[Discussion on existing problems of placebo acupuncture design based on acupuncture analgesia]

In the present article, the authors made an overview about the existing problems of placebo acupuncture design in accordance with the neurological basis of acupuncture analgesia. The neuron-segmental and systemic mechanisms initiated by local somesthetic stimuli at different intensities are involved in acupuncture analgesia. When the local pain locus and the stimulated point are in the same spinal segmental region, stimuli of either higher intensity or lower intensity may produce an obvious anaIgesia effect. If the stimulation site is far from the pain locus (in remote spinal segment region), only higher intensity stimulation works. From this viewpoint, the placebo acupuncture design in current clinical trials for pain treatment exists some unreasonable aspects. Both pain focus and intensity of acupuncture stimulation should be taken into consideration together. The optimal placebo acupuncture design for the treatment of pain conditions is that lower intensity acupuncture stimulation is given for longer distance between the pain origin locus and the stimulated acupoint.