Abstract Details

Title Episodic and "Semanticised" Autobiographical Memories across the Lifespan in Alzheimer's Disease: A Neuropsychological and Volumetric Study

Topic Aging and Dementia

Presentation(s) P07 - (-)

Poster/Presentation
Number 131

Objective

Background BACKGROUND: We hypothesized that the ability to elicit strictly episodic memories would correlate to hippocampal and right prefrontal volumes, whereas evoking events devoid of contextual details would be related to lateral temporal and left prefrontal volumes, reflecting a switch from episodic to "semanticized" memories.

Design/Methods DESIGN/METHODS: AbM was assessed using the modified Crovitz test in 18 prodromal or mild AD patients and 18 controls. We obtained 30 memories per participant over five periods of life. AbM scores in AD patients were compared with controls, and correlated to anterograde memory performances. Moreover AbM results were associated to the volume of temporal and prefrontal lobes sub-regions for a subset of 15 patients.

Results RESULTS: We found (i) impaired AbM following a temporal gradient that spared semanticized remote memories predominantly supported by bilateral superior temporal regions, while correlation to anterograde memory deficit and to right hippocampal atrophy was obtained only for the most recent period of life, evoking encoding deficits. (ii) Strictly episodic memory retrieval impairment for all life periods except childhood, correlated to anterograde memory scores and to bilateral hippocampal atrophy for the three intermediate periods. (iii) Associations with prefrontal lobes were obtained only for the rate of strictly episodic memories, likely reflecting the retrieval process specifically associated with episodic memory.

Conclusions CONCLUSIONS: We confirmed that different temporal patterns of deficit exist for strictly episodic and semanticized memories in AD patients, with an extended impairment of strictly AbM prominently resulting from hippocampal and prefrontal atrophy, while preserved semanticized memories are mainly supported by the temporal neocortex.

Authors/Disclosures
Nathalie Philippi (University Hospital of Strasbourg) PRESENTER	No disclosure on file
	No disclosure on file
	No disclosure on file
Frederic Blanc (Hopital Service de Neurologie)	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Alastair Compston, PhD, FRCP	No disclosure on file

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