Comparative measurement of pelvic floor pain sensitivity in chronic pelvic pain

OBJECTIVE: Women with pelvic pain conditions exhibit enhanced somatic pain sensitivity at extragenital sites. Whether comparable differences exist for pelvic floor or vaginal pain sensitivity is unknown. The present study was undertaken to estimate pelvic floor and vaginal pressure-pain detection thresholds both in women with pelvic pain and healthy women. METHODS: We conducted a cross-sectional study of pelvic floor and vaginal pain detection thresholds comparing 14 women with chronic pelvic pain to 30 healthy women without this condition. Using a prototype vaginal pressure algometer, we recorded continuous ascending pressure and determined each subject's pressure-pain threshold at each of eight paired pelvic floor sites and two adjacent vaginal sites. RESULTS: Mean pain detection thresholds for all 10 sites were significantly lower in women with pelvic pain compared with healthy controls (at right iliococcygeus, controls 1.73±0.60 kg/cm compared with women 0.96±0.38 kg/cm, P<.001, other sites similar), and remained so after controlling for differences in patient age and menopausal status. Pelvic floor and vaginal site pain detection thresholds had moderate-to-strong correlations with each other (r=0.62-0.91). CONCLUSION: Chronic pelvic pain is associated with enhanced pelvic floor and vaginal pressure-pain sensitivity.