Data-driven classification of cognitively normal and mild cognitive impairment subtypes predicts progression in the NACC dataset

INTRODUCTION

Data-driven neuropsychological methods can identify mild cognitive impairment (MCI) subtypes with stronger associations to dementia risk factors than conventional diagnostic methods.

METHODS

Cluster analysis used neuropsychological data from participants without dementia (mean age = 71.6 years) in the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (n = 26,255) and the "normal cognition" subsample (n = 16,005). Survival analyses examined MCI or dementia progression.

RESULTS

Five clusters were identified: "Optimal" cognitively normal (oCN; 13.2%), "Typical" CN (tCN; 28.0%), Amnestic MCI (aMCI; 25.3%), Mixed MCI-Mild (mMCI-Mild; 20.4%), and Mixed MCI-Severe (mMCI-Severe; 13.0%). Progression to dementia differed across clusters (oCN < tCN < aMCI < mMCI-Mild < mMCI-Severe). Cluster analysis identified more MCI cases than consensus diagnosis. In the "normal cognition" subsample, five clusters emerged: High-All Domains (High-All; 16.7%), Low-Attention/Working Memory (Low-WM; 22.1%), Low-Memory (36.3%), Amnestic MCI (16.7%), and Non-amnestic MCI (naMCI; 8.3%), with differing progression rates (High-All < Low-WM = Low-Memory < aMCI < naMCI).

DISCUSSION

Our data-driven methods outperformed consensus diagnosis by providing more precise information about progression risk and revealing heterogeneity in cognition and progression risk within the NACC "normal cognition" group.

Normative data for the Digit Symbol Substitution for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA)

INTRODUCTION

Executive functioning and processing speed are crucial elements of neuropsychological assessment. To meet the needs of the Hispanic/Latino population, we aimed to provide normative data for the Digit Symbol Substitution (DSS) test.

METHODS

The target population for the Study of Latinos-Investigation of Neurocognitive Aging included six heritage backgrounds (n = 6177). Average age was 63.4 ± 8.3 years, 54.5% were female, and mean education was 11.0 ± 4.7 years. Participants were administered the DSS as part of a larger battery. Heritage-adjusted DSS scores, and percentile cut-points were created using survey-adjusted regression and quantile regression models.

RESULTS

Age, education, sex, heritage, and language preference were associated with DSS scores.

DISCUSSION

Significant correlates of DSS performance should be considered when evaluating cognitive performance. Representative DSS norms for Hispanics/Latinos will advance assessment and accuracy of neurocognitive disorder diagnosis in clinical practice. To facilitate interpretation, we provide norms to reduce test biases and developed an online dashboard.

Highlights

Normative data for the Digit Symbol Substitution (DSS) for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) This study is the first to develop norms for the DSS test across four regions of the United States.Factors such as age, education, sex, and Hispanic/Latino heritage and language preference are associated with differences in executive functioning and information processing speed.We created norms and an online dashboard (https://solincalab.shinyapps.io/dsst_shiny/) providing an easily accessible tool to evaluate processing speed and executive functioning in Hispanic/Latino adults.

Disruption of the serial position effect as an early marker of Alzheimer's disease in Spanish-English bilinguals

OBJECTIVES

The present study examined if disruption of serial position effects in list recall could serve as an early marker of Alzheimer's disease (AD) in Spanish-English bilinguals.

METHODS

We tested 20 participants initially diagnosed as cognitively normal or with mild cognitive impairment who declined and eventually received a diagnosis of AD (decliners), and 37 who remained cognitively stable (controls) over at least 2 years. Participants were tested on the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning Test in English or Spanish as part of an annual neuropsychological evaluation.

RESULTS

Compared to controls, decliners exhibited significantly reduced recall including reduced primacy scores (i.e., items recalled from the first three list items on Trial 1), whereas recency scores (i.e., items recalled from the last 3 list items on Trial 1) were equivalent in decliners and controls. Further analyses suggested that the sensitivity of the primacy effect to preclinical AD was initially stronger in participants tested in Spanish, a surprising finding given that the CERAD was developed for English speakers. However, in the subsequent year of testing, primacy scores declined to the same level regardless of language of testing.

CONCLUSIONS

Several list learning measures may facilitate early diagnosis of AD in Spanish-English bilinguals, possibly including the relatively understudied primacy effect. Additional studies are needed to investigate the possibility that linguistic or demographic variables might modulate sensitivity of list learning tests to preclinical AD, which could lead to broader improvements in their utility for early diagnosis of AD in all populations.

The MINT Sprint 2.0: A picture naming test for detection of naming impairments in Alzheimer's disease and in preclinical AD

INTRODUCTION

Evidence on the onset of naming deficits in Alzheimer's disease (AD) is mixed. Some studies showed an early decline, but others did not. The present study introduces evidence from a novel naming test.

METHODS

Cognitively normal (n = 138), mild cognitive impairment (MCI; n = 21), and Alzheimer's disease (AD; n = 31) groups completed an expanded Multilingual Naming Test with a time-pressured administration procedure (MINT Sprint 2.0). Cerebrospinal fluid biomarkers classified participants as true controls (n = 61) or preclinical AD (n = 26).

RESULTS

Total correct MINT Sprint 2.0 scores exhibited good sensitivity and specificity (>0.85) for discriminating true controls from cognitively impaired (MCI/AD) groups and showed significant differences between true controls and preclinical AD groups. Time measurement did not improve classification, but percent resolved scores exhibited promise as an independent AD marker.

DISCUSSION

Naming deficits can be detected in the earliest stages of AD with tests and procedures designed for this purpose.

Autocorrection if→of function words in reading aloud: A novel marker of Alzheimer's risk

OBJECTIVE

The present study investigated cognitive mechanisms underlying the ability to stop "autocorrect" errors elicited by unexpected words in a read-aloud task, and the utility of autocorrection for predicting Alzheimer's disease (AD) biomarkers.

METHOD

Cognitively normal participants (total n = 85; n = 64 with cerebrospinal fluid [CSF] biomarkers) read aloud six short paragraphs in which 10 critical target words were replaced with autocorrect targets, for example, The player who scored that final [paint] for the local team reported [him] experience. Autocorrect targets either replaced the most expected/dominant completion (i.e., point) or a less expected/nondominant completion (i.e., basket), and within each paragraph half of the autocorrect targets were content words (e.g., point/paint) and half were function words (e.g., his/him). Participants were instructed to avoid autocorrecting.

