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

The use of virtual reality as a perspective-taking manipulation to improve self-awareness in Alzheimer's disease

Lack of awareness of symptoms or having a condition referred to as anosognosia is a common feature of individuals with Alzheimer's Disease (AD). Previous literature on AD reported difficulties in evaluating self-abilities, often showing underestimation of limitations. There is increasing evidence that the perspective through which information is presented may moderate the performance appraisal and that anosognosia in AD might be a consequence of a deficit in assuming a third-person perspective. In this context, some studies showed that subjects may better recognize self-and other-difficulties when exposed to a third-person perspective. Considering the variety of approaches aiming to investigate the lack of awareness, there is still a scarcity of methods that provide great ecological validity and consider more than one facet of awareness, thus failing to offer more accurate evaluations of daily experiences. The present paper primarily addresses the theme of the multidimensional character of awareness of abilities in AD and the effect of perspective-taking on its trajectories. The focus turns to virtual reality as a promising tool for a greater evaluation of perspective-taking and self-awareness. Particularly, these systems offer the possibility to involve users in cognitive and sensorimotor tasks that simulate daily life conditions within immersive and realistic environments, and a great sense of embodiment. We propose that virtual reality might allow a great level of complexity, veracity, and safety that is needed for individuals with AD to behave according to their actual abilities and enable to explore the liaison between the subject's viewpoint, performance, and self-evaluation. In addition, we suggest promising clinical implications of virtual reality-based methods for individualized assessments, investigating specific impacts on subjects' life and possible improvements in their awareness.

Toward the optimized assessment of clinical outcomes in studies of novel treatments for Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) is characterized by a progressive decline in cognition and daily function, leading to a greater need for caregiver support. Clinical disease is segmented into a preclinical stage, mild cognitive impairment, and mild, moderate, and severe stages of Alzheimer's dementia. Although AD trials enroll participants at various stages of illness, treatment efficacy is often assessed using endpoints based on measures of outcomes that are held fixed across disease stages. We hypothesize that matching the primary outcomes measured in the endpoint hierarchy to the stage of disease targeted by the trial will increase the likelihood of detecting true treatment benefits.

AREAS COVERED

We discuss current approaches to assessing clinical outcomes in AD trials, followed by a consideration of how effect detection can be improved by linking the stage of AD to the endpoints that most likely reflect stage-specific disease progression.

EXPERT OPINION

Failing to account for stage-specific relevance and sensitivity of clinical outcomes may be one factor that contributes to trial failures in AD. Given the history of failure, experts have begun to scrutinize the relevance and sensitivity of outcomes as a potentially modifiable barrier to successful trials. To this end, we present a framework for refining trial endpoint selection and evaluation.

Does sleep duration moderate genetic and environmental contributions to cognitive performance?

While prior research has demonstrated a relationship between sleep and cognitive performance, how sleep relates to underlying genetic and environmental etiologies contributing to cognitive functioning, regardless of the level of cognitive function, is unclear. The present study assessed whether the importance of genetic and environmental contributions to cognition vary depending on an individual's aging-related sleep characteristics. The large sample consisted of twins from six studies within the Interplay of Genes and Environment across Multiple Studies (IGEMS) consortium spanning mid- to late-life (Average age [Mage] = 57.6, range = 27-91 years, N = 7052, Female = 43.70%, 1525 complete monozygotic [MZ] pairs, 2001 complete dizygotic [DZ] pairs). Quantitative genetic twin models considered sleep duration as a primary moderator of genetic and environmental contributions to cognitive performance in four cognitive abilities (Semantic Fluency, Spatial-Visual Reasoning, Processing Speed, and Episodic Memory), while accounting for age moderation. Results suggested genetic and both shared and nonshared environmental contributions for Semantic Fluency and genetic and shared environmental contributions for Episodic Memory vary by sleep duration, while no significant moderation was observed for Spatial-Visual Reasoning or Processing Speed. Results for Semantic Fluency and Episodic Memory illustrated patterns of higher genetic influences on cognitive function at shorter sleep durations (i.e. 4 hours) and higher shared environmental contributions to cognitive function at longer sleep durations (i.e. 10 hours). Overall, these findings may align with associations of upregulation of neuroinflammatory processes and ineffective beta-amyloid clearance in short sleep contexts and common reporting of mental fatigue in long sleep contexts, both associated with poorer cognitive functioning.

Associations between Cortical Thickness and Metamemory in Alzheimer’s Disease

Metacognitive deficits affect Alzheimer's disease (AD) patient safety and increase caregiver burden. The brain areas that support metacognition are not well understood. 112 participants from the Imaging and Genetic Biomarkers for AD (ImaGene) study underwent comprehensive cognitive testing and brain magnetic resonance imaging. A performance-prediction paradigm was used to evaluate metacognitive abilities for California Verbal Learning Test-II learning (CVLT-II 1-5) and delayed recall (CVLT-II DR); Visual Reproduction-I immediate recall (VR-I Copy) and Visual Reproduction-II delayed recall (VR-II DR); Rey-Osterrieth Complex Figure Copy (Rey-O Copy) and delayed recall (Rey-O DR). Vertex-wise multivariable regression of cortical thickness was performed using metacognitive scores as predictors while controlling for age, sex, education, and intracranial volume. Subjects who overestimated CVLT-II DR in prediction showed cortical atrophy, most pronounced in the bilateral temporal and left greater than right (L > R) frontal cortices. Overestimation of CVLT-II 1-5 prediction and DR performance in postdiction showed L > R associations with medial, inferior and lateral temporal and left posterior cingulate cortical atrophy. Overconfident prediction of VR-I Copy performance was associated with right greater than left medial, inferior and lateral temporal, lateral parietal, anterior and posterior cingulate and lateral frontal cortical atrophy. Underestimation of Rey-O Copy performance in prediction was associated with atrophy localizing to the temporal and cingulate areas, and in postdiction, with diffuse cortical atrophy. Impaired metacognition was associated to cortical atrophy. Our results indicate that poor insight into one's cognitive abilities is a pervasive neurodegenerative feature associated with AD across the cognitive spectrum.

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.

Altered awareness of motor symptoms in Parkinson's disease and Dementia with Lewy Bodies: A systematic review

OBJECTIVES

Altered awareness of motor symptoms is reported in people with Parkinson's disease and Dementia with Lewy Bodies, and may adversely affect quality of life and medication concordance. How symptom awareness is influenced by motor and cognitive disease severity, age and medication use is not fully understood. We carried out a systematic review of the literature on motor symptom awareness in Parkinson's disease and Dementia with Lewy Bodies.

