Rate of decline in Alzheimer disease measured by a Dementia Severity Rating Scale

What is paradoxical lucidity? The answer begins with its definition

Paradoxical lucidity in dementia is a clinically significant but understudied phenomenon. A provisional definition was proposed by the 2018 National Institute on Aging expert workshop and published in Alzheimer's and Dementia. However, several conceptual features of this definition remain vague, creating barriers to robust clinical research. Here, we critically analyze the provisional definition and present a refined definition that can be applied in clinical research. The refined definition is based on an analytic process our research group recently undertook to operationalize paradoxical lucidity for our own study protocol. Our goal is to facilitate debate and potentially harmonize interpretations of paradoxical lucidity among research groups.

Informant-based tools for assessment and monitoring of cognition, behavior, and function in neurocognitive disorders: Systematic review and report from a CCCDTD5 Working Group

OBJECTIVE

As part of the fifth Canadian Consensus Conference on the Diagnosis and Treatment of Dementia, we assessed the literature on informant-based tools for assessment and monitoring of cognition, behavior, and function in neurocognitive disorders (NCDs) to provide evidence-based recommendations for clinicians and researchers.

METHODS

A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards guidelines. Publications that validated the informant-based tools or described their key properties were reviewed. Quality of the studies was assessed using the modified Quality Assessment tool for Diagnostic Accuracy Studies.

RESULTS

Out of 386 publications identified through systematic search, 34 that described 19 informant-based tools were included in the final review. Most of these tools are backed by good-quality studies and are appropriate to use in clinical care or research. The tools vary in their psychometric properties, domains covered, comprehensiveness, completion time, and ability to detect longitudinal change. Based on these properties, we identify different tools that may be appropriate for primary care, specialized memory clinic, or research settings. We also identify barriers to use of these tools in routine clinical practice.

CONCLUSION

There are several good-quality tools available to collect informant-report for assessment and monitoring of cognition, behavior, or function in patients with NCDs. Clinicians and researchers may choose a particular tool based on their specific needs such as domains of interest, desired psychometric properties, and feasibility. Further work is needed to make the tools more user-friendly and to adopt them into routine clinical care.

Modifiable, Non-Modifiable, and Clinical Factors Associated with Progression of Alzheimer's Disease

There is an extensive literature relating to factors associated with the development of Alzheimer's disease (AD), but less is known about factors which may contribute to its progression. This review examined the literature with regard to 15 factors which were suggested by PubMed search to be positively associated with the cognitive and/or neuropathological progression of AD. The factors were grouped as potentially modifiable (vascular risk factors, comorbidities, malnutrition, educational level, inflammation, and oxidative stress), non-modifiable (age at clinical onset, family history of dementia, gender, Apolipoprotein E ɛ4, genetic variants, and altered gene regulation), and clinical (baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs). Although conflicting results were found for the majority of factors, a positive association was found in nearly all studies which investigated the relationship of six factors to AD progression: malnutrition, genetic variants, altered gene regulation, baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs. Whether these or other factors which have been suggested to be associated with AD progression actually influence the rate of decline of AD patients is unclear. Therapeutic approaches which include addressing of modifiable factors associated with AD progression should be considered.

Preference for emotionally meaningful activity in Alzheimer's disease

Objectives: Socioemotional selectivity theory (SST) contends that future time perspective is the central determinant of healthy older adults' prioritization of emotional gratification. We have shown elsewhere that individuals with Alzheimer's disease (AD) are disoriented to future time perspective. This study examined whether these same participants would prioritize emotional gratification despite having distorted time perspective. Method: Performance of individuals with Alzheimer's disease (AD) was compared against young, young-old, and old-old adults on a social activity preference card-sort task. We examined whether activity preferences differentially related to subjective wellbeing. Results: Multidimensional scaling revealed common dimensions along which groups considered social activities. The importance of these dimensions varied across healthy participant groups in ways predicted by SST. Dimensions related to knowledge acquisition were more important in youth than older age; emotional dimensions were more important to the older age groups. Despite AD, these individuals also prioritzed emotional gratification, suggesting that cognitive impairment is not a barrier to socioemotional selectivity. Preference for emotionally meaningful activities was positively associated with subjective wellbeing. Conclusion: Persons with AD are motivated towards emotionally meaningful ends and retain high levels of wellbeing. These findings have implications in the caregiving context for shaping social programs to better match goals and preferences.

Medication Regimen Complexity In 8 Australian Residential Aged Care Facilities: Impact Of Age, Length Of Stay, Comorbidity, Frailty, And Dependence In Activities Of Daily Living

Objective

To explore variation in medication regimen complexity in residential aged care facilities (RACFs) according to resident age, length of stay, comorbidity, dementia severity, frailty, and dependence in activities of daily living (ADLs), and compare number of daily administration times and Medication Regimen Complexity Index (MRCI) as measures of regimen complexity.

