Clinical Manifestations.

Area of Science:

• Neurology
• Geriatrics
• Biomarkers

Background:

• Preclinical Alzheimer's disease (AD) is challenging to detect with standard clinical tools.
• Cognitively unimpaired (CU) individuals may show subtle abnormalities linked to early AD.
• Early intervention is critical for AD, necessitating accessible detection methods.

Purpose of the Study:

• To evaluate the association between Montreal Cognitive Assessment (MoCA) total scores and AD pathology in CU individuals.
• To determine if routine clinical tests can identify preclinical AD.
• To assess the utility of MoCA for prescreening in non-specialized settings.

Main Methods:

• 204 cognitively unimpaired (CU) older adults underwent amyloid PET scans (¹⁸F-FTP and ¹⁸F-MK6240).
• Participants were stratified into CU A+ (amyloid-positive) and CU A- (amyloid-negative) groups.
• Voxel-wise linear regression analyzed the link between MoCA scores and tau pathology.

Main Results:

• CU individuals with both amyloid and tau pathology (A+T+) had significantly lower MoCA scores than A-T- individuals.
• Lower MoCA scores correlated with greater mediobasal temporal tau deposition.
• This association was primarily driven by amyloid-positive (A+) individuals.

Conclusions:

• The MoCA test can detect subtle cognitive dysfunction associated with preclinical AD.
• Simple cognitive tests like MoCA can aid in early AD detection.
• MoCA is a viable option for prescreening older adults in primary care settings.