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

•We review temporal summation and conditioned pain modulation in fibromyalgia (FM).•Results revealed pain sensitization and defective endogenous pain modulation in FM.•Sensitivity analysis uncovered multiple modifying covariates.•Lack of blinding was a critical issue in most of the studies reviewed.•The paradigms studied may serve future diagnosis, treatment, and research on FM.