[P4–184]: Low Cognitive Awareness, but Not Complaint, Is a Good Marker of Preclinical Alzheimer's Disease

Cognitive and neuroimaging features and brain β-amyloidosis in individuals at risk of Alzheimer's disease (INSIGHT-preAD): a longitudinal observational study

“…Moreover, the presence of amyloid brain lesions was associated with a low cognitive awareness in our participants. 34 This result may appear in contradiction with some recent data 56 but it is noteworthy that the subjects were only complainers and did not fully correspond to the definition of subjective cognitive decline 57 . However, an extensive investigation of their subjective feelings was performed, and to our knowledge, INSIGHT-preAD is the first study with such a comprehensive evaluation of different aspects of cognitive complaints, including 6 questionnaires with a total of 88 items all of which administered with the same investigators in participants who were cognitively healthy at study entry.…”

“…Table 1 shows the characteristics of INSIGHT-PreAD study participants at baseline with a mean age of 76.1 years (SD 3.47), a female predominance (63.2 %) and a high education level (mean 6.2; SD=2.1) for a scale from 1 to 8-max 34 . Their mean MMSE score was 28.67 (SD=0.96) and FCSRT total recall score was 46.09 out of 48 (SD=1.98).…”

Memory impairment and Alzheimer's disease pathology in individuals with MCI who underestimate or overestimate their decline

“…Similarly, there were lower Aß 1‐42 levels, greater p‐tau 181‐p levels, and therefore higher ratio of p‐tau 181‐p to Aß 1‐42 in individuals who underestimated their decline than in individuals who overestimated their decline. These results fit well with Cacciamani et al's findings of increased amyloid burden and cortical hypometabolism in individuals with subjective cognitive complaints who underestimated their performance relative to their informants. Thus, the current analyses are consistent with the proposed model of progression of AD, according to which the accumulation of amyloid‐beta and tau, together with hypometabolism, lead to cognitive decline .…”

“…However, informants' reports can be biased as well . While ADNI provides no information on informants, Cacciamani et al found no difference in informant characteristics of individuals with low or high awareness. It is thus unlikely that the current findings represent only informants' biased estimation.…”

“…In addition, some studies demonstrate that lack of awareness of deficit is an independent predictor of conversion from MCI to dementia, and that individuals with MCI who are less aware of their deficits show a more rapid decline in cognitive functions than do individuals who are more aware of their decline . Cacciamani et al argue that individuals with cognitive concerns who exhibit low awareness, as measured by a discrepancy between their own reports and those provided by informants, are likely to have preclinical Alzheimer's disease (AD) pathology. Thus, it might be useful to compare participant and informant estimates of memory decline in order to determine the etiology and prognosis of MCI.…”