The Belgian group gave a questionnaire about Migraines to people after they had the PFO closure.² The Swiss group gave a questionnaire assessing the headache frequency and characteristics for the year before and after the PFO closure.³ There was no appreciable affect on the non-Migraine headache patients. In both studies, the PFO closure was done because doctors suspected that a blood clot passing through the PFO might have caused a stroke. The frequency of Migraine was decreased in both studies after PFO closure. Only the Swiss study evaluated both Migraine and non-Migraine headaches. More information about the effectiveness of PFO closure and headaches from these two studies can be found in the table below.

The implications of these Studies

• These two studies add to the growing body of evidence of an association between a PFO and Migraine.
• The number of people who had Migraine with aura in both studies was higher than in the general population.
• PFO closure was associated with reduction of Migraine symptoms in patients having Migraine both with and without aura.
• In the second study, non-Migraine headaches were not affected by PFO closure.
• These studies are important since if PFO closure proves effective for Migraine prevention, that makes PFO a potentially correctable trigger of Migraine.
• However, these studies do not support PFO closure as a treatment for Migraine due to two major limitations:
• The studies were retrospective (they asked patients for information about their headaches that occurred in the past)
• The studies included only stroke patients. To obtain more conclusive results, a study is needed to evaluate otherwise healthy Migraineurs and collect data in real time (prospectively).

In discussing these studies of PFO and Migraine completed to date, Diener et al summarize the current situation with Migraine and PFO closure quite succinctly,

"These studies, however, have major methodological limitations. Therefore patent foramen ovale closure cannot be recommended for the prevention of Migraine with aura. SUMMARY: At present routine percutaneous closure of isolated patent foramen ovale cannot be recommended for patients with cryptogenic stroke. Patent foramen ovale closure should not be used for the prevention of Migraine."⁴