Acute worsening in migraine symptoms following patent foramen ovale closure

Background and Aim: When they were first presented in 2006, results from the MIST trial suggested that patent foramen ovale (PFO) closure did not cure headache but that headache days and headache burden were significantly reduced in device-treated patients compared with controls. Of note, no short- term effect was reported by the investigators. We therefore sought to assess the effects of PFO closure on migraine status at 1 month. Methods and Results: Fifty seven consecutive patients who underwent transcatheter PFO closure at our institution for cryptogenic strokes were assessed. Migraine symptoms were graded before and 1 month after the procedure using the MIST score. Analysis was performed using SPSS 16. Chi square, Fisher's exact test and Student's T test were used as appropriate, p<0.05 was considered significant. There were no significant differences in cardiovascularriskfactorsandpre-treatment medications. Migraine at baseline was present in 27 patients (48%). Regardless of baseline migraine status, at 1 moth follow up, 30 patients (53%) reported a change in their symptoms early after PFO closure. Of these, 18 patients (60%) reported a worsening of their symptoms and seven (23%) reported an improvement. Notably, five patients (17%) without baseline migraine, experienced symptoms after the procedure. Twenty seven patients (47%) did not experience any change in their migraine status. Among these, two patients had baseline migraine, 25 were asymptomatic at the enrolment. To assess whether baseline migraine severity affected post-closure migraine status, we divided the population in two groups: Group A, 42 patients, (no or mild symptoms, MIST score 0 to 4) and Group B, 15 patients, (moderate to severe symptoms, MIST score 5 to 9). Nine patients (21%) in group A experienced a statistically significant worsening of their symptoms compared to 7 patients (47%) of group B. Conclusion: There is conflicting data about the long-term effects of PFO closure on migraine. Our data suggests a significant change and possible increase in migraines following percutaneous PFO closure at 1 month. This change is more likely to occur in individuals with pre-existing migraines, particularly amongst those with more severe migraines to start of with. Why this may occur is unclear but it has been postulated that increased migraines may occur during the period when the implanted device is not fully endothelialised, leading to enhanced platelet activation and serotonin release. This phenomenon needs further evaluation in larger studies.