RESULTS

Participants produced more autocorrect errors in paragraphs with dominant than with nondominant targets, and with function than with content targets. Cognitively normal participants with high CSF Tau/Aβ42 (i.e., an AD-like biomarker profile) produced more autocorrect total errors than those below the Tau/Aβ42 threshold, an effect also significant with dominant-function targets alone (e.g., saying his instead of him). A logistic regression model with dominant-function errors and age showed errors as the stronger predictor of biomarker status (sensitivity 83%; specificity 85%).

CONCLUSIONS

Difficulty stopping autocorrect errors is associated with biomarkers indicating preclinical AD, and reveals promise as a diagnostic tool. Greater vulnerability of function over content words to autocorrection in individuals with AD-like biomarkers implicates monitoring and attention (rather than semantic processing) in the earliest of cognitive changes associated with AD risk. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Comparison of the telephone-Montreal Cognitive Assessment (T-MoCA) and Telephone Interview for Cognitive Status (TICS) as screening tests for early Alzheimer's disease

INTRODUCTION

Remote screening for cognitive impairment associated with Alzheimer's disease (AD) has grown in importance with the expected rise in prevalence of AD in an aging population and with new potential treatment options.

METHODS

The Telephone Interview for Cognitive Status (TICS) and new telephone adaptation of the Montreal Cognitive Assessment (T-MoCA) were administered to participants independently classified through in-person clinical evaluation as cognitively normal (CN; n = 167), mild cognitive impairment (MCI; n = 25), or dementia (n = 23). Cerebrospinal fluid AD biomarkers were measured (n = 79).

RESULTS

TICS and T-MoCA were highly correlated (r = 0.787; P < 0.001): groups differed on both (CN

DISCUSSION

TICS and T-MoCA are effective for remotely detecting cognitive impairment associated with AD in older adults. Strong correlation between tests provides construct validity for the newer T-MoCA.

HIGHLIGHTS

Construct validity for the telephone adaptation of the Montreal Cognitive Assessment (T-MoCA) was newly established against the Telephone Interview for Cognitive Status (TICS). TICS and T-MoCA effectively detected cognitive impairment with remote administration. Both tests negatively correlated with a composite cerebrospinal fluid Alzheimer's disease (AD) biomarker (tau/amyloid beta 1-42).

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Key Words

• Alzheimer's disease
• cognition
• cognitive screening
• mild cognitive impairment
• remote cognitive assessment

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MESH Headings

• Humans
• Aged
• Alzheimer Disease/epidemiology
• Amyloid beta-Peptides
• Neuropsychological Tests
• Cognitive Dysfunction/epidemiology
• Mental Status and Dementia Tests
• Telephone
• Cognition
• Biomarkers

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Grants

• P30 AG062429 NIA NIH HHS
• R01 AG064002 NIA NIH HHS
• R01AG064002 NIH HHS
• P30-AG062429 NIH HHS

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Alzheimer's Disease Pathology in Middle Aged and Older People with HIV: Comparisons with Non-HIV Controls on a Healthy Aging and Alzheimer's Disease Trajectory and Relationships with Cognitive Function

We determined the prevalence of Alzheimer's disease (AD) pathological hallmarks, amyloid-β and phosphorylated-Tau, in autopsied brains of 49 people with HIV (PWH) (ages: 50-68; mean age = 57.0) from the National NeuroAIDS Tissue Consortium and in a comparative cohort of 55 people without HIV (PWoH) from the UC San Diego Alzheimer's Disease Research Center (17 controls, 14 mild cognitive impairment, 24 AD; ages: 70-102, mean age = 88.7). We examined how AD pathology relates to domain-specific cognitive functions in PWH overall and in sex-stratified samples. Amyloid-β and phosphorylated-Tau positivity (presence of pathology of any type/density) was determined via immunohistochemistry in AD-sensitive brain regions. Among PWH, amyloid-β positivity ranged from 19% (hippocampus) to 41% (frontal neocortex), and phosphorylated-Tau positivity ranged from 47% (entorhinal cortex) to 73% (transentorhinal cortex). Generally, AD pathology was significantly less prevalent, and less severe when present, in PWH versus PWoH regardless of cognitive status. Among PWH, positivity for AD pathology related most consistently to memory-related domains. Positivity for p-Tau pathology related to memory-related domains in women with HIV only, although the sample size of women with HIV was small (n = 10). Results indicate that AD pathology is present in a sizable portion of middle aged and older PWH, although not to the extent in older PWoH. Studies with better age-matched PWoH are needed to examine the effect of HIV status on AD pathology.

Which language is more affected in bilinguals with Alzheimer's disease? Diagnostic sensitivity of the Multilingual Naming Test

OBJECTIVE

This study examined the joint consequences of bilingualism and Alzheimer's disease (AD) for picture naming ability to determine which language is more affected by AD and what scoring methods best distinguish patients from controls.

METHOD

Sixty-five Spanish-English bilinguals including 26 with dementia and 39 controls with equivalent age, education, and bilingual proficiency level, were tested on the Multilingual Naming Test (Gollan et al., 2012).

RESULTS

Bilinguals with AD named fewer pictures than controls, and overall AD seemed to affect both languages about equally, but exploratory analyses suggested that this varied with item difficulty. In the dominant language difficult items exhibited a larger effect of AD than easy items (which were at ceiling for both patients and controls), whereas in the nondominant language items of all difficulty levels were about equally affected by AD. An "either-language" scoring procedure (that counted items as correct if produced only in one of the two languages) increased naming scores especially in balanced bilinguals, and to an equal extent in patients and controls. Receiver Operating Characteristic analyses revealed that dominant language and either-language naming scores classified bilinguals as patients versus controls equally well and adding nondominant language scores did not improve diagnostic sensitivity.

CONCLUSIONS

Testing primarily or exclusively in the dominant language is best for detecting AD naming impairments in bilinguals. However, AD affects the ability to access names in both languages, possibly for different reasons, and simple descriptions of language decline as "parallel" or "asymmetrical" (i.e., AD affecting one language more than the other) may be misleading in terms of the theoretical implications for bilingual language processing. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Optimal Weighting of Preclinical Alzheimer's Cognitive Composite (PACC) Scales to Improve their Performance as Outcome Measures for Alzheimer's Disease Clinical Trials

Introduction

Cognitive composite scales constructed by combining existing neuropsychometric tests are seeing wide application as endpoints for clinical trials and cohort studies of Alzheimer's disease (AD) predementia conditions. Preclinical Alzheimer's Cognitive Composite (PACC) scales are composite scores calculated as the sum of the component test scores weighted by the reciprocal of their standard deviations at the baseline visit. Reciprocal standard deviation is an arbitrary weighting in this context, and may be an inefficient utilization of the data contained in the component measures. Mathematically derived optimal composite weighting is a promising alternative.