Methods

This study was a cross-sectional analysis of baseline data from the SImplification of Medications Prescribed to Long-tErm care Residents (SIMPLER) cluster-randomized controlled trial. The SIMPLER study recruited 242 residents with at least one medication charted for regular administration from 8 RACFs in South Australia. Comorbidity was assessed using the Charlson Comorbidity Index (CCI). Dementia severity was assessed using the Dementia Severity Rating Scale. Frailty was assessed using the FRAIL-NH scale. Dependence in ADLs was assessed using the Katz ADL scale.

Results

The median age of participants was 87 years (interquartile range 81–92). Over one-third of participants (n=86, 36%) had 5 or more daily medication administration times. The number of daily administration times and MRCI scores were positively correlated with resident length of stay (r_s=0.19; 0.27), FRAIL-NH score (r_s=0.23; 0.34) and dependence in ADLs (r_s=−0.21; −0.33) (all p<0.01). MRCI was weakly negatively correlated with CCI score (r_s=−0.16; p=0.013). Neither number of daily administration times nor MRCI score were correlated with age or dementia severity. In multivariate analysis, frailty was associated with number of daily administration times (OR: 1.13, 95% CI: 1.03–1.24) and MRCI score (OR: 1.26, 95% CI: 1.13–1.41). Dementia severity was inversely associated with both multiple medication administration times (OR: 0.97, 95% CI: 0.94–0.99) and high MRCI score (OR: 0.95, 95% CI: 0.92–0.98).

Conclusion

Residents with longer lengths of stay, more dependent in ADLs and most frail had the most complex medication regimens and, therefore, may benefit from targeted strategies to reduce medication regimen complexity.

Alzheimer's Disease Progression: Factors Influencing Cognitive Decline

BACKGROUND

Alzheimer's disease (AD) patients present high variability in the rate of cognitive decline. Despite the wide knowledge on factors influencing dementia risk, little is known on what accounts for AD progression. Previous studies on this topic have mainly analyzed each factor separately without taking into account the interaction between genetic and non-genetic factors.

OBJECTIVE

The aim of the present study is to evaluate the role of demographic, clinical, therapeutic, and genetic factors and their interaction on cognitive decline among newly diagnosed AD patients.

METHODS

We retrospectively selected 160 AD patients diagnosed at the Neurology Unit of Careggi University Hospital of Florence. We evaluated the occurrence of rapid cognitive changes defined as the worsening of more than four points at the Mini-Mental State Examination after 2-year follow up period.

RESULTS

Among the 160 AD patients, 50% presented rapid disease progression. Extrapyramidal signs at disease onset were predictors of worse outcome (OR 2.2), especially among Apolipoprotein E (APOE) ɛ4 allele carriers, while the presence of family history for dementia decreased the risk of rapid progression by about 50%. Higher educated ɛ4-carriers showed a slower AD progression. We identified the chronic use of aspirin as potential secondary preventative strategy for the non ɛ4-carriers.

CONCLUSION

At dementia onset, some clinical and demographic data can be predictors of future progression. The outcomes of the present study support the already hypothesized interaction between genetic and non-genetic factors during disease course and suggest genetic-based approaches.

Dementia severity at death: a register-based cohort study

BACKGROUND

One third of older people are estimated to die with dementia, which is a principal cause of death in developed countries. While it is assumed that people die with severe dementia this is not based on evidence.

METHODS

Cohort study using a large secondary mental healthcare database in North London, UK. We included people aged over 65 years, diagnosed with dementia between 2008 and 2016, who subsequently died. We estimated dementia severity using mini-mental state examination (MMSE) scores, adjusting for the time between last score and death using the average annual MMSE decline in the cohort (1.5 points/year). We explored the association of sociodemographic and clinical factors, including medication use, with estimated MMSE score at death using linear regression.

RESULTS

In 1400 people dying with dementia, mean estimated MMSE at death was 15.3 (standard deviation 7.0). Of the cohort, 22.2% (95% confidence interval 20.1, 24.5) died with mild dementia; 50.4% (47.8, 53.0) moderate; and 27.4% (25.1, 29.8) with severe dementia. In fully adjusted models, more severe dementia at death was observed in women, Black, Asian and other ethnic minorities, agitated individuals, and those taking antipsychotic medication.

CONCLUSIONS

Only one quarter of people who die with dementia are at the severe stage of the illness. This finding informs clinical and public understanding of dementia prognosis. Provision of end-of-life services should account for this and healthcare professionals should be aware of high rates of mild and moderate dementia at end of life and consider how this affects clinical decision-making.

