The AD8: a brief informant interview to detect dementia

Characterizing healthy samples for studies of human cognitive aging

Characterizing the cognitive declines associated with aging, and differentiating them from the effects of disease in older adults, are important goals for human neuroscience researchers. This is also an issue of public health urgency in countries with rapidly aging populations. Progress toward understanding cognitive aging is complicated by numerous factors. Researchers interested in cognitive changes in healthy older adults need to consider these complexities when they design and interpret studies. This paper addresses important factors in study design, patient demographics, co-morbid and incipient medical conditions, and assessment instruments that will allow researchers to optimize the characterization of healthy participants and produce meaningful and generalizable research outcomes from studies of cognitive aging. Application of knowledge from well-designed studies should be useful in clinical settings to facilitate the earliest possible recognition of disease and guide appropriate interventions to best meet the needs of the affected individual and public health priorities.

The Cognitive Change in Women study (CCW): informant ratings of cognitive change but not self-ratings are associated with neuropsychological performance over 3 years

The value of self-reported memory complaints for identifying or predicting future cognitive decline or dementia is controversial, but observations from a third party, or "informant," may prove more useful. The relationship between Informant and Self-ratings of cognitive status and neuropsychological test scores was examined in a cohort of 384 nondemented, community-dwelling women, aged 60 years and older, participating in a single-site Women's Health Initiative ancillary study. Each participant and her respective informant separately completed the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Participants also underwent neuropsychological testing and responded to questionnaires on depression and functioning in complex activities of daily living. All neuropsychological test scores were significantly correlated (P values <0.05 to <0.01) with IQCODE ratings whereas Self-ratings overestimated cognitive functioning in some domains. Furthermore, the Self and Informant ratings were both positively correlated with depression and negatively correlated with participants' activity level. Therefore, informant judgments of functional abilities are robust predictors of cognitive status in high functioning nondemented women. These results suggest that informants may be sensitive to changes that are not clinically significant but that may represent an incipient trend for decline.

The integration of frailty into clinical practice: preliminary results from the Gérontopôle

BACKGROUND

Disability is commonly considered as an irreversible condition of advanced age. Therefore, preventive actions need to be taken before the disabling cascade is fully established, that is in the pre-disability phase defined "frailty syndrome". The complexity and heterogeneity of frailty requires a clinical approach based on multidimensionality and multidisciplinary. In this paper, we present the main characteristics of the newborn Platform for Evaluation of Frailty and Prevention of Disability (Toulouse, France).

INTERVENTION

Persons aged 65 years and older screened for frailty by general practitioners in the Toulouse area are invited to undergo a multidisciplinary evaluation at the Platform. Here, the individual is multidimensionality assessed in order to preventively detect potential risk factors for disability. At the end of the comprehensive evaluation, the team members propose the patient (in agreement with the general practitioner) a preventive intervention program specifically tailored to the his/her needs and resources.

RESULTS

Mean age of our population is 82.7 years, with a large majority aged 75 years and older. Most patients are women (61.9%) Approximately two thirds of patients received any kind of regular help. Regarding level of frailty, 65 patients (41.4%) were pre-frail, and 83 (52.9%) frail. For what concerns the functional status, 83.9% of patients presented slow gait speed, 53.8% were sedentary, and 57.7% had poor muscle strength. Only 27.2% of patients had a SPPB score equal to or higher than 10. Autonomy in ADL was quite well preserved (mean ADL score 5.6 ± 0.8) as expected, suggesting that the patients of the platform have not yet developed disability. Consistently, IADL showed a marginal loss of autonomy reporting a mean score of 6.0 ± 2.3. About one third of patients (33.1%) presented a MMSE score lower than 25. Dementia (measured by the CDR scale) was observed in 11.6% of the platform population, whereas subjects with mild cognitive impairment (that is CDR equal to 0.5) were 65.8%. New diagnosed depressive disorders were relatively rare with only 3.2% of patients showing signs of depression but some people were already treated. Numerous patients presented vision problems with 10.4% having abnormal findings at the Amsler grid. Finally, it is noteworthy that 9% of the platform population presented an objective state of protein-energy malnutrition, 34% an early alteration of nutritional status, while almost everyone (94.9%) had a vitamin D deficiency (partially explained by the period of the year, that is winter-spring, of most of the measurements).

CONCLUSION

The Platform clinically evaluates and intervenes on frailty for the first time at the general population-level. This model may serve as preliminary step towards a wider identification of early signs of the disabling cascade in order to develop more effective preventive interventions.

Improving physician awareness of Alzheimer disease and enhancing recruitment: the Clinician Partners Program

BACKGROUND

Primary care providers routinely evaluate older adults and are thus in a position to first detect symptoms and signs of Alzheimer disease. In urban areas, diagnostic or management difficulties may be referred to specialists; however, in rural areas, specialists may not be available. The Clinician Partners Program (CPP) was initiated to enhance rural health providers' ability in the diagnosis of dementia and care, and to increase research recruitment into dementia research studies of participants from rural communities.

METHODS

The CPP is a 3-day "miniresidency" of didactic, observational, and skill-based teaching techniques. Participants completed pretests and posttests evaluating dementia knowledge, confidence in providing care, and practice behaviors.

RESULTS

Between 2000 and 2009, 146 health care professionals with a mean age of 45.7±10.8 years attended the CPP; 79.2% were white, 58.2% were women, and 58% of participants had been in practice for more than 10 years. Posttests showed an improvement in knowledge and confidence for diagnosis and treatment and increased the use of dementia screening tools. Rural research participation in an urban Alzheimer Disease Research Center increased 52% over the pre-CPP period.

CONCLUSIONS

The following primary goals were accomplished: increased knowledge and confidence, changed practice habits, and enhanced research recruitment. Educational programs such as the CPP may be beneficial for increasing access to accurate diagnoses and appropriate treatment for Alzheimer disease while also enhancing research participation.

Practical clinical tool to monitor dementia symptoms: the HABC-Monitor

Background

Dementia care providers need a clinical assessment tool similar to the blood pressure cuff (sphygmomanometer) used by clinicians and patients for managing hypertension. A “blood pressure cuff ” for dementia would be an inexpensive, simple, user-friendly, easily standardized, sensitive to change, and widely available multidomain instrument for providers and informal caregivers to measure severity of dementia symptoms. The purpose of this study was to assess the reliability and validity of the Healthy Aging Brain Care Monitor (HABC-Monitor) for measuring and monitoring the severity of dementia symptoms through caregiver reports.

Methods

The first prototype of the HABC-Monitor was developed in collaboration with the Indianapolis Discovery Network for Dementia, which includes 200 members representing 20 disciplines from 20 local organizations, and an expert panel of 22 experts in dementia care and research. The HABC-Monitor has three patient symptom domains (cognitive, functional, behavioral/psychological) and a caregiver quality of life domain. Patients (n = 171) and their informal caregivers (n = 171) were consecutively approached and consented during, or by phone shortly following, a patient’s routine visit to their memory care provider.

Results

The HABC-Monitor demonstrated good internal consistency (0.73–0.92); construct validity indicated by correlations with the caregiver-reported Neuropsychiatric Inventory (NPI) total score and NPI caregiver distress score; sensitivity to three-month change compared with NPI “reliable change” groups; and known-groups validity, indicated by significant separation of Mini-Mental Status Examination severity groups and clinical diagnostic groups. Although not designed as a screening study, there was evidence for good operating characteristics, according to area under the receiver-operator curve with respect to gold standard clinical diagnoses, relative to Mini-Mental Status Examination or NPI.

Conclusion

The HABC-Monitor demonstrates good reliability and validity as a clinically practical multidimensional tool for monitoring symptoms of dementia through the informal caregiver.

