Silent strokes common, and a major cause of dementia

The good news is that people can dramatically reduce their risk of silent stroke by eating right
and exercising regularly, said Dr. Antoine Hakim.

“Covert” strokes, also known as “silent” strokes, are more widespread than commonly thought and are a major cause of dementia, according to Dr. Antoine Hakim, who recently published an article about them in the prestigious journal Nature.

Silent strokes can happen without the usual signs and symptoms of stroke, such as sudden numbness, confusion or dizziness. People are usually unaware they’ve suffered a silent stroke. Nevertheless, it causes damage to the brain, and places the person at increased risk for a major stroke in the future.

Anywhere from eight to 28 percent of the population has had a silent stroke, and those who are over age 70 or have vascular health issues are at even higher risk.

“The most troubling aspect of silent strokes is how common they are,” Dr. Hakim wrote. In 1998, roughly nine million people in the United States had a silent stroke, compared with 770,000 who had an obvious stroke. In Canada, this would be the equivalent of 600,000 silent strokes compared with 50,000 obvious strokes that occur each year.

Poor lifestyle choices and other factors contribute to the risk of silent stroke, including diabetes, hypertension, depression, smoking and obesity. Because the brain is more sensitive than the heart to high blood pressure, obesity and sedentary behaviour, Dr. Hakim urged people to adopt healthier eating habits and a more active lifestyle as they grow older.

If people notice lingering signs of brain damage such as sudden difficulty with memory, an unexpected change in personality or a decline in physical ability, they should see their doctor right away, said Dr. Hakim.

Silent strokes are a big contributor to dementia in senior citizens, a problem that is likely to escalate as Canada’s population grows older.

“Dementia is a disease of ageing,” wrote Dr. Hakim. Statistics Canada estimates that, by 2031, almost one-quarter of the country’s population will be aged 65 years or older.

The good news is that people can control how they age and dramatically reduce their risk of suffering a silent stroke by eating right and exercising regularly.

“If there is a silver lining in this story, it is the implication that we have significant control over how well individuals age and over the prevalence of dementia,” concluded Dr. Hakim.

Read the full article in Nature