Cerebrospinal fluid α-synuclein contributes to the differential diagnosis of Alzheimer's disease

INTRODUCTION

The ability of Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers (amyloid β peptide 1-42, total tau, and phosphorylated tau) to discriminate AD from related disorders is limited. Biomarkers for other concomitant pathologies (e.g., CSF α-synuclein [α-syn] for Lewy body pathology) may be needed to further improve the differential diagnosis.

METHODS

CSF total α-syn, phosphorylated α-syn at Ser129, and AD CSF biomarkers were evaluated with Luminex immunoassays in 367 participants, followed by validation in 74 different neuropathologically confirmed cases.

RESULTS

CSF total α-syn, when combined with amyloid β peptide 1-42 and either total tau or phosphorylated tau, improved the differential diagnosis of AD versus frontotemporal dementia, Lewy body disorders, or other neurological disorders. The diagnostic accuracy of the combined models attained clinical relevance (area under curve ∼0.9) and was largely validated in neuropathologically confirmed cases.

DISCUSSION

Combining CSF biomarkers representing AD and Lewy body pathologies may have clinical value in the differential diagnosis of AD.

Life Enhancing Activities for Family Caregivers of people with dementia: protocol for a randomized controlled trial of a positive affect skills intervention

Given the increasing number of family caregivers of persons with dementia (PWD) and the associated burden and detriments to both physical and mental health, interventions that aim to improve such outcomes are important. Studies are increasingly demonstrating the unique importance of positive emotions in coping with stress, independent from the impact of negative emotions. However, none have examined the benefits of interventions that target positive emotions for caregivers of individuals with a chronic and debilitating disease such as dementia. This paper presents the design and methods for a randomized controlled trial (RCT) of a positive affect skills intervention for family caregivers of PWD. The RCT is of a skills-based intervention that seeks to increase the frequency and intensity of positive affect in order to improve outcomes such as well-being, coping, and physical and mental health. The skills are delivered by trained facilitators via five one-to-one Internet video sessions with family caregivers of persons diagnosed with dementia (eg, Alzheimer's disease, vascular dementia, unspecified). The control group is an emotion reporting/waitlist control. Follow-up assessments are conducted post-intervention and at 1, 3, and 6 months post-completion of the intervention. This study promises to be an important and needed step toward improving the lives of caregivers of PWD.

A new direction for Alzheimer's research

Despite decades of research, at present there is no curative therapy for Alzheimer's disease. Changes in the way new drugs are tested appear to be necessary. Three changes are presented here and will be discussed. The first change is that Alzheimer's disease must be considered a disease of four major pathological processes, not one. The four processes are: 1) vascular hypoperfusion of the brain with associated mitochondrial dysfunction, 2) destructive protein inclusions, 3) uncontrolled oxidative stress, and 4) proinflammatory immune processes secondary to microglial and astrocytic dysfunction in the brain. The second change recommended is to alter the standard cognitive measurement tools used to quantify mental decline in test patients. Specifically the Dementia Severity Rating Scale (DSRS) should supersede Mini-Mental State Examination (MMSE) and other popular tests, and a measurement scale developed in research should be used to produce a linear and non-irregular baseline. Finally, accepting the concept that four etiologies cause Alzheimer's disease leads to the last necessary change, that new therapies must be employed directed against all four causes, likely as a combination. There are drugs ready to be employed in such a combinations which are available and used clinically for other purposes so can be used “off label” and one such combination is suggested.

A unique and promising combination of medications for the treatment of Alzheimer's disease

At present there is no therapy for Alzheimer's Disease which completely stops the progressive dementia effecting late onset Alzheimer's Disease (AD) patients. It is felt that the main reason for this failure is that AD appears to be a disease caused by four major pathological processes. To date, efforts to develop treatments have addressed only one or another of these four etiologies. However, even a partially effective therapy against one cause allows the others, untreated, to continue their inexorable destruction of the neurons of the brain. It is suggested that a therapy is required which inhibits all four causes of the disease. Just such a therapy is proposed here with four specific drugs and a vitomer together in a combination treatment. The four major pathologic processes causing AD are: I. vascular hypoperfusion of the brain with associated mitochondrial dysfunction. II. destructive protein occlusions. III. uncontrolled oxidate stress and IV: pro-inflammatory immune processes secondary to microglial and astrocytic dysfunction in the brain. A detailed literature search has provided four drugs and a B6 vitomer which together provide an ideal combination to treat the four etiologies of AD. All four drugs are used clinically for various indications and would be used "off label" in combination to treat AD. The drugs have been used in preliminary studies to treat dementia with favorable indications in all of them inhibiting dementia with only modest side effects. In in vitro studies all five of the combination have been shown effective in inhibiting one or more of the four disease etiologies and together they are effective against all four. The four drugs are Trental, Nicergoline, Nilotinib, and Methylene blue. The vitamer is B6 pyridoxamine. The cumulative benefits of this combination should provide an effective treatment to completely stop the progressive dementia of AD, measured in 12-18months. The use of an endpoint of complete cessation of progressive dementia rather than the standard of a statistical determination of the slowing of progressive dementia allows the study to be conducted with a cohort of only 15 patients (no statistics and no placebo patients) as every AD patient would otherwise show progressive dementia without the effective treatment.

