Relationship between motor reserve, general cognitive functioning and brain atrophy in older adults

<title>Abstract</title> As the population continues to age, a rise in the number of individuals experiencing mild cognitive impairment or dementia symptoms is anticipated. Brain atrophy is strongly associated with cognitive decline that could progress further to dementia. Motor reserve, a cumulative experience of physical activity throughout life, has been identified as a potential protective factor against cognitive decline. This study aimed to investigate the relationship between motor reserve, general cognitive function and brain atrophy in older adults with previously no reported cognitive impairment. All participants underwent detailed assessment of their lifestyle and psychological status, as well as structural magnetic resonance imaging for volumetric brain data. Visual rating scales (Global Cognitive Atrophy scale, Medial Temporal Atrophy scale, Parietal Atrophy scale, Entorhinal Cortex Atrophy, and Frontotemporal Atrophy scale) were used to grade the level of brain atrophy. Montreal Cognitive Assessment screening task was performed to evaluate global cognitive functioning in all subjects. 54 older adults (18.5% men) aged from 65 to 85 (<italic>M</italic> = 71.44 years, <italic>SD</italic> = 5.01 years) were included in the study. The study results showed a tendency towards the relationship between several cortical atrophy scales and the motor reserve; nevertheless, after controlling for global cognition, motor reserve was associated only with ERICA score in the left hemisphere and whole brain, and parietal atrophy score in the left hemisphere. The results suggest that individuals with higher motor reserve scores may be less likely to experience brain atrophy in the entorhinal, medial-temporal and parietal cortices; however, due to the small sample, the results should be interpreted with caution.