Declining motor abilities might be a noninvasive biomarker for Alzheimer's disease (AD). Studying motor ability and AD progression in younger Latinos with autosomal dominant Alzheimer's disease (ADAD) can provide insights into the interplay between motor ability and cognition in individuals with minimal confounding from age-normative changes and comorbid medical conditions. This study aimed to (1) examine motor abilities as a function of years to dementia diagnosis and (2) examine associations between motor ability and cognitive performance. This was a cross-sectional observational study. The study took place at the University of Southern California. 39 predominately Latino individuals (mean age 38.6 ± 10 years old) known to carry (carriers; n=25) or be at 50% risk for inheriting ADAD but not carrying the mutation (noncarriers; n=14). Individuals completed the motor and cognitive batteries from the National Institute of Health Toolbox (NIHTB) and the Cognitive Abilities Screening Instrument (CASI). All models included effects for age, education, primary language, and sex. Compared to noncarriers, ADAD mutation carriers had significantly weaker grip strength at 12 years, worse manual dexterity at 10 years, and slower gait speed seven years before the expected age of dementia diagnosis. Worse motor ability was associated with a more severe cognitive disease stage and worse CASI performance, adjusting for demographic and clinical variables. The findings support the utility of motor performance, precisely grip strength, manual dexterity, and gait speed as potential biomarkers of preclinical AD.

Motor abilities and cognitive performance in Latinos with autosomal dominant Alzheimer's disease