Some migraineurs experience neurological symptoms (i.e., aura), such as flashes of light, blind spots, and tingling in the hands or face. In adult patients, these symptoms often precede the onset of the headache itself. Souvik Sen, an author from the University of South Carolina School of Medicine, said that migraine with aura accounts for at least 20 percent of all migraineurs.
The Atherosclerosis Risk in Communities “ARIC” study examined the relationship between migraine with aura and stroke subtypes. The study included 12,844 US adult patients aged 45 to 64 years and lasted 25 years, with 817 patients presenting with ischemic stroke.
Comparing patients with and without migraine with aura, the investigators found that
Overall, patients with migraine with aura were 2.4 times more likely to have an ischemic stroke than patients without migraine with aura (OR=2.4, 95% CI: 1.6-3.6, P<0.0001);
The association between patients with migraine with aura and cardiogenic stroke was stronger (OR=3.3, 95% CI: 1.4-8.0, p=0.009);
Patients with migraine with aura were twice as likely to have a thrombotic stroke as patients without migraine with aura (OR 2.0, 95% CI: 1.2-3.4, p=0.01);
There was no significant association between the presence of migraine with aura and the occurrence of lacunar cerebral infarction.
Sen said that because migraine affects blood supply to the brain, and the risk of cardiogenic embolism or thrombotic stroke is higher, suggesting that migraine may also affect blood vessels in the heart and neck, which may account for the correlation between migraine and these specific stroke subtypes.
”If we want to prevent strokes in patients with migraine with aura, it’s important to know what kind of stroke they may have so we can be alert to it.” Sen stated.
Ischemic strokes account for 87 percent of all strokes in the United States. The major subtypes of ischemic stroke include thrombotic stroke, cardiogenic stroke and ischemic brain infarction. Previous studies have demonstrated an association between migraine with aura and stroke, but Sen said this study is the first to discuss the subtypes of migraine with aura and stroke.
The investigators also noted that the association between stroke and migraine with aura is usually more likely to affect younger patients than typical stroke patients. Stroke in younger patients means earlier onset of disability and incapacity and may be more influential than in older patients.
”Patients with migraine with aura should make sure they have seen a doctor to assess stroke risk factors.” Risk factors for stroke, including high blood pressure, diabetes, smoking, and high cholesterol, all of which require intervention, Sen said. Migraine and stroke patients should be screened for vascular sclerosis and arrhythmia conditions, which are associated with thrombotic stroke and cardiogenic stroke mechanisms, respectively.
Hormone Replacement Therapy & Migraine & Stroke
Study Highlights
Women who use hormone replacement therapy and have migraine may have an increased risk of stroke.
The increased risk of stroke is more pronounced in patients who experience an exacerbation of migraine during the use of hormone replacement therapy.
The investigators recommend that women with a history of migraine should use hormone replacement therapy with caution, and if hormones are used, the severity of the migraine should be monitored.
Many postmenopausal women use hormone replacement therapy, and a significant proportion also suffer from migraine. Previous studies have separately confirmed the association between the two and stroke, but the findings have been mixed.
Haseeb A. Rahman of Houston Methodist Hospital said, “What we want to know is if migraine is more severe with hormone replacement therapy, then their risk of stroke is elevated.” He added that the study that included changes in migraine severity with hormone replacement therapy as a risk factor for ischemic stroke was, to his knowledge, the first of its kind.
The investigators included 82,208 women aged 50 to 79 years in the early 1990s from 40 clinical centers across 24 states with ethnic and racial diversity.
At baseline, all women reported varying degrees of migraine, and approximately 45 percent of these patients used hormone replacement therapy. The investigators divided the participants into three groups: never used hormone replacement therapy, previously used hormone replacement therapy, and currently using hormone replacement therapy.
After three years of follow-up, patients were asked to complete a questionnaire to confirm whether their migraines had worsened. In total, patients were followed for 12 years, during which time 2,063 patients developed ischemic strokes.
After adjusting for factors including age, high blood pressure, high cholesterol, diabetes, and smoking, the researchers found that
The proportion of patients who had never used hormones, had previously used hormones, and were on hormone replacement therapy was 17.3%, 18.7%, and 20.6% for migraine exacerbation, respectively (p<0.0001);
The likelihood of ischemic stroke was 10% higher in patients on hormone replacement therapy who did not have an exacerbation of migraine (risk ratio, 1.1; p<0.0001);
Women who were on hormone replacement therapy and reported worsening migraine were 30% more likely to have an ischemic stroke (risk ratio, 1.3; p<0.0001).
The findings suggest that women with a history of migraine should weigh the pros and cons of hormone replacement therapy with their physicians and monitor migraine severity if they choose to use it, Rahman said. “Patients should not just ignore migraine exacerbations, but should likewise tell their physicians that migraine exacerbations are occurring in conjunction with the initiation of hormone replacement therapy.”
Female patients, especially those on hormone replacement therapy, should identify their other possible stroke risk factors so that a plan can be developed to improve their situation as much as possible.