Methods

Sample size projections using standard power calculation formulas were used to describe the relative performance of component measures and their composites when used as endpoints for clinical trials. Power calculations were informed by (n=1,333) amnestic mild cognitive impaired participants in the National Alzheimer's Coordinating Center (NACC) Uniform Data Set.

Results

A composite constructed using PACC reciprocal standard deviation weighting was both less sensitive to change than one of its component measures and less sensitive to change than its optimally weighted counterpart. In standard sample size calculations informed by NACC data, a clinical trial using the PACC weighting would require 38% more subjects than a composite calculated using optimal weighting.

Discussion

These findings illustrate how reciprocal standard deviation weighting can result in inefficient cognitive composites, and underscore the importance of component weights to the performance of composite scales. In the future, optimal weighting parameters informed by accumulating clinical trial data may improve the efficiency of clinical trials in AD.

Perception of Fragmented Letters by Patients With Pathologically Confirmed Dementia With Lewy Bodies or Alzheimer Disease

BACKGROUND AND OBJECTIVE

Patients with dementia with Lewy bodies perform worse than those with Alzheimer disease (AD) on tests of visual perception, but the clinical utility of these tests remains unknown because studies often had clinically diagnosed groups that may inadvertently cross-contaminate Lewy body disease (LBD) with pure AD pathology, used experimental tests not easily adaptable for clinical use, and had no way to examine relationships between the severity of LBD pathology and degree of cognitive impairment. Therefore, we sought to determine whether performance on a widely used clinical test of visuoperceptual ability effectively differentiates between patients with autopsy-confirmed LBD or AD and correlates with the severity of LBD pathology.

METHODS

Patients with mild to moderate dementia (n = 42) and cognitively healthy controls (n = 22) performed a Fragmented Letters Test in which they identified letters of the alphabet that were randomly visually degraded by 70% and additional visuospatial and episodic memory tests. At autopsy, dementia cases were confirmed to have LBD (n = 19), all with concomitant AD, or only AD (n = 23). Severity of α-synuclein pathology in the hippocampus and neocortex was rated on an ordinal scale.

RESULTS

Patients with LBD performed worse than those with AD (B = -2.80 ± 0.91, p = 0.009) and healthy controls (B = -3.34 ± 1.09, p = 0.01) on the Fragmented Letters Test after adjustment for age, sex, education, Mini-Mental State Examination score, and ability to name intact letters. Patients with AD did not differ from controls (B = -0.55 ± 1.08, p = 0.87). The test effectively distinguished between patients with LBD or AD with 73% sensitivity and 87% specificity, and the area under the curve in receiver operating characteristic analyses was 0.85 (95% CI 0.72-0.95), higher than for standard tests of visuospatial ability (Block Design; 0.72; CI 0.35-0.75) or memory (California Verbal Learning Test, trials 1-5; 0.55; CI 0.57-0.88). Fragmented Letters Test scores were negatively correlated with LBD pathology density ratings in hippocampus and neocortical regions (Spearman rs = -0.53 to -0.69).

DISCUSSION

Fragmented Letters Test performance can effectively differentiate patients with LBD pathology from those with only AD pathology at a mild to moderate stage of dementia, even when LBD occurs with significant concomitant AD pathology, and may also be useful for gauging the severity of cortical α-synuclein pathology in those with LBD.

TDP-43 Pathology Exacerbates Cognitive Decline in Primary Age-Related Tauopathy

OBJECTIVE

Primary age-related tauopathy (PART) refers to tau neurofibrillary tangles restricted largely to the medial temporal lobe in the absence of significant beta-amyloid plaques. PART has been associated with cognitive impairment, but contributions from concomitant limbic age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) are underappreciated.

METHODS

We compare prevalence of LATE-NC and vascular copathologies in age- and Braak-matched patients with PART (n = 45, Braak stage I-IV, Thal phase 0-2) or early stage Alzheimer disease neuropathologic change (ADNC; n = 51, Braak I-IV, Thal 3-5), and examine their influence on clinical and cognitive decline.

RESULTS

Concomitant LATE-NC and vascular pathology were equally common, and cognition was equally impaired, in PART (Mini-Mental State Examination [MMSE] = 24.8 ± 6.9) and ADNC (MMSE = 24.2 ± 6.0). Patients with LATE-NC were more impaired than those without LATE-NC on the MMSE (by 5.8 points, 95% confidence interval [CI] = 3.0-8.6), Mattis Dementia Rating Scale (DRS; 17.5 points, 95% CI = 7.1-27.9), Clinical Dementia Rating, sum of boxes scale (CDR-sob; 5.2 points, 95% CI = 2.1-8.2), memory composite (0.8 standard deviations [SD], 95% CI = 0.1-1.6), and language composite (1.1 SD, 95% CI = 0.2-2.0), and more likely to receive a dementia diagnosis (odds ratio = 4.8, 95% CI = 1.5-18.0). Those with vascular pathology performed worse than those without on the DRS (by 10.2 points, 95% CI = 0.1-20.3) and executive composite (1.3 SD, 95% CI = 0.3-2.3). Cognition declined similarly in PART and ADNC over the 5 years preceding death; however, LATE-NC was associated with more rapid decline on the MMSE (β = 1.9, 95% CI = 0.9-3.0), DRS (β = 7.8, 95% CI = 3.4-12.7), CDR-sob (β = 1.9, 95% CI = 0.4-3.7), language composite (β = 0.5 SD, 95% CI = 0.1-0.8), and vascular pathology with more rapid decline on the DRS (β = 5.2, 95% CI = 0.6-10.2).

INTERPRETATION

LATE-NC, and to a lesser extent vascular copathology, exacerbate cognitive impairment and decline in PART and early stage ADNC. ANN NEUROL 2022;92:425-438.

Source recognition discriminability impairment in Huntington's versus Alzheimer's disease: Evidence from the CVLT-3

Research suggests that individuals with Huntington's disease (HD) perform better than individuals with Alzheimer's disease (AD) on the California Verbal Learning Test (CVLT) Yes/No Recognition trial. However, those with HD have been shown to have deficits comparable to those with AD on the Source Recognition Discriminability (RD) index (which assesses the ability to distinguish between List A targets and List B distractors), suggesting that HD may involve selective impairment in aspects of yes/no recognition that rely on source memory. However, whether individuals with HD and AD show comparable deficits on Source RD across stages of dementia severity has not been adequately investigated. We examined performance on the CVLT-3 List A vs. List B RD index in individuals with HD or AD and mild or moderate dementia. Among individuals with mild dementia, scores were higher in the HD versus AD group, whereas among individuals with moderate dementia, scores were comparable between the HD and AD groups; this corresponded to differential performance across dementia stages among individuals with HD, but not AD. The present findings suggest that, relative to AD, HD may be associated with disproportionate decline in aspects of yes/no recognition that rely on source memory.

