Viscero‐visceral hyperalgesia in dysmenorrhoea plus previous urinary calculosis: Role of myofascial trigger points and their injection treatment in the referred area

Background Women with dysmenorrhoea plus symptomatic urinary calculosis experience enhanced pain and referred muscle hyperalgesia from both conditions than women with one condition only (viscero‐visceral hyperalgesia). The study aimed at verifying if enhanced dysmenorrhoea persists after urinary stone elimination in comorbid women and if local anaesthetic inactivation of myofascial trigger points (TrPs) in the lumbar area (of urinary pain referral) also relieves dysmenorrhoea. Methods Thirty‐one women with dysmenorrhoea plus previous urinary calculosis (Dys+PrCal) and lumbar TrPs, and 33 women with dysmenorrhoea without calculosis (Dys) underwent a 1‐year assessment of menstrual pain and muscle hyperalgesia in the uterus‐referred area (electrical pain threshold measurement in rectus abdominis, compared with thresholds of 33 healthy controls). At the end of the year, 16 comorbid patients underwent inactivation of TrPs through anaesthetic injections, whereas the remaining 12 received no TrP treatment. Both groups were monitored for another year at the end of which thresholds were re‐measured. Results In year1, Dys+PrCal presented significantly more painful menstrual cycles and lower abdominal thresholds than Dys, thresholds of both groups being significantly lower than normal (p