Longitudinal Associations Between Physical Activity Behavior and Structural Brain MRI Features After Stroke: A...

Area of Science:

• Neuroscience
• Radiology
• Public Health

Background:

• Post-stroke physical activity (PA) may influence brain structure and brain age.
• Inter-individual differences in brain volumes and age estimates after stroke are not fully understood.

Purpose of the Study:

• To examine the longitudinal relationship between post-stroke physical activity and structural brain MRI features.
• To investigate how PA levels and trajectories affect brain age gap and brain volumes.

Main Methods:

• Longitudinal cohort study using accelerometer data for PA assessment.
• Linear mixed models analyzed associations between daily steps, PA trajectories, brain age gap (BAG), and brain volumes (cortical, hippocampal, thalamic).
• Models controlled for age, sex, education, stroke severity, and intracranial volume.

Main Results:

• Increased daily steps correlated with a lower BAG and larger cortical and hippocampal volumes.
• The association between daily steps and thalamic volume showed a curvilinear pattern, peaking at approximately 4700 steps/day.
• Participants in the highest PA trajectory group exhibited significantly lower BAG and larger thalamic volumes compared to the least active group.

Conclusions:

• Higher levels of physical activity post-stroke are associated with beneficial structural brain changes.
• Maintaining physical activity may contribute to a younger brain appearance and preserve brain volume after stroke.