Development of a core outcome set for disease modification trials in mild to moderate dementia: a systematic review, patient and public consultation and consensus recommendations

BACKGROUND

There is currently no disease-modifying treatment available to halt or delay the progression of the disease pathology in dementia. An agreed core set of the best-available and most appropriate outcomes for disease modification would facilitate the design of trials and ensure consistency across disease modification trials, as well as making results comparable and meta-analysable in future trials.

OBJECTIVES

To agree a set of core outcomes for disease modification trials for mild to moderate dementia with the UK dementia research community and patient and public involvement (PPI).

DATA SOURCES

We included disease modification trials with quantitative outcomes of efficacy from (1) references from related systematic reviews in workstream 1; (2) searches of the Cochrane Dementia and Cognitive Improvement Group study register, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, EMBASE, Latin American and Caribbean Health Sciences Literature and PsycINFO on 11 December 2015, and clinical trial registries [International Standard Randomised Controlled Trial Number (ISRCTN) and clinicaltrials.gov] on 22 and 29 January 2016; and (3) hand-searches of reference lists of relevant systematic reviews from database searches.

REVIEW METHODS

The project consisted of four workstreams. (1) We obtained related core outcome sets and work from co-applicants. (2) We systematically reviewed published and ongoing disease modification trials to identify the outcomes used in different domains. We extracted outcomes used in each trial, recording how many used each outcome and with how many participants. We divided outcomes into the domains measured and searched for validation data. (3) We consulted with PPI participants about recommended outcomes. (4) We presented all the synthesised information at a conference attended by the wider body of National Institute for Health Research (NIHR) dementia researchers to reach consensus on a core set of outcomes.

RESULTS

We included 149 papers from the 22,918 papers screened, referring to 125 individual trials. Eighty-one outcomes were used across trials, including 72 scales [31 cognitive, 12 activities of daily living (ADLs), 10 global, 16 neuropsychiatric and three quality of life] and nine biological techniques. We consulted with 18 people for PPI. The conference decided that only cognition and biological markers are core measures of disease modification. Cognition should be measured by the Mini Mental State Examination (MMSE) or the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog), and brain changes through structural magnetic resonance imaging (MRI) in a subset of participants. All other domains are important but not core. We recommend using the Neuropsychiatric Inventory for neuropsychiatric symptoms: the Disability Assessment for Dementia for ADLs, the Dementia Quality of Life Measure for quality of life and the Clinical Dementia Rating scale to measure dementia globally.

LIMITATIONS

Most of the trials included participants with Alzheimer's disease, so recommendations may not apply to other types of dementia. We did not conduct economic analyses. The PPI consultation was limited to members of the Alzheimer's Society Research Network.

CONCLUSIONS

Cognitive outcomes and biological markers form the core outcome set for future disease modification trials, measured by the MMSE or ADAS-Cog, and structural MRI in a subset of participants.

FUTURE WORK

We envisage that the core set may be superseded in the future, particularly for other types of dementia. There is a need to develop an algorithm to compare scores on the MMSE and ADAS-Cog.

STUDY REGISTRATION

The project was registered with Core Outcome Measures in Effectiveness Trials [ www.comet-initiative.org/studies/details/819?result=true (accessed 7 April 2016)]. The systematic review protocol is registered as PROSPERO CRD42015027346.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Comparing Crowdsourcing and Friendsourcing: A Social Media-Based Feasibility Study to Support Alzheimer Disease Caregivers

Background

In the United States, over 15 million informal caregivers provide unpaid care to people with Alzheimer disease (AD). Compared with others in their age group, AD caregivers have higher rates of stress, and medical and psychiatric illnesses. Psychosocial interventions improve the health of caregivers. However, constraints of time, distance, and availability inhibit the use of these services. Newer online technologies, such as social media, online groups, friendsourcing, and crowdsourcing, present alternative methods of delivering support. However, limited work has been done in this area with caregivers.

