Age remains the most consistent risk factor for ischaemic stroke. Surprisingly then an estimated 10% of diagnoses are now seen in people below the age of 50. In many countries vigorous management of vascular risk coupled to improved stroke services have led to falls in stroke incidence and to improvements in morbidity and mortality. However figures for younger adults have remained unchanged or have risen.¹

The blame for the disappointing figures lies with persisting high levels of physical inactivity, smoking, drug use and drinking alcohol. The stresses of everyday life from omnipresent technology, shift work and pollution may play a role. Of particular concern are the comorbidities of obesity, diabetes and atrial fibrillation.

This leaves many asking whether the healthiest stroke generation has come and gone.²

It was thought the prognosis of stroke in younger adults was fairly benign since short-term mortality is much lower than in older individuals. However the story is very different when these patients are compared to normal individuals over an extended period. Of those that survive for 30 days following the stroke, approximately a quarter will die in the next 20 years.

Recurrent stroke is the most important risk factor for mortality, reported to be seven times than expected.³ The likelihood of death from vascular disease remains higher even decades later. This has important implications for secondary prevention⁴ although evidence of its effectiveness is not yet robust.⁵

Having vascular risk factors at a young age probably represents earlier and more aggressive disease with large artery arteriosclerosis carrying the highest risk. While these risk factors are familiar, if under-recognised, younger adults are more likely to have an unusual cause (20%-25%) or have no cause identified for their stroke.⁶

The underlying causes of stroke in young adults are:

With young stroke patients, it is not sufficient that traditional risk factors are identified - other, more unusual, possibilities are actively explored. For insurers it’s important to be aware that the risks persist for many years after the initial event. Attention must be paid to ensure that adequate investigation has taken place and that vascular factors have been well controlled. Given the higher number of strokes in young adults our understanding of the underlying mechanisms and prognostic factors will grow, and with it clarity about the impact of interventions that will help insurers to better manage the risk.

Endnotes

1. Apraricio, HJ et al. (2016) Temporal trends in stroke incidence in the young in the Framlingham study. Neurology. 86. Supplement 12.03.
2. Swerdel, JN et al. (2016) Ischaemic stroke rate increases in young adults: evidence for a generational effect. Journal of the American Heart Association. 5:e004245
   doi: 10.1161/JAHA.116.004245.
3. Aairno, K et al. (2014) Long term mortality after first-ever and recurrent stroke in young adults. Stroke. 45.2670-2676.
4. Rutten-Jacobs, LCA et al. (2013) Long-term Mortality After Stroke Among Adults Aged 18 to 50 Years. JAMA. 309. 1136-1144.
5. Putaala, J. (2016) Ischaemic stroke in the young: Current perspectives on incidence, risk factors and cardiovascular prognosis European Stroke Journal. 1. 28-40.
6. KES, VJ et al. Etiology and diagnostic work-up in young stroke patients (2012) Periodicum Biologorum. 114. 355-359.