Unawareness of cognitive deficit in Alzheimer disease and related dementias

Neuropsychological differential diagnosis of Alzheimer's disease and vascular dementia: a systematic review with meta-regressions

Introduction

Diagnostic classification systems and guidelines posit distinguishing patterns of impairment in Alzheimer's (AD) and vascular dementia (VaD). In our study, we aim to identify which diagnostic instruments distinguish them.

Methods

We searched PubMed and PsychInfo for empirical studies published until December 2020, which investigated differences in cognitive, behavioral, psychiatric, and functional measures in patients older than 64 years and reported information on VaD subtype, age, education, dementia severity, and proportion of women. We systematically reviewed these studies and conducted Bayesian hierarchical meta-regressions to quantify the evidence for differences using the Bayes factor (BF). The risk of bias was assessed using the Newcastle-Ottawa-Scale and funnel plots.

Results

We identified 122 studies with 17,850 AD and 5,247 VaD patients. Methodological limitations of the included studies are low comparability of patient groups and an untransparent patient selection process. In the digit span backward task, AD patients were nine times more probable (BF = 9.38) to outperform VaD patients (β g = 0.33, 95% ETI = 0.12, 0.52). In the phonemic fluency task, AD patients outperformed subcortical VaD (sVaD) patients (β g = 0.51, 95% ETI = 0.22, 0.77, BF = 42.36). VaD patients, in contrast, outperformed AD patients in verbal (β g = -0.61, 95% ETI = -0.97, -0.26, BF = 22.71) and visual (β g = -0.85, 95% ETI = -1.29, -0.32, BF = 13.67) delayed recall. We found the greatest difference in verbal memory, showing that sVaD patients outperform AD patients (β g = -0.64, 95% ETI = -0.88, -0.36, BF = 72.97). Finally, AD patients performed worse than sVaD patients in recognition memory tasks (β g = -0.76, 95% ETI = -1.26, -0.26, BF = 11.50).

Conclusion

Our findings show inferior performance of AD in episodic memory and superior performance in working memory. We found little support for other differences proposed by diagnostic systems and diagnostic guidelines. The utility of cognitive, behavioral, psychiatric, and functional measures in differential diagnosis is limited and should be complemented by other information. Finally, we identify research areas and avenues, which could significantly improve the diagnostic value of cognitive measures.

Intellectual awareness of naming abilities in people with chronic post-stroke aphasia

Anosognosia, or lack of self-awareness, is often present following neurological injury and can result in poor functional outcomes. The specific phenomenon of intellectual awareness, the knowledge that a function is impaired in oneself, has not been widely studied in post-stroke aphasia. We aim to identify behavioral and neural correlates of intellectual awareness by comparing stroke survivors' self-reports of anomia to objective naming performance and examining lesion sites. Fifty-three participants with chronic aphasia without severe comprehension deficits rated their naming ability and completed a battery of behavioral tests. We calculated the reliability and accuracy of participant self-ratings, then examined the relationship of poor intellectual awareness to speech, language, and cognitive measures. We used support vector regression lesion-symptom mapping (SVR-LSM) to determine lesion locations associated with impaired and preserved intellectual awareness. Reliability and accuracy of self-ratings varied across the participants. Poor intellectual awareness was associated with reduced performance on tasks that rely on semantics. Our SVR-LSM results demonstrated that anterior inferior frontal lesions were associated with poor awareness, while mid-superior temporal lesions were associated with preserved awareness. An anterior-posterior gradient was evident in the unthresholded lesion-symptom maps. While many people with chronic aphasia and relatively intact comprehension can accurately and reliably report the severity of their anomia, others overestimate, underestimate, or inconsistently estimate their naming abilities. Clinicians should consider this when administering self-rating scales, particularly when semantic deficits or anterior inferior frontal lesions are present. Administering self-ratings on multiple days may be useful to check the reliability of patient perceptions.

Anosognosia in dementia: A review of current assessment instruments

INTRODUCTION

Anosognosia is a common but underrated symptom in dementia and has significant impact on both patients and caregivers. A proper evaluation of anosognosia is therefore desirable. There are three common methods to determine anosognosia: (1) clinical rating, (2) patient-caregiver discrepancies, and (3) prediction of performance discrepancies. Each of them includes different instruments. This review gives an overview of the current instruments used for the assessment of anosognosia in patients with dementia and aims to determine the most suitable instrument for routine use in clinical practice.

METHODS

A search of the literature in PubMed was performed. Furthermore, electronic databases (PsycINFo, ClinicalKey, and Cochrane Library) and reference lists were searched for additional articles.

RESULTS

Forty-six articles were included in this study, comprising 10 clinical rating instruments, 25 patient-caregiver discrepancy instruments, and 14 prediction-performance discrepancy instruments. For every publication, the aims of the study, the included population, the assessment instrument used, the assessed domains, and the psychometric properties of the assessment instruments are described.

CONCLUSIONS

Currently, there is no consensus on the most suitable method to determine anosognosia in dementia. We recommend the Clinical Insight Rating scale and the Abridged Anosognosia Questionnaire-Dementia as the most appropriate for routine use in clinical practice.

Nicotinic Acetylcholine Receptor Agonists for the Treatment of Alzheimer's Dementia: An Update

A significant portion of the clinical phenotype observed in Alzheimer's disease (AD) occurs through nicotinic acetylcholine receptors (nAChRs). Degeneration of cholinergic neurons, combined with aberrant nAChR expression and activation partially through amyloid-beta peptide (Aβ)-nAChR leads to upregulation of pro-inflammatory pathways and subsequently the progressive cognitive decline of AD. Interestingly, the cholinergic anti-inflammatory pathway is also mediated through nAChR particularly α7 nAChR. Thus, agonists of these receptors will likely exert pro-cognitive benefits through multiple mechanisms including stimulating the cholinergic pathway, modulating inflammation, and buffering the effects of amyloid. Despite this promising theoretical use, trials thus far have been complicated by adverse effects or minimal improvement. This review will provide an update on several pharmacological nAChR agonists tested in clinical trials and reasons that further investigation of nAChR agonists is merited.

IMPLICATIONS

nAChRs have consistently presented a promising theoretical use in the treatment of AD; however, trials thus far have been complicated by adverse effects or minimal improvement. This review will provide an update on several pharmacological nAChR agonists trialed and reasons that further investigation of nAChR agonists is merited.

Participant and Study Partner Reported Impact of Cognition on Functional Activities in Parkinson's Disease

Introduction

Cognitive dysfunction is common in Parkinson's disease (PD) and associated with reduced functional abilities and increased dependence. To date, however, little is known about the relationship between performance of instrumental activities of daily living (IADLs) and cognitive stages in PD, and there are conflicting reports as to whether declines in specific cognitive domains predict IADL impairment.

