Differential Patterns of Domain-Specific Cognitive Complaints and Awareness Across the Alzheimer’s Disease Spectrum

Abstract

Background: Characterizing self- and informant-reported cognitive complaints, as well as awareness of cognitive decline (ACD), is useful for an early diagnosis of Alzheimer’s disease (AD). However, complaints and ACD related to cognitive functions other than memory are poorly studied. Furthermore, it remains unclear which source of information is the most useful to distinguish various groups on the AD spectrum.Methods: Self- and informant-reported complaints were measured with the Everyday Cognition questionnaire (ECog-Subject and ECog-StudyPartner) in four domains (memory, language, visuospatial, and executive). ACD was measured as the subject-informant discrepancy in the four ECog scores. We compared the ECog and ACD scores across cognitive domains between four groups: 71 amyloid-positive individuals with amnestic AD, 191 amnestic mild cognitive impairment (MCI), or 118 cognitively normal (CN), and 211 amyloid-negative CN controls, selected from the ADNI database. Receiver operating characteristic curves analysis was performed to evaluate the accuracy of the ECog and ACD scores in discriminating clinical groups.Results: Self- and informant-reported complaints were generally distributed as follows: memory, language, executive, and visuospatial (from the most severe to the least severe). Both groups of CN participants presented on average more memory and language complaints than their informant. MCI participants showed good agreement with their informants. AD participants presented anosognosia in all domains, but especially for the executive domain. The four ECog-StudyPartner sub-scores allowed excellent discrimination between groups in almost all classifications and performed significantly better than the other two classifiers considered. The ACD was excellent in distinguishing the participants with AD from the two groups of CN participants. The ECog-Subject was the least accurate in discriminating groups in four of the six classifications performed.Conclusion: In research, the study of complaint and anosognosia should not be reduced solely to the memory domain. In clinical practice, non-amnestic complaints could also be linked to Alzheimer’s disease. The presence of an informant also seems necessary given its accuracy as a source of information.

The Alzheimer's Disease Neuroimaging Initiative in the era of Alzheimer's disease treatment: A review of ADNI studies from 2021 to 2022

“…Memory awareness, defined as the difference between subjective and objective cognitive decline, decreases with increasing cognitive impairment 233,234 . In the IMAP cohort with replication in ADNI, subjective memory decline remained similar across increasingly impaired diagnostic groups whereas objective memory decline increased 233 .…”

“…In CU participants, greater subjective memory decline was associated with greater neurodegeneration but the opposite was true in later diagnostic stages (Figure S31 in supporting information) 233 . Informant reports of complaints across the four domains of ECog were lower than self‐reported complaints in CU participants, in good agreement in MCI participants, and higher in AD participants 234 . Anosognosia (lack of awareness of impairment) was associated with greater tau but not Aβ deposition in impaired subjects 235 .…”

“… 233 Informant reports of complaints across the four domains of ECog were lower than self‐reported complaints in CU participants, in good agreement in MCI participants, and higher in AD participants. 234 Anosognosia (lack of awareness of impairment) was associated with greater tau but not Aβ deposition in impaired subjects. 235 These reports suggest that anosognosia increases over time with increasing tau deposition and neurodegeneration and that subjective memory complaints should be interpreted differently in those with normal cognition compared to those with dementia.…”

“…232 Memory awareness, defined as the difference between subjective and objective cognitive decline, decreases with increasing cognitive impairment. 233,234 In the IMAP cohort with replication in ADNI, subjective memory decline remained similar across increasingly impaired diagnostic groups whereas objective memory decline increased. 233 In CU participants, greater subjective memory decline was associated with greater neurodegeneration but the opposite was true in later diagnostic stages (Figure S31 in supporting information).…”