“…The meta-analysis found that patients with TTH exhibited significant reduced PPT at the head (MD −49.11, 95% CI −66.05 to −32.17, n = 2347, Z = 5.68, p < 0.001, Figure 3), the neck (MD −88.17, 95% CI −108.43 to −67.92, Z = 8.53, p < 0.001, Figure 4) and distant pain-free (MD: −98.43, 95% CI −136.78 to −60.09, Z = 5.03, p < 0.001, Figure 5) areas with high heterogeneity (I 2 > 75%) between studies in all the meta-analyses. The heterogeneity was related to the same study (38) on TTH classification in all analyses, and to just one in CTTH (head (27), neck (30), and distant pain-free (44) analyses) and FEETH (head (39), neck (37), and distant pain-free (47) analyses) classifications. The funnel plot showed asymmetry in overall PPTs at the trigeminal area (Supplemental Figure 1) with a significant Egger’s test ( p = 0.0028); therefore, high risk of publication bias was possible, but mostly due to just one study (38).…”