Effects of high-intensity high-frequency transcutaneous electric nerve stimulation in primary dysmenorrhea – a randomised cross-over pilot study

Background: Many women are affected by primary dysmenorrhoea. Transcutaneous Electric Nerve Stimulation (TENS) can be an alternative to analgesics. In one trial, high-intensity, high-frequency TENS was shown to be effective but there is need for more trials.Objectives: To study the effects of high-intensity, high-frequency TENS for primary dysmenorrhoea.Design: Randomised controlled pilot study with cross over design.Methods: Sixteen women with primary dysmenorrhoea participated. Pain, limitation in physical function, other symptoms related to the menstrual period and use of analgesics were registered at baseline, treatment versus control period followed by a wash-out period. Treatment consisted of high-intensity (40 mA) high-frequency (80 Hz) TENS stimulation in sessions of 60 s.Results: The results revealed no significant difference in pain intensity, limitations in physical function, consumption of analgesics and associated symptoms between the groups but a significant lower limitation in physical function during the wash-out period in comparison to the treatment period within the whole group.Conclusion: No significant effect of TENS was seen in contrast to previous studies. The effect is therefore questionable, but results must be interpreted with care, as this was a pilot study and the use of the equipment was not monitored and therefore unknown.Trial registration: FoU i Sverige, R&D in Sweden. Registration number: 257041, 181009, First patient enrolled: June 15, 2016