Plasma biomarkers for Alzheimer's Disease in relation to neuropathology and cognitive change

Plasma biomarkers related to amyloid, tau, and neurodegeneration (ATN) show great promise for identifying these pathological features of Alzheimer's Disease (AD) as shown by recent clinical studies and selected autopsy studies. We have evaluated ATN plasma biomarkers in a series of 312 well-characterized longitudinally followed research subjects with plasma available within 5 years or less before autopsy and examined these biomarkers in relation to a spectrum of AD and related pathologies. Plasma Aβ42, Aβ40, total Tau, P-tau181, P-tau231 and neurofilament light (NfL) were measured using Single molecule array (Simoa) assays. Neuropathological findings were assessed using standard research protocols. Comparing plasma biomarkers with pathology diagnoses and ratings, we found that P-tau181 (AUC = 0.856) and P-tau231 (AUC = 0.773) showed the strongest overall sensitivity and specificity for AD neuropathological change (ADNC). Plasma P-tau231 showed increases at earlier ADNC stages than other biomarkers. Plasma Aβ42/40 was decreased in relation to amyloid and AD pathology, with modest diagnostic accuracy (AUC = 0.601). NfL was increased in non-AD cases and in a subset of those with ADNC. Plasma biomarkers did not show changes in Lewy body disease (LBD), hippocampal sclerosis of aging (HS) or limbic-predominant age-related TDP-43 encephalopathy (LATE) unless ADNC was present. Higher levels of P-tau181, 231 and NfL predicted faster cognitive decline, as early as 10 years prior to autopsy, even among people with normal cognition or mild cognitive impairment. These results support plasma P-tau181 and 231 as diagnostic biomarkers related to ADNC that also can help to predict future cognitive decline, even in predementia stages. Although NfL was not consistently increased in plasma in AD and shows increases in several neurological disorders, it had utility to predict cognitive decline. Plasma Aβ42/40 as measured in this study was a relatively weak predictor of amyloid pathology, and different assay methods may be needed to improve on this. Additional plasma biomarkers are needed to detect the presence and impact of LBD and LATE pathology.

Association of Neurofibrillary Tangle Distribution With Age at Onset-Related Clinical Heterogeneity in Alzheimer Disease: An Autopsy Study

BACKGROUND AND OBJECTIVE

Patients with earlier age at onset of sporadic Alzheimer disease (AD) are more likely than those with later onset to present with atypical clinical and cognitive features. We sought to determine whether this age-related clinical and cognitive heterogeneity is mediated by different topographic distributions of tau-aggregate neurofibrillary tangles (NFTs) or by variable amounts of concomitant non-AD neuropathology.

METHODS

The relative distribution of NFT density in hippocampus and midfrontal neocortex was calculated, and α-synuclein, TAR DNA binding protein 43 (TDP-43), and microvascular copathologies were staged, in patients with severe AD and age at onset of 51-60 (n = 40), 61-70 (n = 41), and >70 (n = 40) years. Regression, mediation, and mixed effects models examined relationships of pathologic findings with clinical features and longitudinal cognitive decline.

RESULTS

Patients with later age at onset of AD were less likely to present with nonmemory complaints (odds ratio [OR] 0.46 per decade, 95% confidence interval [CI] 0.22-0.88), psychiatric symptoms (β = -0.66, 95% CI -1.15 to -0.17), and functional impairment (β = -1.25, 95% CI -2.34 to -0.16). TDP-43 (OR 2.00, 95% CI 1.23-3.35) and microvascular copathology (OR 2.02, 95% CI 1.24-3.40) were more common in later onset AD, and α-synuclein copathology was not related to age at onset. NFT density in midfrontal cortex (β = -0.51, 95% CI -0.72 to -0.31) and midfrontal/hippocampal NFT ratio (β = -0.18, 95% CI -0.26 to -0.10) were lower in those with later age at onset. Executive function (β = 0.48, 95% CI 0.09-0.90) and visuospatial cognitive deficits (β = 0.97, 95% CI 0.46-1.46) were less impaired in patients with later age at onset. Mediation analyses showed that the effect of age at onset on severity of executive function deficits was mediated by midfrontal/hippocampal NFT ratio (β = 0.21, 95% CI 0.08-0.38) and not by concomitant non-AD pathologies. Midfrontal/hippocampal NFT ratio also mediated an association between earlier age at onset and faster decline on tests of global cognition, executive function, and visuospatial abilities.

DISCUSSION

Worse executive dysfunction and faster cognitive decline in people with sporadic AD with earlier rather than later age at onset is mediated by greater relative midfrontal neocortical to hippocampal NFT burden and not by concomitant non-AD neuropathology.

Cognitive Heterogeneity and Risk of Progression in Data-Driven Subtle Cognitive Decline Phenotypes

BACKGROUND

There is increasing recognition of cognitive and pathological heterogeneity in early-stage Alzheimer's disease and other dementias. Data-driven approaches have demonstrated cognitive heterogeneity in those with mild cognitive impairment (MCI), but few studies have examined this heterogeneity and its association with progression to MCI/dementia in cognitively unimpaired (CU) older adults.

OBJECTIVE

We identified cluster-derived subgroups of CU participants based on comprehensive neuropsychological data and compared baseline characteristics and rates of progression to MCI/dementia or a Dementia Rating Scale (DRS) of ≤129 across subgroups.

METHODS

Hierarchical cluster analysis was conducted on individual baseline neuropsychological test scores from 365 CU participants in the UCSD Shiley-Marcos Alzheimer's Disease Research Center longitudinal cohort. Cox regressions examined the risk of progression to consensus diagnosis of MCI or dementia, or to DRS score ≤129, by cluster group.

RESULTS

Cluster analysis identified 5 groups: All-Average (n = 139), Low-Visuospatial (n = 46), Low-Executive (n = 51), Low-Memory/Language (n = 83), and Low-All Domains (n = 46). Subgroups had unique demographic and clinical characteristics. Rates of progression to MCI/dementia or to DRS ≤129 were faster for all subgroups (Low-All Domains progressed the fastest > Low Memory/Language≥Low-Visuospatial and Low-Executive) relative to the All-Average subgroup.