OPTIMIZING DIAGNOSIS AND MANANGEMENT IN MILD-TO-MODERATE ALZHEIMER'S DISEASE

Alzheimer's disease (AD) is characterized by progressive declines in cognitive function and ability to carry out activities of daily living; and the emergence and worsening of behavioral/neuropsychiatric symptoms. While there is no cure for AD, non-pharmacologic interventions and medications that modulate neurotransmission can slow symptomatic progression. Medical foods may also be useful as adjuncts to pharmacologic agents in AD. Medium chain triglycerides aimed at improving cerebral metabolism significantly improve Alzheimer's Disease Assessment Scale-Cognitive scores when added to ongoing pharmacotherapy in patients with mild-to-moderate AD. Combination of interventions, such as non-pharmacologic treatments, pharmacotherapy, and medical foods, with complementary mechanisms of action may provide a rational approach that may result in maximum preservation of cognitive function in patients with AD.

Assessing the diagnostic accuracy (DA) of the Spanish version of the informant-based AD8 questionnaire

INTRODUCTION

The AD8 is a brief informant-based questionnaire that may also be self-administered, and which aids in identifying cognitive impairment (CI). Our goal is to assess the diagnostic accuracy (DA) of a Spanish version of that questionnaire.

MATERIAL AND METHODS

Cross-sectional study of a clinical sample of patient/informant dyads including 330 subjects with suspected CI or dementia (DEM) and 71 controls. We evaluated internal consistency (Cronbach's alpha) and validity (partial correlations with GDS stage, Fototest results and functional index measure [FIM]). We assessed DA for CI vs no CI (GDS stage 3-4) using the area under the ROC curve (AUC), and the cut-off with the highest Youden index was determined to be optimal.

RESULTS

In the sample, 105 subjects had no CI, 99 had CI without DEM and 203 had DEM. Internal consistency was high (α 0.90, 95% confidence interval: 0.89-0.92), as were correlations with the GDS score (r=0.72, P<.001), Fototest results (r=-0.61, P<.001) and FIM (r=0.59, P<.001). The AUC for AD8 was 0.90 (95% confidence interval: 0.86-0.93), which was not significantly different from that of the Fototest (AUC 0.93, 95% confidence interval: 0.89-0.96). The optimal cut-off point was 3/4 with a sensitivity of 0.93 (95% confidence interval: 0.88-0.96) and a specificity of 0.81 (95% confidence interval: 0.72-0.88); 88.8% of the classifications were correct. Combined use of AD8 and the Fototest significantly improved the DA of both (AUC 0.96, 95% confidence interval: 0.93-0.98, P<.05).

CONCLUSIONS

The Spanish version of the AD8 questionnaire preserves the psychometric qualities and DA of the original. Using this test in combination with the Fototest significantly increases the DA of both tests.

Genomic determinants of motor and cognitive outcomes in Parkinson's disease

BACKGROUND

Little is known regarding genetic factors associated with motor or cognitive outcomes in Parkinson's disease (PD).

OBJECTIVE

To identify common genetic variants associated with motor and cognitive outcomes in PD.

METHODS

The sample consisted of 443 PD cases included in the first genome-wide association study (GWAS) of PD. Methods included telephone interview assessments of motor and cognitive outcomes, a median 9 years following the initial clinical assessments. Analyses included Cox proportional hazard models to study the association of 198,345 single nucleotide polymorphisms (SNPs) with survival free of Hoehn and Yahr stage ≥ 4 (motor outcome), and either TICS-M ≤ 27 or AD-8 ≥ 2 (cognitive outcomes).

RESULTS

The SNP rs10958605 in the C8orf4 gene had the smallest p value in analyses of the motor outcome (HR = 1.81; 95% CI = 1.42-2.31; p = 1.51 × 10(-6)). The SNP rs6482992 in the CLRN3 gene had the smallest p value in analyses of the cognitive outcome (HR = 2.03, 95% CI 1.47-2.79, p = 4.08 × 10(-6)). However, no SNP associations were significant after Bonferroni correction. The C8orf4 gene had small p values for both motor and cognitive outcomes, highlighting inflammation as a possible pathogenesis mechanism for progression in PD.

CONCLUSIONS

This study suggests that common variants in several genes may be associated with motor and cognitive outcomes in PD, with biological plausibility.

The clinical problem of symptomatic Alzheimer disease and mild cognitive impairment

Alzheimer disease (AD) is the most common cause of dementia in the elderly. Clinicopathological studies support the presence of a long preclinical phase of the disease, with the initial deposition of AD pathology estimated to begin approximately 10-15 years prior to the onset of clinical symptoms. The hallmark clinical phenotype of AD is a gradual and progressive decline in two or more cognitive domains, most commonly involving episodic memory and executive functions, that is sufficient to cause social or occupational impairment. Current diagnostic criteria can accurately identify AD in the majority of cases. As disease-modifying therapies are being developed, there is growing interest in the identification of individuals in the earliest symptomatic, as well as presymptomatic, stages of disease, because it is in this population that such therapies may have the greatest chance of success. The use of informant-based methods to establish cognitive and functional decline of an individual from previously attained levels of performance best allows for the identification of individuals in the very mildest stages of cognitive impairment.

Alzheimer's disease: a clinical practice-oriented review

Investigation in the field of Alzheimer's disease (AD), the commonest cause of dementia, has been very active in recent years and it may be difficult for the clinician to keep up with all the innovations and to be aware of the implications they have in clinical practice. The authors, thus, reviewed recent literature on the theme in order to provide the clinician with an updated overview, intended to support decision-making on aspects of diagnosis and management. This article begins to focus on the concept of AD and on its pathogenesis. Afterward, epidemiology and non-genetic risk factors are approached. Genetics, including genetic risk factors and guidelines for genetic testing, are mentioned next. Recommendations for diagnosis of AD, including recently proposed criteria, are then reviewed. Data on the variants of AD is presented. First approach to the patient is dealt with next, followed by neuropsychological evaluation. Biomarkers, namely magnetic resonance imaging, single photon emission tomography, FDG PET, PiB PET, CSF tau, and Aβ analysis, as well as available data on their diagnostic accuracy, are also discussed. Factors predicting rate of disease progression are briefly mentioned. Finally, non-pharmacological and pharmacological treatments, including established and emerging drugs, are addressed.

Informant-reported cognitive symptoms that predict amnestic mild cognitive impairment

BACKGROUND

Differentiating amnestic mild cognitive impairment (aMCI) from normal cognition is difficult in clinical settings. Self-reported and informant-reported memory complaints occur often in both clinical groups, which then necessitates the use of a comprehensive neuropsychological examination to make a differential diagnosis. However, the ability to identify cognitive symptoms that are predictive of aMCI through informant-based information may provide some clinical utility in accurately identifying individuals who are at risk for developing Alzheimer's disease (AD).

METHODS

The current study utilized a case-control design using data from an ongoing validation study of the Alzheimer's Questionnaire (AQ), an informant-based dementia assessment. Data from 51 cognitively normal (CN) individuals participating in a brain donation program and 47 aMCI individuals seen in a neurology practice at the same institute were analyzed to determine which AQ items differentiated aMCI from CN individuals.

RESULTS

Forward stepwise multiple logistic regression analysis which controlled for age and education showed that 4 AQ items were strong indicators of aMCI which included: repetition of statements and/or questions [OR 13.20 (3.02, 57.66)]; trouble knowing the day, date, month, year, and time [OR 17.97 (2.63, 122.77)]; difficulty managing finances [OR 11.60 (2.10, 63.99)]; and decreased sense of direction [OR 5.84 (1.09, 31.30)].

CONCLUSIONS

Overall, these data indicate that certain informant-reported cognitive symptoms may help clinicians differentiate individuals with aMCI from those with normal cognition. Items pertaining to repetition of statements, orientation, ability to manage finances, and visuospatial disorientation had high discriminatory power.

