La Dre Sandra Black voit des images d'un cerveau atteinte de la maladie d'Alzheimer

Your head and heart - more connected than you think

Stroke and Alzheimer’s disease are more intimately linked than people realize, says Dr. Sandra Black, Director of the Brain Sciences Research Program at Sunnybrook Research Institute in Toronto.

“It’s tough to keep on top of these two worlds,” says Dr. Black, one of the few clinical scientists who have an international reputation in both stroke and dementia research. “They don’t talk to each other as much as they should, though it’s starting to happen more with the younger generation.”

While it’s widely understood that stroke can deprive brain cells of oxygen and lead to vascular dementia - the second most common form of dementia after Alzheimer’s disease - these two diseases are intertwined in more subtle and surprising ways

Dr. Black points to an influential study of a group of 102 elderly nuns whose brains were examined after death. Those who showed significant signs of brain damage from Alzheimer’s disease and had suffered small strokes were far more likely to have dementia than those whose brains were damaged by Alzheimer’s alone. “I think we need to raise people’s consciousness that prevention of stroke can also delay the dementia of Alzheimer’s disease,” she says.

Dementia means that  memory loss and other problems with thinking, language and judgment have become severe enough that the person needs help carrying out  day-to-day tasks.

“Having advanced Alzheimer’s pathology doesn’t necessarily  mean you will develop Alzheimer’s dementia, expecially if you are very elderly. How’s that for a surprise?” says Dr. Black. 

On the flip side, Alzheimer’s can lead to and worsen the effects of stroke. The amyloid protein deposits in the brain of those with Alzheimer’s can accumulate around the brain’s blood vessels. In turn, vessels are weakened and are more likely to bleed and cause cerebral hemorrhage.

Healthy heart, healthy brain

“Because Alzheimer’s disease and cerebral blood vessel disease often occur together in the brain, it’s important for people to know that the same recommendations for preventing strokes like exercising regularly and eating a heart-healthy diet also apply in delaying Alzheimer’s disease,” explains Dr. Black.

The fact that these two diseases are among the most threatening illnesses of aging, and that their burden on the health-care system will increase relentlessly over the next few decades, motivates Dr. Black to press ahead in her research.

“In terms of my own mortality and future, I suppose there’s an additional motivation – so there’s something available for me and my generation,” says Dr. Black.

“I’d like to be optimistic and think in five to 10 years we may have some real disease-modifying therapies.” 

The Alzheimer Society congratulates Dr. Sandra Black on her recent appointment to the Order of Ontario and is proud to have supported some of her work through the Alzheimer Society Research Program. Her commitment to dementia research has not only deepened our understanding of dementia but is also leading to improved prevention and patient care. 

Learn more about vascular dementia.

Last Updated: 11/08/2017