Neuropsychological Assessments Are Highly Predictive of -Amyloid Positive Alzheimer's Disease

Alzheimer's disease (ad) is the most common cause of dementia, but it is often difficult to accurately diagnose. The current gold standard is β-amyloid positivity on a positron emission tomography (PET) scan. However, these scans are not covered by insurance and are cost prohibitive, making them infeasible for many patients. The aim of this study was to quantitatively assess the accuracy of a neuropsychological battery in distinguishing people with biomarker-confirmed ad versus people who are amyloid-negative.In total, 60 participants completed a full neuropsychological assessment and Florbetapir-PET imaging. We then used linear discriminant analysis to assess the extent to which a neuropsychological battery could accurately distinguish the biomarker-confirmed groups. Sensitivity, specificity, positive and negative likelihood ratio, area under the curve (AUC), and accuracy were computed for each model using the classification results based on neuropsychological assessments versus Florbetapir-PET imaging.Participants between the ages of 55-84 years (M = 70.17, SD = 6.65), including 37 with amyloid-positive ad and 23 amyloid-negative participants, completed all aspects of the present study. Overall, the sensitivity of the model was 94.59% (95% CI: 81.81%-99.34%), specificity was 91.30% (95% CI: 71.96%-98.93%), the AUC was 0.93 (95% CI: 0.85-1.00), the positive likelihood ratio was 10.88 (95% CI: 2.89-40.99), and the negative likelihood ratio was 0.06 (95% CI: 0.02-0.23).Assessments from a neuropsychological battery accurately discriminated β-amyloid positive participants with ad from β-amyloid negative participants. These findings represent a potential alternative, cost-effective method for confirming ad status. Further research is warranted to investigate the most optimal neuropsychological battery for ad diagnosis.