Capillary blood flow in patients with dysmenorrhea treated with acupuncture

OBJECTIVE; To observe capillary blood flow at acu- points during acupuncture treatment of primary dysmenorrhea and gain new insights into its anal- gesic mechanism. METHODS： Patients with primary dysmenorrhea were enrolled and randomly assigned to a treat- ment or control group. Subjects＇ symptoms were differentiated into various Traditional Chinese Medi- cine （TCM） syndromes and treated for 10 sessions with puncturing acupuncture or self-pressing right-hand Hegu （LI 4）, adding other acupoints based on syndrome. Laser speckle was used tocompare the change in the vasomotor amplitude and perfusion of the capillaries in Hegu （LI 4） be- fore and during the treatment. Each subject was re- quired to finish the period pain symptoms observa- tion form, verbal rating scales, numerical rating scale, pain rating index, face rating scale, Zung self-rating depression scale, Zung self-rating anxi- ety scale, and numerical rating scale before and af- ter treatments. RESULTS： After 10 sessions, the symptom scores, pain index （PI）, and visual analog scale （VAS） de- creased significantly in treatment group. The vol- ume of blood flow in Hegu （LI 4） declined slightly. No significant evidence supported that needling caused capillary contraction, but the capillary vaso- motor amplitude at Hegu （LI 4） increased remark- ably. CONCLUSION： Acupuncture can increase the capil- lary blood flow, thus promoting the flow of Qi and blood in terms of TCM theory, which facilitates pain relief.