METHODS

Pubmed and Wed of Science were searched for relevant articles published in or prior to March 2019. Data regarding participant demographics, diagnosis, cognitive status, method of assessing awareness and study findings were extracted from relevant publications.

RESULTS

Sixteen relevant publications were identified. Motor symptom awareness appears to decline over the course of Parkinson's disease. Imaging studies implicate the prefrontal cortex, with different mechanisms involved in hypokinesia and dyskinesia awareness. The hypothesis that people with right hemisphere based disease would have more severely reduced awareness is only weakly supported. Most studies focused on cognitively intact individuals, and on awareness of dyskinesia rather than hypokinesia.

CONCLUSIONS

Whilst reduced awareness of dyskinesia and to a lesser extent hypokinesia is common, there is a lack of longitudinal data on how awareness changes over time, and how it interacts with global cognitive changes. Motor symptom awareness in Dementia with Lewy Bodies is understudied. Future studies of symptom awareness should include robust assessment of overall cognitive functioning, and use a longitudinal design to elucidate how awareness changes over time. J Am Geriatr Soc 68:-, 2020.

Comparing Self to Peers in Percentile Equivalents during Cognitive Testing: More Accurate Self-Appraisal Estimates are Associated with Greater Ability and Less Reliance on the Representativeness Heuristic

OBJECTIVE

For individuals with neurologic disorders, self-awareness of cognitive impairment is associated with indicators of better treatment course and clinical outcomes. Lower self-appraisal accuracy has been found to be associated with impairments in neuropsychological test performance, but individuals who perform unusually well may be equally vulnerable to inaccurate self-ratings. The mixed pattern of cognitive strengths and deficits in individuals with neurologic disorders complicates development of formal metrics for assessment of self-awareness. It remains unclear to what extent distortions in self-appraisal represent a deficit associated with impaired cognitive functioning, or a normal reliance on the "representativeness-heuristic" that results in greater bias in self-ratings in both strong and poor performers.

METHOD

The present study investigated these hypotheses using a common-metric approach (Rothlind, Dukarm, and Kraybill, 2016). Participants included 199 adults, recruited from community sources, including healthy adult volunteers and individuals at-risk for neuropsychological impairment secondary to human immunodeficiency virus (HIV) positive status or active heavy alcohol consumption or both. Immediately following completion of standardized neuropsychological tests, participants estimated their own performance percentile ranking.

RESULTS

Both high and low-scoring examinees displayed a conservative bias in ranking their own neuropsychological performance. However, lower scores were associated with least accurate self-appraisals overall.

CONCLUSION

Findings suggest that cognitive impairments are associated with lower accuracy in self-rating of cognitive ability, but also that normal biases complicate interpretation of self-appraisal ratings across the spectrum of neuropsychological functioning. The importance of recognizing these biases in clinical research and practice is emphasized, and directions for future research are discussed.

Memory complaints inventory profiles: Differentiating neurocognitive impairment, depression, and non-credible performance

The Memory Complaints Inventory (MCI) is a symptom validity measure designed to assess exaggerated memory complaints. The aim of current study was to develop memory complaint profiles on the MCI to distinguish between various neurocognitive disorders, depression, and non-credible performance. This study utilized MCI scores (N = 244) from a neuropsychology clinic to determine the presence of, and difference between, subjective memory complaints between a depression group, non-credible group, and subgroups of cognitive impairment (Alzheimer's Dementia, Vascular Dementia, and Mild Cognitive Impairment). Significant differences were found on MCI endorsement between cognitive impairment, depression, and non-credible groups. This pattern indicated fewer memory complaints for cognitive impairment groups when compared to depression and non-credible groups; the non-credible group had the highest MCI scores overall. ROC analyses revealed recommended clinical cutoff values with high specificity for distinguishing between the non-credible group and other groups. The findings provided further evidence for the MCI as a symptom validity measure, given its ability to differentiate between a non-credible group and clinical groups. Replication of the study's findings would result in reliable genuine subjective memory complaint profiles to provide additional diagnostic and prognostic specificity in neuropsychological practice.

Neural correlates of altered insight in frontotemporal dementia: a systematic review

•

Fractionating insight into objects aids its neuroanatomical exploration in dementia.

•

Distinctive neural correlates seem to underpin different insight objects in FTD.

•

Altered insight into disease/health condition mostly involves right frontal areas.

•

Altered insight into social cognition implicates frontal, temporal and limbic areas.

•

Frontal, medial temporal and parietal areas underpin insight into memory problems.

Altered insight into disease or specific symptoms is a prominent clinical feature of frontotemporal dementia (FTD). Understanding the neural bases of insight is crucial to help improve FTD diagnosis, classification and management. A systematic review to explore the neural correlates of altered insight in FTD and associated syndromes was conducted. Insight was fractionated to examine whether altered insight into different neuropsychological/behavioural objects is underpinned by different or compatible neural correlates. 6 databases (Medline, Embase, PsycINFO, Web of Science, BIOSIS and ProQuest Dissertations & Theses Global) were interrogated between 1980 and August 2019. 15 relevant papers were found out of 660 titles screened. The studies included suggest that different objects of altered insight are associated with distinctive brain areas in FTD. For example, disease unawareness appears to predominantly correlate with right frontal involvement. In contrast, altered insight into social cognition potentially involves, in addition to frontal areas, the temporal gyrus, insula, parahippocampus and amygdala. Impaired insight into memory problems appears to be related to the frontal lobes, postcentral gyrus, parietal cortex and posterior cingulate. These results reflect to a certain extent those observed in other neurodegenerative conditions like Alzheimer's disease (AD) and also other brain disorders. Nevertheless, they should be cautiously interpreted due to variability in the methodological aspects used to reach those conclusions. Future work should triangulate different insight assessment approaches and brain imaging techniques to increase the understanding of this highly relevant clinical phenomenon in dementia.

Late-onset anti-N-methyl-d-aspartate receptor encephalitis in China

PURPOSE

This study aimed to summarize the clinical characteristics and outcome of late-onset anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis in China.

METHOD

All cases of people with a definitive diagnosis of anti-NMDAR encephalitis in West China Hospital between June 2012 and April 2017 were retrospectively reviewed. The demographics, clinical characteristics, and outcome of those patients (age≥45years old) were summarized. Comparisons were conducted between older (≥45years old) and younger (18-44years old) adults.

