Department of Neuroscience, Pediatric Hospital Bambino Gesù, IRCCS, Rome, Italy.
Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark.
Eur J Pain. 2021 Mar;25(3):659-667. doi: 10.1002/ejp.1701. Epub 2020 Dec 12.
The neural mechanism underlying the analgesic effect of acupuncture is largely unknown. We aimed at investigating the effect of abdominal acupuncture (AA) on the laser-evoked potential (LEP) amplitude and laser-pain rating to stimulation of body parts either homotopic or heterotopic to the treated acupoint.
Laser-evoked potentials were recorded from 13 healthy subjects to stimulation of the right wrist (RW), left wrist (LW) and right foot (RF). LEPs were obtained before, during and after the AA stimulation of an abdominal area corresponding to the representation of the RW. Subjective laser-pain rating was collected after each LEP recording.
The amplitude of the N2/P2 LEP component was significantly reduced during AA and 15 min after needle removal to both RW (F = 4.14, p = .02) and LW (F = 5.48, p = .008) stimulation, while the N2/P2 amplitude to RF stimulation (F = 0.94, p = .4) remained unchanged. Laser-pain rating was reduced during AA and 15 min after needle removal only to RW stimulation (F = 5.67, p = .007).
Our findings showing an AA effect on LEP components to both the ipsilateral and contralateral region homotopic to the treated area, without any LEP change to stimulation of a heterotopic region, suggest that the AA analgesia is mediated by a segmental spinal mechanism.
Although abdominal acupuncture has demonstrated to be effective in the reduction in laser-evoked potential (LEP) amplitude and laser-pain rating, the exact mechanism of this analgesic effect is not known. In the current study, we found that treatment of an area in the "turtle representation" of the body led to a topographical pattern of LEP amplitude inhibition that can be mediated by a segmental spinal mechanism.
针刺镇痛的神经机制在很大程度上尚不清楚。我们旨在研究腹针（AA）对刺激身体与治疗穴位同部位或异部位的激光诱发电位（LEP）幅度和激光疼痛评分的影响。
从 13 名健康受试者的右侧手腕（RW）、左侧手腕（LW）和右脚（RF）记录激光诱发电位。在对与 RW 代表相对应的腹部区域进行 AA 刺激之前、期间和之后获得 LEP。在每次 LEP 记录后收集主观激光疼痛评分。
与 RW（F=4.14，p=0.02）和 LW（F=5.48，p=0.008）刺激相比，在 AA 期间和针去除后 15 分钟，N2/P2 LEP 成分的振幅显著降低，而对 RF 刺激（F=0.94，p=0.4）的 N2/P2 振幅保持不变。仅在 AA 期间和针去除后 15 分钟，与 RW 刺激相比，激光疼痛评分降低（F=5.67，p=0.007）。
我们的研究结果表明，AA 对同侧和对侧与治疗区域同部位的 LEP 成分有影响，而对异部位的刺激没有 LEP 变化，这表明 AA 镇痛是由节段性脊髓机制介导的。
尽管腹针已被证明可有效降低激光诱发电位（LEP）幅度和激光疼痛评分，但这种镇痛作用的确切机制尚不清楚。在目前的研究中，我们发现，对身体的“龟代表”区域进行治疗会导致 LEP 幅度抑制的地形模式，这种模式可能由节段性脊髓机制介导。
