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A deficit in empathy has consistently been cited as a central characteristic of Asperger syndrome (AS), but previous research on adults has predominantly focused on cognitive empathy, effectively ignoring the role of affective empathy. We administered the Interpersonal Reactivity Index (IRI), a multi-dimensional measure of empathy, and the Strange Stories test to 21 adults with AS and 21 matched controls. Our data show that while the AS group scored lower on the measures of cognitive empathy and theory of mind, they were no different from controls on one affective empathy scale of the IRI (empathic concern), and scored higher than controls on the other (personal distress). Therefore, we propose that the issue of empathy in AS should be revisited.

Background: Prior findings indicate that both genetic factors and indices of cognitive reserve (CR) influence risk of cognitive decline, with APOE4 genetic status increasing risk, and APOE2 genetic status and higher CR indices decreasing risk. However, it remains unclear whether these genetic and lifestyle variables interact to influence long‐term cognitive trajectories. This study examined whether these variables modify baseline cognitive scores and longitudinal cognitive trajectories in N = 1819 participants who were cognitively normal at baseline and included in the Preclinical AD Consortium (PAC). Method: PAC datasets include harmonized data from five longitudinal cohort studies: ACS, AIBL, BIOCARD, BLSA, and WRAP. Longitudinal cognitive performance was measured by harmonized factor scores for global cognition, memory, and executive function (M follow‐up = 9.8y; Table 1). APOE genotypes were coded with separate indicator variables for APOE2 (n = 233) and APOE4 (n = 581), with APOE3/3 (n = 1005) as the reference group. A CR index was calculated by combining years of education and literacy scores. Result: In longitudinal mixed effect models, using time since baseline as the timescale (Table 2), higher CR index scores were associated with better baseline cognitive performance for all cognitive factor scores, but not with rate of change in cognition over time. In contrast, APOE4 genotype was associated with more negative rates of cognitive change. For the global and memory scores, there were also 3‐way CR index x APOE4 x time interactions, indicating the negative effect of APOE4 genotype on global and memory score change was attenuated among individuals with higher CR index scores (Figure 1). When the models were re‐run with the term for APOE4 genetic status reflecting the number of APOE4 alleles (i.e., 0, 1, 2; Table 3), the patterns of results were similar, except the 3‐way CR index x APOE4 x time interaction for global cognition was only marginal (p = 0.06). Conclusion: Higher CR proxy scores are associated with higher levels of cognitive performance, whereas APOE4 genetic status is associated with greater rates of cognitive decline. Higher levels of CR may attenuate APOE4‐related declines in global cognition and memory, but level of CR and APOE4 have largely independent effects on executive function. [ABSTRACT FROM AUTHOR]

Objective: Smartphones have the potential for capturing subtle changes in cognition that characterize preclinical Alzheimer's disease (AD) in older adults. The Ambulatory Research in Cognition (ARC) smartphone application is based on principles from ecological momentary assessment (EMA) and administers brief tests of associative memory, processing speed, and working memory up to 4 times per day over 7 consecutive days. ARC was designed to be administered unsupervised using participants' personal devices in their everyday environments. Methods: We evaluated the reliability and validity of ARC in a sample of 268 cognitively normal older adults (ages 65–97 years) and 22 individuals with very mild dementia (ages 61–88 years). Participants completed at least one 7-day cycle of ARC testing and conventional cognitive assessments; most also completed cerebrospinal fluid, amyloid and tau positron emission tomography, and structural magnetic resonance imaging studies. Results: First, ARC tasks were reliable as between-person reliability across the 7-day cycle and test-retest reliabilities at 6-month and 1-year follow-ups all exceeded 0.85. Second, ARC demonstrated construct validity as evidenced by correlations with conventional cognitive measures (r = 0.53 between composite scores). Third, ARC measures correlated with AD biomarker burden at baseline to a similar degree as conventional cognitive measures. Finally, the intensive 7-day cycle indicated that ARC was feasible (86.50% approached chose to enroll), well tolerated (80.42% adherence, 4.83% dropout), and was rated favorably by older adult participants. Conclusions: Overall, the results suggest that ARC is reliable and valid and represents a feasible tool for assessing cognitive changes associated with the earliest stages of AD. [ABSTRACT FROM AUTHOR]