Objective

The primary aims of this study were to determine (1) the feasibility of innovating peer support group work delivered through social media with friendsourcing, (2) whether the intervention provides an acceptable method for AD caregivers to obtain support, and (3) whether caregiver outcomes were affected by the intervention. A Facebook app provided support to AD caregivers through collecting friendsourced answers to caregiver questions from participants’ social networks. The study’s secondary aim was to descriptively compare friendsourced answers versus crowdsourced answers.

Methods

We recruited AD caregivers online to participate in a 6-week-long asynchronous, online, closed group on Facebook, where caregivers received support through moderator prompts, group member interactions, and friendsourced answers to caregiver questions. We surveyed and interviewed participants before and after the online group to assess their needs, views on technology, and experience with the intervention. Caregiver questions were pushed automatically to the participants’ Facebook News Feed, allowing participants’ Facebook friends to see and post answers to the caregiver questions (Friendsourced answers). Of these caregiver questions, 2 were pushed to crowdsource workers through the Amazon Mechanical Turk platform. We descriptively compared characteristics of these crowdsourced answers with the friendsourced answers.

Results

In total, 6 AD caregivers completed the initial online survey and semistructured telephone interview. Of these, 4 AD caregivers agreed to participate in the online Facebook closed group activity portion of the study. Friendsourcing and crowdsourcing answers to caregiver questions had similar rates of acceptability as rated by content experts: 90% (27/30) and 100% (45/45), respectively. Rates of emotional support and informational support for both groups of answers appeared to trend with the type of support emphasized in the caregiver question (emotional vs informational support question). Friendsourced answers included more shared experiences (20/30, 67%) than did crowdsourced answers (4/45, 9%).

Conclusions

We found an asynchronous, online, closed group on Facebook to be generally acceptable as a means to deliver support to caregivers of people with AD. This pilot is too small to make judgments on effectiveness; however, results trended toward an improvement in caregivers’ self-efficacy, sense of support, and perceived stress, but these results were not statistically significant. Both friendsourced and crowdsourced answers may be an acceptable way to provide informational and emotional support to caregivers of people with AD.

Empirically Defining Trajectories of Late-Life Cognitive and Functional Decline

BACKGROUND

Alzheimer's disease (AD) is associated with variable cognitive and functional decline, and it is difficult to predict who will develop the disease and how they will progress.

OBJECTIVE

This exploratory study aimed to define latent classes from participants in the Alzheimer's Disease Neuroimaging Initiative (ADNI) database who had similar growth patterns of both cognitive and functional change using Growth Mixture Modeling (GMM), identify characteristics associated with those trajectories, and develop a decision tree using clinical predictors to determine which trajectory, as determined by GMM, individuals will most likely follow.

METHODS

We used ADNI early mild cognitive impairment (EMCI), late MCI (LMCI), AD dementia, and healthy control (HC) participants with known amyloid-β status and follow-up assessments on the Alzheimer's Disease Assessment Scale - Cognitive Subscale or the Functional Activities Questionnaire (FAQ) up to 24 months postbaseline. GMM defined trajectories. Classification and Regression Tree (CART) used certain baseline variables to predict likely trajectory path.

RESULTS

GMM identified three trajectory classes (C): C1 (n = 162, 13.6%) highest baseline impairment and steepest pattern of cognitive/functional decline; C3 (n = 819, 68.7%) lowest baseline impairment and minimal change on both; C2 (n = 211, 17.7%) intermediate pattern, worsening on both, but less steep than C1. C3 had fewer amyloid- or apolipoprotein-E ɛ4 (APOE4) positive and more healthy controls (HC) or EMCI cases. CART analysis identified two decision nodes using the FAQ to predict likely class with 82.3% estimated accuracy.

CONCLUSIONS

Cognitive/functional change followed three trajectories with greater baseline impairment and amyloid and APOE4 positivity associated with greater progression. FAQ may predict trajectory class.

The utility of the Dementia Severity Rating Scale in differentiating mild cognitive impairment and Alzheimer disease from controls

The current study investigated the utility of the Dementia Severity Rating Scale (DSRS) total score to identify individuals at the earliest stage of impairment (ie, mild cognitive impairment/MCI). In addition, the authors sought to investigate how well the measure correlates with an expanded battery of cognitive tests and other measures of functional abilities. Of the 320 participants included in this study, 85 were normal controls, 96 had single-domain or multiple-domain amnestic MCI, and 139 had possible or probable Alzheimer disease (AD). Each participant underwent a thorough cognitive, neurological, and physical examination. Results from this study indicated that the DSRS total scores differed significantly between the 3 groups (P<0.001) and accurately identified 81% of the control group, 60% of the MCI group, and 78% of the AD group in a post hoc discriminant analysis. When combined with a brief cognitive measure (ie, Consortium to Establish a Registry for Alzheimer's Disease Word List 5 min recall test), the DSRS accurately identified 98% of the control group, 76% of the MCI group, and 82% of the AD group. Implications for clinical practice and proposed areas of future research are discussed.

