Widespread gray and white matter microstructural alterations in dual cognitive-motor deficit

Dual cognitive-motor deficit in aging is a strong predictor of dementia, yet its effects on vulnerable gray matter region microstructure remain unexplored.

This study classified 582 individuals aged 36 to 90 into cognitive-motor deficit, isolated cognitive or motor deficit, and control groups. Microstructural differences in 27 temporal and motor-related gray matter (GM) regions and white matter (WM) tracts were assessed using diffusion tensor imaging and mean apparent propagator, a technique well suited for GM analysis.

We found widespread microstructural alterations among individuals with dual cognitive-motor deficit. These changes were not observed in isolated cognitive or motor deficits after multiple comparisons correction.

Dual cognitive-motor deficit is associated with distinct microstructural features that are hypothesized to indicate reduced cellular density in temporal GM, decreased fiber coherence, and potential demyelination in WM tracts. These findings could help understand brain aging and facilitate interventions to slow neurodegeneration and delay dementia onset.

Dual cognitive-motor deficit strongly predicts dementia in older adults.Five hundred eighty-two individuals were classified by cognitive and motor deficiency.Mean apparent propagator magnetic resonance imaging (MRI) and diffusion tensor imaging identified widespread microstructural brain alterations.Only the dual deficit showed significant gray matter and white matter differences after correction.Results support early detection of dementia via diffusion MRI microstructure metrics.