Progress in clinical neurosciences: cognitive markers of progression in Alzheimer's disease

Attention to the domains of Revised Hasegawa Dementia Scale and Mini-Mental State Examination in patients with Alzheimer's disease dementia

BACKGROUND

In Japan, Alzheimer's disease dementia (AD) is the most common cognitive disease, and the most widely used dementia screening tests are the Revised Hasegawa Dementia Scale (HDS-R) and Mini-Mental State Examination (MMSE). This study sought to elucidate the relationships of the individual domains of these tests with age and duration of school education in a large group of patients with AD.

METHODS

Participants were 505 new outpatients diagnosed with AD who completed the HDS-R and MMSE at the first visit. We investigated the relationships of total and individual domains of these tests with age and duration of school education using the least squares method. Next, we plotted regression lines of the individual domain scores against the total test scores.

RESULTS

Younger age and longer duration of school education were significantly associated with higher total HDS-R and MMSE scores in AD. Domain-specific results indicated that younger age was significantly associated with a higher immediate memory score on both the HDS-R and MMSE and with a higher orientation (time), repetition score on the MMSE. Longer duration of school education was significantly associated with a higher working memory score on the HDS-R and with higher serial 7, repetition and writing scores on the MMSE. In addition, shorter duration of school education was significantly associated with higher naming score on the MMSE. The regression lines of orientation of time, remote memory, visual memory, and verbal frequency hit the bottom on the HDS-R (4/30, 8/30, 4/30, and 6/30, respectively) and of orientation of time, serial 7, remote memory, and writing also hit the bottom on the MMSE (8/30, 9/30, 11/30, and 8/30, respectively).

CONCLUSIONS

We should pay attention to age, duration of school education, and the individual domains when using the HDS-R or MMSE to assess patients with AD.

Cognitive and functional progression of dementia in two longitudinal studies

OBJECTIVES

Previous studies have identified several subgroups (ie, latent trajectories) with distinct disease progression among people with dementia. However, the methods and results were not always consistent. This study aims to perform a coordinated analysis of latent trajectories of cognitive and functional progression in dementia across two datasets.

METHODS

Included and analyzed using the same statistical approach were 1628 participants with dementia from the US National Alzheimer's Coordinating Center (NACC) and 331 participants with dementia from the Dutch Clinical Course of Cognition and Comorbidity study (4C-Study). Trajectories of cognition and instrumental activities of daily living (IADL) were modeled jointly in a parallel-process growth mixture model.

RESULTS

Cognition and IADL tended to decline in unison across the two samples. Slow decline in both domains was observed in 26% of the US sample and 74% of the Dutch sample. Rapid decline in cognition and IADL was observed in 7% of the US sample and 26% of the Dutch sample. The majority (67%) of the US sample showed moderate cognitive decline and rapid IADL decline.

CONCLUSIONS

Trajectories of slow and rapid dementia progression were identified in both samples. Despite using the same statistical methods, the number of latent trajectories was not replicated and the relative class sizes differed considerably across datasets. These results call for careful consideration when comparing progression estimates in the literature. In addition, the observed discrepancy between cognitive and functional decline stresses the need to monitor dementia progression across multiple domains.

SPIRIT advance care planning intervention in early stage dementias: An NIH stage I behavioral intervention development trial

People in the early stages of Alzheimer's disease and related dementias (ADRD) are encouraged to engage in advance care planning (ACP) while they are still competent to appoint a surrogate decision maker and meaningfully participate in ACP discussions with the surrogate. In this NIH Stage I behavioral intervention development trial, we will adapt and test an efficacious ACP intervention, SPIRIT (Sharing Patient's Illness Representation to Increase Trust), with people with mild dementia and their surrogates to promote open, honest discussions while such discussions about end-of-life care are possible. We will first adapt SPIRIT (in person) to target people with mild dementia and their surrogates through a process of modification-pretesting-refinement using stakeholders (persons with mild dementia, family caregivers, and clinicians) and experts, including adapting the delivery mode to interactive web-based videoconference format (SPIRIT-remote). Then in a 3-group RCT with 120 patient-surrogate dyads, we will evaluate the feasibility and acceptability of SPIRIT in-person and SPIRIT remote, and preliminary efficacy of SPIRIT compared to usual care on preparedness outcomes for end-of-life decision making (dyad congruence on goals of care, patient decisional conflict, and surrogate decision-making confidence) shortly after the intervention. This Stage I research of SPIRIT will generate valuable insights regarding how to improve ACP for people with mild dementia who will progress to an advanced stage of the disease in the foreseeable future.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03311711, Registered 10/12/2017.

