Evolution of anosognosia in alzheimer's disease and its relationship to amyloid

Abstract

Objective: Unawareness, or anosognosia, of memory deficits is a challenging manifestation of Alzheimer's disease (AD) that adversely affects a patient's safety and decision-making. However, there is a lack of consensus regarding the presence, as well as the evolution, of altered awareness of memory function across the preclinical and prodromal stages of AD. Here, we aimed to characterize change in awareness of memory abilities and its relationship to beta-amyloid (Aβ) burden in a large cohort (N = 1,070) of individuals across the disease spectrum.

Awareness of cognitive decline trajectories in asymptomatic individuals at risk for AD

“…Interestingly, this latter study suggested that these two conditions (hypernosognosia and low ACD) may occur in succession along the preclinical phase of AD. Consistently, a recent longitudinal study [13] found that (i) a subset of individuals with preclinical AD who progressed to MCI showed a 'hypernosognosia' up to 1.6 years before MCI diagnosis; (ii) the participants with MCI who progressed to dementia showed low ACD, eventually constituting a clear anosognosia 3.2 years before the diagnosis of Alzheimer's dementia.…”

“…10,11]; (b) as the discrepancy between the patient's rating and the objective cognitive performance [e.g. 12,13]; (c) a combination of both [14]. These studies lead to discordant results.…”

The Meta-Memory Ratio: A new cohort-independent way to measure cognitive awareness in asymptomatic individuals at risk for Alzheimer’s disease

“…However, ACD is defined in relation to the reference sample. Moreover, using the participantinformant discrepancy, Hanseeuw et al [58] show that although the subject's complaint is initially higher than the informant's, the gap between the two narrows to a reversal of this ratio about 1.6 years before the MCI diagnosis. Thus, there would be a period in which, although ACD has begun to decline, the participant can still be defined as SCD.…”

The Meta-Memory Ratio: A new cohort-independent way to measure cognitive awareness in asymptomatic individuals at risk for Alzheimer’s disease

“…However, ACD is defined in relation to the reference sample. Moreover, using the participant-informant discrepancy, Hanseeuw et al [59] show that although the subject's complaint is initially higher than the informant's, the gap between the two narrows to a reversal of this ratio about 1.6 years before the MCI diagnosis. Thus, there would be a period in which, although ACD has begun to decline, the participant can still be defined as SCD.…”