Fig. 1

Work-flow. Flow chart depicting how studies were selected for this review. Used MeSH terms were “migraine disorders” and “proton pump inhibitors”. Criteria for exclusion were: studies not performed on PPIs, studies not performed on migraine or other headache diseases, studies that were not conducted on humans or studies that were excluded due to different reasons, like studies that were performed on pain sensitivity in headache patients, or that were not written in English language