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Background: Subjective cognitive decline (SCD) is considered as the first symptomatic manifestation of Alzheimer's disease (AD), which is also affected by different cultural backgrounds. Establishing cross-cultural prediction models of SCD is challenging.Objective: To establish prediction models of SCD available for both the Chinese and European populations.Methods: In this project, 330 SCD from China and 380 SCD from Germany are intended to be recruited. For all participants, standardized assessments, including clinical, neuropsychological, apolipoprotein E (APOE) genotype, blood, and multi-parameter magnetic resonance imaging (MRI) at baseline will be conducted. Participants will voluntarily undergo amyloid positron emission tomography (PET) and are classified into amyloid-β (Aβ) positive SCD (SCD+) and Aβ negative SCD (SCD-). First, baseline data of all SCD individuals between the two cohorts will be compared. Then, key features associated with brain amyloidosis will be extracted in SCD+ individuals, and the diagnosis model will be established using the radiomics method. Finally, the follow-up visits will be conducted every 12 months and the primary outcome is the conversion to mild cognitive impairment or dementia. After a 4-year follow-up, we will extract factors associated with the conversion risk of SCD using Cox regression analysis.Results: At present, 141 SCD from China and 338 SCD from Germany have been recruited. Initial analysis showed significant differences in demographic information, neuropsychological tests, and regional brain atrophy in SCD compared with controls in both cohorts.Conclusion: This project may be of great value for future implications of SCD studies in different cultural backgrounds.Trial Registration: ClinicalTrials.gov, NCT04696315. Registered 3 January 2021. [ABSTRACT FROM AUTHOR]

Background: Mounting evidence suggests that sex differences exist in cognitive reserve (CR) for cognitively unimpaired (CU) elderly individuals. Global left frontal connectivity (gLFC connectivity) is a reliable neural substrate of CR.Objective: The purpose of this study was to explore sex differences in gLFC connectivity among CU elderly individuals.Methods: One hundred thirteen normal controls (NCs) (women = 66) and 132 individuals with subjective cognitive decline (SCD) (women = 92) were recruited from the Sino Longitudinal Study on Cognitive Decline (SILCODE) (data 1). Among them, 88 subjects underwent amyloid-β (Aβ) imaging, including 32 Aβ+ and 56 Aβ-subjects. Forty-six subjects underwent another rs-fMRI examination (data 2) to validate the repeatability of the calculation of gLFC connectivity, which was determined through seed-based functional connectivity between the LFC and voxels throughout the whole brain. Independent-sample t-tests were used to evaluate the sex differences in gLFC connectivity across different subgroups (NC versus SCD, Aβ+ versus Aβ-). Partial correlation analysis was used to calculate the correlations between gLFC connectivity and cognitive assessments.Results: Women exhibited lower gLFC connectivity in both the NC (p = 0.001) and SCD (p = 0.020) subgroups than men. Women also exhibited lower gLFC connectivity in both the Aβ-(p = 0.006) and Aβ+ (p = 0.025) groups. However, the significant difference disappeared in the Aβ+ group when considering the covariates of age, education, total intracranial volume, and APOE4-carrying status. In addition, gLFC connectivity values were negatively correlated with Geriatric Depression Scale scores in the SCD group (r = -0.176, p = 0.047).Conclusion: Women showed lower gLFC connectivity among CU elderly individuals. [ABSTRACT FROM AUTHOR]

Background: Visual rating scales for medial temporal lobe atrophy (MTA) and posterior atrophy (PA) have been reported to be useful for Alzheimer's disease diagnosis in routine clinical practice.Objective: To investigate the efficacy of combined MTA and PA visual rating scales to discriminate amnestic mild cognitive impairment (aMCI) patients from healthy controls.Methods: This study included T1-weighted MRI images from two different cohorts. In the first cohort, we recruited 73 patients with aMCI and 48 group-matched cognitively normal controls for training and validation. Visual assessments of MTA and PA were carried out for each participant. Global gray matter volume and density were estimated using voxel-based morphometry analysis as the objective reference. We investigated the discriminative power of a single visual rating scale and the combination of the MTA and PA rating scales for identifying aMCI. The second cohort, consisting of 33 aMCI patients and 45 controls, was used to verify the reliability of the visual assessments.Results: Compared with the single visual rating scale, the combination of the MTA and PA exhibited the best discriminative power, with an AUC of 0.818±0.041, which was similar to the diagnostic accuracy of the gray matter volumetric measures. The discriminative power of the combined MTA and PA was verified in the second cohort (AUC 0.824±0.058).Conclusion: The combined MTA and PA rating scales demonstrated practical diagnostic value for distinguishing aMCI patients from controls, suggesting its potential to serve as a convenient and reproducible method to assess the degree of atrophy in clinical settings. [ABSTRACT FROM AUTHOR]

Background: Subjective cognitive decline (SCD) refers to the self-perception of cognitive decline among cognitively normal elderly individuals. SCD related worry confers a higher risk of developing cognitive decline. However, the clinical characteristics of SCD patients with worry are not clear.Objective: To explore the clinical characteristics of SCD patients with worry.Methods: A cross-sectional study was carried out, with 270 consecutive participants of the Sino Longitudinal Study on Cognitive Decline (SILCODE) study. Participants were classified as normal controls (n = 36), SCD patients without worry (n = 91), or SCD patients with worry (n = 143) and were comprehensively compared on 1) their self-perception of cognitive decline, 2) multiple cognitive domains, 3) neuropsychiatric symptoms, and 4) sleep status.Results: SCD patients with worry had significantly more self-perception of cognitive decline (p < 0.001); increased depression (p < 0.001) and anxiety (p < 0.001); decreased sleep quality (p < 0.001), sleep latency (p < 0.05), sleep time (p < 0.01), and sleep efficiency (p < 0.05); more sleep disorders (p < 0.05) and daytime dysfunction (p < 0.05); and a higher global score on the Pittsburgh Sleep Quality Index (p < 0.001) than normal controls. Although there was a significant increase only in self-perception of cognitive decline (p < 0.001), anxiety (p < 0.001), and Pittsburgh Sleep Quality Index scores (p < 0.05), the severity of the increase in those without worry was between that in SCD patients with worry and normal controls.Conclusion: Our findings show that participants who had SCD with worry showed distinct clinical characteristics compared with normal controls and SCD patients without worry, which could be useful for understanding the higher risk in SCD patients with worry of subsequently developing Alzheimer's disease. [ABSTRACT FROM AUTHOR]