While stroke continues to be a concern, and most common, in older populations, incidence in young people is on the rise. Why exactly is not yet understood by researchers and health experts, but non-traditional risk factors — such as migraine, especially in women — has grabbed the attention of faculty members at the University of Colorado Anschutz School of Medicine.
“We've learned quite a bit over the past five or six years, and I think we're still trying to pick apart the details and really understand it, but more than anything, we've recognized that it is an issue that needs further study,” says vascular neurologist Sharon Poisson, MD, professor of neurology, who takes care of adult stroke patients of all ages and created the young adult stroke clinic at CU Anschutz over a decade ago.
About 10-15% of Poisson’s overall patient population is young adults, she says, a mirror of national statistics. A 2024 report from the Centers for Disease Control and Prevention that compared stroke prevalence from 2011-2013 and 2020-2022 found that stroke increased 14.6% among adults aged 18–44 years and 15.7% among those aged 45–64 years.
Learning more about the factors behind this phenomenon may help clinicians better care for younger patients, who often need lifelong care, and begin to understand what it might take to reverse the trend.
A persisting mystery among young women
Perhaps even more puzzling than the increasing incidence rate of stroke among young people is why it’s more common in women, who seem to experience lower blood pressure and other traditional risk factors that can contribute to a stroke. The 2024 CDC report found a 9.3% increase among women, and 6.2% among men.
New research by CU Anschutz Department of Neurology faculty, led by adjoint assistant professor Michelle Leppert, MD, reveals the hypothesized detection bias — that incidence among women is higher because they seek out care more often than men — doesn’t seem to be the reason why rates among women are higher.
The research, published in the Journal of the American Heart Association, was unable to find a difference in stroke severity between men and women aged 18 to 45 and 45 to 55 in a cohort of over 1,300 stroke cases.
This finding signals to Leppert and Poisson that something else is happening that causes young women to have higher incidences of stroke.
“…women more often seek care for neurological symptoms, which could result in higher likelihood of MRI imaging and consequently higher incidence of stroke than men. Given that both men and women with severe disability would have little choice in seeking medical care, we hypothesized that this ‘detection bias’ would lead to a higher proportion of milder severity strokes in women,” the researchers write in their findings.
“However, using a population‐based cohort of young adults with incident strokes, we did not find a higher proportion of women with milder severity strokes,” they continue. “Instead, there was a trend toward more severe strokes in women aged 46 to 55 years that did not reach statistical significance, which mirrors the literature in older adults. Future work should also address whether there were changes in stroke severity among young adults in the past (three) decades.”
Studying (and collecting) the data
Understanding the evolution of stroke prevalence in young people requires data — more than is currently available, Leppert says.
“I thought in this area of research I would glue together data sets, and then we’d understand the mystery before us by looking at data that's already there,” she says. “It turns out we don't collect what’s required to keep learning more about young people and stroke. You can't study something you don't collect.”
That’s especially important with non-traditional risk factors. One example of this, Leppert says, is data on patent foramen ovales (PFOs), a heart condition where there is a small opening between the heart’s upper chambers that never fully closes after birth. PFO is present in as many as 25% of adults and frequently identified in young patients with ischemic stroke.
“It’s a big risk factor, but the problem is that it’s not common to screen for PFOs unless a person has a blood clot or complication,” Leppert says. “If we wanted to understand this big risk factor, it’s not possible to look at data because it’s not collected. To understand this disease and the phenomena that we're seeing, I think we're going to have to go out and collect data from people.”
Research published by Leppert, Poisson, and their colleagues in 2024 pointed to nontraditional risk factors that could be attributed to rising stroke incidence rates. These risk factors, which included migraine, thrombophilia, and autoimmune disease, were responsible for 28% of strokes in women and 19% in men.
“Our work doesn’t say that traditional risk factors don't cause strokes, like they absolutely do,” Leppert says. “I think that this is still an important part of our work to understand stroke in young people. We still need to address them, but we're missing half of the pie.”
Tailoring care to young people
Typically, when a person has a stroke they’re prescribed a statin, a medication that works to lower low-density lipoprotein (LDL) known as “bad cholesterol.” Patients take these medications indefinitely, often for the rest of their life.
However, researchers, including Leppert, wonder whether there may be better options for young people. Leppert says her young patients often ask her about the possibility of becoming pregnant, having a family, and what 50 years of medications will mean for other aspects of their health.
“We’re treating people who are having strokes at 30 like they’re 65 because that’s the population where strokes happen most often and where the research is,” Leppert says.
Fortunately, there is a growing interest in adapting stroke care to young people, and clinicians are seeing some progress.
“Until we have more concrete research and guidance, we have to take into account extra risks that come up in young people,” Poisson says. “We have to go above and beyond that to think about the extra complications or risks in young people.”
