A stroke can significantly increase the chance of developing dementia. In line with preliminary research to be presented on the American Stroke Association’s 2024 International Stroke Conference, the chance of dementia was highest in the primary 12 months after stroke and remained elevated for twenty years. The meeting can be held in Phoenix on February 7-9 and is the world’s most vital meeting of researchers and clinicians working within the science of stroke and brain health.

Our findings show that stroke survivors are extremely prone to dementia, and the chance could also be as much as 3 times greater in the primary 12 months after stroke. Although the chance decreases over time, it stays elevated in the long run.”

Raed Joundi, MD, PhD, lead creator of the study, assistant professor at McMaster University in Hamilton, Ontario, Canada, and investigator on the Population Health Research Institute, a joint institute of McMaster University and Hamilton Health Sciences

To evaluate the chance of dementia after stroke, researchers used databases from the Institute for Clinical Evaluative Sciences (University of Toronto, Canada), which covers greater than 15 million people within the Canadian province of Ontario. They identified 180,940 individuals who had recently suffered a stroke; either ischemic stroke (attributable to a clot) or intracerebral hemorrhage (bleeding within the brain) -; and matched stroke survivors to 2 control groups; people in the overall population (who haven’t had a heart attack or stroke) and folks who’ve had a heart attack but not a stroke. The researchers assessed the speed of latest cases of dementia starting 90 days after stroke over a median follow-up period of 5.5 years. As well as, they analyzed the chance of developing dementia in the primary 12 months after stroke and over time as much as 20 years.

The study showed:

• The danger of dementia was highest in the primary 12 months after stroke, increasing almost 3-fold, then decreasing to a 1.5-fold increase after 5 years and remaining at an elevated level 20 years later.
• Dementia developed in almost 19% of stroke survivors over a mean follow-up period of 5.5 years.
• The danger of dementia was 80% higher in stroke survivors compared with a matched group from the overall population. The danger of dementia was also almost 80% higher in stroke survivors compared with matched controls who had had a heart attack.
• The danger of dementia in individuals who had had an intracerebral hemorrhage (bleeding within the brain) was almost 150% higher than in the overall population.

“We found that the incidence of post-stroke dementia was higher than the incidence of recurrent stroke through the same period,” Joundi said. “A stroke damages the brain, including areas critical to cognitive function, which might impact each day functioning. Some people experience recurrent stroke, further increasing their risk of dementia, while others may experience progressive cognitive decline just like a neurodegenerative condition.”

Every year, roughly 795,000 people experience a latest or recurrent stroke. In line with 2024 data from the American Heart Disease and Stroke Statistics, about 610,000 of them were first attacks and 185,000 were repeated attacks. In line with the CDC, amongst people age 65 and older, roughly 7 million adults may have dementia in 2014, and by 2060, this number will increase to almost 14 million.

“Our study shows that there’s a high burden of dementia after acute stroke in Canada and indicates that it’s a typical problem that should be addressed. Our findings highlight the importance of monitoring stroke survivors for cognitive decline and implementing appropriate treatments to scale back vascular risk aspects and stop reoccurrence of stroke, in addition to encouraging lifestyle changes reminiscent of quitting smoking and increasing physical activity, which have many advantages. advantages and will reduce the chance of dementia,” Joundi said. “Further research is required to elucidate why some people develop dementia after a stroke and others don’t.”

In a 2023 scientific statement from the American Heart Association, “Cognitive impairment after ischemic and hemorrhagic stroke” suggests post-stroke screening and comprehensive interdisciplinary care to support stroke survivors with cognitive impairment.

A limitation of the study is that administrative data, hospital records, and pharmacy data were used for evaluation. Researchers were unable to perform cognitive assessments or neuroimaging (non-invasive images of the brain) in stroke survivors, so it isn’t possible to substantiate the diagnosis of dementia or the variety of dementia. Nonetheless, the definition of dementia has been previously validated and located to be accurate when put next to medical charts.

Study background and details:

• The study examined data from 2002 to 2022 on a complete population of 15 million adults in Ontario, Canada.
• Data were collected from all hospital admissions, dementia prescribing pharmacies and emergency departments across the province of Ontario.
• The evaluation included 180,940 stroke survivors (mean age 69 years, 45% women) who had suffered an ischemic stroke or intracerebral hemorrhage and remained dementia-free for at the least 90 days.
• The study population was matched 1 to 1 by way of age, gender, rural residence, neighborhood marginalization, hypertension, diabetes (including type 1 and kind 2 combined), high cholesterol, atrial fibrillation, heart failure and peripheral arterial disease; aspects that increase the chance of dementia.