Latent classes of course in Alzheimer's disease and predictors: the Cache County Dementia Progression Study

OBJECTIVE

Several longitudinal studies of Alzheimer's disease (AD) report heterogeneity in progression. We sought to identify groups (classes) of progression trajectories in the population-based Cache County Dementia Progression Study (N = 328) and to identify baseline predictors of membership for each group.

METHODS

We used parallel-process growth mixture models to identify latent classes of trajectories on the basis of Mini-Mental State Exam (MMSE) and Clinical Dementia Rating sum of boxes scores over time. We then used bias-corrected multinomial logistic regression to model baseline predictors of latent class membership. We constructed receiver operating characteristic curves to demonstrate relative predictive utility of successive sets of predictors.

RESULTS

We fit four latent classes; class 1 was the largest (72%) and had the slowest progression. Classes 2 (8%), 3 (11%), and 4 (8%) had more rapid worsening. In univariate analyses, longer dementia duration, presence of psychosis, and worse baseline MMSE and Clinical Dementia Rating sum of boxes were associated with membership in class 2, relative to class 1. Lower education was associated with membership in class 3. In the multivariate model, only MMSE remained a statistically significant predictor of class membership. Receiver operating characteristic areas under the curve were 0.98, 0.88, and 0.67, for classes 2, 3, and 4 relative to class 1.

CONCLUSIONS

Heterogeneity in AD course can be usefully characterized using growth mixture models. The majority belonged to a class characterized by slower decline than is typically reported in clinical samples. Class membership could be predicted using baseline covariates. Further study may advance our prediction of AD course at the population level and in turn shed light on the pathophysiology of progression.

Frequency and clinicopathological characteristics of presenilin 1 Gly206Ala mutation in Puerto Rican Hispanics with dementia

The frequency and clinical and pathological characteristics associated with the Gly206Ala presenilin 1 (PSEN1) mutation in Puerto Rican and non-Puerto Rican Hispanics were evaluated at the University of Pennsylvania's Alzheimer's Disease Center. DNAs from all cohort subjects were genotyped for the Gly206Ala PSEN1 mutation. Carriers and non-carriers with neurodegenerative disease dementias were compared for demographic, clinical, psychometric, and biomarker variables. Nineteen (12.6%) of 151 unrelated subjects with dementia were discovered to carry the PSEN1 Gly206Ala mutation. Microsatellite marker genotyping determined a common ancestral haplotype for all carriers. Carriers were all of Puerto Rican heritage with significantly younger age of onset, but otherwise were clinically and neuropsychologically comparable to those of non-carriers with AD. Three subjects had extensive topographic and biochemical biomarker assessments that were also typical of non-carriers with AD. Neuropathological examination in one subject revealed severe, widespread plaque and tangle pathology without other meaningful disease lesions. The PSEN1 Gly206Ala mutation is notably frequent in unrelated Puerto Rican immigrants with dementia in Philadelphia. Considered together with the increased prevalence and mortality of AD reported in Puerto Rico, these high rates may reflect hereditary risk concentrated in the island which warrants further study.

Neuropsychiatric symptoms, apolipoprotein E gene, and risk of progression to cognitive impairment, no dementia and dementia: the Aging, Demographics, and Memory Study (ADAMS)

OBJECTIVE

To examine the relationship of neuropsychiatric symptoms and apolipoprotein E (APOE) ε4 allele status to dementia at baseline and progression to dementia in older adults with and without cognitive impairment, no dementia (CIND).

METHODS

Adults (n = 856) 71 years and older (mean age = 79.15 years), 12.8% ethnic minority and 60.6% women, completed neuropsychological tests and APOE genotyping, and a proxy informant completed the Neuropsychiatric Inventory.

RESULTS

After adjusting for age and education, neuropsychiatric symptoms and APOE ε4 were independently associated with CIND and dementia status at baseline (compared with cognitively normal). Further, neuropsychiatric symptoms predicted progression to dementia at 16- to 18-month follow-up among participants with CIND at baseline; the presence of these symptoms decreased the risk of progression from normal to CIND or dementia at 36 to 48 months.

CONCLUSION

Findings provide cross-sectional and longitudinal support for the role of neuropsychiatric symptoms in the prediction of cognitive impairment, particularly dementia. APOE ε4, although important, may be a less robust predictor. This investigation highlights the importance of behavioral symptoms, such as neuropsychiatric symptom status or frequency/severity, as predictors of future cognitive decline.