Methods

Participants with PD were drawn from the Pacific Udall Center and included in the study if both participant and study partner IADL ratings and cognitive tests were completed (n = 192). Logistic regression analyses were performed to determine whether participant and/or study partner rating predicted mild cognitive impairment or dementia. Correlations are reported for the relationship between participant/study partner IADL reports as well as for specific cognitive tests.

Results

Although both participant and study partner ratings of IADL performance were associated with a diagnosis of PD with dementia, only participant self-rating of functional ability was significantly associated with a diagnosis of PD with mild cognitive impairment. Functional ability correlated most strongly with measures of processing speed, auditory working memory, and immediate verbal recall for both the participant and study partner ratings.

Conclusion

For participants with PD in the early stages of cognitive decline, self-rating may be more sensitive to the impact of cognitive changes on IADL function than ratings made by a knowledgeable study partner. Changes in executive function, processing speed, and learning may indicate a higher likelihood of IADL impairment. Careful assessment of cognition and IADL performance is recommended to permit individualized interventions prior to significant disability.

Lack of Accurate Self-appraisal is Equally Likely in MCI from Parkinson's Disease and Alzheimer's Disease

BACKGROUND

How accurate are mild cognitive impairment (MCI) patients in assessing their cognitive and functional deficit is often unclear to the clinician. The accuracy of patient self-appraisal in Parkinson's disease-MCI (PD-MCI) has received less attention than amnestic MCI (a-MCI) often associated with Alzheimer's disease. We evaluated if PD-MCI patients demonstrate accurate self-appraisal of their cognitive deficits compared to patients with amnestic a-MCI or non-amnestic MCI (na-MCI).

METHODS

This cross-sectional cohort study included, 30 PD-MCI, 33 a-MCI, and 17 na-MCI patients. Self-appraisal was assessed by comparing responses of caregivers and patients on a validated self-rating questionnaire of cognitive and functional impairments. All patients completed a full neuropsychological evaluation and depression screening measure. Univariate ANOVA, regression, and correlational analyses were employed to identify group differences in self-appraisal scores and relationships between cognitive and functional impairment, depression measures, and self-appraisal scores.

RESULTS

Self-appraisal scores for PD-MCI did not differ significantly from a-MCI and na-MCI. In the PD-MCI group, higher depression scores were associated with lower self-appraisal scores (i.e, patients assessed cognition as worse than caregivers). In a stepwise regression model with self-appraisal scores as the dependent variable, only the depression score was significant predictor among PD-MCI and accounted for 50% of the variance.

CONCLUSIONS

Our findings suggest that impaired patient self-appraisal is equally likely to occur in PD-MCI as in a-MCI and na-MCI patients. Among PD-MCI, depression was the strongest predictor of impaired patient self-appraisal. Impaired insight into cognitive impairment and depression should be considered in both care and research with PD patients.

The relationship among unawareness of memory impairment, depression, and dementia in older adults with memory impairment in Singapore

BACKGROUND

Previous research has studied the relationships among unawareness of memory impairment, depression, and dementia in older adults with severe dementia, but it has not considered the associations and clinical implications at earlier stages of memory impairment. This study therefore sought to examine the relationship among unawareness of memory impairment, depression, and dementia in older adults with memory impairment in Singapore.

METHODS

The participants were 751 older adults with memory impairment in Singapore. They were assessed for objective and subjective memory loss, depression, and dementia severity. Participants' subjective memory loss was determined based on a self-appraisal question on memory, and their objective memory loss was calculated based on their performance on three cognitive tasks. Unawareness was assessed based on the contrast between subjective and objective memory loss.

RESULTS

Descriptive statistics revealed a high prevalence of unawareness (80.4%). Logistic regression analysis revealed that gender and marital status were significantly associated with unawareness. Men (odds ratio (OR) = 2.5) and those who were divorced or separated (OR = 23.0) were more likely to be unaware than women and those who were married, respectively. After chronic conditions and demographic characteristics were controlled for, multivariate logistic regression analyses revealed that older adults with depression were less likely (OR = 0.2) to be unaware than those without depression. Unawareness was also related with dementia severity; older adults with questionable (OR = 0.3) and mild dementia (OR = 0.4) were less likely to be unaware than someone without dementia.

CONCLUSION

Unawareness of memory impairment was common among older adults with memory impairment. However, unawareness may be the result of denial as a strategy for coping with memory loss of which the older adult is aware. Psychological care should be integrated into the overall treatment management of dementia to mitigate the possible risk of depression while increasing individual awareness of memory loss.

Heterogeneity of Cognitive Anosognosia and its Variation with the Severity of Dementia in Patients with Alzheimer's Disease

Currently, the lack of awareness of deficits, i.e., anosognosia, is a major obstacle in the healthcare circuit that delays the diagnosis of Alzheimer's disease (AD). However, a clear framework is lacking in the literature related to this phenomenon in terms of its definition, mechanisms, and objects. The aim of this study is to assess the different levels of cognitive anosognosia using a prediction-performance procedure and to identify the potential correlates of these levels. A sample of patients with probable AD was divided into three groups according to the severity of dementia (mild (MiD), moderate (MoD), and moderately severe (MSD) dementia), ranked according to the results of the Mini-Mental State Examination. We observed the following three scores: the real score, the prediction score, and the anosognosia score. These scores were calculated based on the prediction-performance task MISAwareness from the Dementia Rating Scale for cognitive processes (i.e., Attention, Initiation, Conceptualization, Construction, and Memory). We obtained a strong plateau effect between the MiD and MoD groups for anosognosia scores for actual performance or prediction for both the level of overall functioning and for specific processes. The sole exception was the result for memory processes. Moreover, the profiles of the patients' responses on the Memory subscale were substantially different and, indeed, opposite from those for the other processes. The main results confirm the multidimensionality of anosognosia and its variability with the stage of dementia and specifically implicate memory processes that indicate a cleavage between memory and other cognitive functions.

Perceptions of change over time in early-stage Alzheimer's disease

Emerging models of subjective experience, awareness and coping in early-stage dementia may usefully be enhanced by incorporating a temporal perspective. As an initial step in this direction, we undertook a prospective one-year follow-up of participants with a diagnosis of early-stage Alzheimer's disease whose accounts had contributed to the development of Clare's phenomenological model of awareness incorporating the continuum model of coping in early-stage dementia. All 12 participants from the original study completed a follow-up interview one year later. Interpretative phenomenological analysis was used to identify emergent themes. All participants continued to demonstrate some awareness of difficulties with memory, but individuals varied in their evaluations of the extent and implications of these changes, with the majority tending towards more normalizing explanations. Many were nevertheless making practical adjustments to their activities, and the need to renegotiate relationships was a prominent issue. Subsequently, the data were examined for evidence of the themes identified in the original study, the initial model was reapplied, and changes in individual coping style over time were explored through case study analysis. The range of processes and coping styles observed across participants 12 months earlier was still apparent, with some indication of increased polarization between self-maintaining and self-adjusting styles of coping. A small number of participants showed significant changes in coping style, with changes occurring in both directions. The findings suggest that expression of awareness interacts with coping style, illustrating the need to consider both factors in combination in order to better understand individual expressions of awareness of change.

