In MA+, Pearson’s test disclosed that the N1–P1 habituation slope correlated negatively with attack frequency (r = −0.489, p = 0.034) and positively with days elapsed since last attack (r = 0.578, p = 0.019), correlations that were not found in MA patients (Fig. 4).
Fig. 4 Correlation between the days elapsed between the recordings and the last migraine attack and the slope of N1–P1 VEP amplitude changes over 6 sequential blocks of averaged responses (linear regression: dashed line). This correlation was significant in the group of patients with complex aura (MA+, right panel), but not in patients with pure visual aura (MA, left panel)