BackgroundTendinomuscular Meridians (TMM) are adopted as a treatment paradigm for studying the neuronal mechanisms of acupuncture analgesia in acute thermal pain. The effect of needle combination on analgesia and the corresponding neuronal mechanisms have yet to be fully delineated.ObjectiveTo assess the role of different needle groups in the TMM treatment paradigms of acute pain by determining the peripheral thermal thresholds before and after electroacupuncture (EA) and the corresponding behavioral feedback of thermal pain stimulation and the De Qi sensation of EA.Design, Setting, and ParticipantsA prospective study of 13 individuals conducted at the University of California, San Diego Medical Center.InterventionsParticipants' baseline thermal thresholds (cold, warm, cold and hot pain) were measured at premarked testing sites along the medial aspects of the bilateral lower extremities. Hot pain was delivered for 5 seconds to the testing sites and the corresponding pain visual analog scale (VAS) scores were recorded. Four 30-second EA stimulations were delivered at the Ting points and Gathering point. At the last 10 seconds of each stimulation, 5 seconds of person-specific hot pain stimulation was delivered to the testing sites in random order.Main Outcome MeasuresThe VAS scores of the hot pain and De Qi sensation (tingling) before, during, and after the EA were recorded. The thermal thresholds were obtained immediately and 30 minutes after EA.ResultsA significant (P< .001) elevation of cold, warm, and von Frey thresholds was noted at both the bilateral calf and thigh areas after EA. In addition, a corresponding sustainable decrease of hot pain VAS scores was noticed. In comparison to the contralateral calf area, no additional analgesic benefit was noticed with the local needle placement at the ipsilateral calf testing sites.ConclusionsEA at both the Gathering and Ting points generated an area of analgesic benefit along the medial aspects of the lower extremities, suggesting a dermatomal correlation. Sustainable bilateral analgesic effect suggests a centrally mediated inhibitory modulation.