Investigating poor insight in Alzheimer’s disease

Persons with Alzheimer’s disease (AD) often seem to have a poor insight into the functional deficits brought about by the dementing process. There are many indications that preserved insight into deficits in dementia is of advantage to a person with AD. Various research approaches have been adopted to investigate poor insight related to AD. The purpose of this article was to present various research approaches for investigating poor insight into deficits in AD. The study is based on a literature survey. The findings show that concept of poor insight has been investigated in detail from different perspectives. Each one of the perspectives found, the neuropsychological, the psychological and the socio-psychological, has its merits, but none of them has yet led to study results that make us fully understand what poor insight implies and involves. We need integrated knowledge from the different perspectives, and in multidisciplinary research settings we believe that such knowledge could be developed.

Alone and confused

Despite significant increases in the number of adults who live alone, little is known about adults with cognitive impairment who live without co-resident caregivers. In this study, we examined demographic, cognitive, and functional characteristics and service use patterns of a sample ( N = 343) of older community-residing African Americans with dementia who were referred for assessment. Of this group, 52 percent (179) lived alone. Adults who lived alone were compared with those who had co-resident caregivers to determine differences in cognitive and functional status and formal service use. Comprehensive multidisciplinary assessment included diagnosis and staging of dementia, status evaluation of activities of daily living and instrumental activities of daily living, and informal and formal support. Adults living alone had significantly more caregivers than those with co-resident caregivers. Neighbors and friends were more common primary care providers for live-alone adults. A significant proportion of adults had inadequate care, given their cognitive and functional deficits. Although formal service use was low in both groups, live-alone adults were more likely to receive social services than were adults with a co-resident caregiver. Predictors of formal service use included the presence of a caseworker, Medicaid certification, mild dementia, and living alone. Our results indicate the need for better identification of, and supportive services for, older African Americans with dementia who live alone.

Anosognosia in Alzheimer disease: Disconnection between memory and self-related brain networks

OBJECTIVE

Impaired awareness is a common symptom in many mental disorders including Alzheimer disease (AD). This study aims at improving our understanding of the neural mechanisms underlying anosognosia of memory deficits in AD by combining measures of regional brain metabolism (resting state fluorodeoxyglucose positron emission tomography [FDG-PET]) and intrinsic connectivity (resting state functional magnetic resonance imaging [fMRI]).

METHODS

Twenty-three patients diagnosed with probable AD based on clinical and biomarker data and 30 matched healthy control subjects were recruited in this study. An anosognosia index (difference between subjective and objective memory scores) was obtained in each participant. Resting state FDG-PET for glucose metabolism measurement and resting state fMRI for intrinsic connectivity measurement were also performed. AD and control groups were compared on behavioral data, and voxelwise correlations between anosognosia and neuroimaging data were conducted within the AD group.

RESULTS

AD patients underestimated their memory deficits. Anosognosia in AD patients correlated with hypometabolism in orbitofrontal (OFC) and posterior cingulate (PCC) cortices. Using OFC and PCC as seed regions, intrinsic connectivity analyses in AD revealed a significant association between anosognosia and reduced intrinsic connectivity between these regions as well as with the medial temporal lobe.

INTERPRETATION

Anosognosia in AD is due not only to functional changes within cortical midline structures involved in self-referential processes (OFC, PCC), but also to disconnection between these regions as well as with the medial temporal lobe. These findings suggest that the lack of awareness of memory deficits in AD results from a disruption of the communication within, but also between, the self-related and the memory-related brain networks.

Memory awareness profiles differentiate mild cognitive impairment from early-stage dementia: evidence from assessments of performance monitoring and evaluative judgement

BACKGROUND

Measures of memory awareness based on evaluative judgement and performance monitoring are often regarded as equivalent, but the Levels of Awareness Framework suggests they reflect different awareness phenomena. Examination of memory awareness among groups with differing degrees of impairment provides a test of this proposition.

METHOD

Ninety-nine people with dementia (PwD), 30 people with mild cognitive impairment (PwMCI), and their relatives completed isomorphic performance monitoring and evaluative judgement measures of memory awareness and were followed up at 12 and (PwD only) 20 months. In addition to the resulting awareness indices, comparative accuracy scores were calculated using the relatives' data to establish whether any inaccuracy was specific to self-ratings.

RESULTS

When making evaluative judgements about their memory in general, both PwD and PwMCI tended to overestimate their own functioning relative to informant ratings made by relatives. When monitoring performance on memory tests, PwD again overestimated performance relative to test scores, but PwMCI were much more accurate. Comparative accuracy scores indicated that, unlike PwD, PwMCI do not show a specific inaccuracy in self-related appraisals.

CONCLUSIONS

The results support the proposition that awareness indices at the levels of evaluative judgement and performance monitoring should be regarded as reflecting distinct awareness phenomena.

Awareness of deficits in Alzheimer's disease patients: analysis of performance prediction discrepancies

AIM

Unawareness has been operationalized in terms of a discrepancy between the patient's self-reports and three main categories of standards: judgment of a relative, clinical assessment, and objective test performance. The purpose of this study was to develop a new measure of deficit unawareness based on multidimensional, isomorphic, simple tasks and to examine the relationship between this measure and neuropsychological tests. METHODS : Analysis was conducted on cognitive performance prediction discrepancies in a sample of Alzheimer's disease (AD) patients and a matched comparison group.

RESULTS

Patients rated their cognitive functioning more highly than their performance, but their overall self-reports were lower than the overall self-reports of the comparison group. AD patients performed significantly lower than their predicted scores in all Dementia Rating Scale (DRS) domains, in contrast to comparison participants, who did not consistently perform significantly lower across domains. All unawareness scores were moderately inter-correlated, except for memory, and all unawareness scores with the exception of memory were correlated with overall neuropsychological functioning.

CONCLUSION

A methodological and conceptual difficulty has been identified, and this raises the issue of the generalizability of studies with a focus on memory unawareness. The method proposed seems a good tool to assess the relationships between unawareness and several different aspects of cognitive functioning, in particular executive functioning.

