Alzheimer Disease & Associated Disorders最新文献

Purpose: Lucid episodes (LEs: unexpected episodes of spontaneous, meaningful, and relevant communication or behavior) in Alzheimer disease and related dementias are a new area of scientific inquiry that lacks clinical consensus and require more conceptual attention.

Methods: We aimed to measure consensus from an expert group on: (1) potential medical or clinical explanations for LEs; (2) necessary medical and clinical context to LEs; and (3) interpretation of LEs.

Patients: We convened 13 experts from different disciplines (neurology, psychiatry, psychology, pharmacy, palliative care, hospice, nursing, social work, primary care, geriatrics, and professional home caregivers) to identify elements of LEs.

Results: Experts provided a range of opinions on medical and clinical explanations and questions to understand LEs. Consensus on LEs when presented with clinical vignettes was not reached. Panelists highlighted key medical and contextual factors needed to make a definitive judgement about LEs.

Conclusion: There is variability in how LEs are interpreted by clinical experts, which complicates the identification of LEs in Alzheimer disease and related dementias.

We examined whether there were differences in the presence of centrum semiovale-enlarged perivascular spaces (CSO-ePVS) and basal ganglia-ePVS (BG-ePVS) among patients with Alzheimer disease-related cognitive impairment (ADCI) based on their age of onset. Out of a total of 239 patients with cognitive impairment, 155 with positive amyloid-PET results were included. Among these, 43 had early-onset ADCI (EOADCI) and 112 had late-onset ADCI (LOADCI). Patients with LOADCI exhibited a higher prevalence of hypertension, lacunes, white matter hyperintensities, and BG-ePVS than those with EOADCI. BG-ePVS showed a significant correlation with age at the onset and the number of lacunes, whereas CSO-ePVS did not exhibit any association. The higher prevalence of BG-ePVS in patients with LOADCI might be attributable to vascular risk factors (hypertension) and cerebral small vessel disease (CSVD). These findings support the hypothesis that BG-ePVS is associated with CSVD and vascular risk factors, whereas CSO-ePVS is associated with cerebral amyloid angiopathy.

Purpose: Individuals with behavioral-variant frontotemporal dementia (bvFTD) show changes in brain structure as assessed by MRI and brain function assessed by 18FDG-PET hypometabolism. However, current understanding of the spatial and temporal interplay between these measures remains limited.

Methods: Here, we examined longitudinal atrophy and hypometabolism relationships in 15 bvFTD subjects with 2 to 4 follow-up MRI and PET scans (56 visits total). Subject-specific slopes of atrophy and hypometabolism over time were extracted across brain regions and correlated with baseline measures both locally, via Pearson correlations, and nonlocally, via sparse canonical correlation analyses (SCCA).

Results: Notably, we identified a robust link between initial hypometabolism and subsequent cortical atrophy rate changes in bvFTD subjects. Network-level exploration unveiled alignment between baseline hypometabolism and ensuing atrophy rates in the dorsal attention, language, and default mode networks. SCCA identified 2 significant and highly localized components depicting the connection between baseline hypometabolism and atrophy slope over time. The first centered around bilateral orbitofrontal, frontopolar, and medial prefrontal lobes, whereas the second concentrated in the left temporal lobe and precuneus.

Conclusions: This study highlights 18FDG-PET as a dependable predictor of forthcoming atrophy in spatially adjacent brain regions for individuals with bvFTD.

Introduction: Early classification and prediction of Alzheimer disease (AD) and amnestic mild cognitive impairment (aMCI) with noninvasive approaches is a long-standing challenge. This challenge is further exacerbated by the sparsity of data needed for modeling. Deep learning methods offer a novel method to help address these challenging multiclass classification and prediction problems.

Methods: We analyzed 3 target feature-sets from the National Alzheimer Coordinating Center (NACC) dataset: (1) neuropsychological (cognitive) data; (2) patient health history data; and (3) the combination of both sets. We used a masked Transformer-encoder without further feature selection to classify the samples on cognitive status (no cognitive impairment, aMCI, AD)-dynamically ignoring unavailable features. We then fine-tuned the model to predict the participants' future diagnosis in 1 to 3 years. We analyzed the sensitivity of the model to input features via Feature Permutation Importance.

