Coupling between visual evoked cerebral blood flow velocity responses and visual evoked potentials in migraneurs.

Neurovascular coupling may be altered in migraneurs. Therefore, visual evoked potentials (VEP) and visually evoked cerebral blood flow velocity responses (VEFR) were simultaneously recorded in 30 healthy controls and 30 migraneurs interictally using a checkerboard stimulus with visual contrasts of 1%, 10% and 100%. The VEFR were measured in the posterior cerebral artery using transcranial Doppler and VEP were recorded from occipital leads. We found an increase in VEFR and VEP in both the healthy and migraneur groups (P < 0.01). VEFR were significantly higher in migraneurs (P < 0.01), while VEP did not significantly differ between the groups (P > 0.05). Regression showed a significant association between VEP and VEFR in both healthy controls (r = 0.66, P < 0.01) and migraneurs (r = 0.63, P < 0.01). The regression coefficient of migraneurs (b = 0.88, SE = 0.08) was significantly higher than that of healthy controls (b = 0.55, SE = 0.07) (P = 0.04). We conclude that neurovascular coupling is increased in migraneurs interictally.