Possible mechanisms of auricular acupoint stimulation in the treatment of migraine by activating auricular vagus nerve.

Under the guidance of traditional Chinese medicine theory, the clinical research of auricular acupoint stimulation in the treatment of migraine has gained a lot, and the curative efficacy is definite, but its mechanism remains unclear. In the present paper, we discussed the efficacy of auricular acupoint stimulation including "transcutaneous auricular vagus nerve stimulation" (taVNS) in the treatment of migraine in recent years. Through bibliometric analysis, we screened out top 10 auricular acupoints (Shenmen［TF4］, Pizhixia［AT4］, Jiaogan［AH6a］, Gan［CO12］, Yidan［CO11］, Neifenmi［CO18］, Shen［CO10］, Nie［AT2］, Zhen［AT3］ and E［AT1］) which were the most frequently used for migraine. Majority of these auricular acupoints just distributed in the region innervated by auricular vagus nerve. Thus, we thought that the analgesic effect of needling these auricular acupoints for migraine was produced by triggering the auricular vagus nerve, and concluded that the central mechanism underlying induction of analgesic effect by activating auricular vagus nerve may be achieved by activating the descending pain regulation pathway of the locus coeruleus nucleus and dorsal raphe nucleus. In addition, taVNS-induced 1) regulation of the activities of brain's default network and pain matrix, 2) activation of the cortical descending pain regulation pathway, and 3) inhibition of the neuroinflammatory response may also contribute to its ameliorating effect of migraine. This paper may provide ideas for the future research on the mechanism of auricular acupoint treatment of migraine.在中医理论指导下，耳穴治疗偏头痛的临床研究收获颇丰，疗效确切，但其作用机制尚不明确。本文从耳穴刺激及经皮耳迷走神经刺激（taVNS）治疗偏头痛的疗效展开论述，通过文献计量学分析筛选出治疗偏头痛频次最高的10个耳穴，并与耳的神经分布相联系，观察到治疗偏头痛的穴位多在迷走神经耳支分布区。因此，本研究提出耳穴治疗偏头痛的机制可能是通过刺激迷走神经耳支产生镇痛效应，并总结了taVNS产生镇痛效应的中枢机制可能与激活蓝斑核和中缝背侧核的下行调痛通路，影响脑默认网络和疼痛矩阵，拮抗皮质扩散抑制及减轻神经炎性反应等有关。本文为今后耳穴治疗偏头痛的机制研究提供了思路，论证了耳穴治疗偏头痛的科学性。.