Both Financial and Cognitive Decline Predict Clinical Progression in MCI

We investigated the roles of financial/functional and cognitive abilities in predicting clinical progression in patients with mild cognitive impairment (MCI). In a longitudinal sample of 51 patients with consensus conference diagnosed MCI likely due to Alzheimer disease (AD), two-year change scores were calculated for a performance measure of functional ability, cognitive variables, and 3 outcome measures used to track progression in neurological disorders. We examined patterns of financial and cognitive decline across the 2-year study period, and used these data and the 3 outcome variables to construct discrete predictor models of clinical progression in MCI. We found that both financial skills and cognitive abilities declined over the 2-year study period, were significantly associated with clinical progression, and contributed unique variance to all 3 predictor models. The resulting models accounted for 40% to 75% of variance in clinical progression across outcome variables. Taken together, our results indicate that changes in both cognitive abilities and higher order functional skills appear integral to understanding clinical progression in MCI likely due to AD. Specifically, declines in financial skills contribute unique variance to measures commonly used to track progression in neurological disorders associated with aging, and thus represent an important functional marker of clinical progression in prodromal AD.

Predicting the progression of Alzheimer's disease dementia: A multidomain health policy model

INTRODUCTION

We develop a multidomain model to predict progression of Alzheimer's disease dementia (AD).

METHODS

Data from the US National Alzheimer's Coordinating Center (n = 3009) are used to examine change in symptom status and to estimate transition probabilities between health states described using cognitive function, functional ability, and behavior. A model is used to predict progression and to assess a hypothetical treatment scenario that slows mild to moderate AD progression.

RESULTS

More than 70% of participants moved state over 12 months. The majority moved in domains other than cognitive function. Over 5 years, of those alive more than half are in severe AD health states. Assessing an intervention scenario, we see fewer years in more severe health states and a potential impact (life years saved) due to mortality improvements.

DISCUSSION

The model developed is exploratory and has limitations but illustrates the importance of using a multidomain approach when assessing impacts of AD and interventions.

Dynamic Factor Analysis for Multivariate Time Series: An Application to Cognitive Trajectories

We propose a dynamic factor model appropriate for large epidemiological studies and develop an estimation algorithm which can handle datasets with large number of subjects and short temporal information. The algorithm uses a two cycle iterative approach for parameter estimation in such a large dataset. Each iteration consists of two distinct cycles, both following an EM algorithm approach. This iterative process will continue until convergence is achieved. We utilized a dataset from the National Alzheimer Coordinating Center (NACC) to estimate underlying measures of cognition based on a battery of observed neuropsychological tests. We assess the goodness of fit and the precision of the dynamic factor model estimators and compare it with a non-dynamic version in which temporal information is not used. The dynamic factor model is superior to a non-dynamic version with respect to fit statistics shown in simulation experiments. Moreover, it has increased power to detect differences in the rate of decline for a given sample size.

Dependence scale for Alzheimer's disease: relationship with other clinical indicators and psychometric properties

The objective of this cross-sectional and multicenter study was to evaluate the psychometric properties of the Spanish version of the Dependence Scale (DS) and to assess the relationship between dependence and clinical measures according to disease severity. Medical comorbidities, cognitive status and functional status, behavior, dependence, caregiver burden, and medical and social resources were assessed using standardized instruments. The sample consisted of 343 patients (32.1% mild, 36.7% moderate, and 31.2% severe), the mean age was 78.9 years (standard deviation=7.4), and 67.0% were women. Criterion and construct validity index of DS were appropriate. The DS standard error of measurement was ±1.23. The explained variance in DS ranged between 0.598 and 0.731, and the relative contribution of clinical measures depended on disease severity. Current findings confirm that the Spanish version of the DS has appropriate psychometric indices and suggest that clinical indicators have different contribution to dependence according to disease severity.

The fornix in mild cognitive impairment and Alzheimer's disease

The fornix is an integral white matter bundle located in the medial diencephalon and is part of the limbic structures. It serves a vital role in memory functions and as such has become the subject of recent research emphasis in Alzheimer's disease (AD) and mild cognitive impairment (MCI). As the characteristic pathological processes of AD progress, structural and functional changes to the medial temporal lobes and other regions become evident years before clinical symptoms are present. Though gray matter atrophy has been the most studied, degradation of white matter structures especially the fornix may precede these and has become detectable with use of diffusion tensor imaging (DTI) and other complimentary imaging techniques. Recent research utilizing DTI measurement of the fornix has shown good discriminability of diagnostic groups, particularly early and preclinical, as well as predictive power for incident MCI and AD. Stimulating and modulating fornix function by the way of DBS has been an exciting new area as pharmacological therapeutics has been slow to develop.

Treatment effects in multiple cognitive domains in Alzheimer's disease: a two-year cohort study

Introduction

Despite widespread use of second-generation cholinesterase inhibitors for the symptomatic treatment of Alzheimer’s disease (AD), little is known about the long term effects of cholinergic treatment on global cognitive function and potential specific effects in different cognitive domains. The objectives of this study were to determine the association between cholinergic treatment and global cognitive function over one and two years in a cohort of patients with mild or moderate AD and identify potential differences in domain-specific cognitive outcomes within this cohort.