RESULT

Eighteen (12%) of 151 people were ≥45years old, 9 of whom (50%) were female. Psychiatric symptoms were the most common clinical manifestations of older adults and presented in all individuals. At the last follow-up, 14 (78%) of them had a good outcome (modified Rankin Scale: 0-2) and one (6%) died. Compared with 121 younger adults, older adults had a higher proportion of presenting memory deficit as the initial symptom (17% vs. 2%, p=0.023), longer interval from onset to admission (30 vs. 13days, p=0.013), and longer interval from onset to diagnosis (42.5 vs. 24days, p=0.045). No older adults' condition was accompanied with teratoma compared with 75% of younger adults with tumor (p=0.032). And older adults had a tendency to have a lower rate of positive NMDAR antibody (Ab) in serum (28% vs. 52%, p=0.053).

CONCLUSION

Delayed admission and diagnosis are more common in older adults than in younger adults. A comprehensive consideration of all symptoms and early screening of NMDAR Ab, especially in cerebrospinal fluid, is necessary and beneficial to differential diagnosis.

Neural Correlates of Anosognosia in Alzheimer's Disease and Mild Cognitive Impairment: A Multi-Method Assessment

Patients with Alzheimer's Disease (AD) and Mild Cognitive Impairment (MCI) may present anosognosia for their cognitive deficits. Three different methods have been usually used to measure anosognosia in patients with AD and MCI, but no studies have established if they share similar neuroanatomical correlates. The purpose of this study was to investigate if anosognosia scores obtained with the three most commonly used methods to assess anosognosia relate to focal atrophy in AD and MCI patients, in order to improve understanding of the neural basis of anosognosia in dementia. Anosognosia was evaluated in 27 patients (15 MCI and 12 AD) through clinical rating (Clinical Insight Rating Scale, CIRS), patient-informant discrepancy (Anosognosia Questionnaire Dementia, AQ-D), and performance discrepancy on different cognitive domains (self-appraisal discrepancies, SADs). Voxel-based morphometry correlational analyses were performed on magnetic resonance imaging (MRI) data with each anosognosia score. Increasing anosognosia on any anosognosia measurement (CIRS, AQ-D, SADs) was associated with increasing gray matter atrophy in the medial temporal lobe including the right hippocampus. Our results support a unitary mechanism of anosognosia in AD and MCI, in which medial temporal lobes play a key role, irrespectively of the assessment method used. This is in accordance with models suggesting that anosognosia in AD is primarily caused by a decline in mnemonic processes.

Assessment of Self-Awareness of Cognitive Function: Correlations of Self-Ratings with Actual Performance Ranks for Tests of Processing Speed, Memory and Executive Function in Non-Clinical Samples

Objective

For individuals with neurologic disorders, self-awareness of cognitive impairment is associated with improved treatment course and clinical outcome. However, methods for assessment of levels of self-awareness are limited, and most require collateral information, which may not be readily available. Although distortions in self-awareness are most often associated with low cognitive ability, the frequently mixed pattern of cognitive strengths and deficits in individuals with neurologic disorders complicates assessment. The present study explores relationships between actual test performance and self-ratings, utilizing a brief probe administered during testing. The "common-metric" approach solicits self-appraisal ratings in percentile equivalents and capitalizes on available normative data for specific standardized neuropsychological tests to allow direct comparisons.

Method

A convenience sample of 199 adults recruited from community sources participated in this study, including healthy adults and neuropsychologically "at-risk" volunteers who were HIV positive and/or endorsing heavy current alcohol consumption. Immediately following completion of standardized neuropsychological tests, participants estimated their own percentile ranking.

Results

Across study groups, participant's estimates of their own percentile rank were modestly correlated with actual performance ranking. Highest correlations were obtained for tests of learning, memory and conceptual reasoning, and executive function, with smaller correlations for simple tests of motor and psychomotor speed.

Conclusions

The study reveals normal biases affecting the self-appraisal during standardized testing, and suggests that a common-metric approach for assessing self-appraisal may play a role in establishing clinical thresholds and identifying and quantifying reductions in insight in persons with neuropsychological deficits.

Neural correlates of older adults' self-overestimation of stepping-over ability

A growing body of literature indicates that cognitively intact older adults tend to overestimate their physical functioning (e.g., step-over ability), which may lead to fall risk. However, the neural correlates underlying this phenomenon are still unclear. We therefore investigated the neural basis of older adults' self-overestimation of stepping-over ability. A total of 108 well-functioning community dwelling older adults (mean age = 73.9 years) performed step-over tests (SOT) in two ways: self-estimation of step-over ability and an actual step-over task. During the self-estimation task, participants observed a horizontal bar at a distance of 7 m and estimated the maximum height (EH) of successful SOT trials. The actual SOT was then performed to determine the actual maximum height (AH) of successful trials. Participants also underwent positron emission tomography with ¹⁸F-fluorodeoxyglucose at rest to assess cerebral neural activity. The SOT showed that 22.2 % of participants overestimated their step-over ability. A regression analysis adjusted for potential covariates showed that increased self-estimation error (difference between EH and AH) was correlated with lower glucose metabolism in the bilateral orbitofrontal cortex (OFC) and left frontal pole. Only the significant correlation between self-estimation error and OFC activity persisted after correcting for multiple comparisons. For well-functioning healthy older adults, overlooking one's own functional decline may be influenced by reduced metabolic activity in the anterior prefrontal cortex, particularly in the OFC. Our findings also suggest that functional decline in the OFC prevents older adults from updating the qualitative/quantitative values of their impaired physical abilities.

Self-reported and informant-reported memory functioning and awareness in patients with mild cognitive impairment and Alzheimer´s disease

Background

Awareness of subjective memory is an important factor for adequate treatment of patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). This study served to find out whether awareness of subjective memory complies with objective performance, if differences in awareness are observed longitudinally and whether decrease of awareness can serve as a predictor of AD in MCI patients.

Methods

Thirty-four patients with MCI seeking help in a memory outpatient clinic were included. All participants underwent thorough neuropsychological examination. Awareness of subjective memory was obtained by calculating difference scores between patient and informant ratings on a 16-item questionnaire concerning complaints about loss of memory in every-day life. Retesting was performed after a mean follow-up period of 24 months.

Results

Whole group analyses showed that awareness remained relatively stable across time. Self-reported memory complaints correlated with episodic memory at baseline and with performance on a language task at follow-up. Retests displayed decrease of awareness. At group level differences in awareness between both times of assessment were not significant for MCI and MCI patients converting to mild AD at follow-up. The predictive value of awareness was low.

Conclusions

Awareness of subjective memory deficit is linked to episodic memory function and decreases with decline of cognitive ability. Further studies evaluating predictive power of awareness of subjective memory should include a larger patient sample.

