At(n) Model and Its Association With Neuropsychological Markers

Abstract

Background: The National Institute on Aging and Alzheimer’s Association (NIA-AA) proposed the AT(N) model to diagnose Alzheimer’s disease (AD) considering some biomarkers: amyloid beta (A), phosphorylated tau (T), and neurodegeneration (N). Still, AT(N) correlation with cognitive markers is not yet covered. Objective: To investigate the neuropsychological profile of patients with CSF biomarkers according to AT(N) classification. Methods: Sixty-five patients with thorough neuropsychological data and results of CSF biomarkers were included in the study. We performed a cluster analysis using biomarkers results. The validity was checked by neuropsychological tests scores. Results: We found three clusters: Cluster 1 (n=24), classified as non-AD; Clusters 2 (n=9) and 3 (n=32), classified as AD. Cluster 2 had a higher burden of phosphorylated tau and total tau. All groups were similar regarding sociodemographics and functionality. AD groups had worse memory deficits than the non-AD cluster, but Cluster 2 was more affected than Cluster 3. No other cognitive difference was found, except in the Cubes subtest (Cluster 3>Cluster 2).Conclusion: Memory was the sole domain able to discriminate AD from non-AD, probably due to Cluster 1 heterogeneity. Further studies are warranted to explore this hypothesis. A smaller cluster with AD shows variability in the biomarker profile, which is relevant given its worse cognitive scores.