Individual brain lateralisation, simulation of lesions, and stroke recovery – How the two halves of the brain interact: New insights from neuroimaging

Worldwide, cerebrovascular accidents (stroke) are the second leading cause of death, and almost everyone will suffer neurological symptoms at some point in life.

In Europe, stroke affects ~2 million people every year, a number that is dramatically increasing due to COVID-19 ramifications.

Clinical presentation and neuroimaging can help confirm a stroke diagnosis, but both are limited in predicting recovery.

The prediction is particularly challenging when a patient suffers from a stroke in one half of the brain (hemisphere) and recovers using the other hemisphere.

Neurosciences have long been working under the assumption that each hemisphere is dominant for a different set of functions.

For example, language is considered dominant in the left hemisphere, while visuospatial functions are dominant in the right hemisphere. However, this simple vision is challenged by stroke data.

I propose to revisit the three guiding theories that explain how the hemispheres interact using recent developments in neuroimaging. The two hemispheres of the brain can either work 1) independently, 2) in competition or 3) in collaboration.

It is now possible to test the three mechanisms using advanced neuroimaging and computational modelling and draw meaningful conclusions for precision medicine that will improve our ability to predict and aid recovery after stroke.

In PERSONALISED, I anticipate that brain lateralisation mechanisms are dynamic, not the same for all people or across cognitive functions and may lead to different trajectories of recovery after stroke.

Overall, PERSONALISED will decipher the mechanisms of brain lateralisation at the individual level, demonstrate the added value of advanced neuroimaging for the clinic and open a new avenue for research on the dynamic aspect of brain lateralisation.