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IntroductionWe used sex and apolipoprotein E ε4 (APOE ε4) carrier status as predictors of pathologic burden in early-onset Alzheimer's disease (EOAD).MethodsWe included baseline data from 77 cognitively normal (CN), 230 EOAD, and 70 EO non-Alzheimer's disease (EOnonAD) participants from the Longitudinal Early-Onset Alzheimer's Disease Study (LEADS). We stratified each diagnostic group by males and females, then further subdivided each sex by APOE ε4 carrier status and compared imaging biomarkers in each stratification. Voxel-wise multiple linear regressions yielded statistical brain maps of gray matter density, amyloid, and tau PET burden.ResultsEOAD females had greater amyloid and tau PET burdens than males. EOAD female APOE ε4 non-carriers had greater amyloid PET burdens and greater gray matter atrophy than female ε4 carriers. EOnonAD female ε4 non-carriers also had greater gray matter atrophy than female ε4 carriers.DiscussionThe effects of sex and APOE ε4 must be considered when studying these populations.HighlightsNovel analysis examining the effects of biological sex and apolipoprotein E ε4 (APOE ε4) carrier status on neuroimaging biomarkers among early-onset Alzheimer's disease (EOAD), early-onset non-AD (EOnonAD), and cognitively normal (CN) participants. Female sex is associated with greater pathology burden in the EOAD cohort compared to male sex. The effect of APOE ε4 carrier status on pathology burden was the most impactful in females across all cohorts.

IntroductionMagnetic resonance imaging (MRI) research has advanced our understanding of neurodegeneration in sporadic early-onset Alzheimer's disease (EOAD) but studies include small samples, mostly amnestic EOAD, and have not focused on developing an MRI biomarker.MethodsWe analyzed MRI scans to define the sporadic EOAD-signature atrophy in a small sample (n = 25) of Massachusetts General Hospital (MGH) EOAD patients, investigated its reproducibility in the large longitudinal early-onset Alzheimer's disease study (LEADS) sample (n = 211), and investigated the relationship of the magnitude of atrophy with cognitive impairment.ResultsThe EOAD-signature atrophy was replicated across the two cohorts, with prominent atrophy in the caudal lateral temporal cortex, inferior parietal lobule, and posterior cingulate and precuneus cortices, and with relative sparing of the medial temporal lobe. The magnitude of EOAD-signature atrophy was associated with the severity of cognitive impairment.DiscussionThe EOAD-signature atrophy is a reliable and clinically valid biomarker of AD-related neurodegeneration that could be used in clinical trials for EOAD.HighlightsWe developed an early-onset Alzheimer's disease (EOAD)-signature of atrophy based on magnetic resonance imaging (MRI) scans. EOAD signature was robustly reproducible across two independent patient cohorts. EOAD signature included prominent atrophy in parietal and posterior temporal cortex. The EOAD-signature atrophy was associated with the severity of cognitive impairment. EOAD signature is a reliable and clinically valid biomarker of neurodegeneration.

IntroductionWe examined neuropsychiatric symptoms (NPS) and psychotropic medication use in a large sample of individuals with early-onset Alzheimer's disease (EOAD; onset 40-64 years) at the midway point of data collection for the Longitudinal Early-onset Alzheimer's Disease Study (LEADS).MethodsBaseline NPS (Neuropsychiatric Inventory - Questionnaire; Geriatric Depression Scale) and psychotropic medication use from 282 participants enrolled in LEADS were compared across diagnostic groups - amyloid-positive EOAD (n = 212) and amyloid negative early-onset non-Alzheimer's disease (EOnonAD; n = 70).ResultsAffective behaviors were the most common NPS in EOAD at similar frequencies to EOnonAD. Tension and impulse control behaviors were more common in EOnonAD. A minority of participants were using psychotropic medications, and use was higher in EOnonAD.DiscussionOverall NPS burden and psychotropic medication use were higher in EOnonAD than EOAD participants. Future research will investigate moderators and etiological drivers of NPS, and NPS differences in EOAD versus late-onset AD.

