Episodic memory and associated cortical atrophy in amnestic early-onset and late-onset Alzheimer's disease

BackgroundMemory consolidation problems are often prototypical in Alzheimer's disease (AD). However, it remains undetermined whether episodic memory presents similarly in early-onset Alzheimer's disease (EOAD) relative to the more commonly occurring late-onset Alzheimer's disease (LOAD).ObjectiveThis study examined episodic memory and its neuroanatomical correlates in amnestic early-onset (aEOAD) relative to amnestic late-onset AD (aLOAD).MethodsUsing our single center data set obtained from a memory clinic setting (N = 180), we examined group differences in multiple markers of episodic memory along with associations with volume and thickness of underlying signature brain regions.ResultsWe did not observe any difference for examined measures of memory performance between aEOAD and aLOAD. Associations between episodic memory processes and volume and thickness of the brain regions examined were also largely similar, except for a stronger relationship between memory consolidation and thinner left supramarginal gyrus observed in the aEOAD group.ConclusionsOverall, the current results support similar memory consolidation processes in early- and late-onset amnestic Alzheimer's disease, though the parietal cortex may play a larger role in memory consolidation in aEOAD.