Metacognitive knowledge and experience in recently diagnosed patients with bipolar disorder

INTRODUCTION

Metacognition, which refers to an individual's ability to assess their own cognitive ability or performance, is poorly understood in bipolar disorder. This study was conducted to evaluate two aspects of metacognitive ability in recently diagnosed patients with bipolar disorder: (a) metacognitive knowledge, pertaining to awareness of one's own general cognitive functioning; and (b) metacognitive experience, referring to awareness of one's cognitive performance on a specific, online cognitive task.

METHOD

Participants consisted of 50 clinically euthymic patients recently diagnosed with Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) bipolar I disorder who were within three months of resolution of their first manic episode, and a comparison group of 38 demographically similar healthy volunteers. To assess metacognitive knowledge, participants provided a general rating of their estimated cognitive ability prior to completing a neuropsychological battery, and self-ratings were compared to actual ability based on a composite score of overall cognitive functioning. To assess metacognitive experience, subjects provided a postdiction rating of their perceived memory performance after completing a list learning verbal memory test, and self-ratings were compared to actual memory performance. Measures of both relative and absolute accuracy of ratings were obtained.

RESULTS

Results indicated that patients showed diminished accuracy in rating their general cognitive ability, implying deficits in metacognitive knowledge. In contrast, patients were accurate in rating their online memory performance, suggesting intact metacognitive experience.

CONCLUSIONS

Findings suggest that in patients with bipolar disorder, intact task-specific cognitive self-appraisals may fail to generalize to or to modify inaccurate global cognitive self-appraisals. Further research using more comprehensive metacognitive tasks is warranted in bipolar disorder.

Longitudinal Psychiatric Symptoms in Prodromal Huntington's Disease: A Decade of Data

OBJECTIVE

Psychiatric symptoms are a significant aspect of Huntington's disease, an inherited neurodegenerative illness. The presentation of these symptoms is highly variable, and their course does not fully correlate with motor or cognitive disease progression. The authors sought to better understand the development and longitudinal course of psychiatric manifestations in individuals who carry the Huntington's disease mutation, starting from the prodromal period prior to motor diagnosis.

METHOD

Longitudinal measures for up to 10 years of psychiatric symptoms from the Symptom Checklist-90-Revised were obtained from 1,305 participants (1,007 carrying the Huntington's disease mutation and 298 without [classified as controls]) and 1,235 companions enrolled in the Neurobiological Predictors of Huntington's Disease (PREDICT-HD) study. Participants with the mutation were stratified into three groups according to probability of motor diagnosis within 5 years. Using linear mixed-effects regression models, differences in psychiatric symptoms at baseline and over time between the mutation-positive groups and the controls were compared, as well as between ratings by mutation-positive participants and their companions.

RESULTS

Nineteen of 24 psychiatric measures (12 participant ratings and 12 companion ratings) were significantly higher at baseline and showed significant increases longitudinally in the individuals with the Huntington's disease mutation compared with controls. The differences were greatest in comparisons of symptom reports from companions compared with self-reports, especially in participants who were closest to motor diagnosis.

CONCLUSIONS

The results indicate that psychiatric manifestations develop more often than previously thought in the Huntington's disease prodrome. Symptoms also increase with progression of disease severity. Greater symptom ratings by companions than by mutation-positive participants suggest decreasing awareness in those affected.

[The development of a self-administered dementia checklist: the examination of concurrent validity and discriminant validity]

PURPOSE

The present study aims to develop a self-administered dementia checklist to enable community-residing older adults to realize their declining functions and start using necessary services. A previous study confirmed the factorial validity and internal reliability of the checklist. The present study examined its concurrent validity and discriminant validity.

METHODS

The authors conducted a 3-step study (a self-administered survey including the checklist, interviews by nurses, and interviews by doctors and psychologists) of 7,682 community-residing individuals who were over 65 years of age. The authors calculated Spearman's correlation coefficients between the scores of the checklist and the results of a psychological test to examine the concurrent validity. They also compared the average total scores of the checklist between groups with different Clinical Dementia Rating (CDR) scores to examine discriminant validity and conducted a receiver operating characteristic analysis to examine the discriminative power for dementia.

RESULTS

The authors analyzed the data of 131 respondents who completed all 3 steps. The checklist scores were significantly correlated with the respondents' Mini-Mental State Examination and Frontal Assessment Battery scores. The checklist also significantly discriminated the patients with dementia (CDR = 1+) from those without dementia (CDR = 0 or 0.5). The optimal cut-off point for the two groups was 17/18 (sensitivity, 72.0%; specificity, 69.2%; positive predictive value, 69.2%; negative predictive value, 72.0%).

CONCLUSION

This study confirmed the concurrent validity and discriminant validity of the self-administered dementia checklist. However, due to its insufficient discriminative power as a screening tool for older people with declining cognitive functions, the checklist is only recommended as an educational and public awareness tool.

Present status and road map to achieve inclusive and holistic care for dementia in a Japanese community: analysis using the Delphi method

BACKGROUND/AIMS

Dementia is a priority issue in the public health realm. However, few reports address problems of dementia in the real world or provide comprehensive road maps to solve these problems.

METHODS

Nine groups of questions covering 4 topics were discussed using the Delphi method, relating to (1) current achievements and challenges regarding inclusive and holistic care in the community, (2) patients who are at a high risk of being excluded from care, (3) suggestions for a road map for the establishment of better and more inclusive medical and social care, and (4) unmet needs of patients with dementia.

RESULTS

In total, 477 opinions were obtained. Family issues, psychological/behavioral symptoms, and complications secondary to physical disorders are main factors for being excluded from care. To create a road map for care we have to address the topics of reaffirming care principles, multidisciplinary coalitions, and education for stakeholders.

CONCLUSION

Further effective collaboration to promote dementia care is required.

Awareness of memory deficits in subjective cognitive decline, mild cognitive impairment, Alzheimer's disease and Parkinson's disease

BACKGROUND

Impaired awareness of memory deficits has been recognized as a common phenomenon in Alzheimer's disease (AD) and research is now increasingly focusing on awareness in groups at risk for future dementia. This study aimed to determine whether levels of awareness differ among healthy elderly people and patients with subjective cognitive decline (SCD), amnestic and non-amnestic subtypes of mild cognitive impairment (aMCI, naMCI), Alzheimer's disease (AD) and Parkinson's disease (PD), to explore correlates of awareness and to establish frequencies of memory over- and underestimation within each diagnostic group.

