A new study published in The Lancet Digital Health is providing further insight into how the brain changes following stroke and how these changes may be related to motor recovery.
Researchers examined brain scans from 501 people with chronic unilateral stroke, using machine-learning techniques to estimate the “brain age” of different regions of the brain. The study looked at how these regional brain-age estimates related to the location and size of stroke lesions and to motor function.
What did the researchers find?
The researchers found different patterns of brain changes on the two sides of the brain.
Larger stroke lesions and greater damage to specific brain regions were associated with older-appearing brain regions on the same side as the stroke (the ipsilesional hemisphere). At the same time, greater lesion damage was associated with younger-appearing brain regions on the opposite side of the brain (the contralesional hemisphere).
The study also found that several measures were associated with motor outcomes. In particular, damage to the corticospinal tract and salience network, as well as brain-age measures in the contralesional frontoparietal network, were among the strongest predictors of motor outcomes in the researchers’ models.
The finding involving the contralesional hemisphere is particularly interesting. The researchers suggest that the younger-appearing brain regions may reflect compensatory changes or neuroplasticity — potentially indicating that areas of the brain outside the stroke-damaged region may be recruited to help support movement when the usual pathways have been affected. However, this is a possible explanation rather than something the study directly demonstrated.
Why is this important?
Recovery after stroke involves more than the area of the brain directly affected by the stroke. Understanding how different brain regions and networks respond to stroke could help researchers identify biomarkers of neuroplasticity and better understand why motor recovery varies between individuals.
The researchers suggest that measuring regional brain age could eventually help identify brain changes associated with recovery potential and inform more targeted rehabilitation approaches. In particular, the contralesional frontoparietal network and salience network may warrant further investigation.
Importantly, this study does not show that targeting these brain regions will improve recovery. The researchers note that the study was cross-sectional and focused on people in the chronic stage of stroke recovery, meaning it cannot establish cause and effect. Future longitudinal research will be needed to determine how these brain changes develop over time and whether targeting particular neural networks can actually improve motor recovery.
Looking ahead
This research adds to our understanding of the brain’s capacity to adapt following stroke. By examining changes across different regions and networks — rather than focusing only on the area directly damaged by a stroke — researchers may be able to better understand the complex processes involved in recovery and identify new directions for rehabilitation research.
Source:
Park G, Khan M, Andrushko J et al. Associations between contralesional neuroplasticity and motor impairment through deep learning-derived MRI regional brain age in chronic stroke (ENIGMA): a multicohort, retrospective, observational study. The Lancet Digital Health, 2026; 8. https://doi.org/10.1016/j.landig.2025.100942