Comparative accuracies of two common screening instruments for classification of Alzheimer's disease, mild cognitive impairment, and healthy aging

BACKGROUND

The aim of this study was to compare the utility and diagnostic accuracy of the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) in the diagnosis of Alzheimer's disease (AD) and mild cognitive impairment (MCI) in a clinical cohort.

METHODS

Three hundred twenty-one AD, 126 MCI, and 140 older adults with healthy cognition (HC) were evaluated using the MMSE, the MoCA, a standardized neuropsychologic battery according to the Consortium to Establish a Registry of Alzheimer's Disease (CERAD-NB), and an informant-based measure of functional impairment, the Dementia Severity Rating Scale (DSRS). Diagnostic accuracy and optimal cut-off scores were calculated for each measure, and a method for converting MoCA to MMSE scores is presented.

RESULTS

The MMSE and MoCA offer reasonably good diagnostic and classification accuracy as compared with the more detailed CERAD-NB; however, as a brief cognitive screening measure, the MoCA was more sensitive and had higher classification accuracy for differentiating MCI from HC. Complementing the MMSE or the MoCA with the DSRS significantly improved diagnostic accuracy.

CONCLUSION

The findings support recent data indicating that the MoCA is superior to the MMSE as a global assessment tool, particularly in discerning earlier stages of cognitive decline. In addition, we found that overall diagnostic accuracy improves when the MMSE or MoCA is combined with an informant-based functional measure. Finally, we provide a reliable and easy conversion of MoCA to MMSE scores. However, the need for MCI-specific measures is still needed to increase the diagnostic specificity between AD and MCI.

Cognitive and functional resilience despite molecular evidence of Alzheimer's disease pathology

BACKGROUND

The correlation between neuropathological lesions and cognition is modest. Some individuals remain cognitively intact despite the presence of significant Alzheimer's disease (AD) pathology, whereas others manifest cognitive symptoms and dementia in the same context. The aim of the present study was to examine cognitive and cerebral reserve factors associated with resilient functioning in the setting of AD pathology.

METHODS

University of Pennsylvania Alzheimer's Disease Center research participants with biochemical biomarker evidence of AD pathology (cerebrospinal fluid amyloid-β1-42 <192 pg/mL) and comparable medial temporal lobe atrophy were categorized by Clinical Dementia Rating Scale-Sum of Boxes (CDR-SOB) score as AD dementia (CDR-SOB >1) or AD resilient (CDR-SOB ≤0.5). Groups were compared for a variety of demographic, clinical, and neuroimaging variables to identify factors that are associated with resilience to AD pathology.

RESULTS

A univariate model identified education and intracranial volume (ICV) as significant covariates. In a multivariate model with backward selection procedure, ICV was retained as a factor most significantly associated with resilience. The interaction term between ICV and education was not significant, suggesting that larger cranial vault size is associated with resilience even in the absence of more education.

CONCLUSIONS

Premorbid brain volume, as measured through ICV, provided protection against clinical manifestations of dementia despite evidence of significant accumulations of AD pathology. This finding provides support for the brain reserve hypothesis of resilience to AD.

Effects of general medical health on Alzheimer's progression: the Cache County Dementia Progression Study

BACKGROUND

Several observational studies have suggested a link between health status and rate of decline among individuals with Alzheimer's disease (AD). We sought to quantify the relationship in a population-based study of incident AD, and to compare global comorbidity ratings to counts of comorbid conditions and medications as predictors of AD progression.

METHODS

This was a case-only cohort study arising from a population-based longitudinal study of memory and aging, in Cache County, Utah. Participants comprised 335 individuals with incident AD followed for up to 11 years. Patient descriptors included sex, age, education, dementia duration at baseline, and APOE genotype. Measures of health status made at each visit included the General Medical Health Rating (GMHR), number of comorbid medical conditions, and number of non-psychiatric medications. Dementia outcomes included the Mini-Mental State Examination (MMSE), Clinical Dementia Rating - sum of boxes (CDR-sb), and the Neuropsychiatric Inventory (NPI).

RESULTS

Health status tended to fluctuate over time within individuals. None of the baseline medical variables (GMHR, comorbidities, and non-psychiatric medications) was associated with differences in rates of decline in longitudinal linear mixed effects models. Over time, low GMHR ratings, but not comorbidities or medications, were associated with poorer outcomes (MMSE: β = -1.07 p = 0.01; CDR-sb: β = 1.79 p < 0.001; NPI: β = 4.57 p = 0.01).