CONCLUSION

Faster progression in the Low-Visuospatial, Low-Executive, and Low-Memory/Language groups compared to the All-Average group suggests that there are multiple pathways and/or unique subtle cognitive decline profiles that ultimately lead to a diagnosis of MCI/dementia. Use of comprehensive neuropsychological test batteries that assess several domains may be a key first step toward an individualized approach to early detection and fewer missed opportunities for early intervention.

Impact of potential modifications to Alzheimer's disease clinical trials in response to disruption by COVID-19: a simulation study

BACKGROUND

The COVID-19 pandemic disrupted Alzheimer disease randomized clinical trials (RCTs), forcing investigators to make changes in the conduct of such trials while endeavoring to maintain their validity. Changing ongoing RCTs carries risks for biases and threats to validity. To understand the impact of exigent modifications due to COVID-19, we examined several scenarios in symptomatic and disease modification trials that could be made.

METHODS

We identified both symptomatic and disease modification Alzheimer disease RCTs as exemplars of those that would be affected by the pandemic and considered the types of changes that sponsors could make to each. We modeled three scenarios for each of the types of trials using existing datasets, adjusting enrollment, follow-ups, and dropouts to examine the potential effects COVID-19-related changes. Simulations were performed that accounted for completion and dropout patterns using linear mixed effects models, modeling time as continuous and categorical. The statistical power of the scenarios was determined.

RESULTS

Truncating both symptomatic and disease modification trials led to underpowered trials. By contrast, adapting the trials by extending the treatment period, temporarily stopping treatment, delaying outcomes assessments, and performing remote assessment allowed for increased statistical power nearly to the level originally planned.

DISCUSSION

These analyses support the idea that disrupted trials under common scenarios are better continued and extended even in the face of dropouts, treatment disruptions, missing outcomes, and other exigencies and that adaptations can be made that maintain the trials' validity. We suggest some adaptive methods to do this noting that some changes become under-powered to detect the original effect sizes and expected outcomes. These analyses provide insight to better plan trials that are resilient to unexpected changes to the medical, social, and political milieu.

Normative data for the Brief Spanish-English Verbal Learning Test for representative and diverse Hispanics/Latinos: Results from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

INTRODUCTION

Episodic learning and memory performance are crucial components of cognitive assessment. To meet the needs of a diverse Hispanic/Latino population, we aimed to provide normative data on the Brief Spanish-English Verbal Learning Test (B-SEVLT).

METHODS

The target population for the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) included individuals 45+ years old from Central American, Cuban, Dominican, Mexican, Puerto Rican, and South American backgrounds. Average age was 56.5 years ± 9.92, 54.5% were female, and mean education was 11.0 years ± 5.6 (unweighted n = 9309). Participants were administered the B-SEVLT in their preferred language (Spanish or English). Hispanic/Latino background adjusted B-SEVLT scores and percentile cut-points were created using survey-adjusted regression models.

RESULTS

Higher educational attainment, younger age, and being female were associated with higher learning and memory performance. Hispanic/Latino background groups differed in B-SEVLT performance.

DISCUSSION

Representative learning and memory norms for Hispanic/Latinos of diverse backgrounds will improve cognitive assessment and accuracy of neurocognitive disorder diagnosis.

Improving Detection of Amnestic Mild Cognitive Impairment with Sex-Specific Cognitive Norms

BackgroundDespite a female advantage in verbal memory, normative data for verbal memory tests used to diagnose Alzheimer's disease (AD) dementia and amnestic mild cognitive impairment (aMCI) often are not sex-adjusted.ObjectiveTo determine whether sex-adjusted norms improve aMCI diagnostic accuracy when accuracy was evaluated by progression to AD dementia over time.MethodsNon-sex-specific and sex-specific verbal memory test norms were incorporated into Jak/Bondi aMCI criteria and applied to older (age 65-90) non-demented women (N = 1,036) and men (N = 355) from the Rush Memory and Aging Project. Using sex-specific aMCI diagnosis as the "true" condition versus non-sex-specific aMCI diagnosis as the "predicted" condition, we identified True Positives, False Positives, True Negatives, and False Negatives and compared AD dementia risk over 10 years among groups.ResultsRates of aMCI were higher in men versus women (χ2 = 15.39, p < 0.001) when determined based on typical diagnostic criteria, but this difference reversed when using sex-specific diagnostic criteria (χ2 = 8.38, p = 0.004). We identified 8%of women as False Negatives and 12%of men as False Positives. Risk of incident AD dementia in False Positive men was significantly lower than in True Positive men (HR = 0.26, 95%CI = 0.12-0.58, p = 0.001). Risk of incident AD dementia in False Negative women was substantially higher than in True Negative women (HR = 3.11, 95%CI = 2.09-4.63, p < 0.001).ConclusionResults suggest that previous reports of higher aMCI rates in men versus women may be an artifact of non-sex-adjusted norms/cut-scores. Incorporation of sex-specific norms/cut-scores for verbal memory impairment into aMCI diagnostic criteria may improve diagnostic accuracy and avoid diagnostic errors in approximately 20%.

Data-Driven vs Consensus Diagnosis of MCI: Enhanced Sensitivity for Detection of Clinical, Biomarker, and Neuropathologic Outcomes

BACKGROUND AND OBJECTIVES

Given prior work demonstrating that mild cognitive impairment (MCI) can be empirically differentiated into meaningful cognitive subtypes, we applied actuarial methods to comprehensive neuropsychological data from the University of California San Diego Alzheimer's Disease Research Center (ADRC) in order to identify cognitive subgroups within ADRC participants without dementia and to examine cognitive, biomarker, and neuropathologic trajectories.

METHODS

Cluster analysis was performed on baseline neuropsychological data (n = 738; mean age 71.8). Survival analysis examined progression to dementia (mean follow-up 5.9 years). CSF Alzheimer disease (AD) biomarker status and neuropathologic findings at follow-up were examined in a subset with available data.

RESULTS

Five clusters were identified: optimal cognitively normal (CN; n = 130) with above-average cognition, typical CN (n = 204) with average cognition, nonamnestic MCI (naMCI; n = 104), amnestic MCI (aMCI; n = 216), and mixed MCI (mMCI; n = 84). Progression to dementia differed across MCI subtypes (mMCI > aMCI > naMCI), with the mMCI group demonstrating the highest rate of CSF biomarker positivity and AD pathology at autopsy. Actuarial methods classified 29.5% more of the sample with MCI and outperformed consensus diagnoses in capturing those who had abnormal biomarkers, progressed to dementia, or had AD pathology at autopsy.

