Systemic Analgesic Effects of Electroacupuncture in Healthy Individuals: Thermal Threshhold, Acupuncture Sensation Intensity and De-qi on Quantitative Sensory Test.

Electroacupuncture (EA) has been known to exert analgesic effects according to several reports, but studies investigating the analgesic effect of EA using the quantitative sensory test (QST) are rare.To investigate the analgesic effects of electroacupuncture through changes in thermal thresholds measured using the QST.Pilot, randomized, single-blind, parallel design.The study was conducted at Dongguk University Bundang Oriental Hospital (DUBOH) in South Korea.We included 40 healthy participants age 20 to 40 years.The EA group received EA for 30 minutes at 6 acupuncture points (LI4, PC6, LI10, LI11, ST36, and SP6) and the control group just rested.The primary outcome measure was 4 thermal thresholds including warm detection (WDT), cold detection (CDT), hot pain (HPT), and cold pain (CPT) measured using QST at baseline and after 15, 30 and 60 minutes. The secondary outcomes were the intensity of acupuncture sensation (visual analogue scale [VAS]) and De-qi (Massachusetts General Hospital Acupuncture Sensation Scale [MASS]).The EA group showed significant changes in HPT (P < .001) and CPT (P = .049) compared with the control group, whereas WDT and CDT did not significantly differ. Furthermore, the changes in thermal thresholds were more pronounced in the higher intensity acupuncture sensation group (VAS ≥40) than in the lower intensity group (VAS < 40), although not significantly. The high De-qi group presented greater changes in WDT, CDT, HPT and CPT than the low De-qi group, as measured using MASS. It was especially statistically significant at HPT a feeling of "heaviness" and "dull pain" and at CDT of "tingling." We observed no adverse events related to the study.The change in thermal pain thresholds effected by EA supports the analgesic effect of EA reported in previous studies. The underlying mechanisms need to be holistically considered, and further studies are needed for definitive evidence.