Preventing recurrence of thromboembolic events through coordinated treatment in the District of Columbia

RATIONALE

PROTECT DC examines whether stroke navigators can improve cardiovascular risk factors in urban underserved individuals newly hospitalized for stroke or ischemic attack. Within one-year of hospital discharge, up to one-third of patients no longer adhere to secondary prevention behaviors. Adherence rates are lower in minority-underserved groups, contributing to health disparities. In-hospital programs increase use of stroke prevention therapies but may not be as successful in underserved individuals. In these groups, low literacy, limited healthcare access, and sparse community resources may reduce adherence. Lay community health workers (navigators) improve adherence in other illnesses through education and assisting in overcoming barriers to achieving desired health behaviors and obtaining needed healthcare services.

AIMS AND DESIGN

PROTECT DC is a Phase II, single-blind, randomized, controlled trial comparing in-hospital education plus stroke navigators to usual care. Atherogenic ischemic stroke and transient ischemic attack survivors are recruited from Washington, DC hospitals. Navigators meet with participants during the index hospitalization, perform home visits, and meet by phone. They focus on stroke education, medication compliance, and overcoming practical barriers to adherence. The interventions are driven by the theories of reasoned action and planned behavior.

STUDY OUTCOMES

The primary dependent measure is a summary score of four objective measures of stroke risk factor control: systolic blood pressure, low-density lipoprotein, hemoglobin Hb A1C, and antiplatelet agent pill counts. Secondary outcomes include stroke knowledge, exercise, dietary modification, and smoking cessation.

CONCLUSION

PROTECT DC will determine whether a Phase III trial of stroke navigation for urban underserved individuals to improve adherence to secondary stroke prevention behaviors is warranted.

EFNS guidelines for the diagnosis and management of Alzheimer's disease

BACKGROUND AND OBJECTIVES

In 2008 a task force was set up to develop a revision of the European Federation of the Neurological Societies (EFNS) guideline for the diagnosis and management of Alzheimer's disease (AD) and other disorders associated with dementia, published in early 2007. The aim of this revised international guideline was to present a peer-reviewed evidence-based statement for the guidance of practice for clinical neurologists, geriatricians, psychiatrists, and other specialist physicians responsible for the care of patients with AD. Mild cognitive impairment and non-Alzheimer dementias are not included in this guideline.

METHODS

The task force working group reviewed evidence from original research articles, meta-analysis, and systematic reviews, published before May 2009. The evidence was classified and consensus recommendations graded (A, B, or C) according to the EFNS guidance. Where there was a lack of evidence, but clear consensus, good practice points were provided.

RESULTS

The recommendations for clinical diagnosis, blood tests, neuropsychology, neuroimaging, electroencephalography, cerebrospinal fluid (CSF) analysis, genetic testing, disclosure of diagnosis, treatment of AD, behavioural and psychological symptoms in dementia, legal issues, counselling and support for caregivers were all revised as compared with the previous EFNS guideline.

CONCLUSION

A number of new recommendations and good practice points are made, namely in CSF, neuropsychology, neuroimaging and reviewing non-evidence based therapies. The assessment, interpretation, and treatment of symptoms, disability, needs, and caregiver stress during the course of AD require the contribution of many different professionals. These professionals should adhere to these guideline to improve the diagnosis and management of AD.

Age differences in the perception of hierarchical structure in events

Everyday activities break down into parts and subparts, and appreciating this hierarchical structure is an important component of understanding. In two experiments we found age differences in the ability to perceive hierarchical structure in continuous activity. In both experiments, younger and older adults segmented movies of everyday activities into large and small meaningful events. Older adults' segmentation deviated more from group norms than did younger adults' segmentation, and older adults' segmentation was less hierarchically organized than that of younger adults. Older adults performed less well than younger adults on event memory tasks. In some cases, measures of event segmentation discriminated between those older adults with better and worse memory. These results suggest that the hierarchical encoding of ongoing activity declines with age, and that such encoding may be important for memory.

The Alzheimer's questionnaire: a proof of concept study for a new informant-based dementia assessment

The aim of this pilot study is to determine the feasibility and clinical utility of a brief, informant-based screening questionnaire for Alzheimer's disease (AD) that can be administered in a primary care setting. The Alzheimer's Questionnaire (AQ) was administered to the informants of 188 patients in 3 dementia clinics (50 cognitively normal, 69 mild cognitive impairment (MCI), 69 AD). Total score for the AQ is based upon the sum of clinical symptom items in which the informant responds as being present. Clinical symptoms which are known to be highly predictive of the clinical AD diagnosis are given greater weight in the total AQ score. The mean time of administration of the AQ was 2.6 ± 0.6 minutes. Sensitivity and specificity were found to be high for detecting both AD (98.55, 96.00) and MCI (86.96, 94.00) with ROC curves yielding AUC values of 0.99 and 0.95, respectively. This pilot study indicates that the AQ is a brief, sensitive measure for detecting both MCI and AD and could be easily implemented in a primary care setting.

The Six-Item Screener and AD8 for the detection of cognitive impairment in geriatric emergency department patients

STUDY OBJECTIVE

We evaluate the diagnostic test characteristics of the Six-Item Screener and the AD8 to detect cognitive dysfunction in adults older than 65 years and using the emergency department (ED) for any reason.

METHODS

We conducted an observational cross-sectional cohort study at a single academic urban university-affiliated hospital. Subjects were consenting, non--critically ill, English-speaking adults older than 65 years and receiving care in the ED. We quantitatively assessed the diagnostic test characteristics of the Six-Item Screener and AD8 by using the Mini-Mental State Examination score less than 24 as the criterion standard for cognitive dysfunction.

RESULTS

The prevalence of cognitive dysfunction was 35%, but only 6% of charts noted a pre-existing deficit. The Six-Item Screener was superior to either the caregiver-administered AD8 or the patient-administered AD8 for the detection of cognitive dysfunction.

CONCLUSION

The Six-Item Screener was superior to the caregiver- or patient-administered AD8 to identify older adults at increased risk for occult cognitive dysfunction.

Operationalizing diagnostic criteria for Alzheimer's disease and other age-related cognitive impairment-Part 1

In this article, the challenges faced by several noted population studies for Alzheimer dementia in operationalizing current clinical diagnostic criteria for Alzheimer's disease (AD) have been reviewed. Differences in case ascertainment, methodological biases, cultural and educational influences on test performance, inclusion of special populations such as underrepresented minorities and the oldest old, and detection of the earliest symptomatic stages of underlying AD have been considered. Classification of Alzheimer dementia may be improved by the incorporation of biomarkers for AD if the sensitivity, specificity, and predictive value of the biomarkers are established and if they are appropriate for epidemiological studies, as may occur should a plasma biomarker be developed. Biomarkers for AD could also facilitate studies of the interactions of various forms of neurodegenerative disorders with cerebrovascular disease, resulting in "mixed dementia".

Four sensitive screening tools to detect cognitive dysfunction in geriatric emergency department patients: brief Alzheimer's Screen, Short Blessed Test, Ottawa 3DY, and the caregiver-completed AD8

BACKGROUND

Cognitive dysfunction, including dementia and delirium, is prevalent in geriatric emergency department (ED) patients, but often remains undetected. One barrier to reliable identification of acutely or chronically impaired cognitive function is the lack of an acceptable screening tool. While multiple brief screening instruments have been derived, ED validation trials have not previously demonstrated tools that are appropriately sensitive for clinical use.