Methods

A cohort of patients meeting the revised National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria for mild or moderate AD, including patients both on treatment with a cholinesterase inhibitor and untreated controls (treated = 65, untreated = 65), were recruited from the Cognitive Neurology Clinic at Sunnybrook Health Sciences Centre, as part of the Sunnybrook Dementia Study. Patients were followed for one to two years and underwent standardized neuropsychological assessments to evaluate global and domain-specific cognitive function. Associations between cholinesterase inhibitor use and global and domain-specific cognitive outcome measures at one and two years of follow-up were estimated using mixed model linear regression, adjusting for age, education, and baseline mini mental state examination (MMSE).

Results

At one year, treated patients showed significantly less decline in global cognitive function, and treatment and time effects across tests of executive and visuospatial function. At two years, there was a significant trend towards less decline in global cognition for treated patients. Moreover, treated patients showed significant treatment and time effects across tests of executive functioning, memory, and visuospatial function.

Conclusions

The present study offers two important contributions to knowledge of the effectiveness of cholinesterase inhibitor treatment in patients with mild-moderate AD: 1) that second-generation cholinesterase inhibitors demonstrate long-term effectiveness for reducing global cognitive decline over one to two years of follow-up, and 2) that decline in function for cognitive domains, including executive function, memory, and visuospatial skill that are primarily mediated by frontal networks and by the cholinergic system, rather than memory, may be slowed by treatment targeting the cholinergic system.

The Cache County Study on Memory in Aging: factors affecting risk of Alzheimer's disease and its progression after onset

The Cache County Study on Memory in Aging is a longitudinal, population-based study of Alzheimer's disease (AD) and other dementias. Initiated in 1995 and extending to 2013, the study has followed over 5,000 elderly residents of Cache County, Utah (USA) for over twelve years. Achieving a 90% participation rate at enrolment, and spawning two ancillary projects, the study has contributed to the literature on genetic, psychosocial and environmental risk factors for AD, late-life cognitive decline, and the clinical progression of dementia after its onset. This paper describes the major study contributions to the literature on AD and dementia.

Retrospective cohort study of the efficacy of caprylic triglyceride in patients with mild-to-moderate alzheimer's disease

BACKGROUND

The purpose of this study was to evaluate the effects of caprylic triglyceride (CT) in patients with mild-to-moderate Alzheimer's disease (AD) in routine clinical practice via review of medical records and caregiver questionnaires.

METHODS

Participants were outpatients aged ≥50 years with a diagnosis of probable mild-to-moderate AD who had received CT for ≥6 months. The primary outcome was change from baseline in the patient's condition as rated by the treating physician using a physician's overall assessment.

RESULTS

A total of 55 patients were included. The physician's overall assessment indicated that ~80% of patients who had CT added to ongoing pharmacotherapy were stable or improved. Mini-Mental State Examination scores also remained stable over 15 months of therapy (20.6 ± 3.0 at baseline and 20.1 ± 5.6 at follow-up, P = 0.5233, n = 27). Caregiver assessments indicated that most patients were stable or improved with respect to memory and ability to carry out activities of daily living. The most frequent adverse events with CT involved the gastrointestinal system.

CONCLUSION

Results from this chart review indicate that addition of CT to pharmacotherapy was associated with stable disease or improvement over a follow-up period of 18.8 months.

Retrospective case studies of the efficacy of caprylic triglyceride in mild-to-moderate Alzheimer's disease

Under normal conditions, the adult human brain is fueled primarily by glucose. A prominent feature of Alzheimer's disease (AD) is region-specific decreases in cerebral glucose metabolism. Ketone bodies are a group of compounds produced from fat stores during periods of low glucose availability that can provide an alternative to glucose for brain metabolism. Consumption of sufficient quantities of caprylic triglyceride (CT) increases plasma concentrations of ketone bodies and may be beneficial in conditions of compromised glucose metabolism, such as AD. The present study describes the use of CT in mild-to-moderate AD in routine clinical practice. Case records from eight patients with extensive monitoring of cognitive function using the Mini-Mental State Examination (MMSE) and who had received CT for ≥6 months were reviewed. All were outpatients aged ≥50 years, cared for in standard practice, had a diagnosis of probable AD of mild-to-moderate severity (MMSE 14-24), and had received CT for at least 6 months in addition to other approved pharmacotherapy for AD. Response to CT administration as measured by MMSE scores varied by patient. However, the rate of decline in MMSE scores appeared slower than previously published reports for patients treated with pharmacotherapy alone. Profiling of individual patients may provide insight regarding those most likely to benefit from addition of CT to currently approved AD pharmacotherapy.

