The Oxford Cognitive Screen is a short, bedside assessment for post-stroke cognitive problems.
(Photo credit: Supplied. )
Having a stroke changes the way the brain works, leaving many stroke survivors with difficulties with basic cognitive skills such as memory, attention, and language.
However, the pattern of cognitive problems varies dramatically across stroke survivors, and it's not yet well understood why this is.
Our global research team found surprising factors, such as brain health and an individual's education level, determine why people experience different cognitive problems after a stroke.
Stroke location - the specific brain area damaged by the stroke - does not entirely determine the symptoms a person will experience.
What did we discover?
In the largest and most detailed global study to date, more than 2,000 stroke survivors in Belgium, Italy and the United Kingdom completed the Oxford Cognitive Screen, a standard test of cognitive skills such as language, memory, and attention.
Participants included younger and older patients of varied educational backgrounds and health profiles, who had experienced either ischaemic (blood clot) or haemorrhagic (blood vessel rupture) strokes.
Using this data, our research team identified 13 different patterns of cognitive impairment in stroke survivors.
We found that stroke location was related to the pattern of cognitive problems people had, but this relationship weakened as the time between stroke and testing increased.
At later testing times, a person's overall brain health before the stroke and their education level were more closely linked to patterns of cognitive problems.
Previously, cognitive impairments in stroke were usually understood as a direct consequence of damage to specific brain regions.
This research provides strong evidence that this is not the case.
Challenging understanding of stroke recovery
These findings are important because it helps explain why different people experience different levels of disability and recovery after a stroke.
The research provides essential groundwork to develop tailored rehabilitation strategies for cognitive impairment in stroke and reveals a fundamental change in how cognitive problems are understood.
While some of these patterns corresponded to classic post-stroke problems, such as language difficulties after left-hemisphere strokes, others weren't related to the injury location at all.
Some profiles captured individuals with cognitive problems that were more closely related to age-related cognitive decline than stroke-related problems. Others captured people with mild or no cognitive impairment.
These patterns are significant because they provide doctors and scientists with a new way to understand diversity in stroke symptoms.
Researchers can now aim to track different cognitive patterns over time, exploring whether a pattern type can help identify people who need specific support and rehabilitation after stroke.
Which factors determine a person's stroke recovery?
Our research showed brain health and education were strong predictors of the cognitive impairment patterns people experienced post-stroke.
People with lower levels of education and worse brain health were more likely to have more severe cognitive problems after stroke, even if their strokes weren't more severe.
These results suggest that 'cognitive reserve' - the brain's resilience to resist or delay declining cognitive function - is closely linked to cognitive problems in stroke.
Past research has identified many lifestyle factors that may help improve cognitive reserve, including a healthy diet, regular exercise, good sleep, healthy stress levels, strong social connections, and challenging your brain.
Our finding is important because it helps identify changes that people can make to their lives that are linked to better outcomes after stroke.
Enhancing stroke recovery
Cognitive problems are the most reported unmet need in stroke survivors.
This research provides a new way to simplify patterns of cognitive impairment, potentially helping support more effective communication and education about cognitive outcomes in stroke.
This new approach to understanding cognition after stroke can also be applied to other important research questions related to cognition, recovery, and quality of life after stroke.
About the author
Dr Margaret Moore is an ARC Research Fellow at UQ's Queensland Brain Institute and Faculty of Health, Medicine and Behavioural Sciences.
Collaboration and acknowledgements
The study was conducted with researchers at UQ, KU Leuven, the University of Oxford, NHS USL South-East Tuscany, and the Tuscany Rehabilitation Clinic.