OBJECTIVES

The primary objective was to evaluate and compare the Ottawa 3DY (O3DY), Brief Alzheimer's Screen (BAS), Short Blessed Test (SBT), and caregiver-completed AD8 (cAD8) diagnostic test performance for cognitive dysfunction in geriatric ED patients using the Mini Mental Status Exam (MMSE) as the criterion standard. A secondary objective was to assess the diagnostic accuracy for the cAD8 (which is an informant-based instrument) when used in combination with the other performance-based screening tools.

METHODS

In an observational cross-sectional cohort study at one urban academic university-affiliated medical center, trained research assistants (RAs) collected patients' responses on the Confusion Assessment Method for the Intensive Care Unit, BAS, and SBT. When available, reliable caregivers completed the cAD8. The MMSE was then obtained. The O3DY was reconstructed from elements of the MMSE and the BAS. Consenting subjects were non-critically ill, English-speaking adults over age 65 years, who had not received potentially sedating medications prior to or during cognitive testing. Using an MMSE score of ≤23 as the criterion standard for cognitive dysfunction, the sensitivity, specificity, likelihood ratios, and receiver operating characteristic (ROC) area under the curve (AUC) were computed. Venn diagrams were constructed to quantitatively compare the degree of overlap among positive test results between the performance-based instruments.

RESULTS

The prevalence of cognitive dysfunction for the 163 patients enrolled with complete data collection was 37%, including 5.5% with delirium. Dementia was self-reported in 3%. Caregivers were available to complete the cAD8 for 56% of patients. The SBT, BAS, and O3DY each demonstrated 95% sensitivity, compared with 83% sensitivity for the cAD8. The SBT had a superior specificity of 65%. No combination of instruments with the cAD8 significantly improved diagnostic accuracy. The SBT provided the optimal overlap with the MMSE.

CONCLUSIONS

The SBT, BAS, and O3DY are three brief performance-based screening instruments to identify geriatric patients with cognitive dysfunction more rapidly than the MMSE. Among these three instruments, the SBT provides the best diagnostic test characteristics and overlap with MMSE results. The addition of the cAD8 to the other instruments does not enhance diagnostic accuracy.

Using biomarkers to improve detection of Alzheimer's disease

Disease-modifying approaches for Alzheimer's disease (AD) might be most effective when initiated very early in the course, before the pathologic burden and neuronal and synaptic degeneration make it unlikely that halting disease progression would have a significant impact on patient outcomes. Biomarkers of disease may provide important avenues of research to enhance the diagnosis of individuals with early AD and could assist in the identification of those individuals at risk for developing AD. However, for such biomarkers to become clinically useful, long-term follow-up studies are necessary to evaluate the relevance of cross-sectional biomarker changes to the longitudinal course of the disease. The objective of this article is to review recent progress in AD biomarkers for the early diagnosis, classification, progression and prediction of AD and their usefulness in new treatment trials.

The practice of geriatrics: specialized geriatric programs and home visits

Home visits have a long history in geriatrics. In this narrative review, the literature on home visits performed by specialists in geriatric medicine (or psychiatry) and/or specialized programs in geriatric medicine (or psychiatry) published between January 1988 and December 2008 was examined. The papers reviewed were few and inconsistent in their message. The lessons that can be derived from them are limited. Draft recommendations about the role of home visiting by specialized geriatric programs in Canada are presented.

Application of AD8 questionnaire to screen very mild dementia in Taiwanese

The AD8 questionnaire developed by Washington University in St Louis is a screening tool with 8 questions to reliably differentiate nondemented from demented individuals even at the very mild stage. We recruited 239 participants, including 114 cognitively normal, 73 very mild dementia, and 52 mild dementia to validate its application in Taiwanese. The cut-off value of AD8 was 2 in discriminating cognitively normal from demented individuals with the area under curve (AUC) = 0.961, sensitivity = 97.6%, specificity = 78.1%, positive likelihood ratio (PLR) = 4.5, and negative likelihood ratio (NLR) = 0.03. The cut-off value also was 2 in discriminating nondemented from very mild dementia with the AUC = 0.948, sensitivity = 95.9%, specificity = 78.1%, PLR = 4.4, and NLR = 0.05. The Chinese AD8 is effective in discriminating individuals with dementia, even at its mildest stages from those without dementia with properties identical to the original English version. The cAD8 is a quick dementia screening tool that can be applied across cultures.

Dementia screening, biomarkers and protein misfolding: Implications for public health and diagnosis

Misfolded proteins are at the core of many neurodegenerative diseases, nearly all of them associated with cognitive impairment. For example Creutzfeldt-Jacob disease is associated with aggregation of prion protein, Lewy body dementia and Parkinson disease with α-synuclein and forms of frontotemporal dementia with tau, TDP 43 and host of other proteins, Alzheimer disease (AD), the most common cause of dementia, and its prodromal syndrome mild cognitive impairment (MCI) are an increasing public health problem and a diagnostic challenge to may clinicians. AD is characterized pathologically by the accumulation of amyloid β protein (Aβ) as senile plaques and in the walls of blood vessels as amyloid angiopathy. Additionally, there are accumulations of tau-protein as neurofibrillary tangles and dystrophic neurites. Biological markers of AD and MCI can serve as in vivo diagnostic indicators of underlying pathology, particularly when clinical symptoms are mild and are likely present years before the onset of clinical symptoms. Research to discover and refine fluid and imaging biomarkers of protein aggregation has undergone a rapid evolution and combined analysis of different modalities may further increase diagnostic sensitivity and specificity. Multi-center trials are now investigating whether imaging and/or cerebrospinal fluid (CSF) biomarker candidates can be used as outcome measures for use in phase III clinical trials for AD.

Ascertainment bias in the clinical diagnosis of Alzheimer disease

BACKGROUND

The clinical diagnosis of Alzheimer disease (AD) is often based, at least in part, on poor cognitive test performance compared with normative values.

OBJECTIVE

To examine the presence and extent of an ascertainment bias (omission of affected individuals) produced by such criteria when applied as early as possible in the course of the disease.

DESIGN

Longitudinal study (1979-2008).

SETTING

Washington University Alzheimer Disease Research Center, St Louis, Missouri.

PARTICIPANTS

Of 78 individuals aged 65 to 101 years enrolled as healthy controls, 55 later developed autopsy-confirmed AD; 23 remained cognitively healthy and did not have neuropathologic AD.

MAIN OUTCOME MEASURES

Criteria for the diagnosis of AD based on various cutoff points (1.5, 1.0, and 0.5 SDs below the mean for robust test norms) for 2 standard psychometric measures from each of 3 cognitive domains (episodic memory, visuospatial ability, and working memory) were applied to data from the first assessment associated with an independent clinical diagnosis of cognitive impairment for those who developed symptomatic AD and from the last assessment for those who did not.

RESULTS

Areas under the curve from receiver operating characteristic analyses ranged from 0.71 to 0.49; sensitivities and specificities were unsatisfactory even after adjusting for age and education, using combinations of tests, or examining longitudinal decline before clinical diagnosis.

CONCLUSION

Reliance on divergence from group normative values to determine initial cognitive decline caused by AD results in failure to include people in the initial symptomatic stage of the illness.

Attitudes and Beliefs Predicting Taiwanese Older Adults’ Intentions to Attend Strength and Balance Training Programs

While strength and balance training (SBT) programs are effective in preventing falls, older adults rarely participate. A cross-sectional study design was used to explore factors that influence their decisions to attend SBT programs. Questionnaires were collected that measured theory of planned behavior constructs from 221 community-dwelling Taiwanese older women between the age of 55 and 94. Results suggest that (a) benefits of SBT programs such as increasing independence in daily life, (b) participation approval and involvement from the older adults’ family members, and (c) SBT programs conducted in familiar places strengthened potential participants’ positive attitude, subjective norm, and perceived behavioral control, respectively. Health care professionals should consider incorporating these factors in the recruitment materials or the actual design of SBT programs to enhance older adults’ decision to attend and increase the recruitment rate of such programs.

