膝关节骨关节炎或外侧上髁炎）方面则不然。
