Multimodal nociceptive mechanisms underlying chronic pelvic pain - 02/12/15

Abstract |
Objective |
We sought to evaluate candidate mechanisms underlying the pelvic floor dysfunction in women with chronic pelvic pain (CPP) and/or painful bladder syndrome (PBS)/interstitial cystitis. Notably, prior studies have not consistently controlled for potential confounding by psychological or anatomical factors.
Study Design |
As part of a larger study on pelvic floor pain dysfunction and bladder pain sensitivity, we compared a measure of mechanical pain sensitivity, pressure pain thresholds (PPTs), between women with pelvic pain and pain-free controls. We also assessed a novel pain measure using degree and duration of postexam pain aftersensation, and conducted structural and functional assessments of the pelvic floor to account for any potential confounding. Phenotypic specificity of pelvic floor measures was assessed with receiver operator characteristic curves adjusted for prevalence.
Results |
A total of 23 women with CPP, 23 women with PBS, and 42 pain-free controls completed the study. Women with CPP or PBS exhibited enhanced pain sensitivity with lower PPTs (1.18 [interquartile range, 0.87–1.41] kg/cm2) than pain-free participants (1.48 [1.11-1.76] kg/cm2; P < .001) and prolonged pain aftersensation (3.5 [0-9] vs 0 [0-1] minutes; P < .001). Although genital hiatus (P < .01) was wider in women with CPP there were no consistently observed group differences in pelvic floor anatomy, muscle tone, or strength. The combination of PPTs and aftersensation duration correlated with severity of pelvic floor tenderness (R2, 41-51; P < .01). Even after adjustment for prevalence, the combined metrics discriminated pain-free controls from women with CPP or PBS (area under the curve, 0.87).
Conclusion |
Both experimental assessment of pelvic floor pain thresholds and measurement of sustained pain are independently associated with pelvic pain phenotypes. These findings suggest systematic clinical assessment of the time course of provoked pain symptoms, which occurs over seconds for mechanical pain thresholds vs minutes for aftersensation pain, would be helpful in identifying the fundamental mechanisms of pelvic floor pain. Longitudinal studies of therapies differentially targeting these discrete mechanisms are needed to confirm their clinical significance.
Le texte complet de cet article est disponible en PDF.Key words : painful bladder syndrome, pelvic pain, pressure pain threshold, quantitative sensory testing
Plan
| F.F.T. was supported by National Institutes of Health (NIH) Grant K23HD054645. K.M.H. was supported by a Research Career Development Award from the NorthShore University HealthSystem Research Institute, Evanston, IL. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. |
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| The authors report no conflict of interest. |
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| Cite this article as: Hellman KM, Patanwala IY, Pozolo KE, et al. Multimodal nociceptive mechanisms underlying chronic pelvic pain. Am J Obstet Gynecol 2015;213:827.e1-9. |
Vol 213 - N° 6
P. 827.e1-827.e9 - décembre 2015 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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