Exertion fatigue and chronic fatigue are two distinct constructs in people post-stroke

BACKGROUND AND PURPOSE

Post-stroke fatigue is a common and neglected issue despite the fact that it impacts daily functions, quality of life, and has been linked with a higher mortality rate because of its association with a sedentary lifestyle. The purpose of this study was to identify the contributing factors of exertion fatigue and chronic fatigue in people post-stroke.

METHODS

Twenty-one post-stroke people (12 males, 9 females; 59.5 ± 10.3 years of age; time after stroke 4.1 ± 3.5 years) participated in the study. The response variables included exertion fatigue and chronic fatigue. Participants underwent a standardized fatigue-inducing exercise on a recumbent stepper. Exertion fatigue level was assessed at rest and immediately after exercise using the Visual Analog Fatigue Scale. Chronic fatigue was measured by the Fatigue Severity Scale. The explanatory variables included aerobic fitness, motor control, and depressive symptoms measured by peak oxygen uptake, Fugl-Meyer motor score, and the Geriatric Depression Scale, respectively.

RESULTS

Using forward stepwise regression, we found that peak oxygen uptake was an independent predictor of exertion fatigue (P = 0.006), whereas depression was an independent predictor of chronic fatigue (P = 0.002).

CONCLUSIONS

Exertion fatigue and chronic fatigue are 2 distinct fatigue constructs, as identified by 2 different contributing factors.

Relationship of dementia screening tests with biomarkers of Alzheimer's disease

Screening tests for Alzheimer's disease lack sensitivity and specificity. We developed the AD8, a brief dementia screening interview validated against clinical and cognitive evaluations, as an improvement over current screening methods. Because insufficient follow-up has occurred to validate the AD8 against the neuropathologic findings of Alzheimer's disease, we investigated whether AD8 scores correspond to impairment in episodic memory testing and changes in biomarkers of Alzheimer's disease (cerebrospinal fluid and amyloid imaging with Pittsburgh compound B) characteristic of symptomatic Alzheimer's disease. We also compared informant-based assessments with brief performance-based dementia screening measurements such as the Mini Mental State Exam. The sample (n = 257) had a mean age of 75.4 years with 15.1 years of education; 88.7% were Caucasian and 45.5% were male. The sample was divided into two groups based on their AD8 scores: those with a negative dementia screening test (AD8 score 0 or 1, n = 137) and those with a positive dementia screening test (AD8 score ≥2, n = 120). Individuals with positive AD8 scores had abnormal Pittsburgh compound B binding (P < 0.001) and cerebrospinal fluid biomarkers (P < 0.001) compared with individuals with negative AD8 scores. Individuals with positive AD8 tests and positive biomarkers scored in the impaired range on the Wechsler Logical Memory Story A (mean score 7.0 ± 4.5 for Pittsburgh compound B; mean score 7.6 ± 5.3 for cerebrospinal fluid amyloid beta protein 1-42). The AD8 area under the curve for Pittsburgh compound B was 0.737 (95% confidence interval: 0.64-0.83) and for cerebrospinal fluid amyloid beta protein 1-42 was 0.685 (95% confidence interval: 0.60-0.77) suggesting good discrimination. The AD8 had superior sensitivity in detecting early stages of dementia compared with the Mini Mental State Examination. The AD8 had a likelihood ratio of a positive test of 5.8 (95% confidence interval: 5.4-6.3) and likelihood ratio of a negative test of 0.04 (95% confidence interval: 0.03-0.06), increasing the pre-test probability of an individual having symptomatic Alzheimer's disease. Individuals with AD8 scores of ≥2 had a biomarker phenotype consistent with Alzheimer's disease and lower performance on episodic memory tests, supporting a diagnosis of Alzheimer's disease. Informant-based assessments may be superior to performance-based screening measures such as the Mini Mental State Examination in corresponding to underlying Alzheimer's disease pathology, particularly at the earliest stages of decline. The use of a brief test such as the AD8 may improve strategies for detecting dementia in community settings where biomarkers may not be readily available, and may enrich clinical trial recruitment by increasing the likelihood that participants have underlying biomarker abnormalities.

Screening and case finding tools for the detection of dementia. Part I: evidence-based meta-analysis of multidomain tests

AIM

To evaluate the diagnostic accuracy of all brief multidomain alternatives to the Mini-Mental State Examination (MMSE) in the detection of dementia.

METHODS

A literature search, critical appraisal, and meta-analysis were conducted of robust diagnostic validity studies involving cognitive batteries. Twenty-nine distinct brief batteries were tested in 44 large-scale analyses. Twenty studies took place in specialist settings (11 in memory clinics and 9 in secondary care), ten studies were conducted in primary care, and 14 in the community.

RESULTS

In community settings with a low prevalence of dementia, short screening methods of no more than 10 minutes had an overall sensitivity of 72.0% (95% confidence interval [CI] = 60.4%-82.3%) and a specificity of 88.2% (95% CI = 83.0%-92.5%). The optimal individual tests were the Telephonic interview based on MSQ, Category fluency/Memory impairment screen-Telephonic interview and 6 item Cognitive Impairment Test (6-CIT), but data were limited by the absence of multiple independent confirmation for any individual test. In primary care where the prevalence of dementia is usually modest, the optimal individual tools were the Abbreviated mental test score/Mental status questionnaire (MSQ), and Prueba cognitive de leganes (PCL). Furthermore, the Abbreviated mental test score (AMTS) was superior to the MMSE for case finding, but for screening the MMSE was optimal. If length is not a major consideration, the MMSE may remain the best tool for primary care clinicians who want to rule in and rule out a diagnosis. In specialist settings where the prevalence of dementia is often high, the optimal individual tools were the DEMTECT, Montreal cognitive assessment (MOCA), Memory Alteration test, and MINI-COG. Two tools were potentially superior to the MMSE for rule in and rule out, namely the 6-CIT and MINI-COG. Only four analyses looked specifically at accuracy in early-stage dementia, and each showed at least equivalent diagnostic accuracy, suggesting these methods might be applicable to early identification.

CONCLUSION

A large number of alternatives to the MMSE have now been validated in large samples with favorable rule-in and rule-out accuracy. Evidence to date suggests for those wishing to use brief battery tests then the original MMSE or the AMTS should be considered in primary care and either the 6-CIT or the MINI-COG should be considered in specialist settings.

Validity and reliability of the Korean version of the AD8 informant interview (K-AD8) in dementia

The Alzheimer disease 8 (AD8) is a brief informant-based measure that distinguishes individuals with very mild dementia and mild cognitive impairment from those with normal cognition. The aim of this study was to establish the validity, reliability, and discriminative properties of the Korean version of the AD8 (K-AD8). Evaluation was made on 155 patient-informant dyads. The K-AD8 scores with the Clinical Dementia Rating (CDR) and performance on neuropsychologic tests were compared. Internal consistency of the K-AD8 was significant (Cronbach alpha=0.88). The K-AD8 had strong correlation with CDR (Spearman rho=0.76). Concurrent validity was strong with the K-AD8 scores correlating with CDR domains and performance on neuropsychologic tests. The K-AD8 was found to have excellent test-retest reliability (weighted kappa=0.81) and good interrater reliability (intraclass correlation coefficient=0.89). The area under the receiver operator characteristic curve was 0.88, suggesting good discrimination between nondemented individuals and those with cognitive impairment. To distinguish CDR 0.5 from CDR 0, in particular, the K-AD8 (cutoff score of 2) had a sensitivity of 68% and a specificity of 90%. In conclusion, the K-AD8 is a sensitive screening tool in detecting very early dementia, indicating that the AD8 could work very well in a variety of cultural entities.