ObjectiveThe Longitudinal Early-Onset Alzheimer's Disease Study (LEADS) seeks to provide comprehensive understanding of early-onset Alzheimer's disease (EOAD; onset

The literature on the relationship between social interaction and executive functions (EF) in older age is mixed, perhaps stemming from differences in EF measures and the conceptualization/measurement of social interaction. We investigated the relationship between social interaction and EF in 102 cognitively unimpaired older adults (ages 65–90). Participants received an EF battery to measure working memory, inhibition, shifting, and global EF. We measured loneliness subjectively through survey and social isolation objectively through naturalistic observation. Loneliness was not significantly related to any EF measure (p-values =.13–.65), nor was social isolation (p-values =.11–.69). Bayes factors indicated moderate to extremely strong evidence (BF01 = 8.70 to BF01 = 119.49) in support of no relationship.. Overall, these findings suggest that, among cognitively healthy older adults, there may not be a robust cross-sectional relationship between EF and subjective loneliness or objective social isolation. [ABSTRACT FROM AUTHOR]

INTRODUCTION: We examined the burden of neuropsychiatric symptoms (NPSs) in early‐onset (EO) and late‐onset (LO) Alzheimer's disease (AD) and adjusted for age effects via the inclusion of cognitively unimpaired (CU) individuals. METHODS: Cross‐sectional data from 2940 EOAD, 8665 LOAD, and 8775 age‐stratified CU individuals (early‐CU, n = 2433; late‐CU, n = 6342) from the National Alzheimer's Coordinating Center database were included. Fisher's exact tests compared EOAD and LOAD on the presence and severity of NPSs. Multiple logistic regression models included an age*diagnosis interaction to examine age effects. RESULTS: Presence (ps < 0.0001) and severity (ps < 0.05) of NPS were greater in EOAD than in LOAD. However, after adjusting for base rates in NPS in CU individuals (age effects), only elation and eating behaviors were more frequent in EOAD (ps < 0.05) and nighttime behaviors more frequent and severe in LOAD (ps < 0.05). DISCUSSION: Few NPSs were specific to the EOAD versus LOAD. Previous findings of greater NPS burden in EOAD may partially reflect age effects. Highlights: Adjusting for age effect, elation and eating problems are more frequent in EOAD.Adjusting for age effect, sleep disturbances are more frequent and severe in LOAD.Age effects underlie higher neuropsychiatric symptom presentation in EOAD than in LOAD. [ABSTRACT FROM AUTHOR]

Background: Conventional normative samples include individuals with undetected Alzheimer's disease neuropathology, lowering test sensitivity for cognitive impairment. Objective: We developed Mayo Normative Studies (MNS) norms limited to individuals without elevated amyloid or neurodegeneration (A–N–) for Rey's Auditory Verbal Learning Test (AVLT). We compared these MNS A–N– norms in female, male, and total samples to conventional MNS norms with varying levels of demographic adjustments. Methods: The A–N– sample included 1,059 Mayo Clinic Study of Aging cognitively unimpaired (CU) participants living in Olmsted County, MN, who are predominantly non-Hispanic White. Using a regression-based approach correcting for age, sex, and education, we derived fully-adjusted T-score formulas for AVLT variables. We validated these A–N– norms in two independent samples of CU (n = 261) and mild cognitive impairment (MCI)/dementia participants (n = 392) > 55 years of age. Results: Variability associated with age decreased by almost half in the A–N– norm sample relative to the conventional norm sample. Fully-adjusted MNS A–N– norms showed approximately 7– 9% higher sensitivity to MCI/dementia compared to fully-adjusted MNS conventional norms for trials 1– 5 total and sum of trials. Among women, sensitivity to MCI/dementia increased with each normative data refinement. In contrast, age-adjusted conventional MNS norms showed greatest sensitivity to MCI/dementia in men. Conclusions: A–N– norms show some benefits over conventional normative approaches to MCI/dementia sensitivity, especially for women. We recommend using these MNS A–N– norms alongside MNS conventional norms. Future work is needed to determine if normative samples that are not well characterized clinically show greater benefit from biomarker-refined approaches. [ABSTRACT FROM AUTHOR]

BACKGROUND: Identifying genetic patterns that contribute to Alzheimer's disease (AD) is important not only for pre‐symptomatic risk assessment but also for building personalized therapeutic strategies. METHODS: We implemented a novel simulative deep learning model to chromosome 19 genetic data from the Alzheimer's Disease Neuroimaging Initiative and the Imaging and Genetic Biomarkers of Alzheimer's Disease datasets. The model quantified the contribution of each single nucleotide polymorphism (SNP) and their epistatic impact on the likelihood of AD using the occlusion method. The top 35 AD‐risk SNPs in chromosome 19 were identified, and their ability to predict the rate of AD progression was analyzed. RESULTS: Rs561311966 (APOC1) and rs2229918 (ERCC1/CD3EAP) were recognized as the most powerful factors influencing AD risk. The top 35 chromosome 19 AD‐risk SNPs were significant predictors of AD progression. DISCUSSION: The model successfully estimated the contribution of AD‐risk SNPs that account for AD progression at the individual level. This can help in building preventive precision medicine. [ABSTRACT FROM AUTHOR]