Agreement on diagnosis among patients, companions, and professionals after a dementia evaluation

A diagnosis of dementia is challenging to deliver and to hear; yet, agreement on diagnosis is essential for effective treatment for dementia. We examined consensus on the results of an evaluation of dementia in 90 patients assessed at an Alzheimer's Disease Research Center. Diagnostic impressions were obtained from 5 sources: (1) the physician's chart; (2) the patient who was evaluated; (3) a companion present at the evaluation; (4) a diagnostic summary written by a nurse present during the evaluation; and (5) raters who watched a video of the diagnostic disclosure conversation. Overall, diagnostic consensus was only moderate. Patients and companions exhibited just fair agreement with one another. Agreement was better between physicians and companions compared with that between physicians and patients, although it was imperfect between physicians and video raters and the written summary. Agreement among sources varied by dementia severity, with the lowest agreement occurring in instances of very mild dementia. This study documents discrepancies that can arise in diagnostic communication, which could influence adjustment to a diagnosis of dementia and decisions regarding future planning and care.

Multidimensional assessment of awareness in early-stage dementia: a cluster analytic approach

BACKGROUND/AIMS

Research on awareness in dementia has yielded variable and inconsistent associations between awareness and other factors. This study examined awareness using a multidimensional approach and applied cluster analytic techniques to identify associations between the level of awareness and other variables.

METHODS

Participants were 101 individuals with early-stage dementia (PwD) and their carers. Explicit awareness was assessed at 3 levels: performance monitoring in relation to memory, evaluative judgement in relation to memory, everyday activities and socio-emotional functioning, and metacognitive reflection in relation to the experience and impact of the condition. Implicit awareness was assessed with an emotional Stroop task.

RESULTS

Different measures of explicit awareness scores were related only to a limited extent. Cluster analysis yielded 3 groups with differing degrees of explicit awareness. These groups showed no differences in implicit awareness. Lower explicit awareness was associated with greater age, lower MMSE scores, poorer recall and naming scores, lower anxiety and greater carer stress.

CONCLUSION

Multidimensional assessment offers a more robust approach to classifying PwD according to level of awareness and hence to examining correlates and predictors of awareness.

Awareness of olfactory deficits in healthy aging, amnestic mild cognitive impairment and Alzheimer's disease

BACKGROUND

Olfactory dysfunction is present in early Alzheimer's disease (AD), and has now been reported in people with amnestic mild cognitive impairment (aMCI). Recent evidence suggests that unawareness of an olfactory deficit may predict which MCI patients will subsequently meet AD criteria. However, important methodological limitations challenge this suggestion. While addressing some of the limitations of previous research, this preliminary study explores unawareness of olfactory deficits as a predictive factor of future AD among people with aMCI.

METHODS

Twenty-five participants with aMCI, 25 AD patients, and 22 healthy elderly participants underwent testing of olfactory identification. Subjective reports regarding perceived decline in olfactory detection and olfactory identification were also obtained. A subset of participants was reassessed 12 months later.

RESULTS

Control participants performed better than both aMCI and AD patients on olfactory identification. Almost uniformly, participants did not report decline in either olfactory detection or identification. Prediction of olfactory identification scores from subjective reports of olfactory function was poor, and awareness of olfactory decline bore no relationship to the likelihood of aMCI patients progressing to AD by the 12-month review.

CONCLUSIONS

Treating awareness of olfactory function as a unitary construct can be misleading, and there is a poor relationship between subjective and objective measures of olfactory ability. Our preliminary data suggest that unawareness of olfactory decline does not improve the identification of patients with MCI who are more likely to be in the prodromal phase of AD. Replication in a larger cohort is needed to support these findings.

Metacognitive monitoring in moderate and severe traumatic brain injury

The ability to engage in self-reflective processes is a capacity that may be disrupted after neurological compromise; research to date has demonstrated that patients with traumatic brain injury (TBI) show reduced awareness of their deficits and functional ability compared to caretaker or clinician reports. Assessment of awareness of deficit, however, has been limited by the use of subjective measures (without comparison to actual performance) that are susceptible to report bias. This study used concurrent measurements from cognitive testing and confidence judgments about performance to investigate in-the-moment metacognitive experiences after moderate and severe traumatic brain injury. Deficits in metacognitive accuracy were found in adults with TBI for some but not all indices, suggesting that metacognition may not be a unitary construct. Findings also revealed that not all indices of executive functioning reliably predict metacognitive ability.

Anosognosia in neurodegenerative disease

Patients with neurological disorders are often partially or completely unaware of the deficits caused by their disease. This impairment is referred to as anosognosia, and it is very common in neurodegenerative disease, particularly in frontotemporal dementia. Anosognosia has significant impacts on function and quality of life for patients with neurodegenerative disease and their caregivers, but the phenomenon has received little formal study, especially in non-Alzheimer's (non-AD) dementias. Furthermore, few studies have attempted to systematically verify the potential role of specific cognitive impairments in producing anosognosia. As a result, the mechanisms underlying this phenomenon are poorly understood. Episodic memory likely plays an important role. In addition, the frontal lobe systems are important for intact self-awareness, but the most relevant frontal functions have not been identified. Motivation required to engage in self-monitoring and emotional activation marking errors as significant are often-overlooked aspects of performance monitoring that may underlie anosognosia in some patients. The present review offers a working model that incorporates these functions and stipulates specific processes that may be important for awareness of changes in one's abilities. Specification of the specific processes whose potential failure results in anosognosia can establish a roadmap for future studies.

Priority setting in general practice: health priorities of older patients differ from treatment priorities of their physicians

AIM

To ascertain health priorities of older patients and treatment priorities of their general practitioners (GP) on the basis of a geriatric assessment and to determine the agreement between these priorities.

METHODS

The study included a sample of 9 general practitioners in Hannover, Germany, and a stratified sample of 35 patients (2-5 patients per practice, 18 female, average age 77.7 years). Patients were given a geriatric assessment using the Standardized Assessment for Elderly Patients in Primary Care (STEP) to gain an overview of their health and everyday problems. On the basis of these results, patients and their physicians independently rated the importance of each problem disclosed by the assessment. Whereas patients assessed the importance for their everyday lives, physicians assessed the importance for patients' medical care and patients' everyday lives.

RESULTS

Each patient had a mean ± standard deviation of 18 ± 9.2 health problems. Thirty five patients disclosed a total of 634 problems; 537 (85%) were rated by patients and physicians. Of these 537 problems, 332 (62%) were rated by patients and 334 (62%) by physicians as important for patients' everyday lives. In addition, 294 (55%) were rated by physicians as important for patients' medical care. Although these proportions of important problems were similar between patients and physicians, there was little overlap in the specific problems that each group considered important. The chance-corrected agreement (Cohen κ) between patients and physicians on the importance of problems for patients' lives was low (κ=0.23). Likewise, patients and physicians disagreed on the problems that physicians considered important for patients' medical care (κ=0.18, P<0.001 for each).

CONCLUSION

The low agreement on health and treatment priorities between patients and physicians necessitates better communication between the two parties to strengthen mutual understanding.