DISCUSSION

We identified subtypes of MCI and CN with differing cognitive profiles, clinical outcomes, CSF AD biomarkers, and neuropathologic findings over more than 10 years of follow-up. Results demonstrate that actuarial methods produce reliable cognitive phenotypes, with data from a subset suggesting unique biological and neuropathologic signatures. Findings indicate that data-driven algorithms enhance diagnostic sensitivity relative to consensus diagnosis for identifying older adults at risk for cognitive decline.

Self-reported subjective cognitive decline is associated with global cognition in a community sample of Latinos/as/x living in the United States

INTRODUCTION

Although subjective cognitive decline (SCD) may be an early risk marker of Alzheimer's Disease (AD), research on SCD among Hispanics/Latinos/as/x (henceforth Latinos/as) living in the U.S. is lacking. We investigated if the cross-sectional relationship of self-reported SCD with objective cognition varies as a function of ethnic background (Latinos/as versus Non-Hispanic Whites [NHWs]). Secondary analyses conducted solely within the Latino/a group investigated if informant reported SCD is associated with objective cognition and whether self-reported SCD is related to markers of brain health in a sub-sample of Latinos/as with available MRI data.

METHODS

Eighty-three participants (≥60 years of age) without dementia (35 Latinos/as; 48 NHWs) completed the Mattis Dementia Rating Scale (MDRS) and the Subjective Cognitive Decline-Questionnaire (SCD-Q). Additionally, 22 Latino/a informants completed the informant-version of the SCD-Q. Hierarchical regression models investigated if ethnicity moderates the association of MDRS and SCD-Q scores after adjusting for demographics and depressive symptoms. Correlational analyses within the Latino/a group investigated self- and informant-reported associations of SCD-Q scores with objective cognition, and associations of self-reported SCD-Q scores with medial temporal lobe volume and thickness.

RESULTS

Latinos/as had lower education and MDRS scores than NHWs. Higher SCD-Q scores were associated with lower MDRS scores only in Latinos/as. Within the Latino/a group, self, but not informant reported SCD was related to objective cognition. Medium to large effect sizes were found whereby higher self-reported SCD was associated with lower entorhinal cortex thickness and left hippocampal volume in Latinos/as.

CONCLUSIONS

The association of SCD and concurrent objectively measured global cognition varied by ethnic background and was only significant in Latinos/as. Self-reported SCD may be an indicator of cognitive and brain health in Latinos/as without dementia, prompting clinicians to monitor cognition. Future studies should explore if SCD predicts objective cognitive decline in diverse groups of Latinos/as living in the U.S.

Arterial stiffening acts synergistically with APOE genotype and AD biomarker status to influence memory in older adults without dementia

BACKGROUND

Arterial stiffening has emerged as an important risk factor for Alzheimer's disease (AD) and related dementias. Carotid-femoral pulse wave velocity has been proposed as a non-invasive and reproducible method to assess arterial stiffness. However, the association of pulse wave velocity with performance across multiple cognitive domains as well as interactions with in vivo AD biomarkers and apolipoprotein E (APOE) genotype has received limited study.

METHOD

We studied 193 older adult volunteers (167 with normal cognition and 26 with mild cognitive impairment) who underwent comprehensive medical and neuropsychological evaluation at the University of California, San Diego Alzheimer's Disease Research Center. Cerebrospinal fluid (CSF) biomarkers were available on 123 participants (63%). Linear models examined whether pulse wave velocity significantly interacted with APOE ε4 status and CSF AD biomarker positivity (based on the ratio of total tau over beta-amyloid [tau/Aβ42]) on memory, language, executive functioning, attention, and visuospatial abilities.

RESULTS

After adjusting for demographic characteristics and vascular risk burden, across the entire sample, pulse wave velocity was associated with poorer executive functioning but not the performance in the other cognitive domains. When the modifying effects of AD genetic risk and CSF AD biomarkers were considered, pulse wave velocity interacted with APOE genotype and CSF tau/Aβ ratio such that a stronger association between elevated pulse wave velocity and poorer memory performance was found among those positive for CSF and genetic AD markers. There were no significant interaction effects for non-memory cognitive domains.

CONCLUSION

The findings suggest that pulse wave velocity, a non-invasive method to assess arterial wall properties, may be a useful marker of risk for cognitive decline, particularly among individuals who are APOE ε4 carriers or CSF AD biomarke0r-positive.

A survey of smartphone and interactive video technology use by participants in Alzheimer's disease research: Implications for remote cognitive assessment

INTRODUCTION

Participants from a longitudinal cohort study were surveyed to evaluate the practical feasibility of remote cognitive assessment.

METHODS

All active participants/informants at the University of California San Diego Alzheimer's Disease Research Center were invited to complete a nine-question survey assessing technology access/use and willingness to do cognitive testing remotely.

RESULTS

Three hundred sixty-nine of 450 potential participants/informants (82%) completed the survey. Overall, internet access (88%), device ownership (77%), and willingness to do cognitive testing remotely (72%) were high. Device access was higher among those with normal cognition (85%) or cognitive impairment (85%) than those with dementia (52%), as was willingness to do remote cognitive testing (84%, 74%, 39%, respectively). Latinos were less likely than non-Latinos to have internet or device access but were comparable in willingness to do remote testing.

DISCUSSION

Remote cognitive assessment using interactive video technology is a practicable option for nondemented participants in longitudinal studies; however, additional resources will be required to ensure representative participation of Latinos.

Age-at-Onset and APOE-Related Heterogeneity in Pathologically Confirmed Sporadic Alzheimer Disease

OBJECTIVE

To characterize age-related clinical heterogeneity in Alzheimer disease (AD) and determine whether it is modified by APOE genotype or concomitant non-AD pathology, we analyzed data from 1,750 patients with sporadic, pathologically confirmed severe AD.

METHODS

In this retrospective cohort study, regression and mixed effects models assessed effects of estimated age at onset, APOE genotype, and their interaction on standardized clinical, cognitive, and pathologic outcome measures from the National Alzheimer's Coordinating Center database.