METHODS

756 consecutive outpatients of a memory clinic and 211 healthy controls underwent thorough neuropsychological testing. Impairment of awareness was measured as the difference between subjective memory appraisals (16-item questionnaire on current memory-related problems in everyday life) and objective memory performance (15-item delayed recall task). Subgroups of over- and underestimators were classified using percentile ranks of controls.

RESULTS

At group level, awareness significantly decreased along the naMCI→aMCI→AD continuum, with naMCI patients showing a tendency towards overestimation of memory dysfunction. PD patients showed accurate self-appraisals as long as memory function was largely unaffected. However, there was a considerable between-group overlap in awareness scores. Furthermore, different correlates of awareness were observed depending on the diagnostic group. In general, unawareness seems to be associated with decreased cognitive performance in various domains (especially memory), higher age and lower levels of depression and self-reported functional impairment.

CONCLUSION

Impaired awareness is an important symptom in aMCI. Yet, given the considerable variability in awareness scores, longitudinal studies are required to evaluate their predictive power.

Anosognosia in people with cognitive impairment: association with cognitive deficits and behavioral disturbances

AIMS

To investigate, in a group of subjects at an early stage of cognitive impairment, the relationship between anosognosia and both cognitive and behavioral symptoms by exploring the various domains of insight.

METHODS

One hundred and eight subjects affected by cognitive impairment were consecutively enrolled. The level of awareness was evaluated by means of the Clinical Insight Rating Scale (CIRS). Psychiatric symptoms were evaluated using the Italian version of the Neuropsychiatric Inventory (NPI), whereas memory (memory index, MI) and executive (executive index, EI) functions were explored using a battery of neuropsychological tests and qualified by means of a single composite cognitive index score for each function.

RESULTS

A significant positive correlation between the total NPI score and global anosognosia score was found. Furthermore, both the MI and EI scores were lower in subjects with anosognosia than in those without anosognosia (p < 0.001 and p < 0.007, respectively). When the single domains of the CIRS were considered, anosognosia of reason of visit correlated with the EI score (r = -0.327, p = 0.01) and night-time behavioral disturbances (r = 0.225; p = 0.021); anosognosia of cognitive deficit correlated with depression (r = -0.193; p = 0.049) and the MI score (r = -0.201; p = 0.040); anosognosia of functional deficit correlated with the MI score (r = -0.257; p = 0.008), delusions (r = 0.232; p = 0.015) and aberrant motor behavior (r = 0.289; p = 0.003); anosognosia of disease progression correlated with the MI score (r = -0.236; p = 0.015), agitation (r = 0.247; p = 0.011), aberrant motor behavior (r = 0.351; p = 0.001) and night-time behavioral disturbances (r = 0.216; p = 0.027).

CONCLUSIONS

Our study suggests that, in the early stage of cognitive impairment, anosognosia is associated with both cognitive deficits and behavioral disorders according to the specific functional anatomy of the symptoms.

Abridged scale for the screening anosognosia in patients with dementia

The objective of this cross-sectional study was to validate an abridged version of the Anosognosia Questionnaire--Dementia (AQ-D) for screening anosognosia in daily practice. The authors reduce the AQ-D from 30 items to 9, with a large sample (n = 352) of patients with Alzheimer disease (AD). The Cronbach α was .793 and an area under the receiver-operating characteristic curve was 0.946. The κ index between new abridged AQ-D (AAQ) and original AQ-D was .800. The AAQ presents good validity and reliability indicators and kept concordance with the original scale. It is quick and easy to administer and it can simplify the clinical screening of anosognosia in patients with AD.

Neural substrates of socioemotional self-awareness in neurodegenerative disease

BACKGROUND

Neuroimaging studies examining neural substrates of impaired self-awareness in patients with neurodegenerative diseases have shown divergent results depending on the modality (cognitive, emotional, behavioral) of awareness. Evidence is accumulating to suggest that self-awareness arises from a combination of modality-specific and large-scale supramodal neural networks.

METHODS

We investigated the structural substrates of patients' tendency to overestimate or underestimate their own capacity to demonstrate empathic concern for others. Subjects' level of empathic concern was measured using the Interpersonal Reactivity Index, and subject-informant discrepancy scores were used to predict regional atrophy pattern, using voxel-based morphometry analysis. Of the 102 subjects, 83 were patients with neurodegenerative diseases such as behavioral variant frontotemporal dementia (bvFTD) or semantic variant primary progressive aphasia (svPPA); the other 19 were healthy older adults.

RESULTS

bvFTD and svPPA patients typically overestimated their level of empathic concern compared to controls, and overestimating one's empathic concern predicted damage to predominantly right-hemispheric anterior infero-lateral temporal regions, whereas underestimating one's empathic concern showed no neuroanatomical basis.

CONCLUSIONS

These findings suggest that overestimation and underestimation of one's capacity for empathic concern cannot be interpreted as varying degrees of the same phenomenon, but may arise from different pathophysiological processes. Damage to anterior infero-lateral temporal regions has been associated with semantic self-knowledge, emotion processing, and social perspective taking; neuropsychological functions partly associated with empathic concern itself. These findings support the hypothesis that-at least in the socioemotional domain-neural substrates of self-awareness are partly modality-specific.

Clinical correlates of awareness for balance, function, and memory: evidence for the modality specificity of awareness

Awareness in dementia is increasingly recognized not only as multifactorial, but also as domain specific. We demonstrate differential clinical correlates for awareness of daily function, awareness of memory, and the novel exploration of awareness of balance. Awareness of function was higher for participants with mild cognitive impairment (aMCI and non-aMCI) than for those with dementia (due to Alzheimer disease; AD and non-AD), whereas awareness of memory was higher for both non-aMCI and non-AD dementia patients than for those with aMCI or AD. Balance awareness did not differ based on diagnostic subgroup. Awareness of function was associated with instrumental activities of daily living and caregiver burden. In contrast, awareness of balance was associated with fall history, balance confidence, and instrumental activities of daily living. Clinical correlates of awareness of memory depended on diagnostic group: associations held with neuropsychological variables for non-AD dementia, but for patients with AD dementia, depression and instrumental activities of daily living were clinical correlates of memory awareness. Together, these data provide support for the hypothesis that awareness and dementia are not unitary and are, instead, modality specific.

Neuropsychological patterns underlying anosognosia in people with cognitive impairment

AIMS

To investigate, in a group of subjects with cognitive impairment, the relationship between anosognosia, in each dimension of insight, and neuropsychological domains.

