The number of young people affected by strokes is increasing worldwide, according to an 11-year study released today.

The Global and Regional Burden of Stroke in 1999-2010 study is in Thursday's issue of the medical journal The Lancet, which takes a comprehensive look at stroke rates by country and region.

Stroke doctor

Neurologists say 90 per cent of strokes can be avoided through lifestyle changes. (Suzanne Plunkett/Reuters)

"Now we have over 80,000 children and youth affected by stroke every year," said study author Prof. Valery Feigin, director of the National Institute for Stroke and Applied Neurosciences at Auckland University of Technology in New Zealand. "This is incredible."

Strokes are normally associated with the elderly.

But a journal commentary accompanying the study called the global increase of 25 per cent in the incidence of stroke in those aged 25 to 64 "a worrying finding."  

Feigin said the epidemic of obesity, and Type 2 diabetes in children and young people is increasing worldwide, which will be important risk factors for stroke 20 or 30 years down the road.

"Stroke burden worldwide continues to increase," Feigin said in an interview. "It's increasing at an increased pace, more than we expected, disproportionately affecting low- to middle-income countries."

Signs of stroke include sudden:

  • Weakness.
  • Difficulty speaking.
  • Vision problems.
  • Severe and unusual headache.
  • Loss of balance.

Source: Heart and Stroke Foundation

If the trends in low-income and middle-income countries continue, by 2030, there will be almost 12 million stroke deaths and 70 million stroke survivors worldwide, the researchers projected.
 
More than 90 per cent of strokes are preventable through lifestyle changes such as avoiding fast food and quitting smoking, Feigin said.  
 
In the most wealthy countries, incidence of stroke decreased by 12 per cent from 1990 to 2010. The researchers suggest that good health services and stroke prevention such as quitting smoking, controlling blood pressure, most likely explain the reduction.

"In view of the worldwide epidemic of diabetes, and increasing prevalence of other cardiovascular risk factors in young adults and overall, especially in low-income and middle-income countries, the shift in stroke burden towards younger populations is likely to continue globally unless effective preventive strategies are urgently implemented," the study's authors concluded.

Stroke prevention and care

"Urgent preventive measures and acute stroke care should be promoted in low-income and middle-income countries, and the provision of chronic stroke care should be developed worldwide," Maurice Giroud, Agnes Jacquin, and Yannick BĂ©jot from the University of Burgundy in France agreed in a journal commentary.

In 2009, more than 14,000 Canadians died from stroke, Statistics Canada said. 

According to the Heart and Stroke Foundation, there are two main types of stroke:

  • Hemorrhagic, whereby blood vessels in the brain rupture.
  • Ischemic, an interruption of blood flow to the brain. 

In a second study also in Thursday's Lancet, the New Zealand-led team said most stroke burden in terms of illness and death were hemorrhagic, the deadliest form that is mainly caused by high blood pressure.

Again, the bulk of hemorrhagic stroke incidence and deaths in the study were in low- and middle-income countries.  

The average age that people suffered both types of strokes was three to five years younger in poorer countries compared to the high-income countries.  

The researchers acknowledged that high-quality data from low- and middle-income countries is scarce.
 
The studies were funded by the Bill & Melinda Gates Foundation.

With files from CBC's Pauline Dakin