Predicting cognitive decline in older people by structural and molecular imaging

Area of Science:

• Neurology
• Radiology
• Biomarkers

Background:

• The advent of disease-modifying treatments and recognition of predementia stages in Alzheimer's disease (AD) highlight the prognostic significance of biomarkers, particularly imaging markers.
• The clinical utility of imaging biomarkers for predicting AD progression is under active investigation.

Approach:

• Review of current literature on the prognostic and predictive value of various neuroimaging modalities in Alzheimer's disease.
• Evaluation of imaging markers including amyloid PET, tau PET, FDG-PET, and structural MRI.

Key Points:

• In cognitively normal individuals, the positive predictive value of amyloid PET for progression to prodromal AD or AD dementia is low (<25%).
• In mild cognitive impairment (MCI), imaging markers demonstrate higher positive predictive values (>60%), with amyloid PET showing moderate advantages and combined molecular and neurodegeneration markers offering added value.
• Current evidence does not support the use of imaging for individual prognosis in cognitively normal individuals, recommending their use for risk stratification in clinical trials.

Conclusions:

• For individuals with MCI, amyloid PET, tau PET, FDG-PET, and MRI provide relevant predictive accuracy for clinical counseling within specialized diagnostic programs.
• Future research should prioritize the systematic and patient-centered integration of imaging markers into evidence-based care pathways for individuals with prodromal AD.