People who have a stroke may have a higher risk for developing dementia. In fact, the risk for dementia was the highest in the first year post-stroke and stayed high in the subsequent 20 years.
The research will be presented at the American Stroke Association’s International Stroke Conference happening next week.
“Our findings show that stroke survivors are uniquely susceptible to dementia, and the risk can be up to three times higher in the first year after a stroke. While the risk decreases over time, it remains elevated over the long-term,” Raed Joundi, MD, lead author and an assistant professor at McMaster University in Hamilton, Ontario, said in a statement.
The team evaluated data based on 180,940 people who had recent strokes, including ischemic and intracerebral strokes. The scientists matched the stroke survivors with two control groups: The first were people in the general population who hadn’t had a stroke or heart attack, and the second group was people who had a heart attack but not a stroke.
Then the team assessed the rate of new cases of dementia starting at 90 days after stroke over an average follow-up time of 5.5 years. The team also analyzed individuals’ dementia risks in the first year after the stroke and up to 20 years after the incident.
The risk of dementia was highest in the first year after stroke, with almost a three times higher risk. That risk went down to a 1.5 times risk five years after stroke and stayed elevated up to 20 years later, the researchers found.
At 5.5 years after having a stroke, 19% of the people had dementia. The risk for dementia was 80% higher in stroke survivors compared with the people in the first control group, and it was almost 80% higher in people who had a stroke compared with those who had a heart attack.
People who had an intracerebral hemorrhage stroke had a 150% higher risk for developing dementia compared with the people in the general-population control group, data showed.
“Stroke injures the brain including areas critical for cognitive function, which can impact day-to-day functioning,”Joundi said. “Some people go on to have a recurrent stroke, which increases the risk of dementia even further, and others may experience a progressive cognitive decline similar to a neurodegenerative condition.”