Post-Mortem diagnosis of dementia by informant interview

The diagnosis of normal cognition or dementia in the Brazilian Brain Bank of the Aging Brain Study Group (BBBABSG) has relied on postmortem interview with an informant.

OBJECTIVES

To ascertain the sensitivity and specificity of postmortem diagnosis based on informant interview compared against the diagnosis established at a memory clinic.

METHODS

A prospective study was conducted at the BBBABSG and at the Reference Center for Cognitive Disorders (RCCD), a specialized memory clinic of the Hospital das Clínicas, University of São Paulo Medical School. Control subjects and cognitively impaired subjects were referred from the Hospital das Clínicas to the RCCD where subjects and their informants were assessed. The same informant was then interviewed at the BBBABSG. Specialists' panel consensus, in each group, determined the final diagnosis of the case, blind to other center's diagnosis. Data was compared for frequency of diagnostic equivalence. For this study, the diagnosis established at the RCCD was accepted as the gold standard. Sensitivity and specificity were computed.

RESULTS

Ninety individuals were included, 45 with dementia and 45 without dementia (26 cognitively normal and 19 cognitively impaired but non-demented). The informant interview at the BBBABSG had a sensitivity of 86.6% and specificity of 84.4% for the diagnosis of dementia, and a sensitivity of 65.3% and specificity of 93.7% for the diagnosis of normal cognition.

CONCLUSIONS

The informant interview used at the BBBABSG has a high specificity and sensitivity for the diagnosis of dementia as well as a high specificity for the diagnosis of normal cognition.

EEG markers discriminate among different subgroup of patients with mild cognitive impairment

Aim of the study is to discriminate among participants with mild cognitive impairment through electroencephalography brain rhythms. A total of 79 participants with MCI were classified into 4 subgroups based on the beginning of memory complaints up to the time of first visit. All participants underwent electroencephalography recording, magnetic resonance imaging, apolipoprotein E characterization, and volumetric morphometry estimation of hippocampal region. Electroencephalography markers show 2 distinct patterns: (1) increase of theta/ delta power ratio and highest value of alpha2 band power in the group with shorter duration of disease, the greater right-left hippocampal volume difference and worst memory performance; (2) the highest value of alpha3 band power and the highest alpha3/alpha2 power ratio in the group with the lesser total hippocampal volume but preserved memory performance. Apolipoprotein E4 is linked to a major risk of early beginning of disease. Electroencephalography markers allow a mean correct percentage of correct classification up to 89%.

Screening properties of the German IQCODE with a two-year time frame in MCI and early Alzheimer's disease

BACKGROUND

The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) is a widely used screening tool for dementia. We aimed to determine the ability of the German version of the 16-item IQCODE with a two-year time frame to discriminate healthy mature control participants (NC) from mild cognitive impairment (MCI) and probable early Alzheimer's disease (AD) patients (all with Mini-mental State Examination (MMSE) scores >or= 24/30) and to optimize diagnostic discriminability by shortening the IQCODE.

METHODS

453 NC (49.7% women, age = 69.5 years +/- 8.2, education = 12.2 +/- 2.9), 172 MCI patients (41.9% women, age = 71.5 years +/- 8.8, education = 12.3 +/- 3.1) and 208 AD patients (59.1% women, age = 76.0 years +/- 6.4, education = 11.4 +/- 2.9) participated. Stepwise binary logistic regression analyses (LR) were used to shorten the test. Receiver operating characteristic curves (ROC) determined sensitivities, specificities, and correct classification rates (CCRs) for (a) NC vs. all patients; (b) NC vs. MCI; and (c) NC vs. AD patients.

RESULTS

The mean IQCODE was 3.00 for NC, 3.35 for MCI, and 3.73 for AD. CCRs were 85.5% (NC-patient group), 79.9% (NC-MCI), and 90.7% (NC-AD), respectively. The diagnostic discriminability of the shortened 7-item IQCODE (i.e. items 1, 2, 3, 5, 7, 10, 14) was comparable with the longer version (i.e. 7-item CCRs: NC-patient group: 85.3%; NC-MCI: 80.1%, NC-AD: 90.5%).

CONCLUSIONS

The German 16-item IQCODE with two-year time frame showed excellent screening properties for MCI and early AD patients. An abbreviated 7-item version demonstrated equally high diagnostic discriminability, thus allowing for more economical screening.

Should older adults be screened for dementia?

The question of whether to screen for dementia and Alzheimer's disease (AD) has been discussed in many forums throughout the world. Generally, medical advisory groups and policy-making groups have recognized the importance of early diagnosis but have uniformly avoided making recommendations to screen at-risk populations. This presentation reflects the support for reconsidering the importance of screening individuals at risk or above a certain age. In this statement, the majority of the authors support the consideration of dementia risk factors in individuals at age 50, with routine yearly screening after 75. Other authors remain concerned that the benefits of treatments of early disease do not yet support a general screening recommendation. These statements are made to encourage progress toward the development of a consensus regarding the widespread institution of screening policy. Accordingly, members of the worldwide scientific community are invited to add their perspective by contributing short commentaries (1500 words) on this subject.

Long-term cognitive decline in older subjects was not attributable to noncardiac surgery or major illness

BACKGROUND

Persistent postoperative cognitive decline is thought to be a public health problem, but its severity may have been overestimated because of limitations in statistical methodology. This study assessed whether long-term cognitive decline occurred after surgery or illness by using an innovative approach and including participants with early Alzheimer disease to overcome some limitations.

METHODS

In this retrospective cohort study, three groups were identified from participants tested annually at the Washington University Alzheimer's Disease Research Center in St. Louis, Missouri: those with noncardiac surgery, illness, or neither. This enabled long-term tracking of cognitive function before and after surgery and illness. The effect of surgery and illness on longitudinal cognitive course was analyzed using a general linear mixed effects model. For participants without initial dementia, time to dementia onset was analyzed using sequential Cox proportional hazards regression.

RESULTS

Of the 575 participants, 214 were nondemented and 361 had very mild or mild dementia at enrollment. Cognitive trajectories did not differ among the three groups (surgery, illness, control), although demented participants declined more markedly than nondemented participants. Of the initially nondemented participants, 23% progressed to a clinical dementia rating greater than zero, but this was not more common after surgery or illness.

CONCLUSIONS

The study did not detect long-term cognitive decline independently attributable to surgery or illness, nor were these events associated with accelerated progression to dementia. The decision to proceed with surgery in elderly people, including those with early Alzheimer disease, may be made without factoring in the specter of persistent cognitive deterioration.

Chronic traumatic encephalopathy in athletes: progressive tauopathy after repetitive head injury

Since the 1920s, it has been known that the repetitive brain trauma associated with boxing may produce a progressive neurological deterioration, originally termed dementia pugilistica, and more recently, chronic traumatic encephalopathy (CTE). We review 48 cases of neuropathologically verified CTE recorded in the literature and document the detailed findings of CTE in 3 profession althletes, 1 football player and 2 boxers. Clinically, CTE is associated with memory disturbances, behavioral and personality changes, parkinsonism, and speech and gait abnormalities. Neuropathologically, CTE is characterized by atrophy of the cerebral hemispheres, medial temporal lobe, thalamus, mammillary bodies, and brainstem, with ventricular dilatation and a fenestrated cavum septum pellucidum. Microscopically, there are extensive tau-immunoreactive neurofibrillary tangles, astrocytic tangles, and spindle-shaped and threadlike neurites throughout the brain. The neurofibrillary degeneration of CTE is distinguished from other tauopathies by preferential involvement of the superficial cortical layers, irregular patchy distribution in the frontal and temporal cortices, propensity for sulcal depths, prominent perivascular, periventricular, and subpial distribution, and marked accumulation of tau-immunoreactive astrocytes. Deposition of beta-amyloid, most commonly as diffuse plaques, occurs in fewer than half the cases. Chronic traumatic encephalopathy is a neuropathologically distinct slowly progressive tauopathy with a clear environmental etiology.