RESULTS

A bimodal distribution of age at onset frequency in APOE ε4- cases showed best separation at age 63. Using this age cutoff, cases were grouped as ε4- early-onset AD (EOAD) (n = 169), ε4+ EOAD (n = 273), ε4- late-onset AD (LOAD) (n = 511), and ε4+ LOAD (n = 797). Patients with EOAD were more likely than patients with LOAD to present with noncognitive behavioral or motor symptoms or nonmemory cognitive complaints, and had more executive dysfunction, but less language impairment on objective cognitive testing. Age at onset and ε4- genotype were independently associated with lower baseline Mini-Mental State Examination scores and greater functional impairment and patients with EOAD had faster cognitive and functional decline than patients with LOAD regardless of APOE genotype. Patients with EOAD were more likely than patients with LOAD to receive a non-AD clinical diagnosis even though they were more likely to have pure AD without concomitant vascular or other non-AD neurodegenerative pathology.

CONCLUSIONS

Early-onset sporadic AD is associated with a greater likelihood of an atypical, non-memory-dominant clinical presentation, especially in the absence of the APOE ε4 allele, which may lead to misattribution to non-AD underlying pathology.

Cognition at Each Stage of Lewy Body Disease with Co-occurring Alzheimer's Disease Pathology

Background:

Alzheimer’s disease neuropathologic change (ADNC) may contribute to dementia in patients with Lewy body disease (LBD) pathology.

Objective:

To examine how co-occurring ADNC impacts domain specific cognitive impairments at each pathologic stage (brainstem, limbic, cerebral cortical) of LBD.

Methods:

2,433 participants with antemortem longitudinal neuropsychological assessment and postmortem neuropathological assessment from the National Alzheimer’s Coordinating Center’s Uniform Data Set were characterized based on the evaluation of ADNC and LBD. Longitudinal mixed-models were used to derive measures of cumulative cognitive deficit for each cognitive domain at each pathologic stage of LBD (brainstem, limbic, and cerebral cortical).

Results:

111 participants with a pathologic diagnosis of LBD, 741 participants with combined LBD and ADNC, 1,357 participants with ADNC only, and 224 with no pathology (healthy controls) were included in the analyses. In the executive/visuospatial domain, combined LBD and ADNC showed worse deficits than LBD only when Lewy bodies were confined to the brainstem, but no difference when Lewy bodies extended to the limbic or cerebral cortical regions. The cerebral cortical LBD only group exhibited greater executive/visuospatial deficits than the ADNC only group. By contrast, the ADNC only group and the combined pathology group both demonstrated significantly greater cumulative memory deficits relative to Lewy body disease only, regardless of stage.

Conclusion:

The impact of co-occurring ADNC on antemortem cumulative cognitive deficits varies not only by domain but also on the pathological stage of Lewy bodies. Our findings stress the cognitive impact of different patterns of neuropathological progression in Lewy body diseases.

Revisiting total recognition discriminability in Huntington's and Alzheimer's disease: New insights from the CVLT-3

The original and second editions of the California Verbal Learning Test (CVLT) used nonparametric and parametric methods, respectively, to assess Total Recognition Discriminability (RD). In a previous study, we found evidence that the nonparametric formula may be more sensitive than the parametric formula to high false positive (FP) rates and provide more accurate assessments of yes/no recognition in neurodegenerative populations prone to high FP rates, including Alzheimer's disease (AD). In the present study, we extended our investigation to examine the utility of CVLT-3 nonparametric and parametric Total RD indices in the assessment and comparison of yes/no recognition in individuals with Huntington's disease (HD) and AD in mild and moderate stages of dementia. Findings suggested that the CVLT-3 nonparametric Total RD index was more sensitive than the parametric index to HD and AD differences in yes/no recognition across mild and moderate stages of dementia. Additionally, group differences on total FP errors were more closely mirrored by group differences on the nonparametric Total RD index. The present results bolster our previous findings and highlight the utility of examining nonparametric (in addition to parametric) Total RD on the CVLT-3 in assessments of yes/no recognition involving clinical populations prone to high FP rates.

Event-related potential and EEG oscillatory predictors of verbal memory in mild cognitive impairment

Reliable biomarkers of memory decline are critical for the early detection of Alzheimer's disease. Previous work has found three EEG measures, namely the event-related brain potential P600, suppression of oscillatory activity in the alpha frequency range (∼10 Hz) and cross-frequency coupling between low theta/high delta and alpha/beta activity, each of which correlates strongly with verbal learning and memory abilities in healthy elderly and patients with mild cognitive impairment or prodromal Alzheimer's disease. In the present study, we address the question of whether event-related or oscillatory measures, or a combination thereof, best predict the decline of verbal memory in mild cognitive impairment and Alzheimer's disease. Single-trial correlation analyses show that despite a similarity in their time courses and sensitivities to word repetition, the P600 and the alpha suppression components are minimally correlated with each other on a trial-by-trial basis (generally |r _s| < 0.10). This suggests that they are unlikely to stem from the same neural mechanism. Furthermore, event-related brain potentials constructed from bandpass filtered (delta, theta, alpha, beta or gamma bands) single-trial data indicate that only delta band activity (1-4 Hz) is strongly correlated (r = 0.94, P < 0.001) with the canonical P600 repetition effect; event-related potentials in higher frequency bands are not. Importantly, stepwise multiple regression analyses reveal that the three event-related brain potential/oscillatory measures are complementary in predicting California Verbal Learning Test scores (overall R ^{2 '} s in 0.45-0.63 range). The present study highlights the importance of combining EEG event-related potential and oscillatory measures to better characterize the multiple mechanisms of memory failure in individuals with mild cognitive impairment or prodromal Alzheimer's disease.

Differentiating among stages of cognitive impairment in aging: Version 3 of the Uniform Data Set (UDS) neuropsychological test battery and MoCA index scores

INTRODUCTION

Federally funded Alzheimer's Disease Centers in the United States have been using a standardized neuropsychological test battery as part of the National Alzheimer's Coordinating Center Uniform Data Set (UDS) since 2005. Version 3 (V3) of the UDS replaced the previous version (V2) in 2015. We compared V2 and V3 neuropsychological tests with respect to their ability to distinguish among the Clinical Dementia Rating (CDR) global scores of 0, 0.5, and 1.

METHODS

First, we matched participants receiving V2 tests (V2 cohort) and V3 tests (V3 cohort) in their cognitive functions using tests common to both versions. Then, we compared receiver-operating characteristic (ROC) area under the curve in differentiating CDRs for the remaining tests.

RESULTS

Some V3 tests performed better than V2 tests in differentiating between CDR 0.5 and 0, but the improvement was limited to Caucasian participants.

DISCUSSION

Further efforts to improve the ability for early identification of cognitive decline among diverse racial groups are required.

