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

## TL;DR

This study explores how motor abilities like grip strength and gait speed may serve as early signs of Alzheimer's disease in younger Latino individuals with a genetic risk.

## Contribution

The study identifies specific motor abilities as potential biomarkers for preclinical Alzheimer's disease in a younger, genetically at-risk population.

## Key findings

- ADAD carriers showed weaker grip strength 12 years before diagnosis and worse manual dexterity 10 years before.
- Slower gait speed was observed in carriers seven years before expected dementia onset.
- Poorer motor abilities correlated with more severe cognitive decline after adjusting for demographic factors.

## Abstract

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.