Foramen ovale perméable et migraine

Recent epidemiological data suggest a bidirectional link between patent foramen ovale (PFO) and migraine with aura (MA) with a relative risk of 2 for PFO in subjects with MA and for MA in subjects with PFO. There is no evidence for a link between PFO and migraine without aura. This link is not systematic and applies only to subsets of PFO, mostly large ones, and to subsets of patients with MA. Although comorbidity cannot be ruled out, it may be that this link is partly causal and that some large PFOs may favor MA attacks in genetically predisposed subjects, by allowing vasoactive substances, platelet emboli or paradoxical emboli to bypass the lung filter and trigger the cortical spreading depression of the aura. The first double blind randomised trial of PFO closure in refractory MA, "MIST", has failed to show a benefit on the primary efficacy end point: cessation of attacks during the analysis period included between 3 and 6 months after the procedure. There is thus at present no scientific reason to look for PFO or to close PFO in migraine patients.