Failure to stop autocorrect errors in reading aloud increases in aging especially with a positive biomarker for Alzheimer's disease

The present study examined the effects of aging and CSF biomarkers of Alzheimer's disease (AD) on the ability to control production of unexpected words in connected speech elicited by reading aloud. Fifty-two cognitively healthy participants aged 66-86 read aloud 6 paragraphs with 10 malapropisms including 5 on content words (e.g., "window cartons" that elicited autocorrect errors to "window curtains") and 5 on function words (e.g., "thus concept" that elicited autocorrections to "this concept") and completed a battery of neuropsychological tests including a standardized Stroop task. Reading aloud elicited more autocorrect errors on function than content words, but these were equally correlated with age and Aβ1-42 levels. The ability to stop autocorrect errors declined in aging and with lower (more AD-like) levels of Aβ1-42, and multiplicatively so, such that autocorrect errors were highest in the oldest-old with the lowest Aβ1-42 levels. Critically, aging effects were significant even when controlling statistically for Aβ1-42. Finally, both autocorrect and Stroop errors were correlated with Aβ1-42, but only autocorrect errors captured unique variance in predicting Aβ1-42 levels. Reading aloud requires simultaneous planning and monitoring of upcoming speech. These results suggest that healthy aging leads to decline in the ability to intermittently monitor for and detect conflict during speech planning and that subtle cognitive changes in preclinical AD magnify this aging deficit. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Development of a novel cognitive composite outcome to assess therapeutic effects of exercise in the EXERT trial for adults with MCI: The ADAS-Cog-Exec

INTRODUCTION

Use of cognitive composites as primary outcome measures is increasingly common in clinical trials of preclinical and prodromal Alzheimer's disease (AD). Composite outcomes can decrease intra-individual variability, resulting in improved sensitivity to detect longitudinal change and increased statistical power. We developed a novel composite outcome, the ADAS-Cog-Exec, for use in the EXERT trial-a Phase 3 randomized, controlled, 12-month exercise intervention in mild cognitive impairment (MCI).

METHODS

Three combinations of cognitive measures selected from the Alzheimer's Disease Assessment Scale-Cognitive Subscale version 13 (ADAS-Cog13), tests of executive function, and the Clinical Dementia Rating (CDR) were created based on previously documented sensitivity to longitudinal change in MCI and to the effects of exercise. Optimally weighted composites of each combination were modeled using data from the ADNI-1 MCI cohort. Ten-fold cross-validation was performed to obtain a bias-corrected mean to standard deviation ratio (MSDR). The cognitive composites were assessed for their sensitivity to detect 12-month change in MCI.

RESULTS

The MSDR of 12-month change for each of the composite outcomes tested exceeded that of the ADAS-Cog13 total score. The composite with the highest MSDR (MSDR = 0.48) and associated statistical power included scores on ADAS-Cog13 Word Recall, Delayed Word Recall, Orientation, and Number Cancellation subtests; Trail-Making Tests A & B, Digit Symbol Substitution and Category Fluency; and cognitive components of the CDR (Memory, Orientation, Judgement & Problem Solving).

DISCUSSION

An optimally weighted cognitive composite measure was identified and validated for use in EXERT. This composite contained selected subtests from the ADAS-Cog13, additional measures of executive function, and box scores for cognitive components of the CDR. Because this composite score demonstrated high sensitivity to longitudinal change in MCI it will be used as the primary outcome measure for the EXERT trial.

Association of anticholinergic medications and AD biomarkers with incidence of MCI among cognitively normal older adults

OBJECTIVE

To determine the cognitive consequences of anticholinergic medications (aCH) in cognitively normal older adults as well as interactive effects of genetic and CSF Alzheimer disease (AD) risk factors.

METHODS

A total of 688 cognitively normal participants from the Alzheimer's Disease Neuroimaging Initiative were evaluated (mean age 73.5 years, 49.6% female). Cox regression examined risk of progression to mild cognitive impairment (MCI) over a 10-year period and linear mixed effects models examined 3-year rates of decline in memory, executive function, and language as a function of aCH. Interactions with APOE ε4 genotype and CSF biomarker evidence of AD pathology were also assessed.

RESULTS

aCH+ participants had increased risk of progression to MCI (hazard ratio [HR] 1.47, p = 0.02), and there was a significant aCH × AD risk interaction such that aCH+/ε4+ individuals showed greater than 2-fold increased risk (HR 2.69, p < 0.001) for incident MCI relative to aCH-/ε4-), while aCH+/CSF+) individuals demonstrated greater than 4-fold (HR 4.89, p < 0.001) increased risk relative to aCH-/CSF-. Linear mixed effects models revealed that aCH predicted a steeper slope of decline in memory (t = -2.35, p = 0.02) and language (t = -2.35, p = 0.02), with effects exacerbated in individuals with AD risk factors.

CONCLUSIONS

aCH increased risk of incident MCI and cognitive decline, and effects were significantly enhanced among individuals with genetic risk factors and CSF-based AD pathophysiologic markers. Findings underscore the adverse impact of aCH medications on cognition and the need for deprescribing trials, particularly among individuals with elevated risk for AD.

Community memory screening as a strategy for recruiting older adults into Alzheimer's disease research

Background

Growing awareness of Alzheimer’s disease (AD) has prompted a demand for quick and effective ways to screen for memory loss and cognitive decline in large numbers of individuals in the community. Periodic Memory Screening Day events provide free, brief cognitive screening aimed at those 65 years and older, and can serve as an opportunity to gauge participants’ attitudes towards AD research and recruit them into ongoing research projects.

Methods

Over 6 single-day events in 2 years, more than 574 individuals were individually screened using the MoCA and a story recall task (immediate and delayed), given feedback about their performance, and introduced to AD research and opportunities to participate.

Results

Screening classified 297 individuals (52.0%) as having “No Decline,” 192 (33.6%) as “Possible decline,” and 82 (14.4%) as “Likely decline.” Those with “Likely decline” were older and less educated, had more memory concerns, were more likely to be men, and were less likely to have a positive family history of dementia than those with “No Decline.” Subsequent validation of screening procedures against a full clinical evaluation showed 72% classification accuracy with a skew towards over-calling Possible and Likely decline and thereby guiding questionable individuals to a more thorough evaluation. Of those screened, 378 (66%) agreed to additional research and consented to being listed in a research registry, and a majority (70–85%) of those consenting reported they were amenable to various AD research procedures including lumbar puncture, MRI, and autopsy. Overall, 19.1% of those screened met inclusion criteria for ongoing studies and were successfully recruited into AD research.

Conclusions

Conducting a few concentrated community memory screening events each year may help meet the public’s demand for brief assessment of memory concerns and can be a relatively effective and efficient recruitment strategy for AD research.