Consciência da doença na demência do tipo Alzheimer: uma revisão sistemática de estudos longitudinais

OBJETIVOS: Avaliar as definições, métodos de avaliação e hipóteses etiológicas utilizadas em estudos longitudinais sobre consciência da doença na demência do tipo Alzheimer. MÉTODO: Pesquisa, nas bases de dados Medline, ISI, Lilacs e SciELO, de estudos longitudinais sobre consciência da doença na demência do tipo Alzheimer entre 1999 e 2009. As palavras-chave utilizadas foram: "Alzheimer", "dementia", "anosognosia", "awareness of deficit", "awareness of disease", "insight" e "longitudinal study". Os artigos examinados foram classificados conforme as hipóteses etiológicas encontradas. RESULTADOS: Os nove artigos selecionados foram divididos em duas áreas: hipóteses etiológicas biológicas e hipóteses etiológicas psicossociais. Os termos "falta de consciência dos déficits", "consciência do déficit", "insight" e "negação do déficit de memória" são utilizados nos estudos como sinônimos do termo "anosognosia", mesmo sendo, conceitualmente, diferentes. O método de avaliação mais utilizado foi o uso de questionários de discrepância entre os relatos dos pacientes e cuidadores. CONCLUSÕES: Os estudos longitudinais apresentam hipóteses etiológicas heterogêneas, além da inexistência de um padrão conceitual e metodológico de avaliação. Essas dificuldades impossibilitam a obtenção de resultados homogêneos, o que gera a necessidade de aprofundamento dos estudos na área.

Awareness of memory abilities in community-dwelling older adults with suspected dementia and mild cognitive impairment

AIMS

To examine awareness of memory abilities by groups (healthy control, suspected dementia/mild cognitive impairment, MCI, and diagnosed dementia/MCI), and to describe group differences in the relationship between awareness and cognitive performance in a community sample.

METHODS

In a cross-sectional design, 183 subjects were evaluated in a community setting and categorized into 3 groups based on their cognitive performance and reported medical history. Awareness of memory abilities was quantified using a published anosognosia ratio (AR) comparing the estimated to the objective memory performance by subjects. Each group was further categorized into 'overestimators', 'accurate estimators', and 'underestimators' based on their AR scores.

RESULTS

The suspected and diagnosed dementia/MCI groups had significantly higher AR scores than the controls. The suspected group also had a significantly larger proportion (96.2%) of overestimators than the diagnosed (73.3%) and control groups (26.1%). Impaired awareness in overestimators of the suspected and diagnosed groups was correlated with deficits in executive function, language or global cognition.

CONCLUSION

Impaired awareness of memory abilities was prevalent in community-dwelling older adults with suspected and diagnosed dementia or MCI. Those with suspected dementia or MCI were more likely to overestimate their memory abilities than their diagnosed counterparts, suggesting that limited awareness of deficits may hinder utilization of dementia diagnostic services.

Standardised measurement of self-awareness deficits in FTD and AD

BACKGROUND

Diminished ability to perceive one's own impairments, whether cognitive or social, is common in dementia, in particular frontotemporal dementia (FTD), where 'lack of insight' is listed as a core diagnostic feature. Yet, there is no currently accepted method for measuring insight in dementia. The most commonly used methods, which involve comparing patients' opinions of their level of impairment with the opinions of care givers or close family members, are subjective and require the participation of a knowledgeable informant. Here, the authors introduce a new method that allows objective quantification of an individual's awareness of their cognitive abilities and relies upon objective bedside testing.

METHODS

The authors administered several tests of everyday, real-world functions to patients with FTD (n=10) and Alzheimer's disease (AD, n=10) and to control subjects (n=10). Prior to the tasks, participants were asked to predict their performance using a percentile-based rating system. They were also asked to estimate their performance after task completion. Differences between their self-rated and actual performances were calculated.

RESULTS

Whereas the control group showed very little discrepancy between pretest predictions, post-task estimates and actual performance (mean difference of 3.9 percentile points for prediction/3.0 percentile points for post-task estimate), both patient groups overpredicted and overestimated their performance, with a significantly greater discrepancy for FTD (49.0/54.3 percentile points) than AD (27.2/28.3 percentile points).

DISCUSSION

Failures of insight and self-awareness of cognitive dysfunction can be objectively measured in dementia without the assistance of an informant, which will facilitate further study of this key component of higher cognitive functioning.

Insight and danger in Alzheimer's disease

To determine the frequency, and demographic and clinical correlates of dangerous behaviours in Alzheimer's disease (AD). We assessed a consecutive series of 278 patients with AD and 45 age-comparable healthy controls with a comprehensive psychiatric and neuropsychological evaluation. Caregivers rated the frequency of patients' exposure to dangerous situations or commission of dangerous behaviours. The frequency of dangerous behaviours was 16% in the AD group and 2% in the healthy control group. The presence of anosognosia was associated with a threefold increase in the risk of dangerous behaviours, but there was no significant association between dangerous behaviours and patients' age, years of education, diagnosis of major or minor depression and presence of suicide ideation. Sixteen per cent of a consecutive series of patients with AD had dangerous behaviours during the month preceding the clinical evaluation. Anosognosia was the main clinical correlate of dangerous behaviours in this population.

Metamemory monitoring in mild cognitive impairment: Evidence of a less accurate episodic feeling-of-knowing

This study aimed at exploring metamemory and specifically the accuracy of memory monitoring in mild cognitive impairment (MCI) using an episodic memory feeling-of-knowing (FOK) procedure. To this end, 20 people with MCI and 20 matched control participants were compared on the episodic FOK task. Results showed that the MCI group made less accurate FOK predictions than the control group by overestimating their memory performance on a recognition task. The MCI overestimation behavior was found to be critically related to the severity of their cognitive decline. In the light of recent neuroanatomical models showing the involvement of a temporal-frontal network underlying accurate FOK predictions, the role of memory and executive processes was evaluated. Thus, participants were also administered memory and executive neuropsychological tests. Correlation analysis revealed a between-group differential pattern indicating that FOK accuracy was primarily related to memory abilities in people with MCI, whereas it was specifically related to executive functioning in control participants. The lesser ability of people with MCI to assess their memory status accurately on an episodic FOK task is discussed in relation to both their subjective memory complaints and to their actual memory deficits which might be mediated by the brain vulnerability of their hippocampus and medial temporal system. It is suggested that their memory weakness may lead people with MCI to use other less reliable forms of memory monitoring.

Approaches to the assessment of awareness: conceptual issues

Recent interest in the empirical exploration of patients' awareness in relation to their clinical states has resulted in a range of approaches taken to evaluate such awareness. These approaches vary in terms of the bases on which awareness is determined and rated, the contents of the measures used, the level of detail and complexity of judgements required, etc. The approaches use different definitions and objects of awareness and hence give rise to different (and on occasions divergent) awareness phenomena. Such differences help to explain both the contradictory nature of published results and the difficulties involved in generalising from them. In practical terms, these differences should encourage the development of management and rehabilitation strategies that are individual to specific phenomena of awareness.