Caregiver personality predicts rate of cognitive decline in a community sample of persons with Alzheimer's disease. The Cache County Dementia Progression Study

BACKGROUND

Environmental influences on the rate of Alzheimer's disease (AD) progression have received little attention. Our objective was to test hypotheses concerning associations between caregiver personality traits and the rate of AD progression.

METHODS

Care receivers (CR) were 161 persons with AD from a population-based dementia progression study; 55 of their caregivers were spouses and 106 were adult children. Cognitive status of the CR was measured with the Mini-Mental State Examination every six months, over an average of 5.6 (range: 1-14) years. Linear mixed models tested rate of cognitive decline as a function of caregiver personality traits from the NEO Five-Factor Inventory.

RESULTS

Significantly faster cognitive decline was observed with higher caregiver Neuroticism overall; however, in stratified models, effects were significant for adult child but not spouse caregivers. Neuroticism facets of depression, anxiety, and vulnerability to stress were significantly associated with faster decline. Higher caregiver Extraversion was associated with slower decline in the CR when caregivers were adult children but not spouses.

CONCLUSIONS

For adult child caregivers, caregiver personality traits are associated with rate of cognitive decline in CRs with AD regardless of co-residency. Results suggest that dementia caregiver interventions promoting positive care management strategies and ways to react to caregiving challenges may eventually become an important complement to pharmacologic and other approaches aimed at slower rate of decline in dementia.

Slowing progression of early stages of AD with alternative therapies: a feasibility study

This pilot study identified the feasibility and efficacy of the effect of combining healing touch (HT) and body talk cortices (BTC) on the progression of Alzheimer's disease (AD). Both HT and BTC elicit the relaxation response and support cognitive function from two different perspectives. A two-group, repeated measures design was used. Subjects (n = 22), 65 or older with early stage (less than four) AD, residing in the community (n = 2) or in care agencies (n = 20), were assigned to either the HT-BTC group (n = 12) or the control group (n = 10) randomized by residence. The treatment group received, 6 months of weekly HT and performed the BTC technique daily. The usual medical regimen for all subjects was continued. The control group had no additional interventions. Both groups were assessed at baseline, 3 and 6 months. The groups did not differ significantly at baseline on cognitive reserve, age, gender, and ethnicity, nor on the outcome variables (cognitive function, mood, & depression). Adherence (76%) to the BTC protocol, the major feasibility problem, related to memory deficits. Significant interactions occurred regarding cognitive function and mood. Significant improvements in cognitive function (p = .008), mood (p = .001), and depression (p = .028) were observed in the treatment group which is not the usual course of AD. A decline in cognitive function occurred in the control group typical of AD's usual course. Although the number of subjects in this pilot study was small, and there were feasibility challenges with recruitment and adherence, important trends were noted suggesting areas for future study.

Smell identification function as a severity and progression marker in Alzheimer's disease

BACKGROUND

Olfactory dysfunction, impaired smell identification in particular, is known as a diagnostic and a marker of conversion in Alzheimer's disease (AD). We aimed to evaluate the associations of olfactory identification impairments with cognition, illness severity, and progression in AD patients.

METHODS

Fifty-seven outpatients with late onset mild to moderate AD and 24 elderly non-demented controls (NDC) were assessed, at baseline and after three months, for Mini-Mental State Examination (MMSE), University of Pennsylvania Smell Identification Test (UPSIT), and Bristol Activities of Daily Living and Neuropsychiatry Inventory. AD participants were classified as Rapid Cognitive Decliners (RCD) defined on a priori with a loss of ≥2 points in MMSE within the previous six months.

RESULTS

AD participants had lower olfactory scores than NDC. RCD had lower olfaction scores compared with Non-Rapid Cognitive Decliners (NRCD). Although the baseline UPSIT scores were associated with baseline MMSE scores, it did not interact significantly with change in MMSE over the follow-up period. Using a median split for olfactory scores, the AD participants were classified as Rapid Olfactory Progressors (ROP) (UPSIT ≤ 15) and Slow Olfactory Progressors correlating significantly with RCD/NRCD groups. The ROP group with higher olfactory impairment indicated more symptomatic illness or severity, i.e. lower cognition, higher functional dependence, and presence of behavioral symptoms.

CONCLUSIONS

Our study supports association of smell identification function with cognition and its utility as an adjunct clinical measure to assess severity in AD. Further work, including larger longitudinal studies, is needed to explore its value in predicting AD progression.

Caregiver coping strategies predict cognitive and functional decline in dementia: the Cache County Dementia Progression Study

OBJECTIVES

Few longitudinal studies have studied the influence of the care environment on the clinical progression of dementia. We examined whether caregiver coping strategies predict dementia progression in a population-based sample.

DESIGN

Longitudinal, prospective cohort study.

SETTING

Cache County (Utah) population.

PARTICIPANTS

A total of 226 persons with dementia, and their caregivers, were assessed semiannually for up to 6 years.