Background: The balance between production, clearance, and toxicity of Ab peptides is central to AD pathobiology. Though highly variable in terms of age of symptom onset (AAO), hundreds of pathogenic variants in Presenilin‐1 (PSEN1) cause autosomal dominant forms of AD (ADAD). PSEN1 forms the catalytic core of the γ‐secretase complex and thereby directly mediates the production of longer, aggregation‐prone Aβ peptides relative to shorter, non‐aggregating peptides. We hypothesized that the broad AAO and biomarker heterogeneity seen across ADAD would be predictable based on mutation‐specific differences in γ‐secretase function, as measured by a ratio of production of shorter vs. longer Aβ species. Methods: Aβ‐37, 38, 40, 42, and 43 production was quantified from 162 unique PSEN1 variants expressed in HEK293 cells engineered to lack endogenous wild‐type PSEN1/2 (Figure 1). Prediction of AAO was carried out in 107 PSEN1 variants (characterized by Liu et al, 2022) and then replicated with a set 55 unique PSEN1 variants represented in the Dominantly Inherited Alzheimer Network (DIAN; n = 190 corresponding variant carriers with detailed cognitive and biomarker data; Figure 2). Results: Mutation‐level variations in Aβ production, including a novel composite representing γ‐secretase function (lower score = less g‐processivity), from the cellular model were highly predictive of actual AAO across the 162 mutants examined (Non‐DIAN variants [N = 107]: r = 0.71, p <2.2e‐16; DIAN variants [N = 55]: r = 0.61, p = 6.10e‐07). Our cell‐based γ‐secretase function composite was strongly associated with cerebral PiB‐PET β‐amyloid burden (B[SE] = ‐0.03[0.01], p = 4.06e‐07), MRI gray matter volume (B[SE] = 44.22[6.4], p = 5.15e‐01), cerebrospinal fluid Aβ42/40 (B[SE] = 6.3e‐04[1.5e‐04], p = 4.46e‐05) and phosphorylated tau‐217 (B[SE] = ‐0.01[0.002], p = 1.98e‐05), Clinical Dementia Rating®‐ Sum of Boxes (B[SE] = ‐0.07[0.02], p = 4.86e‐05), and Mini‐Mental State Exam (B[SE] = 0.11[.03], p = 2.17e‐04). Conclusions: Biochemical variations in γ‐secretase function across PSEN1 pathogenic variants broadly predicted the cross‐sectional clinical, cognitive, and biomarker course of ADAD, including AAO. These findings elucidate the critical link between γ‐secretase function, Aβ production, and severity of AD. The novel approach designed here also represents a tool to account for heterogeneity in ADAD clinical trials and to assess the pathogenicity of PSEN1 variants of unknown significance or with limited family history. [ABSTRACT FROM AUTHOR]

Background: A recently recognized subset of older individuals are an anomaly of cognitive decline; the "SuperAgers", unsurprisingly named, achieve cognitive scores equivalent to much younger cognitively normal (CN) middle‐aged adults. Using longitudinal cognitive data harmonized across eight cohorts of aging and Alzheimer's Dementia (AD), we investigated the genetic drivers of SuperAging. Method: Harmonized memory, executive function, and language scores were estimated leveraging latent variable modeling and made available through the ADSP Phenotype Harmonization Consortium. SuperAgers (N = 1,095) were defined as individuals over 80 years with a mean sex‐adjusted memory score equal or exceeding CN individuals aged 50‐60, score within one age and sex‐adjusted standard deviation in the other two cognitive domains, and remain CN for all longitudinal visits. Young Cases (N = 1,906) were defined as individuals aged 50‐75 with a clinical diagnosis of AD. Old Controls (N = 3,247) were defined as CN individuals over 80, scoring within one age‐ and sex‐adjusted standard deviation in all three domains. We performed a GWAS on non‐Hispanic Whites using logistic regression comparing SuperAgers and their counterparts (Young Cases and Old Controls) with covaried adjustment for age, sex, education, and principal components for population substructure. Result: Comparing SuperAgers with Young Cases (Figure 1), only variants in the well‐established APOE region were associated with genome‐wide significance (GWAS; P<510−8). Additionally, we observed a locus on chromosome 13 approach GWS (rs138699163, P = 6.5610−8). The locus centered on a relatively uncharacterized ncRNA, MIR4500. Analyses comparing SuperAgers to Old Controls did not find any GWS associations, with the strongest association observed at rs116535931 on chromosome 5 (P = 1.5210−6). Conclusion: Our extreme‐phenotype GWAS comparing SuperAgers to Young Cases identified established and novel loci for AD. However, larger sample sizes may allow better characterization of the genetic architecture of SuperAging. Future analyses will extend to Case comparison groups to include Old Cases (age>80 years) and All Cases (age>50 years) and Control comparison groups to include Young Controls (age between 50‐60) and Agnostic Controls (age>50 years) with similar criteria. [ABSTRACT FROM AUTHOR]