METHODS

Two hundred and seventy-one subjects affected by cognitive impairment were consecutively enrolled. Anosognosia was evaluated by means of the Clinical Insight Rating Scale (CIRS). The general level of cognitive impairment was evaluated by means of the Mini-Mental State Examination, while 8 cognitive domains were examined by means of neuropsychological tests.

RESULTS

The number of subjects with anosognosia evaluated by means of the CIRS total score as well as those with anosognosia divided according to the reason for visit was higher in moderately cognitively impaired subjects than in mildly cognitively impaired subjects (p < 0.001). A relationship between anosognosia and neuropsychological scores was only found in mild cognitive impairment, with subjects with anosognosia displaying significantly lower Raven's Colored Progressive Matrices Test and Rey Auditory Verbal Learning Test-delayed recall scores than subjects without anosognosia.

CONCLUSIONS

Our study suggests that the relationship between the severity of cognitive deficits and anosognosia in subjects with cognitive impairment is partial and depends on the specific domain of unawareness. Furthermore, in the early phase of cognitive impairment, the presence of specific cognitive deficits suggests that the nature of anosognosia is domain-specific.

Aspects of awareness in patients with Alzheimer's disease

BACKGROUND

The purpose of the present study was to gain insight into Alzheimer's disease (AD) patients' perception of the world through the study of a few aspects of awareness. The aspects in focus of the study were disease awareness, metacognition, managing of everyday life, and as a complement, the agreement (calibration) between patients and their spouses on the studied aspects was considered.

METHOD

A mixed-method evaluation design was used involving 15 AD patients, their spouses, and 15 elderly healthy control subjects. The study comprised both a semistructured interview (AD patients and spouse) and a neuropsychological assessment (AD patients and control subjects).

RESULTS

The patients were aware of their disease and able to report on their illness. Despite this awareness, they were unable to realize and manage the practical and cognitive implications of their impairment. The results also indicate that patients and spouses were not well calibrated regarding thoughts about the disease and problems in handling the cognitive deterioration.

CONCLUSIONS

The findings of our study have relevance to patients' well being and how they manage everyday life. An open dialogue on these issues between spouses and in the care for AD patients would hopefully enhance quality of life for all parties involved.

Cognitive anosognosia and behavioral changes in probable Alzheimer's disease patients

Anosognosia, impairment insight and unawareness of deficits are used as equivalent terms in this study.

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.

Self-referential processing in Alzheimer's disease: two different ways of processing self-knowledge?

Two previous studies showed that self-reference encoding had no effect on Alzheimer's disease (AD) patients' recollective experience when it was compared to other-reference encoding, whereas it did have an effect when it was compared to semantic processing, but only for emotional trait adjectives. In the present study, the performance of 22 AD patients was compared with that of 21 normal controls on a task involving recognition of emotional versus neutral adjective traits following self-reference versus other-reference encoding, using the remember/know/guess paradigm. Results showed that although AD patients had a positive explicit view of themselves, their self became salient for negative adjective traits only. We concluded that there might exist two ways of processing self-referential knowledge in human cognition: one explicit and the other more implicit.

Cognitive rehabilitation therapies for Alzheimer's disease: a review of methods to improve treatment engagement and self-efficacy

Cognitive rehabilitation therapies for Alzheimer's disease (AD) are becoming more readily available to the geriatric population in an attempt to curb the insidious decline in cognitive and functional performance. However, people with AD may have difficulty adhering to these cognitive treatments due to denial of memory deficits, compromised brain systems, cognitive incapacity for self-awareness, general difficulty following through on daily tasks, lack of motivation, hopelessness, and apathy, all of which may be either due to the illness or be secondary to depression. Cognitive rehabilitation training exercises are also labor intensive and, unfortunately, serve as a repeated reminder about the memory impairments and attendant functional consequences. In order for cognitive rehabilitation methods to be effective, patients must be adequately engaged and motivated to not only begin a rehabilitation program but also to remain involved in the intervention until a therapeutic dosage can be attained. We review approaches to cognitive rehabilitation in AD, neuropsychological as well as psychological obstacles to effective treatment in this population, and methods that target adherence to treatment and may therefore be applicable to cognitive rehabilitation therapies for AD. The goal is to stimulate discussion among researchers and clinicians alike on how treatment effects may be mediated by engagement in treatment, and what can be done to enhance patient adherence for cognitive rehabilitation therapies in order to obtain greater cognitive and functional benefits from the treatment itself.

The frequency and correlates of anxiety in patients with first-time diagnosed mild dementia

BACKGROUND

Anxiety in persons with dementia has received little attention despite its severe consequences. In this observational cross-sectional study, we investigated the frequency of anxiety and associations between anxiety and socio-demographic and clinical variables in an outpatient sample with first-time diagnosed mild dementia.

METHODS

The study sample (n = 169) comprised participants recruited from clinics in geriatric medicine and old age psychiatry for a longitudinal dementia study. Symptoms of anxiety were rated by a caregiver on the Neuropsychiatric Inventory (NPI) and by the patient on the anxiety tension item on the Montgomery and Åsberg Depression Rating Scale. Measures of caregiver stress, dementia-related impairment (Clinical Dementia Rating (CDR) scale), and cognitive functioning were also included.

RESULTS

According to caregiver reports, 19.5% had clinically significant anxiety and an additional 22.5% had subclinical anxiety. Half of the patients reported experiencing anxiety from time to time. Patients with Lewy-body dementia reported anxiety more often compared to patients with Alzheimer's disease. Anxiety was associated with depression, higher caregiver stress, and more dementia-related impairment, but not with cognitive test performance. Caregiver stress and higher CDR score increased the odds for anxiety significantly, even when controlling for depression.

CONCLUSION

Anxiety is common in patients with mild dementia, and seems to be associated not so much with cognitive test performance than with caregiver distress and the patient's ability to function in daily life. Anxiety should be taken into account when assessing dementia, as well as screened for when examining patients with known dementia.

The role of premorbid personality and cognitive factors in awareness of illness, memory, and behavioural functioning in Alzheimer's disease

INTRODUCTION

Research has suggested an association between personality factors and awareness in patients with dementia, yet valid measurement of premorbid personality is problematic. The present study aimed to better reveal the relationship between premorbid personality and awareness by using improved methodology. Moreover, the study aims to contrast the strength of the relationship of premorbid personality and awareness with that of cognitive factors.

