Fig. 2

Comparison of VEGF (A), TGF-ß1 (B), CX3CL1 (C) and ß-NGF (D) concentrations for the 4 post-COVID headache groups: no headaches, unchanged headaches, more severe headaches, and newly onset headaches. Patient samples were analyzed for biomarker concentrations of VEGF (A), TGF-ß1 (B), CX3CL1 (C), and ß-NGF (D) across the four post-COVID headache groups: those with no headaches, unchanged headaches, more severe headaches, and newly onset headaches. Only biomarkers showing significant values < 0.05 in the global analysis of all biomarkers using the Chi-Square test are presented. Box and Whiskers plots are depicted