Background: Utilization of NIA-AA Research Framework requires dichotomization of tau pathology. However, due to the novelty of tau-PET imaging, there is no consensus on methods to categorize scans into "positive" or "negative" (T+ or T–). In response, some tau topographical pathologic staging schemes have been developed. Objective: The aim of the current study is to establish criterion validity to support these recently-developed staging schemes. Methods: Tau-PET data from 465 participants from the Alzheimer's Disease Neuroimaging Initiative (aged 55 to 90) were classified as T+ or T– using decision rules for the Temporal-Occipital Classification (TOC), Simplified TOC (STOC), and Lobar Classification (LC) tau pathologic schemes of Schwarz, and Chen staging scheme. Subsequent dichotomization was analyzed in comparison to memory and learning slope performances, and diagnostic accuracy using actuarial diagnostic methods. Results: Tau positivity was associated with worse cognitive performance across all staging schemes. Cognitive measures were nearly all categorized as having "fair" sensitivity at classifying tau status using TOC, STOC, and LC schemes. Results were comparable between Schwarz schemes, though ease of use and better data fit preferred the STOC and LC schemes. While some evidence was supportive for Chen's scheme, validity lagged behind others—likely due to elevated false positive rates. Conclusions: Tau-PET staging schemes appear to be valuable for Alzheimer's disease diagnosis, tracking, and screening for clinical trials. Their validation provides support as options for tau pathologic dichotomization, as necessary for use of NIA-AA Research Framework. Future research should consider other staging schemes and validation with other outcome benchmarks. [ABSTRACT FROM AUTHOR]

Background: We studied the effect of apolipoprotein E (APOE) ε4 status and sex on rates of cognitive decline in early‐ (EO) and late‐ (LO) onset Alzheimer's disease (AD). Method: We ran mixed‐effects models with longitudinal cognitive measures as dependent variables, and sex, APOE ε4 carrier status, and interaction terms as predictor variables in 998 EOAD and 2562 LOAD participants from the National Alzheimer's Coordinating Center. Results: APOE ε4 carriers showed accelerated cognitive decline relative to non‐carriers in both EOAD and LOAD, although the patterns of specific cognitive domains that were affected differed. Female participants showed accelerated cognitive decline relative to male participants in EOAD only. The effect of APOE ε4 was greater in EOAD for executive functioning (p < 0.0001) and greater in LOAD for language (p < 0.0001). Conclusion: We found APOE ε4 effects on cognitive decline in both EOAD and LOAD and female sex in EOAD only. The specific patterns and magnitude of decline are distinct between the two disease variants. Highlights: Apolipoprotein E (APOE) ε4 carrier status and sex differentiate rates of cognitive decline in early‐onset (EO) and late‐onset (LO) Alzheimer's disease (AD).APOE ε4 in EOAD accelerated decline in memory, executive, and processing speed domains.Female sex in EOAD accelerated decline in language, memory, and global cognition.The effect of APOE ε4 was stronger for language in LOAD and for executive function in EOAD.Sex effects on language and executive function decline differed between EOAD and LOAD. [ABSTRACT FROM AUTHOR]

Objective: To characterize and compare the neuropsychological profiles of patients with primary progressive apraxia of speech (PPAOS) and apraxia of speech with progressive agrammatic aphasia (AOS-PAA). Method: Thirty-nine patients with PPAOS and 49 patients with AOS-PAA underwent formal neurological, speech, language, and neuropsychological evaluations. Cognitive domains assessed included immediate and delayed episodic memory (Wechsler Memory Scale-Third edition; Logical Memory; Visual Reproduction; Rey Auditory Verbal Learning Test), processing speed (Trail Making Test A), executive functioning (Trail Making Test B; Delis-Kaplan Executive Functioning Scale – Sorting), and visuospatial ability (Rey-Osterrieth Complex Figure copy). Results: The PPAOS patients were cognitively average or higher in the domains of immediate and delayed episodic memory, processing speed, executive functioning, and visuospatial ability. Patients with AOS-PAA performed more poorly on tests of immediate and delayed episodic memory and executive functioning compared to those with PPAOS. For every 1 unit increase in aphasia severity (e.g. mild to moderate), performance declined by 1/3 to 1/2 a standard deviation depending on cognitive domain. The degree of decline was stronger within the more verbally mediated domains, but was also notable in less verbally mediated domains. Conclusion: The study provides neuropsychological evidence further supporting the distinction of PPAOS from primary progressive aphasia and should be used to inform future diagnostic criteria. More immediately, it informs prognostication and treatment planning. [ABSTRACT FROM AUTHOR]