Results: We demonstrated (1) the masked Transformer-encoder was able to perform prediction with sparse input data; (2) high multiclass current cognitive status classification accuracy (87% control, 79% aMCI, 89% AD); (3) acceptable results for 1- to 3-year multiclass future cognitive status prediction (83% control, 77% aMCI, 91% AD).

Conclusion: The flexibility of our methods in handling inconsistent data provides a new venue for the analysis of cognitive status data.

Background: Allostatic load (AL) has been studied in the context of biomarkers that may be affected by environmental and contextual stressors, including social determinants of health. The specific stressor studied here is the provision of caregiving to older persons with Alzheimer disease and related disorders. The aims were to examine the factor structure of stress and nonstress biomarkers, different methods for calculating AL, and the relationship of AL with other variables.

Methods: Latent variable models were used to examine biomarkers. Regression analyses were performed with the outcomes: AL calculated as percentile-based and clinically-based for both stress and nonstress components. The sample was 187 Hispanic caregivers to individuals with dementia.

Results: The results of the confirmatory factor analyses (CFAs) suggested defining 2 factors: nonstress and stress-related. Performance was better for the CFA results and the associations with covariates when stress and nonstress components were examined separately. Despite some limitations, this is one of the first studies of biomarkers in Hispanic caregivers to patients with dementia. It was possible to explain almost 30% of the variance in the nonstress AL component.

Conclusion: It may be important to differentiate among biomarkers indicative of cardiovascular, metabolic, and immune response as contrasted with the more stress-related biomarkers.

Several studies have suggested that white matter hyperintensity volume (WMHV) is increased among apolipoprotein E (APOE) ε4 carriers while others have reported contradictory findings. Although APOE ε4 carriage is associated with greater AD pathology, it remains unclear whether cerebrovascular damage is also associated with APOE ε4 carriage. The aim of this meta-analysis was to determine whether WMHV is associated with APOE ε4 carrier status. 12 studies that were included yielded a total sample size of 16,738 adult subjects (ε4 carrier n = 4,721; ε4 noncarrier n = 12,017). There were no significant differences in WMHV between ε4 carriers and noncarriers (Hedge's g = 0.07; 95% CI (-0.01 to 0.15), P = 0.09). Subgroup analysis of community-based studies (n = 8) indicated a small effect size where ε4 carriers had greater WMHV relative to noncarriers (Hedge's g = 0.09 95% CI (0.02 to 0.16), P = 0.008). Among clinic-based studies (n = 3) there was no significant difference in WMHV by APOE ε4 carrier status (Hedge's g = -0.09, 95% CI (-0.60 to 0.41), P = 0.70). Observed APOE ε4-associated WMHV differences may be context-dependent and may also be confounded by a lack of standardization for WMHV segmentation.

Purpose: The overall goal of this review was to identify what is known about triadic (clinician-patient-caregiver) communication in mild cognitive impairment (MCI) and dementia care settings throughout the care continuum.

Methods: Using a structured search, we conducted a systematic scoping review of relevant published journal articles across 5 databases. Study titles/abstracts and selected full-text articles were screened by 2 investigators in Covidence systematic review software. Articles were excluded if they were not about clinical communication, focused only on caregiver-patient communication or communication in residential care, were interventional, lacked empirical data, or were not in English. Extracted data were documented using Google Forms.

Results: The study team screened 3426 article titles and abstracts and 112 full-text articles. Forty-four articles were included in the final review. Results were categorized by 3 communication scenarios: diagnostic communication (n=22), general communication (n=16), and advanced care planning communication (n=6).

Conclusions and relevance: Across the included articles, the conceptualization and assessment of communication lacked homogeneity. Future directions include addressing these research gaps, establishing recommendations for clinicians to effectively communicate with individuals with dementia and caregivers, and creating and testing communication skills trainings for caregivers/family members, clinicians, and/or individuals with dementia to facilitate effective communication.

