Effects of Transcutaneous Electrical Nerve Stimulation (TENS) On Hormone profiles In Subjects With Primary Dysmenorrhoea - A Preliminary Study

Background & Objective: Primary dysmenorrhoea (PD) is the occurrence of painful menstrual cramps of uterine origin which occurs in the absence of any underlying disease. The objective of this study was to evaluate the effect of TENS on the hormones; cortisol and prolactin in individual with PD. Methods: Plasma levels of cortisol and prolactin were studied in twenty-one (21) subjects with mean age of 23 + 2 years by obtaining blood sample from each subject, pre-and post-TENS therapy on the first day of menstruation. Visual Analogue Scale (VAS) was used to assess the pre-and post-treatment pain intensity. The TENS unit was applied for a duration of 30 minutes. Results: The paired t-test showed that there was an overall reduction in the mean cortisol and prolactin from pre treatment values of 28.45µg/dl±5.27 and 56.81ng/ml±31.86 to post treatment values of 27.33µg/dl±5.13 and 53.23ng/ml±37.63 respectively. However these differences were not statistically significant (P>0.05). Pain intensity was significantly reduced comparing pre and post treatment VAS scores. Conclusion: The probable mechanism by which TENS effects alteration in cortisol and prolactin levels and pain reduction in PD might be through the opioid-modulating analgesia system, which releases B-endorphins and other endogenous opiates in response to pain. This is because there is close relationship between B-endorphin, cortisol and neurons, which secrete dopamine into the hypothalamic-pituitary-portal system. However this study gives further evidence that women with PD have disturbed hormonal profiles. KEY WORDS: Primary dysmenorrhoea, TENS, Cortisol, Prolactin.