Informant-based dementia screening in a population-based sample of African Americans

BACKGROUND

An informant-based screening tool for dementia may be useful in population-based studies of minority populations.

OBJECTIVE

Investigate the feasibility of screening for very mild dementia in a community sample of African Americans using an informant-based screening tool (AD8).

DESIGN

Cohort study.

PARTICIPANTS

One hundred forty-seven persons from the African American Health (AAH) project were screened for dementia; 61 of 93 who were invited had follow-up clinical assessments for dementia diagnosis.

MEASUREMENTS

The AD8, Mini-Mental State Examination, Short Blessed Test, Brief Instrument for Dementia Detection, and a neuropsychologic battery were administered at visit 1. The Clinical Dementia Rating (CDR) was administered at visit 2 by clinicians blinded to visit 1 results; the presence of dementia was determined by a CDR greater than 0.

RESULTS

Four hundred sixty-five individuals from the AAH cohort were sent a letter describing the study and, among this group, 252 individuals were contacted by phone to request participation in this study. Six percent (14/252) of the participants contacted by phone were unable to identify an informant (required for the AD8). One hundred fifty individuals agreed by phone to participate of which 2% (n=3) did not have an informant available at the time of participation. The AD8 alone was effective at discriminating between CDR 0 and CDR 0.5 (area under the curve=0.847; P<0.001; 95% confidence interval, 0.73-0.96).

CONCLUSIONS

A brief informant-based instrument, the AD8, has high sensitivity and specificity for distinguishing CDR 0 from CDR 0.5 in the community. Informant availability may not be a barrier for using the AD8 in an African American community sample; however, further study in larger samples with a higher response rate, different community settings (eg, community clinics), and among older age groups (eg, age 75+) is warranted to confirm this.

Screening for memory disorders, dementia and Alzheimer’s disease

Dementia and its most common cause, Alzheimer’s disease, affect memory and occur predominantly in the elderly. Dementia has become increasingly prevalent in the world as health has improved and life expectancy has increased. However, the fields of clinical care have not responded adequately to develop diagnostic tools and treatments for this rapidly increasing group of conditions. While scientists search for cures for the numerous causes of dementia, improvement of diagnostic measures are needed now and should begin with screening elderly populations for memory difficulties and other cognitive problems. This review examines the history of cognitive screening tests, the numerous excellent tests that are currently available and ready for use, and directions and methods that will lead to progressively better evaluations.

Towards an earlier diagnosis of Alzheimer disease (Proceedings of the 5th MCI Symposium, 2007)

The 5th annual Mild Cognitive Impairment Symposium, held on April 13th and 14th, 2007, in Miami Beach, Florida, focused on the question of whether the time has come to revise criteria for Alzheimer disease (AD). The symposium, sponsored by the Wien Center for Alzheimer's Disease and Memory Disorders, Mt Sinai Medical Center in Miami Beach, Florida; and the Byrd Alzheimer Center and Research Institute in Tampa, Florida, brought together an international group of clinicians and researchers to examine current evidence for developing new criteria for AD and for outlining areas that still require clarification. Neuropathologic, neuroimaging, epidemiologic, and clinical perspectives were presented and discussed, as well as the impact of ethnic and cultural differences. As became evident, each perspective introduces different challenges in terms of selecting the appropriate assessment tools; determining when, where, and by whom the diagnosis should be given; and deciding whether multiple sets of criteria are needed for use in different settings, for example, research versus primary care practices. As was intended, the symposium delivered no consensus; however, there was substantial support for the idea that AD can and probably should be diagnosed before the onset of dementia, particularly as new interventions become available.

Diagnosis and treatment of dementia: 3. Mild cognitive impairment and cognitive impairment without dementia

BACKGROUND

Mild cognitive impairment and cognitive impairment, no dementia, are emerging terms that encompass the clinical state between normal cognition and dementia in elderly people. Controversy surrounds their characterization, definition and application in clinical practice. In this article, we provide physicians with practical guidance on the definition, diagnosis and treatment of mild cognitive impairment and cognitive impairment, no dementia, based on recommendations from the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia, held in March 2006.

METHODS

We developed evidence-based guidelines using systematic literature searches, with specific criteria for study selection and quality assessment, and a clear and transparent decision-making process. We selected studies published from January 1996 to December 2005 that had mild cognitive impairment or cognitive impairment, no dementia, as the outcome. Subsequent to the conference, we searched for additional articles published between January 2006 and January 2008. We graded the strength of evidence using the criteria of the Canadian Task Force on Preventive Health Care.

RESULTS

We identified 2483 articles, of which 314 were considered to be relevant and of good or fair quality. From a synthesis of the evidence in these studies, we made 16 recommendations. In brief, family physicians should be aware that most types of dementia are preceded by a recognizable phase of mild cognitive decline. They should be familiar with the concepts of mild cognitive impairment and of cognitive impairment, no dementia. Patients with these conditions should be closely monitored because of their increased risk for dementia. Leisure activities, cognitive stimulation and physical activity could be promoted as part of a healthy lifestyle in elderly people and those with mild cognitive impairment. Vascular risk factors should be treated optimally. No other specific therapies can yet be recommended.

INTERPRETATION

Physicians will increasingly see elderly patients with mild memory loss, and learning an approach to diagnosing states such as mild cognitive impairment is now warranted. Close monitoring for progression to dementia, promotion of a healthy lifestyle and treatment of vascular risk factors are recommended for the management of patients with mild cognitive impairment.

Diagnosis and treatment of dementia: 2. Diagnosis

BACKGROUND

Dementia can now be accurately diagnosed through clinical evaluation, cognitive screening, basic laboratory evaluation and structural imaging. A large number of ancillary techniques are also available to aid in diagnosis, but their role in the armamentarium of family physicians remains controversial. In this article, we provide physicians with practical guidance on the diagnosis of dementia based on recommendations from the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia, held in March 2006.

METHODS

We developed evidence-based guidelines using systematic literature searches, with specific criteria for study selection and quality assessment, and a clear and transparent decision-making process. We selected studies published from January 1996 to December 2005 that pertained to key diagnostic issues in dementia. We graded the strength of evidence using the criteria of the Canadian Task Force on Preventive Health Care.

RESULTS

Of the 1591 articles we identified on all aspects of dementia diagnosis, 1095 met our inclusion criteria; 620 were deemed to be of good or fair quality. From a synthesis of the evidence in these studies, we made 32 recommendations related to the diagnosis of dementia. There are clinical criteria for diagnosing most forms of dementia. A standard diagnostic evaluation can be performed by family physicians over multiple visits. It involves a clinical history (from patient and caregiver), a physical examination and brief cognitive testing. A list of core laboratory tests is recommended. Structural imaging with computed tomography or magnetic resonance imaging is recommended in selected cases to rule out treatable causes of dementia or to rule in cerebrovascular disease. There is insufficient evidence to recommend routine functional imaging, measurement of biomarkers or neuropsychologic testing.

INTERPRETATION

The diagnosis of dementia remains clinically integrative based on history, physical examination and brief cognitive testing. A number of core laboratory tests are also recommended. Structural neuroimaging is advised in selected cases. Other diagnostic approaches, including functional neuroimaging, neuropsychological testing and measurement of biomarkers, have shown promise but are not yet recommended for routine use by family physicians.

The Mayo Clinic Study of Aging: design and sampling, participation, baseline measures and sample characteristics

BACKGROUND

The objective of this study was to establish a prospective population-based cohort to investigate the prevalence, incidence and risk factors for mild cognitive impairment (MCI) and dementia.

