[Patent foramen ovale and migraine, a fortuitus association or a causal relationship?].

Epidemiologic studies have shown a clear comorbidity between migraine with aura and a patent foramen ovale (PFO). Under the age of 55, migraine with aura is a risk factor for ischemic stroke and a proportion of the latter is due to a PFO. It remains to be determined whether PFO is causally related to migraine attacks, or is a fortuitous association due to common genetic factors. Cortical spreading depression which is the underlying mechanism of the migrainous aura, could be favoured by a PFO. Several retrospective and uncontrolled studies suggest that percutaneous closure of a PFO for stroke or decompression illness in divers reduces frequency of migraine attacks with, but also without aura. Multicentric, prospective and controlled trials of this intervention in migraineurs are underway or in preparation. As long as their results are not known, there is no rationale for proposing PFO closure for migraine.