Fig. 4

Cumulative correlation analysis between pre-/postnVNS OXY levels and nVNS outcome in headache frequency (headache days/month). Assessment of cumulative pre- and post-nVNS OXY levels showed a trend towards association with the headache days per month (r = 0.379, p = 0.08). OXY Oxytocin, IL-1ß Interleukin-1ß, HC healthy controls, ns not significant