MEASUREMENTS

Ways of Coping Checklist-Revised, Mini-Mental State Examination (MMSE), and Clinical Dementia Rating (CDR).

RESULTS

Mean (SD) age of dementia onset in persons with dementia was 82.11 (5.84) years and mean caregiver age was 67.41 (13.95) years. Mean (SD) follow-up was 1.65 (1.63) years from baseline. In univariate linear mixed-effects models, increasing use of problem-focused and counting blessings by caregivers was associated with slower patient worsening on the MMSE. Problem-focused coping, seeking social support, and wishful thinking were associated with slower Clinical Dementia Rating Scale sum of boxes (CDR-sb) worsening. Considering covariates, increasing use of problem-focused coping was associated with 0.70 points per year less worsening on the MMSE and 0.55 points per year less worsening on the CDR-sb. Compared with no use, the "regular" use of this strategy was associated with 2 points per year slower worsening on the MMSE and 1.65 points per year slower worsening on the CDR-sb.

CONCLUSIONS

Caregiver coping strategies are associated with slower dementia progression. Developing interventions that target these strategies may benefit dementia patients.

Does Alzheimer's disease with early onset progress faster than with late onset? A case-control study of clinical progression and cerebrospinal fluid biomarkers

BACKGROUND

Early-onset Alzheimer's disease (EOAD) is generally thought to have a more rapid course compared to late-onset Alzheimer's disease (LOAD). The faster progression of EOAD observed in some studies has also been thought to correlate with cerebrospinal fluid (CSF) biomarkers. Our clinical experience has not been suggestive of any difference in disease progression; therefore, we decided to investigate whether differences in clinical progression and CSF biomarkers between EOAD and LOAD could be demonstrated.

METHODS

Case-control study with 42 patients, 21 EOAD and 21 matched LOAD patients. Rates of progression were calculated and these, as well as CSF biomarker levels, were statistically compared.

RESULTS

There were no statistically significant differences in clinical progression between the EOAD group and the LOAD group. There was no significant difference in the absolute values of CSF biomarkers, but a tendency towards lower levels of β-amyloid in patients with EOAD was observed.

CONCLUSIONS

Our findings did not converge with results from the majority of previous studies, which have been suggestive of a faster clinical progression in EOAD. Possibly, the very strict algorithm by which our patients were matched explains our findings. However, the findings should be repeated in a larger study population.

Long-term progression of Alzheimer's disease in patients under antidementia drugs

BACKGROUND

Patients with Alzheimer's disease (AD), even in the presence of symptomatic relief from medical intervention, face a persistent worsening of cognitive decline and performance in activities of daily living. Data regarding the long-term disease progression outside of therapeutic trials are lacking. We examined the effects of standard of care for AD patients on the prognosis of the disease in a real-life study over a 4-year period.

METHODS

A total of 686 patients with mild-moderate AD were enrolled in 16 memory clinics (REseau sur la maladie d' Alzheimer FRançais [REAL.FR] cohort) and followed up twice annually with tools used in therapeutic trials (Mini-Mental Status Examination, Alzheimer Disease Assessment Scale-cognitive subscale [ADAS-cog]: cognitive function, Clinical Dementia Rating: dementia severity, Activity of Daily Living [ADL]: incapacities, NeuroPsychiatric Inventory: neuropsychiatric symptom).

RESULTS

More than 90% of the patients used AD-specific medication over 4 years. Patients lost on average 2.4 points per year on the Mini-Mental Status Examination and gained 4.5 points on the ADAS-cog. ADL and NeuroPsychiatric Inventory scores became significantly worse over time. Incidence of incapacities for ADL and worsening of neuropsychiatric symptoms were 52.5 (95% confidence interval [CI]: 47.7-57.4) and 51.1 (95% CI: 46.2-56.1), respectively. Rates of mortality and institutionalization were 7.4 (95% CI: 6.2-8.5) and 13.4 (95% CI: 11.7-15.1). In all, 17% of patients in mild stage at baseline (Clinical Dementia Rating = 0.5) did not experience a major event (functional disabilities, neuropsychiatric symptoms, or death) over a 4-year period.

CONCLUSIONS

As compared with previous surveys, the current study shows slower rates of decline in AD patients. The present data also underline the high level of variability of disease progression among AD patients. Outcome measures commonly used in clinical trials will need to take into account the recent changes in the prognosis of the disease.

Determining the minimum clinically important differences for outcomes in the DOMINO trial

BACKGROUND

Although less likely to be reported in clinical trials than expressions of the statistical significance of differences in outcomes, whether or not a treatment has delivered a specified minimum clinically important difference (MCID) is also relevant to patients and their caregivers and doctors. Many dementia treatment randomised controlled trials (RCTs) have not reported MCIDs and, where they have been done, observed differences have not reached these.

