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Background: Subjective cognitive decline (SCD) is a self-perceived cognitive worsening without objective cognitive impairment. Due to its heterogeneity and potential risk of Alzheimer's disease (AD), baseline biomarkers to predict progression are clinically important. In the present study, cognitive trajectories during a 24-month period were compared between amyloid-positive SCD (A+SCD) and amyloid-negative SCD (A−SCD) subjects, and biomarkers associated with memory decline were investigated. Methods: Data from a prospective cohort study in Korea between 2016 and 2019 were analyzed. SCD subjects ≥50 years of age were eligible. All participants underwent neuropsychological tests, brain magnetic resonance imaging, and florbetaben positron emission tomography scans. Amyloid burden and regional volumes were measured. Cognitive changes corrected for age were compared between A+SCD and A−SCD groups. Biomarkers associated with memory decline were assessed. Results: Forty-seven SCD subjects (69.9 ± 6.7 years, mini-mental state examination (MMSE) score 27.5) were enrolled, and 31 completed at least 1 annual follow-up (mean follow-up: 24.7 months). Baseline characteristics except age, hippocampal atrophy, and white matter hyperintensities were similar between A+SCDs (n = 12, 25.6%) and A−SCDs (n = 35). A+SCD subjects showed greater decline in the verbal memory function compared with the A−SCD subjects after adjustment for age. MMSE scores decreased more in the A+SCD (1.1 in the A+SCD; 0.55 in the A−SCD), although it was not statistically significant. Amyloid burden and baseline memory score were associated with memory decline. Conclusions: Within SCD, A+SCD subjects showed faster memory decline compared with the A−SCD subjects and amyloid burden might be associated with future memory decline in SCD. [ABSTRACT FROM AUTHOR]

Introduction: Subjective cognitive decline (SCD) can be considered as the preclinical manifestation of Alzheimer's disease (AD). The National Institute on Aging and the Alzheimer's Association criteria for preclinical AD proposed that subtle cognitive changes appear along with AD biomarkers in the late stage of preclinical AD. The objective of this study was to explore whether subtle cognitive impairment (SCI) in individuals with SCD is associated with brain amyloid-β (Aβ) status and SCD severity. Methods: One hundred twenty individuals with SCD (mean age: 70.87 ± 6.10 years) were included in this study. SCI was defined as performance ≤ −1.0 SD on at least two neuropsychological tests. Participants underwent an amyloid positron emission tomography, which was assessed visually and quantitatively using standardized uptake value ratio (SUVR). The severity of SCD was assessed using two self-reported questionnaires: the SCD questionnaire based on the SCD-plus features and the Korean-Everyday Cognition (K-ECog) scale. Results: SCD individuals with SCI (n = 25) had more Aβ positivity than the SCD only group (n = 95) (44% vs. 15.79%; p = 0.002). In addition, the SCI group had a higher global SUVR than the SCD only group (p = 0.048). For self-reported questionnaires, there were no differences in SCD questionnaire total scores and K-ECog global and cognitive domain-specific scores between two groups. Conclusions: In SCD individuals, SCI was associated with higher Aβ positivity, but not with the severity of self-reported cognitive decline, compared to the SCD only group. These results suggest that the recognition of objectively defined subtle cognitive deficits may contribute to the early identification of AD in SCD. [ABSTRACT FROM AUTHOR]

Background/Aims: The aims of this study were to determine baseline factors related to the progression of subjective memory impairment (SMI) in elderly subjects and to develop a new modeling scale to predict progression. Methods: Elderly subjects with SMI were recruited from the nationwide Clinical Research Centers for Dementia of South Korea (CREDOS) multicenter cohort and divided into two groups: (1) progressed to mild cognitive impairment or Alzheimer's disease or (2) stable without progression. Baseline clinical characteristics were compared between the groups, and the most relevant predictors of progression were assessed. A new modeling scale combining the predictors was developed. Results: In total, 129 subjects with SMI were analyzed. The follow-up duration was 0.5-4.7 years, and the median time to event was 3.64 years. The progressing group (n = 29) differed from the stable group (n = 100) in terms of baseline age, apolipoprotein E4 (APOE4) status, and some cognitive domains. Older age, a lower Mini-Mental State Examination recall score, APOE4 carrier, and a lower verbal delayed recall score were the most relevant predictors of progression, and a new modeling scale with these 4 predictors provided a better explanation of progression. Conclusion: SMI subjects with a higher risk of progression can be identified using a new modeling scale and might need further evaluations and more frequent follow-up. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Our study aimed to compare cognitive status and declines in AD with/without small vessel disease (SVD) and SIVD at baseline and 1-year follow-up. Patients with Alzheimer's disease without small vessel disease (AD(−)SVD) (n =148), Alzheimer's disease with small vessel disease (AD(+)SVD) (n =94) and SIVD (n =60) were recruited from database of multiple centers in Korea. Basic demographics and detailed neuropsychological results were compared. AD, regardless of SVD, showed worse memory and better executive function than SIVD at baseline. Mini-Mental State Examination scores and visual memory function declined more in AD than those in SIVD whereas Barthel Activities of Daily Living (B-ADL) scores declined more in SIVD. AD showed different patterns of cognitive impairment compared with SIVD. After 1 year, AD showed more rapid cognitive decline in some domains. Further investigations with longer follow-up duration may be needed to confirm the cumulative effects of SVD in AD and different patterns of decline between AD and SIVD. [Copyright &y& Elsevier]