Can a patent foramen ovale (PFO) lead to new onset migraines?

Patent Foramen Ovale and New Onset Migraines

Yes, a patent foramen ovale (PFO) can lead to new onset migraines, particularly in patients with migraine with aura, though the evidence is stronger for association than direct causation.

Relationship Between PFO and Migraine

The connection between PFO and migraine is supported by several observations:

• The prevalence of migraine is higher in patients with PFO than in the general population 1
• Migraine with aura is particularly associated with PFO, with studies showing 68% of PFO patients with migraine experiencing migrainous aura 1
• After PFO closure for cryptogenic stroke, significant reductions in migraine frequency have been observed in some patients 1

Proposed Mechanisms

Several mechanisms have been proposed to explain how PFO might trigger or worsen migraines:

• Microembolus-triggered cortical spreading depression (CSD): Small emboli passing through the PFO may trigger CSD, a known mechanism in migraine pathophysiology 2
• Vasoactive substance hypothesis: Substances normally filtered by the lungs may bypass pulmonary circulation through the PFO and directly enter cerebral circulation 2, 3
• Impaired cerebral autoregulation: PFO may affect brain structure and function, particularly in areas involved in pain processing 2
• Possible genetic connection: There may be a common genetic basis for both conditions 2

Evidence Quality and Clinical Implications

The evidence linking PFO and migraine has limitations:

• While observational studies show association, randomized controlled trials have produced mixed results
• The PREMIUM trial (2017) failed to meet its primary endpoint of 50% reduction in migraine attacks after PFO closure, though secondary endpoints showed some benefit 4
• Complete migraine remission for 1 year occurred in 8.5% of patients after PFO closure versus 1% in the control group (p=0.01) 4
• Patients who underwent PFO closure had a significantly greater reduction in headache days (-3.4 vs. -2.0 days/month, p=0.025) 4

Clinical Considerations

When evaluating patients with new-onset migraines and PFO:

• The presence of aura increases the likelihood of PFO association 1, 5
• Patients with right-sided cardiac disease and elevated right-sided filling pressures may be more susceptible to right-to-left shunting through a PFO 6
• Neuroimaging may reveal structural and functional changes in the brain, particularly in subcortical regions, deep white matter, and posterior circulation 2

Management Implications

Current guidelines do not specifically recommend PFO closure for migraine alone:

• PFO closure is primarily indicated for patients with cryptogenic stroke or TIA attributed to PFO 6
• For patients with both migraine and cryptogenic stroke/TIA, PFO closure may provide dual benefit 6
• The American Heart Association and American College of Cardiology emphasize thorough evaluation to exclude alternative etiologies before attributing symptoms to PFO 3

Conclusion

While a PFO can contribute to new onset migraines through several potential mechanisms, the relationship is complex and not fully established as causal. The strongest evidence exists for patients with migraine with aura, where PFO closure has shown some benefit in reducing migraine frequency in selected patients, particularly those who have had cryptogenic stroke.