METHODS

As part of the development of the Statistical Analysis Plan for the DOMINO trial, investigators met to consider expert opinion- and distribution-based values for the MCID and triangulated these to provide appropriate values for three outcome measures, the Standardised Mini-mental State Examination (sMMSE), Bristol Activities of Daily Living Scale (BADLS) and Neuropsychiatric Inventory (NPI). Only standard deviations (SD) were presented to investigators who remained blind to treatment allocation.

RESULTS

Adoption of values for MCIDs based upon 0.4 of the SD of the change in score from baseline on the sMMSE, BADLS and NPI in the first 127 participants to complete DOMINO yielded MCIDs of 1.4 points for sMMSE, 3.5 for BADLS and 8.0 for NPI.

CONCLUSIONS

Reference to MCIDs is important for the full interpretation of the results of dementia trials and those conducting such trials should be open about the way in which they have determined and chosen their values for the MCIDs.

Progression of cognitive, functional, and neuropsychiatric symptom domains in a population cohort with Alzheimer dementia: the Cache County Dementia Progression study

OBJECTIVES

Progression of Alzheimer dementia (AD) is highly variable. Most estimates derive from convenience samples from dementia clinics or research centers where there is substantial potential for survival bias and other distortions. In a population-based sample of incident AD cases, we examined progression of impairment in cognition, function, and neuropsychiatric symptoms, and the influence of selected variables on these domains.

DESIGN

Longitudinal, prospective cohort study.

SETTING

Cache County (Utah).

PARTICIPANTS

Three hundred twenty-eight persons with a diagnosis of possible/probable AD.

MEASUREMENTS

Mini-Mental State Exam (MMSE), Clinical Dementia Rating sum-of-boxes (CDR-sb), and Neuropsychiatric Inventory (NPI).

RESULTS

Over a mean follow-up of 3.80 (range: 0.07-12.90) years, the mean (SD) annual rates of change were -1.53 (2.69) scale points on the MMSE, 1.44 (1.82) on the CDR-sb, and 2.55 (5.37) on the NPI. Among surviving participants, 30% to 58% progressed less than 1 point per year on these measures, even 5 to 7 years after dementia onset. Rates of change were correlated between MMSE and CDR-sb (r = -0.62, df = 201, p < 0.001) and between the CDR-sb and NPI (r = 0.20, df = 206, p < 0.004). Female subjects (LR χ = 8.7, df = 2, p = 0.013) and those with younger onset (likelihood ratio [LR] χ = 5.7, df = 2, p = 0.058) declined faster on the MMSE. Although one or more apolipoprotein E ε 4 alleles and ever use of FDA-approved antidementia medications were associated with initial MMSE scores, neither was related to the rate of progression in any domain.

CONCLUSIONS

A significant proportion of persons with AD progresses slowly. The results underscore differences between population-based versus clinic-based samples and suggest ongoing need to identify factors that may slow the progression of AD.

Epidemiology, assessment, and treatment of dementia

The risk of developing dementia is associated with increasing age, lifestyle, and cardiovascular health. Alzheimer dementia is characterized by progressive cognitive deficits and decline in functional ability. Using history, examination, and laboratory testing, the clinician can evaluate the patient with dementia. Specific to these conditions are assessments of cognition, neuropsychiatric symptoms, and level of functioning. Managing neuropsychiatric symptoms is challenging and requires a team approach in which nonpharmacological strategies are preferred before medications are considered. Various diagnostic methods are being developed to discriminate disease from nondisease and track progression. Drug discovery is identifying novel molecules that target underlying disease mechanisms.

Alzheimer's disease: the strength of association of costs with different measures of disease severity

OBJECTIVE

To identify Alzheimer's disease (AD) severity measures for use in cost-effectiveness models that effectively capture the impact of AD on costs.

METHODS

A review of the literature and data abstraction from papers that present 1) mean AD costs (direct, indirect, or total) by disease severity, defined using measure of cognition, functional status, and behavior; and/or 2) the results of regression analyses that estimate the strength of the association between AD costs and disease severity.

RESULTS

All papers reviewed showed that mean total costs increase with disease severity regardless of severity-measurement method. The relative difference in mean total costs between patients with severe disease compared to those with moderate disease, or moderate disease compared to mild disease, was fairly consistent across studies, suggesting that any of the disease-severity measures may be used to broadly categorize patients by cost. However, when regression analysis included multiple disease-severity measures, independent associations with costs were noted for the different measures. Cognitive and functional status measures were consistently associated with direct costs, whereas functional status and behavioral measures were consistently associated with indirect costs and caregiver hours.

CONCLUSIONS

Either multidimensional disease-severity measures, or a single disease-severity measure, that capture the impact of cognition, functional status, and behavior on costs are needed for cost-effectiveness models.

Follow-up for Alzheimer patients: European Alzheimer Disease Consortium position paper

BACKGROUND AND PURPOSE

Alzheimer disease (AD) is one of the leading causes of dependence in the elderly. Providing care for patients with AD is complex and the type of care required depends on the stage of the disease and varies over time. The aim of this article is to discuss available care strategies once the AD diagnosis has been made and to propose a follow-up plan as standard of care at a European level.