Introduction: As Alzheimer's disease (AD) biomarkers rapidly develop, tools are needed that accurately and effectively communicate risk of AD dementia. Methods: We analyzed longitudinal data from >10,000 cognitively unimpaired older adults. Five‐year risk of AD dementia was modeled using survival analysis. Results: A demographic model was developed and validated on independent data with area under the receiver operating characteristic curve (AUC) for 5‐year prediction of AD dementia of 0.79. Clinical and cognitive variables (AUC = 0.79), and apolipoprotein E genotype (AUC = 0.76) were added to the demographic model. We then incorporated the risk computed from the demographic model with hazard ratios computed from independent data for amyloid positron emission tomography status and magnetic resonance imaging hippocampal volume (AUC = 0.84), and for plasma amyloid beta (Aβ)42/Aβ40 (AUC = 0.82). Discussion: An adaptive tool was developed and validated to compute absolute risks of AD dementia. This approach allows for improved accuracy and communication of AD risk among cognitively unimpaired older adults. [ABSTRACT FROM AUTHOR]

A crucial aspect of any clinical trial is using the right outcome measure to assess treatment efficacy. Compared to the rapidly evolved understanding and measurement of pathophysiology in preclinical and early symptomatic stages of Alzheimer's disease (AD), relatively less progress has been made in the evolution of clinical outcome assessments (COAs) for those stages. The current paper aims to provide a benchmark for the design and evaluation of COAs for use in early AD trials. We discuss lessons learned on capturing cognitive changes in predementia stages of AD, including challenges when validating novel COAs for those early stages and necessary evidence for their implementation in clinical trials. Moving forward, we propose a multi‐step framework to advance the use of more effective COAs to assess clinically meaningful changes in early AD, which will hopefully contribute to the much‐needed consensus around more appropriate outcome measures to assess clinical efficacy of putative treatments. Highlights: We discuss lessons learned on capturing cognitive changes in predementia stages of AD.We propose a framework for the design and evaluation of performance based cognitive tests for use in early AD trials.We provide recommendations to facilitate the implementation of more effective cognitive outcome measures in AD trials. [ABSTRACT FROM AUTHOR]

Background: Traditional pen‐and‐paper neuropsychological assessments fail to capture subtle cognitive changes in the early stages of Alzheimer's disease (AD). Remote and unsupervised digital assessments available on smartphones, tablets, and personal computers may offer a solution to this by increasing the amount and types of data available to researchers and clinicians, while simultaneously improving ecological validity and alleviating patient burden. As these remote and unsupervised digital cognitive assessment tools become more widely available, it is important that they are validated in a systematic way. In this review, we evaluate the validity of available remote tools, focusing on active assessment tools with which the patient interacts with (i.e., cognitive tests, active speech) that have been used to investigate subtle cognitive differences in preclinical AD, defined as clinically unimpaired individuals with biomarkers indicating increased risk of dementia due to AD. Methods: We performed a systematic literature review on PubMed, Web of Science, and PsycInfo using terms such as "digital," "remote," "unsupervised," "cognition," "aging," and "Alzheimer's," which resulted in a total of 1,453 unique peer‐reviewed articles and pre‐prints. After filtering for tools that were remotely self‐administered in humans, and excluding papers detailing findings in populations with other diseases than AD (e.g., multiple sclerosis, Parkinson's disease) or papers reporting findings of intervention studies, 14 papers reporting the use or planned use of 14 tools to detect AD pathology in preclinical AD were selected (as of Jan. 2024). Results: We evaluate each tool with regards to its use‐case and usability, as well as various types of validity, and suggest a framework with which future tools may also be evaluated. Additionally, we discuss current directions in the field of remote and unsupervised digital cognitive assessment in early AD. Conclusion: With this review, we hope to show that the systematic and validated use of such tools will increase our understanding of subtle changes in cognition due to AD pathology, as well as make screening for clinical trials and treatment more accessible. [ABSTRACT FROM AUTHOR]

