Being young doesn't mean you are immune to a stroke. You may feel healthy; you may be 18 or a vigorous 50. And yet you could be more vulnerable than you know. That could be because of the role played by silent risk factors in stroke.
Now, as a result of research from Hopital Notre Dame in Montreal, two silent factors − leukoaraiosis and silent brain infarcts − are not so silent any more.
Lead investigator, neurologist Dr. Alexandre Poppe, suggests that patients aged 18 to 50 who present with stroke should have brain MRIs to identify those who have experienced silent strokes, in an effort to prevent further damage.
Silent brain infarcts (SBI) are tiny strokes which can be seen on brain imaging but are asymptomatic; the patient is completely unaware of their occurrence, but this does not mean they are not causing damage.
Research tells us that these conditions are common in older adults with acute ischemic stroke and predict recurrent stroke and cognitive decline. Their presence can help neurologists assess the risk of future stroke-related disease and emphasize prevention. Now, in a world-first study, Dr. Poppe has shifted the focus from elderly patients to a much younger, under-investigated age group: 18 to 50 year-olds.
Dr. Poppe and his co-investigators studied 168 stroke patients in this younger age group, all of whom underwent MRI after a first stroke. They were followed for an average of 27 months. Over that time, stroke recurred in 11 per cent.
Those with silent or covert strokes identified on their MRI were three times more likely to experience a recurrent stroke than patients without these covert lesions.
"This study tells us that when younger people come in with a first stroke, they may already have signs of pre-existing damage in their brains," says Dr. Poppe. "We should pay particular attention to those who do, because they are at higher risk of having a second stroke, and prevention efforts need to be greatly emphasized."
"All young people with stroke should be scanned preferably using MRI," he says. "Doing a CT scan alone is often insufficient to pick up the brain changes caused by covert brain infarcts; with an MRI you can actually tell how old the lesions are. You can see if they occurred before the stroke."
Next, Dr. Poppe plans to determine if the location, size, and number of silent lesions have an impact not only on recurrent stroke but also cognitive decline.
"While MRI is helpful in young patients who've already had a stroke, at this stage it is too early to recommend screening for all 18-50 year-olds with a family history of stroke," he says.
"Stroke in the young is under-appreciated," says Canadian Stroke Network spokesperson Dr. Antoine Hakim. "Ten per cent of stroke patients are under 50."
He notes that with risk factors in all age groups increasing, it's especially important for younger adults to manage their stroke risk factors.
"Younger people may be becoming more vulnerable to stroke because of the larger number of Canadians indulging in unhealthy eating and living habits," says Dr. Hakim. "This may be accelerating the impact of risk factors, especially high blood pressure, which are now converging and have the potential to erase the progress we've made in treating heart disease and stroke over the last 50 years."
The recent Heart and Stroke Foundation report card on Canadians' health noted that young people are beginning their adult lives with multiple risk factors for heart disease and stroke.
"Over the past 15 years, Canada has seen significant increases in overweight and obesity, and diabetes mellitus," says Heart and Stroke Foundation spokesperson Dr. Michael Hill. "There are more than 250,000 young Canadians in their 20s and 30s with high blood pressure - the number one risk factor for stroke."
Dr. Hill recommends that adults of all ages pay attention to stroke risk factors, including high blood pressure, diabetes, smoking, obesity, high blood cholesterol, physical inactivity, stress and excess alcohol consumption.