METHODS

The proposals developed in this article stem from the collaborative work of a panel of multidisciplinary experts involved in the care of AD patients (European Alzheimer Disease Consortium) based on the results of published scientific studies and on their experience from clinical practice.

CONCLUSION

Suggestions for follow-up frequency and easily administered and scored assessment tools are provided, thereby increasing efficiency and quality of care for patients with Alzheimer disease.

Caregiver-recipient closeness and symptom progression in Alzheimer disease. The Cache County Dementia Progression Study

Applying Rusbult's investment model of dyadic relationships, we examined the effect of caregiver-care recipient relationship closeness (RC) on cognitive and functional decline in Alzheimer's disease. After diagnosis, 167 participants completed up to six visits, observed over an average of 20 months. Participants were 64% women, had a mean age of 86 years, and mean dementia duration of 4 years. Caregiver-rated closeness was measured using a six-item scale. In mixed models adjusted for dementia severity, dyads with higher levels of closeness (p < .05) and with spouse caregivers (p = .01) had slower cognitive decline. Effect of higher RC on functional decline was greater with spouse caregivers (p = .007). These findings of attenuated Alzheimer's dementia (AD) decline with closer relationships, particularly with spouse caregivers, are consistent with investment theory. Future interventions designed to enhance the caregiving dyadic relationship may help slow decline in AD.

Longitudinal multimodal imaging in mild to moderate Alzheimer disease: a pilot study with memantine

OBJECTIVE

To study the feasibility of multimodal neuroimaging in mild to moderate Alzheimer disease (AD) and to estimate the size of possible treatment effects of memantine on potential functional, structural and metabolic biomarkers of disease progression.

METHODS

In this randomised, double-blind, placebo-controlled pilot study, 36 patients with moderate AD received 52 weeks of memantine (20 mg/day) or placebo. Patients were re-evaluated after 26 and 52 weeks to measure the change from baseline in several outcome measures including global and regional glucose metabolism, total brain and hippocampal volumes, as well as chemical shift imaging-derived global and regional N-acetylaspartate and myoinositol concentrations.

RESULTS

In the total population, global glucose metabolism decreased by 2.3% (p<0.01), total brain volume by 2.1% (p<0.001) and hippocampal volume by 2.7% (p<0.01) after 52 weeks. Chemical shift imaging (CSI) spectra were severely affected by patient-induced artefacts and highly variable. Patients receiving memantine showed less decline in glucose metabolism in all brain areas than patients on placebo. Their loss of hippocampal volume was substantially smaller (2.4% vs 4.0%). No between-group differences were seen for changes in total brain volume.

CONCLUSIONS

The results support the use of multimodal imaging including MRI and positron emission tomography (PET) to monitor the progression of moderate AD. CSI yielded unreliable longitudinal results. The data suggest that memantine has potentially protective effects in AD and they can be used for planning larger confirmatory studies on the cerebral effects of memantine.

Alzheimer's Disease, Diagnosis and the Need for Biomarkers

Alzheimer's disease (AD) is a progressive neurodegenerative disorder of aging that presents with memory loss, disorientation, confusion and a reduction in cognitive ability. Although a definite diagnosis of the disorder can only be made post-mortem by histopathological analysis, a number of methods are currently available for the in vivo assessment of AD including psycho-metric tests and neuro-imaging. However, these clinical assessments are relatively nonspecific and imaging is very costly. Genetic testing can be performed if familial AD is suspected, although such cases represent a very small minority of total AD cases. Apolipoprotein E genotype provides a measure for analysing the risk of developing AD, but does not act as an absolute predictive biomarker for AD. Therefore there is a need for an accurate, universal, specific and cost-effective biomarker to facilitate not only ante-mortem diagnosis of AD, but also to allow progression of the disease and response to therapy to be monitored. This is the ultimate goal that our group is pursuing through the pan-European AddNeuroMed project.

Blood Pressure Variability and Dementia Rating Scale Performance in Older Adults With Cardiovascular Disease

OBJECTIVE

The present study examined the relationship between multiple indices of blood pressure (BP) and cognitive function (as measured by the Dementia Rating Scale).

BACKGROUND

Cardiovascular disease (CVD) is associated with cognitive dysfunction and cerebrovascular pathology in the elderly and is a known risk factor for stroke and Alzheimer disease. Yet, the mechanisms for the effects of CVD on cognitive function are not well understood.

METHODS

Participants were 97 nondemented older adults with CVD who underwent neuropsychologic assessment, and a 2-hour cardiovascular laboratory protocol.