Background: Variants in the apolipoprotein E (APOE) gene represent the greatest genetic risk factor for Alzheimer disease (AD). Carriers of the ε4 allele have an increased risk of developing AD pathology and a lower age of symptom onset. While prior work has focused on the sporadic form of AD, little is known about how the ε4 allele impacts AD‐specific pathology in autosomal dominant AD (ADAD). Method: 430 participants from the Charles and Joanne F. Knight Alzheimer Disease Research Center and 276 ADAD mutation‐carriers from the Dominantly Inherited Alzheimer Network, were included in these analyses. Participants were classified as ε4‐positive or ‐negative, and further grouped using Clinical Dementia Rating® (CDR®) scores as cognitively impaired or –unimpaired (Table 1). All participants completed magnetic resonance imaging (MRI), beta‐amyloid positron emission tomography (Ab‐PET), and cognitive testing within a 12‐month period. Result: Using regression models, we replicated prior work demonstrating that the ε4 allele is associated with an increase in AD pathology measured by Ab‐PET and MRI in a sporadic AD cohort. Furthermore, the ε4 allele was also associated with a decline in cognitive performance. Follow‐up pairwise comparisons revealed that within the sporadic‐AD cohort, the influence of the ε4 allele was most pronounced in individuals who were cognitively impaired. In contrast, in a cohort of individuals possessing autosomal dominant mutations, the ε4 allele was not associated with increases in pathology measured by Ab‐PET and MRI, nor was it associated with a decrease in cognition (Table 1; Figure 1). Conclusion: We present quantitative evidence that the APOE‐ ε4 allele differentially impacts the pathology and cognitive outcomes of sporadic‐ and autosomal dominant AD. In those with sporadic AD, possession of at least one copy of the ε4 allele is associated with increased amyloid deposition and cortical thinning, as well as decreased cognition, particularly in individuals who are cognitively impaired. However, in ADAD mutation‐carriers, these same patterns are not evident. We propose that this is due to the overwhelming influence of the autosomal dominant genetic mutations that drive this unique and rare form of AD. [ABSTRACT FROM AUTHOR]

Background: White matter (WM) injury visible on MRI is a common finding in Alzheimer's disease (AD) and is often attributed to small vessel ischemic changes secondary to increased systemic vascular risk. Increased WM injury has been associated with the progression of Autosomal Dominant AD (ADAD), though ADAD pathogenic variant carriers are relatively young and may not have elevated vascular risk factors. We hypothesized that WM injury in ADAD may reflect worsening of cerebral amyloid angiopathy (CAA) and neurodegeneration. Here we examine this hypothesis using cross‐sectional and longitudinal data from the Dominantly Inherited Alzheimer Network observational study (DIAN). Method: MRI data from ADAD pathogenic variant carriers (n=223) and non‐carriers (n=136) were used in the present study (Table 1). We extracted FreeSurfer‐based WM lesion (WML) volume from T1‐weighted images (hypointensities). Cortical microbleed (CMB) burden was assessed visually on susceptibility weighted/T2*‐weighted gradient echo images by experienced radiologists (blineded to the mutation status) at the Mayo Clinic in Rochester. Linear regression models compared WML volume at baseline in people with and without CMB. Linear mixed effect models assessed the relationships between longitudinal WML and both CMBs and FreeSurfer‐based total gray matter (GM) volume. Models were corrected for age and estimated years to symptom onset (EYO). Result: Greater baseline WML volume was seen in ADAD carriers vs. non‐carriers, particularly close to the age of estimated symptom onset. Baseline WML volume was greater in carriers with CMBs compared to those without (t=2.9, p=0.003, Figure 1). Longitudinal increase in WML amongst ADAD pathogenic variant carriers with CMBs was estimated to be 214 mm3/year greater than that amongst carriers without CMBs (t=4.1, p<0.001, Figure 2). Independent of this CMB effect, decreasing GM volume was strongly associated with increasing longitudinal WML volume (t=‐6.2, p<0.001, Figure 3). Similar analyses in the non‐carrier group yielded no significant findings. Conclusion: Consistent with prior reports, WML volume was increased in ADAD pathogenic variant carriers. However, the results here suggest WML in ADAD may not solely be due to small vessel ischemic changes, but rather may be a result of worsening CAA and more rapid neurodegeneration. [ABSTRACT FROM AUTHOR]