Reduction of Pain Sensitivity is Associated with the Response to Treatment in Women with Chronic Pelvic Pain.

OBJECTIVE: The objective of this study was to evaluate whether pain thresholds to electrical stimulation of the skin change in the response to treatment in women with chronic pelvic pain (CPP).

METHODS: Fifty-eight women with persistent pelvic pain for at least 6 months, from a tertiary care setting, were included in this study. All women were evaluated before the therapeutic intervention and at 6 months of multidisciplinary treatment. To estimate the pain threshold, we used transcutaneous electrical nerve stimulation on the anterior surface of the nondominant arm. The intensity of clinical pain was estimated by a visual analog scale and by the McGill questionnaire.

RESULTS: The mean of pain threshold increased from 14.2 to 17.4 after 6 months of treatment (P < 0.0001). The effect sizes of the increase of electrical pain threshold were 0.86 (95% CI, 0.38 to 1.34) in the group with pain reduction and 0.53 (95% CI, -0.08 to 1.15) in the group without pain reduction.

CONCLUSION: The sensitivity to experimental pain was reduced after 6 months of multidisciplinary treatment for CPP. Our data provided additional evidence of central sensitization in women with CPP.