Cognitive impairment increased the risk of developing dementia after stroke
German scientists conducted a systematic review and meta-analysis of more than a hundred articles on risk factors for dementia after stroke. They found that baseline cognitive impairment has the strongest impact on the likelihood of dementia. In addition, diabetes mellitus, atrial fibrillation and hyperintensity of the brain white matter on magnetic resonance imaging increased the risk. The results of the analysis are published in The Lancet Healthy Longevity.
Because of the ever-increasing number of stroke survivors, doctors and scientists are concerned about the long-term effects of stroke. It has been reported that 80 percent of stroke survivors have post-stroke cognitive impairment four years after stroke, and post-stroke dementia occurs in 40 percent of stroke survivors one year after stroke. However, there is no consensus on what may increase the risk of developing these conditions.
It is known that older age and severe stroke can reliably be considered such factors. Studies have shown with varying degrees of certainty that the risk of cognitive impairment after stroke is increased in people with atrial fibrillation and diabetes, a history of stroke, and several markers of cerebral small vessel disease on magnetic resonance imaging.
A team of scientists led by Martin Dichgans of the University of Munich conducted a systematic review of 162 studies and a meta-analysis of 113 papers on various risk factors for post-stroke cognitive impairment and post-stroke dementia. The total sample of the meta-analysis was 160783 stroke patients. Overall, effect estimates for post-stroke cognitive impairment were strongly correlated with those for post-stroke dementia (p < 0.0001).
The strongest risk factor for post-stroke cognitive impairment was baseline pre-stroke cognitive impairment (relative risk 2.00). Modifiable, that is, treatable, baseline factors associated with cognitive impairment were diabetes mellitus (relative risk 1.29, atrial fibrillation (relative risk 1.29), moderate or severe cerebral white matter hyperintensity on magnetic resonance imaging. In addition, age, stroke severity, education level, and several brain changes on magnetic resonance imaging influenced the risk.
Similarly, the strongest risk factor for poststroke dementia was baseline cognitive impairment (relative risk 3.10), followed by diabetes mellitus (relative risk 1.38) and moderate to severe cerebral white matter hyperintensity on magnetic resonance imaging.
This meta-analysis brings new insights into the understanding of risk factors for the development of post-stroke cognitive impairment. These results will allow for the development of new interventions to prevent and diagnose complications of stroke.
However, doctors are looking for ways to prevent strokes themselves. And perhaps soon that prevention will become easier. We recently reported that semaglutide significantly reduced the risk of myocardial infarction, stroke, and death from cardiovascular causes.