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Uncovering covert strokes to stop dementia

Dr. Eric Smith is working to predict who is at risk for stroke-related dementia, and ultimately prevent it

Both of Dr. Eric Smith’s grandmothers died of stroke. 

Dr Eric Smith

Dr. Eric Smith

“I recall my parents making tough decisions and advocating on their behalf because both of them had strokes that affected their speaking,” says the University of Calgary researcher.

“That was one of the experiences that made me realize how terrible a problem stroke is, and how much more we need to learn and do to help people who’ve been affected by stroke.”

Today Dr. Smith is engaged in a unique study aimed at shedding light on one of the most devastating consequences of stroke: dementia.

Dementia refers to problems with memory and thinking. Mild dementia can limit your ability to drive or do basic math; in its progressed stage, it can prevent you from looking after basic tasks like bathing, dressing and communicating.

About a third of all dementia is related to stroke, and the two diseases share common risk factors. So by preventing stroke, we can reduce our risk for dementia too.

Dr. Smith is focusing on covert strokes – small strokes in the brain that cause only very subtle symptoms. Covert strokes are now considered to be quite common among Canadians, and could be as likely to lead to dementia as large strokes. 


“What we’re finding is that covert strokes are actually pretty common in the Canadian population. Up to 20 per cent of people in their 70s can have one or more of these,” explains Dr. Smith.

”My research is defining this problem so that we can identify the extent to which covert strokes are predicting problems with memory and thinking, or to the risk of large strokes – or dementia. It’s the first step to developing prevention strategies and treatments for this condition.”

Dr. Smith’s PURE-MIND study is the first to focus on this area in Canada, and also among the first to look at covert strokes not just in people in their 70s and 80s, but in people aged late 30s, 40s, and 50s.

The study, supported by Heart and Stroke Foundation donors, is looking at 1,500 people aged 40 to 75. The researchers use brain scans to look for evidence that someone has had a covert stroke. Matching that information with memory tests at three-year intervals, Dr. Smith hopes to identify people in midlife who might be at risk in later life for memory and thinking problems, or dementia.

By figuring out who is at risk of dementia, Dr. Smith hopes we can do more to prevent it, through lifestyle changes and medication.

 “It’s more than a coincidence that my career is in stroke research,” he says. “My family history with my grandmothers is one of the things that made me want to go into medicine for stroke, to try to help people and help other families hopefully not experience those kind of tragedies.”

9 Responses

    1. Sharon Hollingsworth

      Hi Mary and thank you for your question about volunteering for the Heart and Stroke Foundation. There are many different ways that volunteers help the Foundation achieve our mission and we are always delighted when people like you step up and offer to share your time and talents with us. I don’t know what province you live in, but if you go to and look for the Your Province menu on the right hand side of the screen, you can then select your province of residence. On the screen that then pops up, look for the About Us menu on the top left, and you can select the provincial office(s) that show on the screen and easily see the telephone numbers to connect with the correct office. Thank you again for your interest in our organization, and best wishes for a healthy and happy summer! Sincerely, Sharon at the Heart and Stroke Foundation

    1. Sharon Hollingsworth

      Hi Cheryl, and thank you for your interest in the Heart and Stroke blog. I have passed your inquiry along to one of our staff who works closely with Dr. Smith and should he be looking for individuals to participate in the covert stroke/dementia study, you will hear from his office directly.

      Thanks again for getting in touch – hope you are enjoying your summer! Sincerely, Sharon at the Heart and Stroke Foundation

  1. Martine

    My dad had a stroke ten years ago. Since then, he has a hard time to plan a project, solve a problem, and now cannot drive the car with the radio on. He is denying it and keeps saying that the stroke had no effect on his cognition. My question is: when people who had a stroke begin to show dementia symptoms, is it too late? Is there anything we can do to stop the evolution of stroke-related dementia? Do you have strategies to suggest to bring these people to recognize that they should do something about that?

    1. Sharon Hollingsworth

      Hi Martine and thank you for your comment on the Heart & Stroke blog. We’re sorry to hear about your Dad’s cognition problems following his stroke. While I don’t have an answer to your question, I will pass it along to Dr. Smith, the author of the study and get back to you with his response. Thank you again for your interest. Sincerely, Sharon at Heart & Stroke

      1. Sharon Hollingsworth

        Hello Martine – apologies for the delay getting back to you. Here are some thoughts regarding your question about covert stroke and dementia from our health experts:

        It is never too late to start preventing stroke or dementia. Once evidence of covert strokes is determined, the focus can be put on a person’s blood vessel health to ensure that vascular risk factors are being managed to prevent further damage including a bigger stroke.

        Know and control blood pressure; eat a healthy, balanced diet; be physicall active; be smoke-free; manage diabetes; limit alcohol.

        Some key behaviours are emerging:

        • Long-term, regular physical activity, including vigorous activity and walking, has been shown to be beneficial. One study noted that 21 per cent of dementias may be attributed to physical inactivity and overall sedentary lifestyles. This supports consistent evidence that physical activity in midlife is associated with better cognitive functioning and less vascular dementia.

        • Evidence continues to emerge to support how new learning promotes good brain health, for example, learning a new language or musical instrument. The key is that it must be a new activity, not just something habitual. Exercising the brain and developing new skills creates new pathways that can be called upon later to perform tasks.

        Trusting that this information is helpful and answers your questions. Have a great day! Sincerely, Sharon at Heart & Stroke

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