CONCLUSIONS

Given that time-varying GMHR, but not baseline GMHR, was associated with the outcomes, it seems likely that there is a dynamic relationship between medical and cognitive health. GMHR is a more sensitive measure of health than simple counts of comorbidities or medications. Since health status is a potentially modifiable risk factor, further study is warranted.

CSF biomarkers cutoffs: the importance of coincident neuropathological diseases

The effects of applying clinical versus neuropathological diagnosis and the inclusion of cases with coincident neuropathological diagnoses have not been assessed specifically when studying cerebrospinal fluid (CSF) biomarker classification cutoffs for patients with neurodegenerative diseases that cause dementia. Thus, 142 neuropathologically diagnosed neurodegenerative dementia patients [71 Alzheimer's disease (AD), 29 frontotemporal lobar degeneration (FTLD), 3 amyotrophic lateral sclerosis, 7 dementia with Lewy bodies, 32 of which cases also had coincident diagnoses] were studied. 96 % had enzyme-linked immunosorbant assay (ELISA) CSF data and 77 % had Luminex CSF data, with 43 and 46 controls for comparison, respectively. Aβ(42), total, and phosphorylated tau(181) were measured. Clinical and neuropathological diagnoses showed an 81.4 % overall agreement. Both assays showed high sensitivity and specificity to classify AD subjects against FTLD subjects and controls, and moderate sensitivity and specificity for classifying FTLD subjects against controls. However, among the cases with neuropathological diagnoses of AD plus another pathology (26.8 % of the sample), 69.4 % (ELISA) and 96.4 % (Luminex) were classified as AD according to their biomarker profiles. Use of clinical diagnosis instead of neuropathological diagnosis led to a 14-17 % underestimation of the biomarker accuracy. These results show that while CSF Aβ and tau assays are useful for diagnosis of AD and neurodegenerative diseases even at MCI stages, CSF diagnostic analyte panels that establish a positive diagnosis of Lewy body disease and FTLD are also needed, and must be established based on neuropathological rather than clinical diagnoses.

Quality, and not just quantity, of education accounts for differences in psychometric performance between african americans and white non-hispanics with Alzheimer's disease

The effect of race on cognitive test performance in the evaluation of Alzheimer's disease (AD) remains controversial. One factor that may contribute substantially to differences in cognitive test performance in diverse populations is education. The current study examined the extent to which quality of education, even after controlling for formal years of education, accounts for differences in cognitive performance between African Americans and White Non-Hispanics (WNHs). The retrospective cohort included 244 patients diagnosed with AD who self-identified as African Americans (n = 51) or WNHs (n = 193). The Wechsler Test of Adult Reading (WTAR) was used as an estimate of quality of education. In an analysis that controlled for traditional demographics, including age, sex, and years of formal education, African Americans scored significantly lower than WNHs on the Mini-Mental State Examination, as well as on neuropsychological tests of memory, attention, and language. However, after also adjusting for reading level, all previously observed differences were significantly attenuated. The attenuating effect remained even after controlling for disease severity, indicating that reading scores are not confounded by severity of dementia. These findings suggest that quality, and not just quantity, of education needs to be taken into account when assessing cognitive performance in African Americans with AD.

Ethnoracial differences in the clinical characteristics of Alzheimer's disease at initial presentation at an urban Alzheimer's disease center

OBJECTIVE

To compare presentation of Alzheimer disease (AD) at the time of initial evaluation at a university specialty clinic across three ethnoracial groups in order to understand similarities and differences in the demographic, clinical, cognitive, psychiatric, and biologic features.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 1,341 self-identified African American, Latino (primarily of Caribbean origin), and white non-Hispanic ("WNH") subjects were recruited from primary care sites or by referral by primary care physicians.

MEASUREMENTS

Demographic variables and age of onset of AD, as well as cognitive, functional, and mood impairments at the time of initial presentation and frequencies of apolipoprotein E genotypes, were compared across groups.

RESULTS

Differences among ethnoracial groups were found for nearly all variables of interest. In particular, the largely immigrant Puerto Rican Latino group had an earlier age of onset of AD, more cognitive impairment, and greater severity of cognitive impairment at the time of initial evaluation in the setting of low average education and socioeconomic status. There was more depression in the Latinos compared with African Americans and WNHs. Greater severity of symptoms was not accounted for by a difference in lag time between onset of symptoms and initial evaluation. The apolipoprotein E-4 genotype was not associated with AD in the Latino cohort.

CONCLUSIONS

Minority groups in Philadelphia, especially Latinos, exhibit a more severe profile of AD at the time of presentation than WNHs. Important potential confounds need to be considered and future research comparing immigrant and nonimmigrant Latino groups will be necessary to elucidate the highly significant differences reported.