Different perception of cognitive impairment, behavioral disturbances, and functional disabilities between persons with mild cognitive impairment and mild Alzheimer's disease and their caregivers

Insight in dementia is a multifaceted concept and ability, which includes the persons' perception of their behavioral and cognitive symptoms and functional disability. This ability seems to deteriorate as dementia progresses. The aim of this study was to evaluate the level of insight in the cognitive, behavioral, and functional disorders in a group of persons with mild cognitive impairment (MCI) or mild AD (Alzheimer's disease) and to compare their perception of their illness with that of their caregivers. The study involved a group of 121 persons with MCI and mild AD and their caregivers. The persons with MCI and mild AD were administered the tests Mini-Mental State Examination, Instrumental Activities of Daily Living, Activities of Daily Living, Neuropsychiatric Inventory, Schedule for the Assessment of Insight, Clinical Insight Rating Scale, and a short interview. Major differences were identified between how the persons with MCI or mild AD and their caregivers perceived the persons' cognitive and behavioral disorders. The group with MCI or mild AD underestimated their deficits, which were considered serious and disabling by their caregivers.

A diagnostic formulation for anosognosia in Alzheimer's disease

OBJECTIVE

To determine the earliest symptoms of anosognosia in people with Alzheimer's disease and to validate a criteria-guided strategy to diagnose anosognosia in dementia.

METHODS

A consecutive series of 750 patients with very mild or probable Alzheimer's disease attending a memory clinic, as well as their respective care givers, was assessed using a comprehensive psychiatric evaluation.

RESULTS

The factors of anosognosia for (1) basic activities of daily living (bADL), (2) instrumental activities of daily living (iADL), (3) depression and (4) disinhibition were produced by a principal component analysis on the differential scores (ie, caregiver score minus patient score) on the anosognosia questionnaire for dementia. A discrepancy of two or more points in the anosognosia-iADL factor was found to have a high sensitivity and specificity to identify clinically diagnosed anosognosia in people with Alzheimer's disease. By logistic regression analysis, the severity of dementia and apathy were both shown to be noticeably associated with anosognosia in people with Alzheimer's disease.

CONCLUSION

Anosognosia in those with Alzheimer's disease is manifested as poor awareness of deficits in iADL and bADL, depressive changes and behavioural disinhibition. The frequency of anosognosia is found to increase considerably with the severity of dementia. The validity of a specific set of criteria to diagnose anosognosia in people with Alzheimer's disease was shown, which may contribute to the early identification of this condition.

Unawareness of deficits in Alzheimer's disease and other dementias: operational definitions and empirical findings

Individuals with dementia frequently demonstrate decreased awareness of their cognitive difficulties. Empirical research examining this phenomenon has addressed a number of aspects of unawareness in Alzheimer's disease and other dementias, including occurrence in various disorders; possible neuroanatomical substrates; relationship to general cognitive functioning, executive functioning, and psychiatric symptomatology; and progression over time and across cognitive domains. Limitations of the current research literature are discussed, particularly issues surrounding operational definitions of unawareness and the current limited understanding of the role of the frontal lobes. A number of conclusions regarding unawareness that appear to be supported by the current body of empirical research and possible future directions are discussed.

Symptoms underlying unawareness of memory impairment in patients with mild Alzheimer's disease

Patients with Alzheimer's disease (AD) are often unaware of their cognitive impairment. This unawareness might have a multifactorial etiology, including impairment of cognitive domains and psychiatric symptoms. We conducted this study to determine the factors underlying unawareness of memory impairment (UMI) in patients with AD. In 103 patients with mild AD, the UMI was quantified as the difference between the patient's self-rating and the rating of the patient's caregiver on a standardized memory questionnaire system, the Everyday Memory Checklist. We then examined the relationships between UMI and memory, attention, language, visuospatial/constructive perception, frontal lobe function, and psychiatric symptoms. UMI was positively associated with memory impairment and delusions when effects of age, sex, and education were partialled out, suggesting that these symptoms are involved in the formation of UMI in the patients. Thus, existing treatments for memory impairment and delusions may be beneficial for increasing the awareness of mild AD patients of their cognitive impairment.

The role of personality and coping style in relation to awareness of current functioning in early-stage dementia

This study investigated the role of psychological factors in unawareness in early-stage dementia, focusing on personality and coping strategies. Forty-nine individuals with a 'non-frontal' dementia and their partners completed standardized self-report questionnaires. Multiple regression analyses indicated that personality factors, in particular negative attitudes towards emotional expression, were related to avoidant coping in managing the threat of dementia. Neither negative attitudes towards emotional expression nor avoidant behavioural coping related to unawareness after controlling for relevant disease-related and emotional variables. However, a relationship was found between conscientiousness and unawareness. The findings were interpreted with reference to literature on processes of denial and a distinction between conscious behavioural avoidance and unconscious defensive denial was made. Implications for clinical practice were considered.

Anosognosia in very mild Alzheimer's disease but not in mild cognitive impairment

OBJECTIVE

To study awareness of cognitive dysfunction in patients with very mild Alzheimer's disease (AD) and subjects with mild cognitive impairment (MCI).

METHODS

A complaint interview covering 13 cognitive domains was administered to 82 AD and 79 MCI patients and their caregivers. The patient groups were comparable according to age and education, and Mini Mental State Examination (MMSE) scores were > or =24 in all cases. The discrepancy between the patients' and caregivers' estimations of impairments was taken as a measure of anosognosia.

RESULTS

Self-reports of cognitive difficulties were comparable for AD and MCI patients. However, while in comparison to caregivers MCI patients reported significantly more cognitive impairment (p < 0.05), AD patients complained significantly less cognitive dysfunctions (p < 0.001).

CONCLUSIONS

While most MCI patients tend to overestimate cognitive deficits when compared to their caregiver's assessment, AD patients in early stages of disease underestimate cognitive dysfunctions. Anosognosia can thus be regarded as a characteristic symptom at a stage of very mild AD (MMSE > or =24) but not MCI. Accordingly, medical history even in mildly affected patients should always include information from both patient and caregiver.

Awareness in dementia: A review of assessment methods and measures

A comprehensive range of literature on awareness in dementia published in peer-reviewed journals during the last 15 years was reviewed with the aim of extracting details of the methods and measurement instruments adopted for the purposes of assessing awareness. Assessment approaches fell into five categories: clinician rating methods, questionnaire-based methods, performance-based methods, phenomenological methods, and multidimensional or combined methods. Ranges of objects of awareness assessment were identified both within and across domains. Strengths and limitations of methods in each category were identified. Reasons for the inconclusive findings from research using the methods described here were considered, and suggestions for future directions were made.

