Incidence of stroke in young adults has witnessed a sharp increase, according to a study of more than 94,000 people in Oxfordshire, reflecting growing evidence that the medical emergency in that demographic is a growing problem in high-income countries.

Stroke is a major health problem that can have devastating consequences. It occurs when the blood supply to the brain is cut off. This leads to the death of brain cells and dysfunction in one or more parts.

The restricted blood supply can be the result of an artery supplying blood to the brain being blocked, a blood vessel rupture causing a bleed inside the brain, or a brief reduction in blood supply to the brain.

The traditional view is that vascular risk factors such as high blood pressure, diabetes, and obesity play a minor role in stroke among young adults. However, recent studies have begun to contradict this view, according to this latest research.

The new study, led by researchers from the Nuffield Department of Clinical Neuroscience at the University of Oxford, has been published in the Journal of the American Medical Association.

The researchers explored whether stroke incidence in younger and older people changed from 2002 to 2018. They drew on data from The Oxford Vascular Study, which comprises 94,567 people registered with General Practitioners' practices across Oxfordshire.

Incidence refers to the number of people who develop a specific disease or health-related event -- in this case stroke -- during a particular time period.

The researchers also took into account other factors such as lifestyle, changes in diagnostic practices, control of traditional vascular risk factors, and sex-specific causes.

They found that between 2002-2010 and 2010-2018, there was a 67 per cent increase in stroke incidence among younger adults (under 55 years) and a 15 per cent decrease among older adults (55 years or older). A similar divergence in incidence was not found for other vascular events such as heart attacks.

Among young people who had a stroke, there was a significant increase in the proportion of those in more skilled occupations, particularly professional or managerial jobs, the study said.

This could suggest a role for work-related stress, low physical activity, and long working hours, each of which was more strongly associated with the risk of stroke than heart attack, according to the study.

The prevalence of traditional vascular risk factors in young people with stroke was also high, emphasising the importance of identifying and managing these factors, it said.

Medical Research Foundation Fellow Dr Linxin Li from the University of Oxford said, "Our study shows a worrying rise in young stroke cases across Oxfordshire, reflecting a similar picture across other high-income countries."

"Establishing the importance of known risk factors in young stroke will help to raise general awareness of the need for better control. We also need better ways of identifying young people at high risk of stroke, as current risk models are based on predictors of stroke in older people."

Medical Research Foundation Chief Executive Dr Angela Hind said, "Historically, we have thought of stroke as only affecting older adults, but studies like this suggest a growing problem in young adults.

Stroke in young adults can have a huge impact, often occurring when they are starting a family or already have young children to look after, and have yet to reach the peak of their careers.

"The economic, social, and personal consequences can be devastating. More research needs to be done to increase understanding of the causes of young stroke and the best ways of preventing it. This is why we’re supporting researchers like Dr Li, who are pushing forward the boundaries of knowledge surrounding a young stroke." 

October 29 is observed as World Stroke Day.