A Canadian study published in Neurology found that around 20% of stroke survivors eventually develop dementia. Researchers analyzed health data from 1,74,817 stroke survivors and compared it with an equal number of individuals without a stroke history. The average age of participants was 69, and they were tracked for an average of six years. During this period, 19% of stroke survivors were diagnosed with dementia, compared to 13% of those without a stroke, highlighting a significant association between stroke and cognitive decline.
The study found that stroke survivors had a 76% higher risk of developing dementia than those without a stroke, even after adjusting for factors like age, sex, high blood pressure, and diabetes. The risk was highest in the immediate aftermath of a stroke, with survivors being 2.5 times more likely to develop dementia within a year. This risk gradually declined over time but remained elevated, with a 50% increased risk at five years and a 30% increased risk even after two decades.
Researchers also noted that the risk of dementia after a stroke was twice as high as the risk of experiencing a second stroke. While much of the focus in stroke management has been on preventing recurrences, the study suggests that greater attention should be given to interventions aimed at reducing dementia risk in stroke survivors. Given the global rise in dementia cases and the increasing number of stroke survivors, the findings underscore the need for further research into strategies for long-term cognitive health after a stroke.