In 2009, 10% of males and 22% of females in the US reported experiencing migraines or severe headaches, according to the Centers for Disease Control and Prevention. Now, a new study suggests older individuals who suffer from migraines may be more likely to have silent brain injury and have double the odds of experiencing "silent strokes," compared with those who do not have migraines.
The researchers, who publish their findings in the American Heart Association's journal Stroke, explain that silent strokes - also known as silent brain infarctions - are symptomless brain injuries caused by a blood clot interrupting blood flow to the brain.
In addition, these silent strokes are a risk factor for future strokes, the team says.
The Centers for Disease Control and Prevention (CDC) say stroke is the fourth leading cause of death in the US and a major factor in adult disability. Each year in the US, around 800,000 people experience a stroke.
Given that May is American Stroke Month, Medical News Today recently wrote a feature on stroke, outlining the risks and symptoms.
Researchers from this latest study - led by Dr. Teshamae Monteith, assistant professor of clinical neurology and chief of the Headache Division at the University of Miami Miller School of Medicine - say previous studies have suggested migraine could be a crucial risk factor for stroke in younger people.
But Dr. Monteith says she does "not believe migraine sufferers should worry, as the risk of ischemic stroke in people with migraine is considered small."
"However," she adds, "those with migraine and vascular risk factors may want to pay even greater attention to lifestyle changes that can reduce stroke risk, such as exercising and eating a low-fat diet with plenty of fruits and vegetables."
Can preventive migraine treatment reduce stroke risk?
In a collaborative analysis between the University of Miami and Columbia University, researchers from the Northern Manhattan Study (NOMAS) assessed a group of older adults in New York City with an average age of 71.
Hispanics and African-Americans have an increased stroke risk, so the team says the group was multi-ethnic and 65% of participants were Hispanic.
Participants with a history of migraine had twice as many silent strokes, compared with participants who did not have a migraine history.
In total, there were 104 people with a history of migraine, and the researchers compared these individuals with 442 participants who did not have a migraine history.
After comparing magnetic resonance imaging (MRI) results, the team found that those with migraine had twice as many silent brain infarctions, compared with those without migraine - even after adjusting for other stroke-related factors.
Additionally, they found for both groups, there was no increase in the volume of white-matter small blood vessel abnormalities, which have been associated with migraine in previous studies.
Changes in vision or other senses accompanying the headache, known as migraines with aura, were not common in participants, note the researchers, who add that this was not necessary for the link with silent strokes.
Though high blood pressure - which is another significant risk factor for stroke - was more common in those with migraine, the association between migraine and silent strokes was also observed in participants who had normal blood pressure.
The team says their findings pose the question of whether treatment to prevent severity and number of migraines could reduce risk of stroke.
"We still don't know if treatment for migraines will have an impact on stroke risk reduction," says Dr. Monteith, "but it may be a good idea to seek treatment from a migraine specialist if your headaches are out of control."
Speaking with Medical News Today, Dr. Monteith said she and her colleagues plan to conduct further research through the NOMAS study:
"We plan to next look at the association between migraine, stroke and other vascular outcomes by race/ethnicity and sex. We will also take a careful look at the relationship between migraine and hypertension in the Northern Manhattan Study. We have collected markers of inflammation, atherosclerosis and metabolism that can be analyzed based on self-reported history of migraines."
In March, we reported on a device approved by the US Food and Drug Administration that prevents migraines.