Self- versus informant-based cognitive complaints: Relation of E-Cog scores to imaging, biomarkers and clinical Status in ADNI-2

Abstract

Cognitive complaints are common in older adults including controls with generally intact psychometric performance (HC) as well as those with early or late mild cognitive impairment (EMCI, LMCI). We analyzed the relationships between imaging biomarkers, clinical performance, and cognitive complaints on the Measurement of Everyday Cognition (E-Cog) from both the participant and his or her informant in the ADNI-2 cohort. Data from 895 participants were analyzed (256 HC, 287 EMCI, 210 LMCI, 142 AD). Measures of amyloid deposition, glucose metabolism, and brain atrophy from target regions of interest (ROIs) were extracted from Florbetapir PET, fluorodeoxyglucose (FDG) PET, and structural MRI, respectively. PET scans were processed using standard techniques to generate SUVR measures intensity normalized to the whole cerebellum (Florbetapir) and pons (FDG). MRI scans were analyzed using Freesurfer (R0Is) and SPM8 (voxel based morphometry). Clinical, diagnostic, CSF, and cognitive performance data was also obtained for all available participants at the first ADNI-GO/2 visit. Associations between amyloid deposition, glucose metabolism, brain atrophy, CSF A β and tau levels, cognitive performance, and the extent of cognitive complaints on the E-Cog from the participant and informant were assessed. Diagnostic groups differed in E-Cog scores for both participants and informants as expected (Table 1), with greater complaints in the MCI and AD groups. Significant associations between E-Cog self and informant measures and cognitive performance, amyloid deposition, glucose metabolism, CSF A β and tau, and brain atrophy were also observed across the full sample and within diagnostic groups (Figure 1). Generally, informant E-Cog scores in the memory domain and across all cognitive domains showed more significant associations with biomarkers and clinical performance than self-ratings by the participant. A notable exception was depressive symptoms which were more significantly associated with self E-Cog scores than informant scores.