RESULTS

After controlling for age and years of education, results of hierarchical linear regression analyses indicate a significant positive relationship between a function of BP variability (SD of systolic BP divided by the average diastolic BP) and cognitive function (R change=0.042, F (1, 85)=5.434, P<0.05). No relationship emerged between any other BP index and cognitive function.

CONCLUSIONS

Contrary to expectations, greater BP variability was associated with better, not poorer, cognitive test performance. These findings suggest that the relationship between BP and cognitive function is more complicated than originally conceptualized and requires further investigation.

Strategies to optimize the validity of disease models in the drug discovery process

Models of human diseases are necessary for experimental research into the biological basis of disease and for the development of treatments. They have an enormous impact upon the success of biomedical research. However, in spite of this, a consistent system for evaluating, expressing and comparing the clinical validity of disease models is not available. The purpose of this paper is, therefore, to provide a theoretical discussion of the concepts behind disease models and to develop a terminology and a framework to analyze and express the clinical validity of disease models.

Longitudinal metric properties of disability rating scales for Parkinson's disease

OBJECTIVES

This study analyzes the longitudinal metric attributes of three Parkinson's disease (PD) disability scales, taking Hoehn and Yahr (HY) staging as the reference measure of PD progression.

METHODS

A sample of 87 PD patients was assessed during regular medical visits, using the HY, the Unified Parkinson's Disease Rating Scale--Activities of Daily Living Section (UPDRS-ADL), the Schwab and England Scale (SES), and the Intermediate Scale for Assessment of PD (ISAPD), across a follow-up period of 2.6 +/- 1.0 years.

RESULTS

The following cross-sectional attributes were analyzed, at baseline and again on conclusion of the study: floor and ceiling effects, convergent validity, reliability, and standard error of measurement, all of which were found to be adequate. Longitudinal reproducibility values (intraclass correlation coefficient) were 0.81 (ISAPD) to 0.84 (UPDRS-ADL). Insofar as longitudinal validity was concerned, the change scores of the three disability scales correlated significantly with the HY change score, absolute value r = 0.33 to 0.45, P < 0.003. Slightly lower values were found when taking the annual rate of change, absolute value r = 0.20 to 0.36. The three scales were acceptable, even though there were small differences among them. The "minimal clinically important difference" proposed for these scales is: SES, -6; UPDRS-ADL, +2; ISAPD, +1.5 points.

CONCLUSIONS

The three scales proved adequate for longitudinal assessment of PD disability. UPDRS-ADL was more precise and ISAPD more consistent. Magnitude of change and correlation with change in HY were slightly higher with the ISAPD. Effect size and standardized response mean for the minimal change in HY were higher for the UPDRS-ADL.

Comparison between neuropsychological evaluation instruments for severe dementia

OBJECTIVE: To study the correlation between two tools for cognitive evaluation, Mini-Mental State Examination-severe (MMSE-s) and Severe Impairment Battery (SIB), and the Bristol Daily Activities Functional Scale. METHOD: 50 patients from the Behavioral Neurology Section - EPM-UNIFESP - were evaluated. Mean age was 76.8±7.9 (range 57 to 95); 32% were males; mean education was 5.0±2.3 years (range 4 to 15); mean disease duration was 3.9±1.5 years (range 2 to 10). RESULTS: Preliminary results in a small sample drawn from the study group do indicate a difference between the three cognitive scales. SIB and MMSE-s had a better correlation with functional score than MMSE, and MMSE-s had a correlation slightly better than SIB. CONCLUSION: These data indicate that it is possible to follow dementia patients up to severe stage as long as adequate instruments are used, and that there may be differences between scales with regard to sensitivity.

Relation of brain natriuretic peptide levels to cognitive dysfunction in adults > 55 years of age with cardiovascular disease

Cardiovascular disease (CVD) is associated with cognitive deficits long before the onset of stroke or dementia. Recent work has extended these findings and shown that patients with congestive heart failure also exhibit reduced cognitive performance. Brain natriuretic peptide (BNP) is used to help diagnose heart failure, but no study has examined whether BNP predicts cognitive dysfunction in older patients with CVD. BNP values and performance on the Dementia Rating Scale were assessed in 56 older adults with documented CVD. Forty-eight percent of the participants were women, and their average age was 70 +/- 8 years. All participants had Mini-Mental State Examination scores greater than the cutoff for dementia and no histories of neurologic or severe psychiatric disorders. The average BNP level was 122 +/- 202 pg/ml. Hierarchical regression analyses showed that log-transformed BNP levels predicted Dementia Rating Scale total score after adjusting for possible demographic and medical confounders (DeltaR2 = 0.09, F[1, 44] = 6.14, p = 0.017). Partial correlation analysis adjusting for these possible confounders showed a particularly strong relation to the conceptualization subtest (r = -0.44, p = 0.002), a measure of verbal and nonverbal abstraction abilities. In conclusion, the results of the present study provide the first evidence for an independent relation between BNP and cognitive dysfunction in older adults with CVD.