A common and treatable cause of dementia is going largely undetected, researchers say.
Vascular damage in the brain accounts for at least one-third of all dementia cases in Canada. But experts say the true number is likely much higher.
“[Vascular dementia is] the second most common cause of dementia and is usually treatable,” said Eric Smith, a professor of neurology and the endowed Katthy Taylor Chair in Vascular Dementia at the University of Calgary.
Most Canadians are living with risks that lead to vascular cognitive impairment (VCI), but are often unaware of them.
This has experts calling for increased efforts to recognize early warning signs of vascular damage in the brain, and to address overlooked opportunities for dementia prevention.
“There is complete lack of awareness around dementia,” said Claire Webster, founder of the Dementia Education Program at McGill University.
‘Mixed dementia’
In 2025, about 650,000 Canadians had dementia. This number is projected to rise to one million by 2030 and to 1.7 million by 2050.
Smith says “there is an over-diagnosis of Alzheimer’s Disease as the only cause of dementia.” In reality, many people living with dementia have “multiple processes going on in the same brain.”
Researchers are drawing attention to mixed dementia, a form of dementia with multiple causes for the cognitive symptoms, such as a combination of Alzheimer’s Disease and vascular dementia.
Smith says the number of people living with dementia who also have vascular changes in the brain are two or three times greater than what population studies report.
“Millions of older people have these vascular changes in the brain and are at risk of VCI,” he said.
Vascular risks
Vascular risks begin early in childhood and accumulate over time, ranging from exposure to environmental pollutants to high-risk behaviours such as smoking and drinking alcohol.
Ninety per cent of Canadians have at least one of the preventable risk factors for VCI. These factors include high blood pressure in 8.2 million individuals, and diabetes in nearly four million people.
Stroke is the most commonly recognized risk factor for VCI.
About one-fifth of stroke survivors in Ontario developed signs of cognitive impairment in the first year after a stroke, and the risk of developing dementia persisted even 20 years later.
The latest Canadian Stroke Best Practices guideline strongly recommends screening for VCI in people who have had a stroke or transient ischemic attack, a type of “mini-stroke” that often leads to future strokes.
“You don’t need a clinical stroke to have vascular dementia,” said Hugo Aparicio, a vascular neurologist at Boston Medical University.
Silent strokes and small vessel disease exist in many seniors, and can trigger cognitive decline.
But “you wouldn’t know about it unless you did a brain scan,” Smith said.
Preventative strategies
Sources say early detection and prevention has historically not received the attention it needs.
“[W]e have preventive strategies to identify and treat vascular risk factors,” said Smith.
Eradicating vascular risks to the brain would prevent a third of dementia cases in the U.S., the American Heart Association reported in a new statement.
Early screening is also important, because people with VCI can get better or remain stable for years if vascular risks are managed well, says Smith.
If VCI is suspected, a CT or MRI scan of the brain can detect silent strokes, microbleeds, hardened arteries and blood clots. These signs of vascular damage in the brain suggest a diagnosis of VCI.
Once VCI is diagnosed, rigorous assessment and treatment of both medical and lifestyle risks is recommended.
“Prevention has taken a backseat to acute treatment and miracle drugs,” said Aparicio, of Boston Medical University.
“If you invest in prevention and identifying risk factors for heart disease, for example, then you can reduce the rates of mortality and the disease burden,” said Aparacio.
Encouraging signs
There are some signs of a growing shift towards prevention.
Last July, the Canadian Institute of Health Research invested nearly $45 million to advance research in the detection, treatment and prevention of dementia.
“We are on a path to be able to prevent the pathology [of Alzheimer’s Disease],” George Vradenburg, founding chairman of the Davos Alzheimer’s Collaborative, said in an interview.
Vradenberg encourages businesses to develop strategic efforts to address early-life risk factors on a global scale.
Last year, the American Alzheimer’s Association also completed its first randomized control trial demonstrating that reducing vascular risks with lifestyle choices can preserve cognitive abilities in adults at risk for dementia.
“If we invest in prevention, including addressing vascular risk factors, there’s a payoff in enhancing brain health,” Smith said.
Aparicio notes that a “pivot” is needed for addressing top health risks in this century.
Since the 1940s, with advancements in the science and technology of treating heart disease and strokes, “we’re surviving the heart attack, but now we’re living longer,” Aparicio said.
“It’s just a similar pivot for the next century … that we identify risk factors that aren’t good for the arteries in the brain and reduce the burden of dementia over time.”
