Objective:

To examine the association between muscle strength and brain morphology in older adults with and without mild traumatic brain injury (mTBI).

Background:

Muscle strength declines with aging  and can result in falls and functional decline. Mild traumatic brain injury (mTBI) may accelerate this neurodegenerative changes process by potentially affecting brain volumes and physical performance. Understanding these associations could inform targeted interventions for aging populations with a history of mTBI.

Design/Methods:

This secondary analysis of the Kerala Einstein Study cohort included 717 community-dwelling adults aged 60 years and older (136 with mTBI, 581 controls). Physical performance was assessed using grip strength, gait speed, unipedal stance, and repeated chair rises. Structural MRI was used to evaluate hippocampal volume and frontal lobe grey matter density. Group comparisons were conducted and corrected for multiple comparisons using false discovery rate (FDR).

Results:

Participants with mTBI demonstrated significantly slower performance on repeated chair rises (p = 0.01 suggesting possible reduction in lower-body strength. However, no significant differences were found in grip strength, gait speed, or unipedal stance. MRI analyses revealed no significant morphological differences in hippocampal or frontal lobe volumes between groups after FDR correction.

Conclusions:

Older adults with mTBI showed impaired lower-body strength, but this was not supported by any detectable morphological differences in brain structure when compared to controls. These findings suggest that while mTBI may impact physical performance, it does not appear to be associated with structural brain changes detectable by conventional MRI. Further research using advanced neuroimaging techniques in a larger sample is warranted