METHODS

The Olmsted County, Minn., population, aged 70-89 years on October 1, 2004, was enumerated using the Rochester Epidemiology Project. Eligible subjects were randomly selected and invited to participate. Participants underwent a comprehensive in-person evaluation including the Clinical Dementia Rating Scale, a neurological evaluation and neuropsychological testing. A consensus diagnosis of normal cognition, MCI or dementia was made by a panel using previously published criteria. A subsample of subjects was studied via telephone interview.

RESULTS

Four hundred and two subjects with dementia were identified from a detailed review of their medical records but were not contacted. At baseline, we successfully evaluated 703 women aged 70-79 years, 769 women aged 80-89 years, 730 men aged 70-79 years and 517 men aged 80-89 years (total n = 2,719). Among the participants, 2,050 subjects were evaluated in person and 669 via telephone.

CONCLUSIONS

Strengths of the study are that the subjects were randomly selected from a defined population, the majority of the subjects were examined in person, and MCI was defined using published criteria. Here, we report the design and sampling, participation, baseline measures and sample characteristics.

Psychosocial determinants of intention to screen for Alzheimer's disease

BACKGROUND

There is little information about how receptive older adults are to discuss memory problems with healthcare providers. Here we test the psychosocial factors explaining older adults' intention to undergo screening for Alzheimer disease (AD).

METHODS

A population-based, random-digit dialing strategy surveyed 1,039 older adults. The Behavioral Model of Health Services Use was used as a conceptual framework for a questionnaire testing constructs from several behavioral theories. Structural equation modeling assessed the relationship of latent variables to each construct with goodness-of-fit indices.

RESULTS

The study had an 82% response rate and 72% completer rate. The respondents' mean age was 62.7 +/- 10.2 years (range, 50 to 97 years). The sample was 67% women, 86% were white, and less than 40% had personal experience with AD. Respondents were nondemented (Short Blessed scores, 1.7 +/- 2.2). Predictors of intention to screen included perceived benefits (gamma = .35), knowledge of dementia (gamma = .26), self-efficacy (gamma = .23), preventive health behaviors (gamma = .17), and perceived susceptibility (gamma = .14). Knowledge was positively correlated with perceived benefits (phi = .29) and susceptibility (phi = .20). Preventive behaviors (phi = .20) were positively correlated with perceived benefits. Self-efficacy correlated positively with preventive behaviors (phi = .24) and perceived benefits (phi = .37) and negatively with perceived susceptibility (phi = -.11). Goodness-of-fit indices suggested a good fit of this model (root mean square error of approximation, .037; comparative fit index, 0.98; relative fit index; .96).

DISCUSSION

Older adults who have knowledge of dementia and perceive benefit from diagnosis and treatment are more likely to exhibit willingness and confidence to be tested for cognitive problems. Individuals with high self-efficacy, perceived susceptibility, and positive preventive health behaviors are also more likely to exhibit intention. These constructs can now be used to develop interventions to evaluate cognitive health in the elderly.

Telephonic Remote Evaluation of Neuropsychological Deficits (TREND): longitudinal monitoring of elderly community-dwelling volunteers using touch-tone telephones

Use of interactive voice response (IVR) technology to monitor cognitive functioning in cognitively normal (CN), mild cognitive impairment (MCI), and mild dementia (MD) participants was examined using 107 community-dwelling participants, 65 to 88 years old. Baseline Clinical Dementia Ratings identified 36 participants as CN, 37 with MCI, and 34 as MD. Alzheimer's Disease Assessment Scale (ADAS) and Mini-Mental State Examinations were administered during clinic visits at weeks 0, 8, 16, and 24. IVR cognitive testing was completed at each visit and from participants' homes at weeks 4, 12, and 20. Study partners provided dementia symptoms severity ratings via IVR. The assessment system received 719 participant and 723 partner calls. All calls initiated by CN participants, 99.2% by MCI participants, and 87.3% by MD participants were completed. Telephonic Remote Evaluation of Neuropsychological Deficit tasks showed significant performance differences between participant groups, good reliability, and convergent validity with Mini-Mental State Examinations and ADAS-Cog measures. Automated cognitive testing calls took about 18 minutes to complete, and informant calls took approximately 4 minutes. IVR informant data were convergent with the ADAS-Noncog measure. Computer-automated assessments of cognitive functioning via IVR provided reliable, valid data. Such assessments might benefit routine clinical care and large-scale, longitudinal research in the future, but will require additional research over longer periods.

Clinical prediction of Alzheimer disease dementia across the spectrum of mild cognitive impairment

OBJECTIVE

To determine whether clinical assessment methods that grade the severity of impairments within the spectrum of mild cognitive impairment (MCI) can predict clinical course, particularly among very mildly impaired individuals who do not meet formal MCI criteria as implemented in clinical trials.

DESIGN

Cohort.

SETTING

Community volunteers.

PARTICIPANTS

From a longitudinal study of normal (Clinical Dementia Rating [CDR] = 0; n = 77) and mildly impaired (CDR = 0.5; n = 167) participants with 5 or more annual clinical assessments, baseline level of cognitive impairment in daily life was graded using CDR sum of boxes (CDR-SB) and level of cognitive performance impairment was graded using neuropsychological test scores.

MAIN OUTCOME MEASURES

Five-year outcome measures included (1) probable Alzheimer disease (AD) diagnosis and (2) clinical "decline" (CDR-SB increase > or = 1.0). Logistic regression models were used to assess the ability of baseline measures to predict outcomes in the full sample and separately in the subjects who did not meet formal MCI criteria as implemented in a multicenter clinical trial (n = 125; "very mild cognitive impairment" [vMCI]).

RESULTS

The presence of both higher CDR-SB and lower verbal memory and executive function at baseline predicted greater likelihood of probable AD and decline. Five-year rates of probable AD and decline in vMCI (20%, AD; 49%, decline) were intermediate between normal participants (0%, AD; 28%, decline) and participants with MCI (41%, AD; 62%, decline). Within vMCI, likelihood of probable AD was predicted by higher CDR-SB and lower executive function.

CONCLUSIONS

Even in very mildly impaired individuals who do not meet strict MCI criteria as implemented in clinical trials, the degree of cognitive impairment in daily life and performance on neuropsychological testing predict likelihood of an AD diagnosis within 5 years. The clinical determination of relative severity of impairment along the spectrum of MCI may be valuable for trials of putative disease-modifying compounds, particularly as target populations are broadened to include less impaired individuals.

Combining the Memory Impairment Screen and the Isaacs Set Test: A Practical Tool for Screening Dementias

OBJECTIVES

To assess the accuracy of combining the Memory Impairment Screen (MIS) with the Isaacs Set Test (IST) in distinguishing subjects with dementia from controls without dementia.

DESIGN

The weighted sum of MIS and IST scores was calculated, and the logical "or" rule combination was performed using two different patient and control samples. Combination results were compared with each test used alone and with Mini-Mental State Examination to detect all types of dementias.

SETTING

Database of the Regional Network for Diagnostic Aid and Management of Patients with Cognitive Impairment in the Franche-Comté, France, geographical area.

PARTICIPANTS

A cohort of 444 patients with Alzheimer's disease, non-Alzheimer's dementia, and reversible dementia and 311 controls.

MEASUREMENTS

Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the combination of these two tests.

RESULTS

The weighted sum had overall sensitivities of 0.92 and 0.84 for mild cases, with a specificity of 0.92. The "or" rule had overall sensitivities of 0.92 and 0.89 for mild cases, with a specificity of 0.90. This pairing requires no more than 5 minutes. Its scoring is simple with the "or" rule combination.

CONCLUSIONS

The combination of MIS and IST could be a useful tool for screening dementias. The "or" rule combination seems particularly adapted to medical practice.