We thank Dr. Bugnicourt and Dr. Godefroy for their comments on our article.1 We agree with their statements on the potential release of vasoactive factors during migraine aura and on the limitations around reversibility and the potentially low prevalence of an index vein. Naturally, a case series has to deal with the data given, and only 1 patient had follow-up imaging. The aim of our study was to introduce the phenomenon of the index vein. It would be of incredible value to calculate accuracy measures of the index vein for making the diagnosis of migraine aura in the emergency setting. We therefore strongly encourage using the definition of the index vein provided in our study for future studies to obtain sensitivity, specificity, and negative or positive predictive values of this finding. The question of involvement of the cerebral arteries during migraine aura for reversible vasoconstriction—although important—has not been the focus of this case series and remains to be determined. In this respect, time-of-flight MR angiography was indeed normal in all reported patients.