Introduction:

Episodic memory (EM) allows us to recall events or lived experiences. EM is associated to the medial temporal lobe (MTL) activity, which has circuits integrated by different cortical association areas. EM impairment is the first symptom of Alzheimer's disease (AD), which is explained by the abnormal beta amyloid (βA) and phosphorylated tau protein (PTF) deposition in the MTL.

Development:

A review about EM components and its assessment is done, especially related to preclinical stages of genetic AD. The relationship of EM components to βA and TFP deposition and the activity of MTL networks, using positron emission tomography (PET) of the brain, particularly in asymptomatic members of families at genetic risk for early AD, caused by the E280A mutation in preseniline 1 (PSN1), is revised.

Conclusions:

The reviewed studies trend to validate the hypothesis, which would suggest that EM allows us to consolidate and recalling lived subjective experiences, which also allows us learning from the past. EM has been assessed with verbal declarative memory tasks. The asymptomatic members, carrying the E280A PSN1 mutation for genetic AD, have showed lower scores than asymptomatic non carriers on these memory tasks, which significantly correlates to PET-amyloid and PET-tau of MTL signals, up to 20 years before dementia onset.