Migraine and patent foramen ovale: connecting flight or one-way ticket?

Abstract

Context: The genesis of migraine in patients with patent foramen ovale (PFO) and its relationship with paradoxical stroke is still debated. Some authors agree that migraine with aura and PFO have higher coincidences than would be expected by chance and that it is possible that both conditions are inherited together. Objective: The present review aims to make a comprehensive attempt at clarifying the PFO-migraine connection in light of recent evidence from literature. Evidence acquisition: A Medline search using both OVID and PubMed was performed by searching for literature in English regarding randomized trials, prospective cohort studies, meta-analyses, reviews and editorials about PFO and migraine between 1998 and 2008. Search key words were ‘migraine’ and ‘patent foramen ovale’ matched with ‘prevalence’, ‘echocardiography’, ‘transcranial Doppler ultrasound’, ‘magnetic resonance imaging’, ‘coagulation abnormalities’ and ‘transcatheter closure treatment’. Additional reference material was obtained from the proceedings of relevant conferences on PFO and migraine, and the author’s personal experience. Evidence synthesis: Echocardiographic, transcranial Doppler and MRI studies suggest that migraine patients are at higher risk of stroke compared with the normal population and often have white matter brain lesions on MRI. A large proportion of PFO patients have migraine, in particular migraine with aura, and migraine with aura patients plus PFO have larger shunts compared with migraine-free patients. It has been suggested that patients with migraine and large PFO have an increased risk of paradoxical embolism. Most patients with PFO and migraine respond well to transcatheter closure and this fact is unlikely to be caused just by a placebo effect. Conclusions: Although many gray areas are still present, migraine with aura and large PFO seem to be strictly related to both anatomic and functional states at least in a proportion of patients.