Dynamic Pain-Related Changes in Pulse-Graph Measurements in Patients with Primary Dysmenorrhea before and after Electroacupuncture Intervention and Its Correlation with TCM Pattern

OBJECTIVE: To explore the dynamic changes recorded in pulse graph related to the changes in the severity of pain before and after electroacupuncture (EA) intervention among young women suffering from primary dysmenorrhea (PD). METHODS: A total of 147 female college students were recruited in this study. Based on participants' symptoms associated with menstruation, they were divided into the PD group and the healthy control group. In addition, participants in the PD group were further sorted into the Cold Coagulation and Blood Stasis Pattern (CCBSP) and Qi Stagnation and Blood Stasis Pattern (QSBSP) based on TCM diagnoses and their pulses differences. Participants in the PD group received EA at maximal pain during menstruation. The primary acupuncture points selected were SP 6 and RN 3, additional RN 4 for CCBSP, and LR 3 for QSBSP. Four observation time points were 7–10 days before menstruation (T(0)), maximal pain during menstruation (T(1)), immediately after EA (T(2)), and 30 mins after EA (T(3)). The severity of pain was assessed by a visual analog scale (VAS) along with a pulse analyzer to record the variations of the pulse graph throughout the changes of pain level. RESULTS: (1) The average VAS score in the PD group decreased from 5.44 ± 1.46 at T(1) to 1.72 ± 1.27 at T(2) and 1.59 ± 1.30 at T(3). The average VAS score in participants of CCBSP at T(1), T(2), and T(3) was higher than that of QSBSP. (2) At T(1), h(2), h(3), h(4), and w(1)/t were all significantly increased, compared with those at T(0). At T(2), t and t(5) were both significantly increased, and w(1)/t, t(1), and t(1)/t were all significantly decreased, compared with those at T(1). At T(3), w(1)/t, t(1), and t(1)/t were all significantly increased, and t and t(5) were both significantly decreased, compared with those at T(2). (3) Comparing the pulse graphs between the healthy control and the PD groups, h(1) was significantly lower at T(0); w(1)/t was significantly higher at T(1); t was significantly higher at T(2); and t(1) and t(1)/t were both significantly higher at T(3) in PD group. (4) When comparing the pulse graphs between QSBSP and CCBSP, t(4)/t(5) was significantly higher at T(0) and t(1) was significantly higher at T(1) in the CCBSP group. CONCLUSION: EA is effective in relieving primary dysmenorrhea. Our results showed the opposite changing of the pulse graph recorded before the onset of pain to the maximum pain and that from maximum pain to pain relief. Indeed, there were differences in the recorded pulse graphs between CCBSP and QSBSP (two patterns of PD) as described in traditional Chinese pulses diagnosis. The study has been registered in the Chinese Clinical Trial Registry (registered number: ChiCTR2000040065; registered date: 2020/11/19).