About one-fifth of stroke survivors will eventually get a diagnosis of dementia, finds a Canadian study published in the journal _Neurology_.
To explore the link between stroke and dementia, researchers analysed the health data of 1,74,817 stroke survivors, matching them with an equal number of people without stroke. The average age of participants was 69.
Over an average follow-up period of six years, 19 per cent of stroke survivors developed dementia, compared with 13 per cent of individuals without a history of stroke. “As the rates of dementia are rising globally, and more people are surviving stroke, understanding how stroke contributes to dementia risk is of great importance,” said the author.
Stroke survivors faced a 76 per cent higher risk of developing dementia compared with those without a stroke, after accounting for factors like age, sex, high blood pressure and diabetes. The risk changed over time and was highest immediately following a stroke. Stroke survivors had a 2.5 times increased risk of dementia within a year of their stroke, a 50 per cent increased risk at five years and a 30 per cent increased risk after 20 years.
“Importantly, our research also found that the risk of dementia after stroke was double the risk of having a second stroke,” said the study. “While much research has been focused on reducing the risk of a second stroke, our findings make it clear that that more research also is needed on developing interventions to help prevent dementia after stroke.”