METHODS

Awareness of illness, symptoms, mnemonic and behavioural impairments, and treatment compliance were measured in 27 patients with mild-to-moderate Alzheimer's disease (AD) diagnosed by standard criteria for probable AD. Participant premorbid personality was measured using average retrospective Neuroticism-Extroversion-Openness Inventory (NEO-FFI) scores from two informants. Correlations were performed to investigate the relationship between awareness and personality dimensions, as well as measures of cognitive style, neuropsychological function, mood, carer burden, and sociodemographic factors.

RESULTS

There was little relationship between awareness and personality scores, but modest associations between awareness and mood, age, and age of onset of first symptoms. Awareness of memory was related to memory functioning. Increased carer burden was associated with lack of awareness of cognitive-behavioural deficits but there were only few and weak associations between awareness and measures of cognitive functioning.

CONCLUSIONS

There was little support for an association between previous personality and awareness in dementia. However, increased carer burden was associated specifically with lack of awareness of cognitive-behavioural deficits not deficits in ADL, whereas lower awareness of ADL and not cognitive-behavioural deficits was associated with age. Awareness of memory appeared to be a metamemory capacity. Mood and age rather than personality and cognition are stronger predictors of awareness in early Alzheimer's disease.

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.

Lack of awareness of symptoms in people with dementia: the structural and functional basis

OBJECTIVE

To review studies investigating the brain correlates of unawareness of cognitive and behavioural symptoms in people with dementia.

DESIGN

A detailed search of the literature was conducted to include all the peer-reviewed studies published in English aimed at identifying the structural or functional brain correspondents of unawareness in dementia patients. Their results were interpreted in relation to the methodological differences in terms of type of dementia studied, the protocol adopted to measure lack of awareness, the imaging techniques employed, the experimental designs and statistical analyses performed.

RESULTS

Eighteen studies undertaken to explore the functional and structural correlates of unawareness of cognitive symptoms in dementia were identified. Although their results showed a disparate range of brain correlates, they were mainly localized in frontal and temporo-parietal regions.

CONCLUSIONS

Although the anatomical correlates of unawareness of disease in dementia have not yet been exhaustively explored, understanding the correlates of unawareness may also contribute to understand the brain correlates of self-awareness and self-reflection. We discuss the current knowledge base and consider potential future directions for research.

Anosognosia for memory impairment in Alzheimer's disease

Stewart G, McGeown WJ, Shanks MF, Venneri A. Anosognosia for memory impairment in Alzheimer's disease. Objective To investigate whether patients with Alzheimer's disease (AD) were able to alter their awareness of memory deficits after exposure to a memory task.

METHODS

Thirty normal older adults and 23 mild AD patients participated in the study. Anosognosia was assessed using discrepancies between self- and informant-evaluations of cognitive and functional performance. Participants estimated their performance on the Verbal Paired Associates task at different points in time (before, immediately after the task and after a 1-h delay).

RESULTS

AD patients were generally less able to judge their memory abilities than healthy older adults, and tended to overestimate their task performance beforehand. Their prediction accuracy increased immediately after the task, but after a 1-h delay, they again misjudged their abilities at pretesting accuracy levels. Self-carer discrepancy scores of awareness of deficits in memory and other areas correlated significantly with memory tests but not with other neuropsychological tasks in the assessment, and larger discrepancy scores were associated with poorer performance.

CONCLUSION

AD patients can monitor their task performance online, but are unable to maintain awareness of their deficits over time. Loss of awareness of memory deficits (or of any other deficits) in early stage AD may indicate damage to a system which updates a personal knowledge base with recent information. Failure to retain this information impedes abstraction from episodic to semantic memory.

A brief metacognition questionnaire for the elderly: comparison with cognitive performance and informant ratings the Cache County Study

OBJECTIVE

To examine the utility of a brief, metacognition questionnaire by examining its association with objective cognitive testing and informant ratings. We hypothesized that the association between self-ratings of change and both outcomes would be greater among individuals without dementia than among those with dementia.

METHODS

Participants were 535 persons without dementia and 152 with dementia from the Cache County Memory Study who had completed a metacognition questionnaire, two administrations of the Modified Mini-Mental State Exam (3 MS) and who had data on the Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE). Cronbach's alpha was calculated as a measure of internal consistency of the metacognition questionnaire. Multiple regression was used to examine the relationship between metacognition and 3 MS change. Logistic regression was used to examine the relationship between metacognition and IQCODE ratings (no change vs. worse).

RESULTS

Cronbach's alpha was 0.75. Among individuals without dementia, metacognition significantly predicted 3 MS change (p = .027) and IQCODE ratings (OR = 4.0, 95% CI = 1.2-13.8, p = .029), suggesting consistency among measures. For those with dementia, there was a weak, inverse relationship between 3 MS change and metacognition (r = -0.16, p = .056). IQCODE ratings were not significantly associated with metacognition (p = .729). Degree of dementia severity did not modify the relationship between metacognition and either outcome (p > .05).

CONCLUSIONS

We demonstrated adequate internal consistency and evidence for validity of a brief metacognition questionnaire. The questionnaire may provide a useful adjunct to memory and functional assessments for assessing anosognosia in elderly populations.

Anosognosia in Alzheimer's disease: the role of impairment levels in assessment of insight across domains

Impaired insight for deficits (anosognosia) is common in Alzheimer's disease (AD). However, it has not yet been determined clearly (a) whether different methods for assessing insight are comparable, and (b) whether anosognosia affects different domains to different degrees (domain-specificity). Impaired insight was investigated in 32 patients with AD, who were each accompanied by a caregiver. Anosognosia was assessed by a global clinical rating, questionnaire discrepancies (patient vs. caregiver) covering different domains, and performance discrepancies (self-assessment vs. performance) based on four neuropsychological tests which were compared with those of a healthy control sample. The results of clinical rating and questionnaire discrepancies were closely correlated, but performance discrepancies showed no association with the other methods. Anosognosia was present in the majority of the sample, and occurred across domains. The domains corresponding to core deficits in AD (recent memory, activities of daily living) appeared especially prone to anosognosia. However, results do not suggest that anosognosia itself is domain-specific. Rather, it appears that insight may be invariant, while differences in patient-caregiver discrepancies arise largely from different degrees of deficit across domains.

Quality of life as an outcome in Alzheimer's disease and other dementias--obstacles and goals

Background

The number of individuals at risk for dementia will probably increase in ageing societies as will the array of preventive and therapeutic options, both however within limited economic resources. For economic and medical purposes valid instruments are required to assess disease processes and the efficacy of therapeutic interventions for different forms and stages of illness. In principal, the impact of illness and success of an intervention can be assessed with biomedical variables, e.g. severity of symptoms or frequency of complications of a disease. However, this does not allow clear judgement on clinical relevance or comparison across different diseases.

