Medial temporal lobe atrophy patterns in early- versus late-onset amnestic Alzheimer's disease

Abstract

BackgroundThe medial temporal lobe (MTL) is hypothesized to be relatively spared in early-onset Alzheimers disease (EOAD). Yet, detailed examination of MTL subfield volumes and drivers of atrophy in amnestic EOAD is lacking. MethodsBioFINDER-2 participants with memory impairment, abnormal amyloid-{beta} status and tau-PET were included. Forty-one EOAD individuals aged [≥]65 years and, as comparison, late-onset AD (LOAD, [≤]70 years, n=154) and A{beta}-negative cognitively unimpaired controls were included. MTL subregions and biomarkers of (co-)pathologies were measured. ResultsAD groups showed smaller MTL subregions compared to controls. Atrophy patterns were similar across AD groups, although LOAD showed thinner entorhinal cortices compared to EOAD. EOAD showed lower WMH compared to LOAD. No differences in MTL tau-PET or transactive response DNA binding protein 43-proxy positivity was found. ConclusionsWe found in vivo evidence for MTL atrophy in amnestic EOAD and overall similar levels to LOAD of MTL tau pathology and co-pathologies.