Background: Highly penetrant inherited mutations in the prion protein gene (PRNP) offer a window to study the pathobiology of prion disorders.Method: Clinical, neuropsychological, and neuroimaging characterization of a kindred.Results: Three of four mutation carriers have progressed to a frontotemporal dementia phenotype. Declines in neuropsychological function coincided with changes in FDG-PET at the identified onset of cognitive impairment.Conclusions and Relevance: Gene silencing treatments are on the horizon and when they become available, early detection will be crucial. Longitudinal studies involving familial mutation kindreds can offer important insights into the initial neuropsychological and neuroimaging changes necessary for early detection. [ABSTRACT FROM AUTHOR]

Women are widely assumed to be more talkative than men. Challenging this assumption, Mehl et al. (2007) provided empirical evidence that men and women do not differ significantly in their daily word use, speaking about 16,000 words per day (WPD) each. However, concerns were raised that their sample was too small to yield generalizable estimates and too age and context homogeneous to permit inferences beyond college students. This registered report replicated and extended the previous study of binary gender differences in daily word use to address these concerns. Across 2,197 participants (more than five-fold the original sample size), pooled over 22 samples (631,030 ambient audio recordings), men spoke on average 11,950 WPD and women 13,349 WPD, with very large individual differences (< 100 to > 120,000 WPD). The estimated gender difference (1,073 WPD; d = 0.13; 95% CrI [316, 1,824]) was about twice as large as in the original study. Smaller differences emerged among adolescent (513 WPD), emerging adult (841 WPD), and older adult (-788 WPD) participants, but a substantially larger difference emerged for participants in early and middle adulthood (3,275 WPD; d = 0.32). Despite the considerable sample size(s), all estimates carried large statistical uncertainty and, except for the gender difference in early and middle adulthood, provide inconclusive evidence regarding whether the two genders ultimately speak a practically equivalent number of WPD, based on the preregistered ± 1,000 WPD regions of practical equivalence criterion. Experienced stress had no meaningful effect on the gender difference, and no clear pattern emerged as to whether the gender difference is accentuated for subjectively rated compared with objectively observed talkativeness. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Introduction: Early-onset Alzheimer's disease (EOAD) and late-onset Alzheimer's disease (LOAD) share similar amyloid etiology, but evidence from smaller-scale studies suggests that they manifest differently clinically. Current analyses sought to contrast the cognitive profiles of EOAD and LOAD., Methods: Z-score cognitive-domain composites for 311 amyloid-positive sporadic EOAD and 314 amyloid-positive LOAD participants were calculated from baseline data from age-appropriate control cohorts. Z-score composites were compared between AD groups for each domain., Results: After controlling for cognitive status, EOAD displayed worse visuospatial, executive functioning, and processing speed/attention skills relative to LOAD, and LOAD displayed worse language, episodic immediate memory, and episodic delayed memory., Discussion: Sporadic EOAD possesses distinct cognitive profiles relative to LOAD. Clinicians should be alert for non-amnestic impairments in younger patients to ensure proper identification and intervention using disease-modifying treatments., Highlights: Both early-onset Alzheimer's disease (EOAD) and late-onset Alzheimer's disease (LOAD) participants displayed widespread cognitive impairments relative to their same-aged peers. Cognitive impairments were more severe for EOAD than for LOAD participants in visuospatial and executive domains. Memory and language impairments were more severe for LOAD than for EOAD participants Results were comparable after removing clinical phenotypes of posterior cortical atrophy (PCA), primary progressive aphasia (lv-PPA), and frontal-variant AD., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Introduction: Early-onset Alzheimer's disease (EOAD) manifests prior to the age of 65, and affects 4%-8% of patients with Alzheimer's disease (AD). The current analyses sought to examine longitudinal cognitive trajectories of participants with early-onset dementia., Methods: Data from 307 cognitively normal (CN) volunteer participants and those with amyloid-positive EOAD or amyloid-negative cognitive impairment (EOnonAD) were compared. Cognitive trajectories across a comprehensive cognitive battery spanning 42 months were examined using mixed-effects modeling., Results: The EOAD group displayed worse cognition at baseline relative to EOnonAD and CN groups, and more aggressive declines in cognition over time. The largest effects were observed on measures of executive functioning domains, while memory declines were blunted in EOAD., Discussion: EOAD declined 2-4× faster than EOnonAD, and EOAD pathology is not restricted to memory networks. Early identification of deficits is critical to ensure that individuals with sporadic EOAD can be considered for treatment using disease-modifying medications., Highlights: Represents the most comprehensive longitudinal characterization of sporadic EOAD to date. The trajectory of cognitive declines was steep for EOAD participants and worse than for other groups. Executive functioning measures exhibited the greatest declines over time in EOAD., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)