Evidence of localized and widespread pressure pain hypersensitivity in patients with tension-type headache: A systematic review and meta-analysis.

Objective: This meta-analysis evaluates pressure pain sensitivity values in symptomatic and distant pain-free areas comparing individuals with tension-type headache to controls. Databases and data treatment: Electronic databases were searched for cross-sectional or prospective case-control studies comparing pressure pain thresholds in patients with tension-type headache to headache-free controls. Data were extracted by three reviewers. The methodological quality was assessed by the Newcastle-Ottawa Quality Assessment Scale. Meta-analyses of trigeminal, extra-trigeminal (neck) and distant pain-free areas in tension-type headache were compared to headache-free controls. Frequency of tension-type headache and gender were taken into account. Results: Twenty studies were included. Patients with tension-type headache exhibited lower pressure pain thresholds than headache-free controls: Trigeminal (MD −49.11 kPa, 95% CI −66.05 to −32.17), cervical spine (MD −88.17 kPa, 95% CI −108.43 to −67.92) and distant pain-free areas (MD −98.43 kPa, 95% CI −136.78 to −60.09). Differences were significant for chronic, episodic, and mixed episodic and chronic tension-type headache within the trigeminal and neck (symptomatic areas), but only significant for chronic tension-type headache (MD −102.86, 95% CI −139.47 to −66.25 kPa) for distant pain-free areas. In general, women had lower pressure pain thresholds than men. The methodological quality ranged from fair (45%) to good (40%). The results showed a high heterogeneity and publication bias. Conclusion: This first meta-analysis addressing pressure pain thresholds differences in symptomatic and distant pain-free areas between patients with tension-type headache and controls found low to moderate evidence supporting the presence of pressure pain hypersensitivity in the trigeminal and neck areas in tension-type headache in comparison with headache-free controls. Sensitivity to pressure pain was widespread only in chronic, not episodic, tension-type headache (moderate evidence). Registration number: https://doi.org/10.17605/OSF.IO/R29HY [ABSTRACT FROM AUTHOR]