Reduced pain thresholds and signs of sensitization in women with persistent pelvic pain and suspected endometriosis

Abstract

Introduction: Endometriosis is a gynecological disorder that may cause considerable pelvic pain in women of fertile age. Determining pain mechanisms is necessary in order to optimize the treatment of the disease. The objective of the study was to evaluate pain thresholds in women with persistent pelvic pain with and without confirmed endometriosis, and healthy, unaffected controls, and analyze how pain thresholds in these cohorts related to duration of pelvic pain, quality of life, and symptoms of anxiety and depression. Material and methods:Pain thresholds for heat, cold and pressure were assessed with quantitative sensory testing on six locations on a reference group of 55 healthy women and on 37 women with persistent pelvic pain who had been admitted for diagnostic laparoscopy on the suspicion of endometriosis. Validated instruments were applied to assess quality of life and symptoms of anxiety and depression. Data were analyzed by means of uni-and multivariate analysis of variance and Spearman's rank-order correlation. Results:The women with persistent pelvic pain had significantly lower pain thresholds compared with the reference women. In the women with pain, no differences were observed in pain thresholds between women with (n = 13) and women without (n = 24) biopsy-proven endometriosis. The duration of pelvic pain correlated significantly positively with reduced pain thresholds, ie, the longer the duration, the more sensitization. In the persistent pelvic pain group, pain thresholds for heat correlated significantly with the Short Form Health Survey 36 dimension of bodily pain, and thresholds for cold correlated with Short Form Health Survey 36 bodily pain and with symptoms of depression. Conclusions:Our results showed widespread alterations in pain thresholds in women with persistent pelvic pain that are indicative of central sensitization and a time-dependent correlation. Women with pelvic pain and suspicion of endometriosis should probably be treated more thoroughly to prevent or at least minimize the concomitant development of central sensitization. K E Y W O R D Schronic pain, endometriosis, health-related quality of life, pain thresholds, persistent pelvic pain, quantitative sensory testing, sensitization

Associations between pain thresholds for heat, cold and pressure, and Pain Sensitivity Questionnaire scores in healthy women and in women with persistent pelvic pain

“…In our previously published study concerning pain thresholds in women with PPP, we found widespread alterations in pain thresholds in women with PPP that are indicative of central sensitization and a time‐dependent correlation (Grundström et al, ). The present study represents a secondary analysis of the data from that study.…”

“…The pressure was registered in a protocol and the arithmetic average was calculated and used as the actual pressure pain threshold (Mücke et al, ). Since the differences in pain thresholds between the PPP and controls on all sites were almost similar and symmetric for bilateral sites (Grundström et al, ) and in order to minimize multiple testing, we choose to use a composite measure of pain threshold in the analyses. The mean value for each modality (heat, cold and pressure) was calculated as the average of the pain thresholds on all locations and used in the analyses.…”

“…In women with persistent pelvic pain (PPP) symptoms usually originate from a combination of nociceptive, inflammatory, angiogenetic, neurovascular and neuropathic mechanisms, and sometimes manifest as dysmenorrhea or endometriosis (Kobayashi, Yamada, Morioka, Niiro & Shigemitsu, ). Pain hypersensitivity has been detected in women with PPP as assessed by QST (As‐Sanie et al, ; Bajaj, Bajaj, Madsen, & Arendt‐Nielsen, ; Grundström et al, ; He, Liu, Zhang, & Guo, ; Laursen, Bajaj, Olesen, Delmar, & Arendt‐Nielsen, ; Stratton, Khachikyan, Sinaii, Ortiz & Shah, ). The hypersensitivity profile includes increased pain sensitivity (As‐Saine et al, ; Bajaj et al, ) widespread generalized hyperalgesia (Grundström et al, ; He et al, ; Laursen et al, ), decreased pain thresholds (Grundström et al, ; He et al, ; Stratton et al, ), elevated sensory thresholds (He et al, ) and myofascial trigger points (Stratton et al, ).…”

Effect of hysterectomy on pain in women with endometriosis: a population‐based registry study

“…Prolonged exposure to pain could trigger a state of central sensitisation, with an altered perception of pain 26 . It was recently shown that women with chronic pelvic pain had a lower pain threshold than healthy controls and that pain threshold decreases with increasing symptom duration 27,28 . This supports the idea that prolonged exposure to pain increases the risk of developing an altered perception to pain, which could be harder to treat with hormonal and surgical means.…”

Estimate of the proportion of uncertain diagnoses of pudendal neuralgia in women with chronic pelvic‐perineal pain: A systematic review with a descriptive data synthesis

“…The pathophysiology of the pain is unclear. Authors have reported mechanisms of viscero‐somatic referral sensitization 4,5 and central sensitization according to the time‐lapse in which patients complain of their pain 6 . Moreover, chronic pelvic pain is associated with psychological distress, psychiatric disorders, 7 and previous sexual abuse history 8 suggesting psychological involvement in pain perception.…”