The age at which a patient develops migraine with aura may be an important factor in assessing stroke risk, according to a prospective cohort study published in Headache.
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Patients who had onset of migraine with visual aura after age 50 years had an increased risk of ischemic stroke, compared with patients with no headache, the researchers found. Patients with longer exposure to migraine with visual aura – that is, onset before age 50 years – did not have significantly increased ischemic stroke risk, said X. Michelle Androulakis, MD, of the department of neurology at the University of South Carolina in Columbia, and her colleagues.
“Migraine, especially migraine with aura, is associated with increased risk of ischemic stroke,” but whether age of migraine onset affects the risk of cardiovascular disease has been unclear, the researchers said.
To examine the risk of ischemic stroke in migraineurs with and without aura with onset before and after age 50 years, the investigators conducted a post hoc analysis of data from the ongoing Atherosclerosis Risk in Communities (ARIC) study. The researchers adjusted for potential confounders, including diabetes, body mass index, hypertension, and hyperlipidemia.
In ARIC, participants completed a questionnaire about their migraine history at their third study visit (1993-1995) and were followed for ischemic stroke incidence over 20 years.
Of the 11,592 ARIC participants included in the analysis (mean age, 61 years; 76.5% white; and 55.3% female), 447 had migraine with aura, and 1,128 had migraine without aura. Onset of migraine with aura at age 50 years or older (average duration, 4.75 years) was associated with more than twofold greater risk of ischemic stroke, compared with no headache (multivariable adjusted hazard ratio = 2.17). Onset of migraine with aura before age 50 years (average duration, 28.17 years) was not significantly associated with stroke. A logistic regression model yielded consistent results.
In addition, patients with migraine without aura did not have an increased risk of stroke, regardless of the age of onset. The absolute risk for stroke in migraine with aura was 8.27%, and the absolute risk in migraine without aura was 4.25%.
“We found unexpected results suggesting that the onset of migraine with aura before age 50 is not associated with ischemic stroke. ... These results are specific to first-time ischemic stroke incidents that occurred in mid- to late life; therefore, it cannot be generalized to stroke in younger patients,” the authors wrote.
It could be that migraine with aura symptoms that start at a later age are a red flag for paradoxical emboli from a patent foramen ovale or microemboli, Dr. Androulakis and her colleagues noted. It also is possible that the degree of cortical spreading depression required to induce migraine with aura symptoms is different later in life versus earlier in life.
“This study underscores the importance of MA symptoms onset in evaluation of ischemic stroke risk in late life,” the researchers concluded.
The authors had no relevant conflicts of interest. ARIC has been funded by the National Heart, Lung, and Blood Institute.
SOURCE: Androulakis XM et al. Headache. 2019 Jan 21. doi: 10.1111/head.13468.