Introduction: Traumatic brain injury (TBI) is associated with an accelerated course of dementia, although biological relationships are incompletely understood.

Methods: The study examined 1124 participants, including 343 with Alzheimer disease (AD), 127 with AD with TBI, 266 cognitively normal adults with TBI, and 388 cognitively normal adults without TBI. Cortical thickness was quantified from T1-weighted magnetic resonance imaging data. Multiple linear regression was used to determine the interaction between AD and TBI on cortical thickness.

Results: Among those with AD, TBI was associated with an earlier age of AD onset but, counterintuitively, less cortical thinning in frontotemporal regions relative to non-AD controls.

Discussion: AD with TBI represents a distinct group from AD, likely with distinct pathologic contributions beyond gray matter loss. This finding has important implications for the diagnosis and treatment of AD in the presence of TBI and indicates that models of AD, aging, and neural loss should account for TBI history.

Objective: This study assessed older adults' preferences for how to communicate dementia risk information to maximize motivation for behavior change.

Method: Eighty-nine community-dwelling older adults (aged 61 to 92 years, M=72.93, SD=6.36, 76% women) received dementia risk factor information in 2 formats: "traffic lights" (green=risk absent, amber=risk emerging, and red=risk present) or red/risk-only. Participants reported motivation to change risk-related behaviors, motivation to maintain good health behaviors, liking of the formats, categorical preference for traffic lights versus risk-only formats, reasons for preferences (open-ended), total applicable risks, and Motivation to Change Lifestyle and Health Behaviour for Dementia Risk Reduction.

Results: Traffic lights presentation was more motivating ( Z =4.16, P <0.001), more liked ( Z =4.80, P <0.001), and preferred, N Traffic =71, N Red =14, χ 2 (1)=38.22, P <0.001, over risk-only. Self-efficacy and motivation to maintain good health behaviors were significant unique predictors of motivation to change risk-related behaviors following traffic lights presentation over age, sex, education, total applicable risks, perceived susceptibility, cues to action, and liking of the traffic lights presentation format. Themes indicated (1) traffic light presentation is informative and clear, and (2) green-light information increases self-efficacy.

Conclusions: Traffic light presentation increases patient motivation to reduce dementia risk. Green-light information increases self-efficacy. Maximizing motivation through information presentation can decrease dementia prevalence.

Objective: We examined how cognitive complaint types (CCTs) correlate with cognitive testing, perceived stress, and symptom distress in older adults with normal cognition and dementia.

Methods: Older adults (n = 259) with normal cognition, mild cognitive impairment, or mild-stage Alzheimer disease completed cognitive testing and self-report measures (Cognitive Difficulties Scale, Global Distress Index, Perceived Stress Scale). Cross-sectional analyses examined: (1) CCT composition by classification method,( 2) CCTs by diagnostic group, (3) correlations of CCTs with cognitive testing scores, and (4) correlations of CCTs with perceived stress and symptom distress.

Results: CCTs derived from 2 classification approaches loaded onto 4 factors: memory, attention-concentration (AC), temporal orientation, and praxis. Memory contained complaints about both memory and executive functioning. AC contained both classifications of AC complaints. Complaints about AC (AC1 and AC2) differed by diagnostic group (all P < 0.05). One of 2 classifications of AC (AC1) complaints discerned between impaired and unimpaired long-delay memory scores (both P < 0.05). In multivariable analyses, that same classification of AC (AC1) complaints correlated with higher perceived stress (both P < 0.001) but not symptom distress (both P > 0.05).

Conclusion: CCTs showed a factor structure that was mostly robust between classification methods; however, some content-divergent CCTs shared factors, suggesting construct overlap. Relatively slight variations in content altered how CCTs correlated with diagnostic groups, perceived stress, and symptom distress. Most CCTs did not discern between impaired and unimpaired cognitive test scores. Research is needed to better understand CCTs as clinical markers and targets of clinical interventions.