Defective Endogenous Pain Modulation in Fibromyalgia: A Meta-Analysis of Temporal Summation and Conditioned Pain Modulation Paradigms

To study the characteristics of temporal summation (TS) and conditioned pain modulation (CPM) in fibromyalgia (FM) patients, we systematically searched Pubmed and EMBASE for studies using TS or CPM comparing FM patients with healthy controls. We computed Hedges' g, risk of bias, sensitivity analysis, and meta-regression tests with 10,000 Monte-Carlo permutations. Twenty-three studies (625 female and 23 male FM patients and 591 female and 81 male healthy controls) were included. The meta-analyses showed an effect size of .53 for TS (P?P?

Perspective

This novel meta-analysis provides evidence for defective endogenous pain modulation in FM patients. We explored the effect of covariates on between-study variability in these paradigms. These biomarkers may aid in diagnosis, and treatment of patients. However, validation requires further investigation under strict methodological settings, and into individual patient covariates.