Awareness in dementia: conceptual issues

There has been a recent proliferation of studies exploring awareness in people with dementia and, as is the case with similar studies in other clinical areas, results are generally mixed and inconsistent. One of the reasons underlying variability in study results relates to the complexities around the concept of awareness itself. Two sources of conceptual problems are explored. First, the meaning of awareness is examined and, within the dementia literature, various conceptualizations of awareness are identified which could be traced to three broad frameworks within which awareness and related terms are conceived. Differences between meanings of awareness are thus highlighted and the importance of making such differences explicit in studies was discussed. Second, the relational aspect of awareness is raised as a crucial issue determining the phenomenon of awareness elicited in clinical practice. Thus, in dementia, awareness is related to various "objects" including the illness as a whole, memory problems, activities of daily living, affective changes and many others. In each case, however, the object of awareness will elicit a different phenomenon of awareness, again carrying implications for the generalizability of study results. Clarification of conceptual problems is essential for future work in this area in order that empirical studies can provide meaningful answers concerning the therapeutic and predictive validity of different aspects of awareness.

Consciência da doença na demência: resultados preliminares em pacientes com doença de Alzheimer leve e moderada

OBJETIVO: Avaliar a presença e o grau de consciência da doença na doença de Alzheimer (DA) em estágio leve e moderado. MÉTODO: Pacientes com DA leve/moderada (n=42) avaliados em corte transversal através da Escala de Avaliação do Impacto Psicossocial do Diagnóstico de Demência (APSID), Mini-Exame do Estado Mental (MEEM) e Estadiamento Clínico das Demências (CDR). RESULTADOS: No estágio leve (n=18), 66,7% dos pacientes perceberam os sintomas cognitivos e os prejuízos causados na vida cotidiana. No estágio moderado (n=24), 20,8% tinham consciência da doença preservada; em 45,8% observou-se somente a noção sobre a presença de sintomas cognitivos; ausência total de consciência da doença foi encontrada em 33,3%. CONCLUSÃO: Os dados encontrados indicam a associação entre consciência e evolução clínica da doença. Pacientes com CDR 1 reconhecem melhor os sintomas cognitivos e dificuldades de atividade de vida diária. A maioria dos pacientes com CDR 2 reconhece seus sintomas, mas não percebe a gravidade e as conseqüências nas atividades de vida diária.

Conscience des déficits et anosognosie dans la maladie d’Alzheimer

This article reviews studies concerning unawareness of deficits in Alzheimer's disease. Unawareness of the deficits associated with dementia has frequently been reported in clinical descriptions of the later stages of the disease. Consistent with the literature, we shall use the expressions impaired awareness, unawareness of deficits, anosognosia, and lack of insight interchangeably. Anosognosia can be defined as an impaired ability to recognize the presence or appreciate the severity of deficits in sensory, perceptual, motor, affective, or cognitive functioning. Unawareness has been operationally defined in a variety of ways. Unawareness can be measured as the discrepancy between the patient's self-report and the report of a natural caregiver or the clinical rating of a health care professional. The reports generally concern with several domains, most often memory domain. Discrepancy between subjective ratings and neuropsychological performance during clinical assessment has also been used to measure anosognosia. Advantages, limits and equivalence of these different methods are discussed. The impact of family burden has to be considered as a systematic methodological bias if the natural caregiver is implicated in the assessment. The psychometric properties of the clinical assessment have also to be discussed. The psychological nature of the discrepancy between patient's self-report and cognitive performances has to be analyzed and the necessity of ecological protocols, longitudinal assessment is discussed. The major results concerning prevalence, nature of anosognosia and the associated disorders are analyzed. In particular, the notion of heterogeneity of anosognosia and the correlates with depression, severity of dementia and executive dysfunction are developed. Prevalence is largely function of methodological choices and conceptual definition of anosognosia. Three major researches are compared and the contrast between their results (prevalence from 23% to 75% in AD) is analyzed. Particularly, the hypotheses about anosognosia play a great role in the findings. At first time of research, anosognosia was considered as a general symptom and so, studies were centered on the unawareness related to only one cognitive function. But the 90's findings suggest that patients with AD have impaired awareness for some types of deficits (affective or cognitive functions) but can more accurately appraise other deficits. Currently anosognosia cannot be considered as a unitary entity. It may be that patients with AD are unaware of some types of deficits, but are aware of others, and that nature and intensity of their anosognosia may change during the course of the dementia. It has been proposed that depression is more common when disease is mild and awareness of deficits is retained, and that depression becomes less common when disease increases and awareness declines. Depression is conceived as a psychological reaction. However, the correlations between anosognosia level and depression scores reveal either weak relationships or no relationships. Alternative hypothesis is that anosognosia is related to overall dementia severity and to memory impairment. However, correlations of unawareness of deficits, i.e. the difference between self-report and relative's -rating, with a measure of dementia and with patient's performance on objective memory tasks did not reveal strong, consistent relationships between degree of anosognosia and severity of dementia or of memory impairment. On the other hand, the best neuropsychological predictors of impaired insight are Trail Making Test or Wisconsin Card Sorting Test, i.e. tests that have been shown to be sensitive to a frontal lobe dysfunction. SPECT measures of regional cerebral blood flow have been used in the study of anosognosia. The main findings are that unawareness in AD is associated with hypoperfusion of the right dorsolateral frontal lobe. Anosognosia may result from the disruption of broader cognitive process that is subsumed by the frontal lobes. The mechanisms of unawareness are not well known and studies are essentially descriptive works and try to give information about pre-valence or clinical associated disorders of anosognosia. Several authors have proposed that unawareness is part of a defensive mechanism that would protect demented patients from depressive feelings. Other authors have proposed that anosognosia may result from dysfunction in specific brain areas. It is suggested that anosognosia in AD may result from greater impairment of a central executive system, which is a metacognitive structure that is involved in planning, cognitive resource allocation, and set shifting. The main problem with those both major hypotheses is their incapacity to explain the heterogeneous impairment of awareness. Other authors speculate that the impaired insight of Alzheimer's disease has several components, psychological and neuropsychological. This view doesn't seem convincing and new components have to be taken in account in order to propose a theoretical framework about anosognosia in AD. Environmental and dispositional components and an interactional view could be interesting. Those possible directions for future research and solutions concerning methodological and conceptual problems are outlined. In particular, a neuro-psycho-social view of unawareness is introduced.

The apathy inventory: assessment of apathy and awareness in Alzheimer's disease, Parkinson's disease and mild cognitive impairment

OBJECTIVE

This study was designed to establish the validity and reliability of the apathy inventory (IA), a rating scale for global assessment of apathy and separate assessment of emotional blunting, lack of initiative, and lack of interest.

METHOD

Information for the IA can be obtained from the patient or from a caregiver. We evaluated 115 subjects using the IA, consisting of 19 healthy elderly subjects, 24 patients with Mild Cognitive Impairment (MCI), 12 subjects with Parkinson's disease (PD) and 60 subjects with Alzheimer's disease (AD).

