A younger ‘brain age’, gained through optimum brain health, can help achieve better post-stroke outcomes, a new study has revealed.
Understanding why some stroke survivors show better recovery than others despite similar damage to the brain has been a critical goal in stroke research.
Now, through a new study from the Keck School of Medicine of USC, neuroimaging has shown the importance of brain age as a biomarker in outcomes after stroke.
The findings could lead to better ways to predict post-stroke outcomes, say the researchers, and offer insight on new potential treatment targets to improve recovery.
“Brain age has not been widely explored in stroke. A lot of stroke research has focused on how damage to the brain results in negative health outcomes, but there has been less research on how the integrity of the remaining brain tissue supports recovery,” says lead author Dr Sook-Lei Liew.
“We expected that younger-appearing brains would be buffered from the effects of the lesion damage and therefore have less impacts on behaviour.
“The health of your overall brain can protect you from the functional consequences of stroke. That is, the healthier your brain is, first, the less likely you are to have a stroke, and second, the less likely you are to have poor outcomes if you do have a stroke.”
Much of the research in the past two decades has focused on the specific location of brain damage and how the lesion affects connected networks in the brain.
This study, however, takes into consideration global brain health, a new way of analysing the health of the brain based on its cellular, vascular, and structural integrity.
Although global brain health has been widely examined in ageing and neurodegenerative disease such as Alzheimer’s disease, it had not previously been studied in relation to stroke rehabilitation outcomes.
A higher brain predicted age difference, calculated as the difference between a person’s predicted brain age minus their chronological age, suggests that the brain appears to be older than the person’s chronological age.
An older-appearing brain has been associated with conditions including Alzheimer’s disease, major depression and traumatic brain injury.
The research team conducted an observational study using a multi-site data set of 3D brain structural MRIs and clinical measures from ENIGMA Stroke Recovery, a collaborative working group of more than 100 experts worldwide who pool together post-stroke MRI data to create well-powered, diverse samples.
The new study showed that younger brain age is associated with superior post-stroke outcomes.
The researchers note that inclusion of imaging-based assessments of brain age and brain resilience may improve the prediction of post-stroke outcomes and open new possibilities for potential therapeutic targets.
“There’s so much research on the ageing brain right now, and therapeutics being developed to slow brain ageing,” says Dr Liew.
“This study ties brain ageing to stroke outcomes, so any therapeutics developed to slow brain ageing might also be helpful to improve outcomes after stroke.”
For this study, the team of experts used high-resolution MRI data from research studies.
They plan to progress their brain age assessment work by applying it to routine clinical MRI data to determine if it can be an easily implemented biomarker for stroke rehabilitation outcomes.
