ORLANDO, FLA—Patients with a history of stroke and a patent foramen ovale have a higher prevalence of migraine with aura than the general population, and after percutaneous patent foramen ovale closure for stroke prevention purposes, they report a reduced frequency of migraine attacks, a new study showed. The finding suggests that a paradoxical embolism passing through the right-to-left shunt in the heart caused by an open foramen ovale may cause not only strokes but migraine as well, the investigators said.

In a separate paper, the same investigators reported interim findings of an ongoing study examining the prevalence of patent foramen ovale and ischemic brain lesions in patients with migraine compared with healthy controls. Although they are still accruing patients in this study, the results to date suggest an increased prevalence of both patent foramen ovale and ischemic brain lesions among the migraine patients versus controls. Both papers were presented at the American Heart Association’s Scientific Sessions 2003.

ASSOCIATIONS WITH STROKE AND MIGRAINE?

Patent foramen ovale is already implicated as a cause of stroke, particularly in young people, and percutaneous closure of patent foramen ovale is now done for secondary stroke prevention in people in whom other causes of stroke have been ruled out.

Beginning in 1999, several reports from neurologists using transcranial Doppler suggested that patients with migraine with aura—but not migraine without aura—appeared to have more cardiac right-to-left shunts than controls, said lead author Markus Schwerzmann, MD, of the Swiss Cardiovascular Center Bern, in Switzerland (now at the University of Toronto).

“Clinically, symptoms of aura are sometimes difficult to distinguish from the symptoms of transient ischemic attack,” Dr. Schwerzmann said in an interview. “We were wondering whether these patients with migraine with aura might also have more often a patent foramen ovale that might be responsible for triggering their migraine attacks.”

CLOSING OFF MIGRAINE

In the first report, neurologists and cardiologists from the University of Bern examined a group of patients who had a patent foramen ovale, a previous stroke, and subsequent patent foramen ovale closure as a secondary prevention measure. They asked these patients about their migraine frequency before and after the patent foramen ovale closure to determine whether the intervention had had an impact in reducing migraine attacks.

In 215 patients, the prevalence of migraine with and without aura was established using International Headache Society criteria. The impact of patent foramen ovale closure on headache frequency and headache impact on daily life was investigated using the Headache Impact Test (HIT-6).

“What we found was first, patients with a patent foramen ovale and a history of stroke had migraine much more often than we expect in the general population, and if we closed this patent foramen ovale for stroke prevention reasons, we also reduced the frequency of migraine attacks in these patients, which was at the time of patent foramen ovale closure not intended,” Dr. Schwerzmann said.

Of the 215 patients, 48 (22%) suffered from migraine in the year prior to patent foramen ovale closure, compared with an expected prevalence of about 10% to 12% in the general European population. Of these, 37 (17%) patients had migraine with aura, and 11 (5%) had migraine without aura. This finding was also contrary to results in the general population where most migraine, about two thirds, is migraine without aura, Dr. Schwerzmann said.

After patent foramen ovale closure, the frequency of headache attacks was significantly reduced in both types of migraine: in migraine with aura by 54% and in migraine without aura by 62%. A decrease in the frequency of nonmigraine headaches did not reach statistical significance. The HIT-6 score improved in all groups, but significantly more for migraine with and without aura than nonmigraine headache.

Previously, a link has been seen between migraine and stroke risk, Dr. Schwerzmann noted. “One hypothesis that we are investigating is—if patients with migraine more often have a patent foramen ovale and these patent foramina ovalia make them more prone to stroke—whether that’s why patients with migraines may have strokes more often,” he speculated. “It might not be migraine, but the patent foramen ovale might be the common link.”

THE IMPACT OF AURA

In a second study, Dr. Schwerzmann and colleagues are elaborating on their prior investigation, comparing a group of patients with migraine with aura to a group of healthy controls, using contrast transesophageal echocardiography (TEE) to ascertain the presence or absence of patent foramen ovale, and cranial MRI to establish the presence of ischemic brain lesions.

The study is still ongoing, Dr. Schwerzmann noted, with more patients being enrolled, but an interim report showed that a patent foramen ovale was present on TEE in 25 of 57 patients with migraine with aura (44%) and nine of 55 controls (odds ratio, 4.0).

After correction for hypertension and age, the presence of a patent foramen ovale increased—independently of migraine—the incidence of one or more ischemic brain lesions by a factor of 2.4, the investigators reported.

If their study ultimately confirms that there is an increased risk for ischemic brain lesions in patients with migraine related to patent foramen ovale, Dr. Schwerzmann said, “then I guess the next step would really have to be a randomized study of patent foramen ovale closure in migraine patients. If you see that the group undergoing patent foramen ovale closure has an improvement in migraine frequency, then that might be the point in time where we can say that patent foramen ovale closure, in addition to established medical treatment, is a further option for a selected group of patients with migraine.”

NR

—Susan Jeffrey

Suggested Reading
Anzola GP, Magoni M, Guindani M, et al. Potential source of cerebral embolism in migraine with aura: a transcranial Doppler study. Neurology. 1999;52:1622-1625.
Horton SC, Bunch TJ. Patent foramen ovale and stroke. Mayo Clin Proc. 2004;79:79-88.
Morandi E, Anzola GP, Angeli S, et al. Transcatheter closure of patent foramen ovale: a new migraine treatment? J Interv Cardiol. 2003;16:39-42.

Return to table of contents