Biomarkers

Area of Science:

• Neuroimaging
• Aging Research
• Neurodegenerative Diseases

Background:

• Memory loss affects 40% of individuals over 65, often with early motor decline, signaling potential neurodegenerative diseases like Alzheimer's.
• Gray matter (GM) and white matter (WM) changes in temporal-meta and motor regions are key indicators of aging and Alzheimer's disease (AD).

Purpose of the Study:

• To characterize cognitive and motor impairments in an aging cohort.
• To assess GM and WM microstructural changes using advanced MRI techniques (MAP-MRI and DTI).
• To validate imaging findings with standard cognitive screening (MoCA).

Main Methods:

• Utilized a dataset of 707 subjects (36-90 years) from the Human Connectome Project-Aging (HCP-A).
• Classified participants into four groups (cognitive-motor normal, cognitive impairment, motor impairment, cognitive-motor impairment) using k-means clustering based on NIH-Fluid and walk-endurance measures.
• Examined five MAP-MRI and four DTI metrics in segmented GM and WM regions, employing linear regression adjusted for covariates (sex, YOE, BMI, site).

Main Results:

• The cognitive-motor impairment (CMI) group showed significantly higher MAP-MRI metrics (RTOP, RTAP, RTPP) and lower DTI metrics (RD, TR) in motor and cognitive-motor regions compared to the cognitive-motor normal (CMN) group.
• Significant inverse results were observed between CMN and cognitive impairment (CI) groups in specific brain regions (caudate, pallidum, nigrostriatal).
• No significant differences were found between CMN and motor impairment (MI) groups.

Conclusions:

• Concomitant motor and cognitive impairment are associated with more significant gray and white matter microstructural changes in the aging population.
• These findings highlight the importance of assessing both cognitive and motor functions in aging individuals to detect early signs of neurodegeneration.