RESULTS

Internal consistency, item reliability, and between-rater reliability were high. A test-retest reliability study demonstrated that caregiver responses to IA questions were stable over short intervals. A concurrent validity study showed that the IA assesses apathy as effectively as the Neuro Psychiatric Inventory apathy domain. In the caregiver-based evaluation, AD subjects had significantly higher scores than controls, both for global apathy score and for the lack of interest dimension. When the AD patients were subdivided according to diagnostic criteria for apathy, apathetic patients had significantly higher scores than non apathetic patients. With the patient-based evaluations, no differences were found among the AD, MCI and control groups. The scores in the patient-based evaluations were only higher for the PD group versus the control subjects. The results also indicated that AD patients had poor awareness of their emotional blunting and lack of initiative.

CONCLUSIONS

The IA is a reliable method for assessing in demented and non-demented elderly subjects several dimensions of the apathetic syndrome, and also the subject's awareness of these symptoms.

Effects of a multimedia project on users' knowledge about normal forgetting and serious memory loss

OBJECTIVE

The aim of the project was to develop and evaluate the effectiveness of a CD-ROM-based multimedia program as a tool to increase user's knowledge about the differences between "normal" forgetfulness and more serious memory loss associated with Alzheimer's disease.

DESIGN AND MEASUREMENTS

The research was a controlled randomized study conducted with 113 adults who were recruited from the community and who expressed a concern about memory loss in a family member. The intervention group (n=56) viewed a module entitled "Forgetfulness: What's Normal and What's Not" on a laptop computer in their homes; the control group (n=57) did not. Both groups completed a 25-item knowledge-about-memory-loss test (primary outcome) and a sociodemographic and technology usage questionnaire; the intervention group also completed a CD-ROM user's evaluation.

RESULTS

The mean (SD) number of correct responses to the knowledge test was 14.2 (4.5) for controls and 19.7 (3.1) for intervention participants. This highly significant difference (p<0.001) corresponds to a very large effect size. The program was most effective for participants with a lower level of self-reported prior knowledge about memory loss and Alzheimer's disease (p=0.02). Viewers were very satisfied with the program and felt that it was easy to use and understand. They particularly valued having personal access to a confidential source that permitted them to become informed about memory loss without public disclosure.

CONCLUSION

This multimedia CD-ROM technology program provides an efficient and effective means of teaching older adults about memory loss and ways to distinguish benign from serious memory loss. It uniquely balances public community outreach education and personal privacy.

Insight in Alzheimer's patients: results of a longitudinal study using three assessment methods

Three direct measures of dementia insight were administered to 20 participants in a longitudinal Alzheimer's disease (AD) rehabilitation research project and to subsets of these participants that completed one (N = 19), two (N = 12), and three (N = 6) years of program participation. The measures were: (1) responses to a discourse prompt question about AD (ADPQ); (2) endorsements of seven items on the Geriatric Depression Scale (GDS) about the effects of dementia (separate analyses were done for two of the seven items that related specifically to memory and thinking); and (3) a sentence-completion exercise. Responses to measures 1 and 2 and the subset of 2 were quantified, tracked over time, and subjected to correlational analyses with age, Mini-Mental State Exam (MMSE) score, and depression, as measured by total GDS score, and with each other.

MAJOR FINDINGS

There were no decreases in insight from baseline to year 1, 2, or 3, as measured by free responses to the AD prompt question. There was a significant decline in insight from baseline to year one on the GDS measure, but no change from year 1 to year 2 and a return to baseline level at year 3. There was no correlation between insight and baseline age, between insight and MMSE score at any time point, between MMSE score and depression, as measured by total GDS score, or between MMSE score and depression score, except for the year 3 completers, where depression score was negatively correlated with MMSE score at year 3 only. GDS insight and ADPQ scores were not correlated. Several participants that showed no insight on the quantified measures did so on the sentence completions.

The nosology of dementia

The nosology of dementia has evolved from the simple distinctions between senility, degenerative dementia, and vascular insults that existed a few decades ago. The differentiation of normal cognitive aging from very mild dementia has sharpened considerably; however, appreciation of the heterogeneity of Alzheimer's disease (AD) and its clinical and pathologic overlap with other dementing disorders has blurred previous classification systems. Rather than viewing AD and vascular dementia, for example, as dichotomous entities, it may be more relevant to consider their additive or synergistic interactions producing dementia. Further elucidation of the nature and contribution of genetic factors in AD and related disorders will accelerate the use of genotype-phenotype correlations in dementia classification.

Lay person-based screening for early detection of Alzheimer's disease: development and validation of an instrument

Symptoms of cognitive impairment reported to telephone interviewers by caregivers of 272 patients were analyzed with respect to research diagnoses of dementia. All patients received neuropsychological evaluation for establishing the research diagnoses. A data mining program that used machine learning algorithms produced an optimized binary decision tree for differentiating patient groups according to all available information. The results of this analysis were used to help four dementia experts create a dementia screening instrument amenable to application and scoring by nonclinical personnel. The validity of the resulting instrument was then evaluated in an independent sample of 103 patients administered neuropsychological testing within the previous 60 days. The psychometric properties of the empirically derived scale and its performance for discriminating control from probable or possible Alzheimer's patients indicate strong potential for use as a dementia screener for the general population.

Acetylcholine in mind: a neurotransmitter correlate of consciousness?

The cholinergic system is one of the most important modulatory neurotransmitter systems in the brain and controls activities that depend on selective attention, which are an essential component of conscious awareness. Psychopharmacological and pathological evidence supports the concept of a 'cholinergic component' of conscious awareness. Drugs that antagonize muscarinic receptors induce hallucinations and reduce the level of consciousness, while the nicotinic receptor is implicated as being involved in the mechanism of action of general (inhalational) anaesthetics. In degenerative diseases of the brain, alterations in consciousness are associated with regional deficits in the cholinergic system. In Alzheimer's disease (AD), there is a loss of explicit (more than implicit) memory and hypoactivity of cholinergic projections to the hippocampus and cortex, while the visual hallucinations experienced by subjects with Dementia with Lewy bodies (DLB) are associated with reductions in neocortical ACh-related activity. In Parkinson's disease, the additional loss of pedunculopontine cholinergic neurones, which control REM (rapid eye movement) sleep or dreaming, is likely to contribute to REM abnormalities, which also occur in DLB. Widespread basal-forebrain and rostral brainstem cholinergic pathways, which include converging projections to the thalamus, appear to be located strategically for generating and integrating conscious awareness. Alleviation of a range of cognitive and non-cognitive symptoms by drugs that modulate the cholinergic system, which are being developed for the treatment of AD and related disorders, could be caused by changes in consciousness.