Discussion

Outcome model variables such as quality of life (QoL) or health care resource utilization require the patient to appraise their own well-being or third parties to set preferences. In Alzheimer's disease and other dementias the evaluation process performed by the patient is subject to the disease process itself because over progress of the disease neuroanatomical structures are affected that mediate evaluation processes.

Summary

Published research and methodological considerations thus lead to the conclusion that current QoL-instruments, which have been useful in other contexts, are ill-suited and insufficiently validated to play a major role in dementia research, decision making and resource allocation. New models integrating biomedical and outcome variables need to be developed in order to meet the upcoming medical and economic challenges.

Neural correlates of Alzheimer's disease and mild cognitive impairment: a systematic and quantitative meta-analysis involving 1351 patients

Alzheimer's disease is the most common form of dementia. Its prodromal stage amnestic mild cognitive impairment is characterized by deficits of anterograde episodic memory. The development of standardized imaging inclusion criteria has to be regarded as a prerequisite for future diagnostic systems. Moreover, successful treatment requires isolating imaging markers predicting the disease. Accordingly, we conducted a systematic and quantitative meta-analysis to reveal the prototypical neural correlates of Alzheimer's disease and its prodromal stage. To prevent any a priori assumptions and enable a data-driven approach only studies applying quantitative automated whole brain analysis were included. Finally, 40 studies were identified involving 1351 patients and 1097 healthy control subjects reporting either atrophy or decreases in glucose utilization and perfusion. The currently most sophisticated and best-validated of coordinate-based voxel-wise meta-analyses was applied (anatomical likelihood estimates). The meta-analysis reveals that early Alzheimer's disease affects structurally the (trans-)entorhinal and hippocampal regions, functionally the inferior parietal lobules and precuneus. Results further may suggest that atrophy in the (trans-)entorhinal area/hippocampus and hypometabolism/hypoperfusion in the inferior parietal lobules predicts most reliably the progression from amnestic mild cognitive impairment to Alzheimer's disease, whereas changes in the posterior cingulate cortex and precuneus are unspecific. Fully developed Alzheimer's disease involved additionally a frontomedian-thalamic network. In conclusion, the meta-analysis characterizes the prototypical neural substrates of Alzheimer's disease and its prodromal stage amnestic mild cognitive impairment. By isolating predictive markers it enables successful treatment strategies in the future and contributes to standardized imaging inclusion criteria for Alzheimer's disease as suggested for future diagnostic systems.

The clinical significance of subjective memory complaints in the diagnosis of mild cognitive impairment and dementia: a meta-analysis

BACKGROUND

Subjective memory complaints (SMC) are frequently reported by individuals with objective evidence of cognitive decline although the exact rate of complaints and their diagnostic value is uncertain.

METHOD

A meta-analysis was conducted for all studies examining SMC and either concurrent dementia or mild cognitive impairment (MCI).

RESULTS

Eight studies reported the rate of SMC in dementia, seven studies reported the rate of SMC in MCI and of these four compared the rate of SMC in dementia and MCI head-to-head. SMC were present in 42.8% of those with dementia and 38.2% of those with MCI. Across all levels of cognitive impairments 39.8% of people had SMC compared with 17.4% in healthy elderly controls (Relative Risk 2.3). In head-to-head studies there was a significantly higher rate of SMC in dementia vs MCI (48.4% vs 35.1%). Examining the diagnostic value of SMC in dementia, the meta-analytic pooled sensitivity was 43.0% and specificity was 85.8%. For MCI, meta-analytic pooled sensitivity was 37.4% and specificity was 86.9%. In community studies with a low prevalence the positive and negative predictive values were 18.5% and 93.7% for dementia and 31.4% and 86.9% for MCI. The clinical utility index which calculates the value of a diagnostic method suggested 'poor' value for ruling in a diagnosis of dementia but 'good' value for ruling out a diagnosis.

CONCLUSIONS

When assessed by simple questions, SMC appear to be present in the minority of those with mild cognitive impairment and dementia. In cross-sectional community settings, even when people agree that they have SMC there is only a 20% or 30% chance that dementia or MCI are present, respectively. Despite this, the absence of SMC may be a reasonable method of excluding dementia and MCI and could be incorporated into short screening programs for dementia and MCI but replication is required in clinical settings.

Neuroanatomical correlates of unawareness of memory deficits in early Alzheimer's disease

BACKGROUND/AIMS

To investigate neuroanatomical substrates of unawareness of memory deficits in patients with early Alzheimer's disease (AD).

METHODS

We compared regional perfusion deficits between AD patients with awareness (n = 19) and unawareness (n = 19). SPECT data were analyzed by statistical brain imaging method.

RESULTS

Statistical maps demonstrated a more extensive and severe reduction in perfusion in the unaware group than in the aware group. Quantitative analysis demonstrated a significant difference between the groups in the right subcallosal, anterior cingulate and cingulate gyri and left orbital, subcallosal, and anterior cingulate gyri.

CONCLUSION

Functional damage to the inferior, medial and orbital frontal lobes as well as the anterior cingulate gyri may be associated with the lack of awareness in patients with early AD.

[Awareness of memory deficits in patients with dementias: a study with the Everyday Memory Checklist]

AIM

We examined the level of awareness of memory deficits in 63 patients with Alzheimer's disease (AD), 17 patients with dementia with Lewy bodies (DLB), 14 patients with vascular dementia (VaD), and 56 patients with amnestic mild cognitive impairment (MCI).

METHODS

The unawareness of memory impairment was evaluated with a standardized memory questionnaire system based on the Everyday Memory Checklist (EMC). The EMC scores for the patient's own rating, the caregivers' rating and the unawareness score, defined as the discrepancy between these (caregiver rating-patient rating), were analyzed.

RESULTS

Although the EMC self-rating scores were comparable among the four groups, the EMC scores in caregivers were significantly higher in the AD group than in the DLB, VaD, and MCI groups. Therefore, the unawareness scores were significantly higher in the AD groups than in other groups. When an unawareness score of 9 or more was defined as significant, impaired awareness was found in 41 (65%) patients with AD, 1 (6%) patient with DLB, 5 (36%) patients with VaD, and in 19 (34%) patients with MCI.

CONCLUSION

We found that impaired awareness was found in two-thirds of patients with mild AD and even in one-third of patients with MCI. However, other dementias, in particular DLB, had less severe and less frequent unawareness of memory deficits than AD, suggesting the difference in the pathophysiology between them.