Associations among measures of awareness of cognitive deficits in dementia

Clinical and Neuropathological Correlates of Substance Use in American Football Players

Background

Chronic traumatic encephalopathy (CTE) is a neurodegenerative tauopathy more frequently found in deceased former football players. CTE has heterogeneous clinical presentations with multifactorial causes. Previous literature has shown substance use (alcohol/drug) can contribute to Alzheimer's disease and related tauopathies pathologically and clinically.

Objective

To examine the association between substance use and clinical and neuropathological endpoints of CTE.

Methods

Our sample included 429 deceased male football players. CTE was neuropathologically diagnosed. Informant interviews assessed features of substance use and history of treatment for substance use to define indicators: history of substance use treatment (yes vs no, primary variable), alcohol severity, and drug severity. Outcomes included scales that were completed by informants to assess cognition (Cognitive Difficulties Scale, BRIEF-A Metacognition Index), mood (Geriatric Depression Scale-15), behavioral regulation (BRIEF-A Behavioral Regulation Index, Barratt Impulsiveness Scale-11), functional ability (Functional Activities Questionnaire), as well as CTE status and cumulative p-tau burden. Regression models tested associations between substance use indicators and outcomes.

Results

Of the 429 football players (mean age = 62.07), 313 (73%) had autopsy confirmed CTE and 100 (23%) had substance use treatment history. Substance use treatment and alcohol/drug severity were associated with measures of behavioral regulation (FDR-p-values<0.05, ΔR2 = 0.04-0.18) and depression (FDR-p-values<0.05, ΔR2 = 0.02-0.05). Substance use indicators had minimal associations with cognitive scales, whereas p-tau burden was associated with all cognitive scales (p-values <0.05). Substance use treatment had no associations with neuropathological endpoints (FDR-p-values>0.05).

Conclusions

Among deceased football players, substance use was common and associated with clinical symptoms.

Association between objective neurocognitive functioning and neurocognitive complaints in recurrent high-grade glioma: longitudinal evidence of cognitive awareness from EORTC brain tumor trials

BACKGROUND

Patients' reduced awareness of neurocognitive functioning (NCF) may negatively affect the reliability of patient-reported outcomes (PROs) and clinical decision-making. This study evaluated cognitive awareness, defined as the association between NCF and neurocognitive complaints, over the disease course of patients with recurrent high-grade glioma (HGG).

METHODS

We assessed NCF using the EORTC core clinical trial battery and neurocognitive complaints using the Medical Outcome Study questionnaire. Patients were categorised as impaired or intact, based on their neurocognitive performance. Spearman's rank correlations were calculated between NCF and neurocognitive complaints at baseline and each 12 weeks, until 36. The association between changes in NCF and neurocognitive complaints scores between these follow-up assessments was determined using Pearson's correlation.

RESULTS

A total of 546 patients were included. Neurocognitively impaired patients (n = 437) had more neurocognitive complaints (range: 10.51 [p < 0.001] to 13.34 [p = 0.001]) than intact patients (n = 109) at baseline, at 12 and 24 weeks. In intact patients, NCF and neurocognitive complaints were correlated for only one domain at baseline (0.202, p = 0.036), while in impaired patients correlations were more frequently found in various domains and time points (range: 0.164 [p = 0.001] to 0.334 [p = 0.011]). Over the disease course, NCF and neurocognitive complaints were correlated for only one domain at baseline (0.357, p = 0.014) in intact patients while in impaired patients they were correlated for more domains and time points (range: 0.222 [p < 0.001] to 0.366 [p < 0.001]).

CONCLUSION

Neurocognitively impaired patients with recurrent HGG are aware of their neurocognitive limitations at study entry and during follow-up, which should be considered in clinical decision-making and when interpreting PRO results.

Anosognosia for memory in dementia with Lewy bodies compared with Alzheimer's disease

OBJECTIVES

Anosognosia is the inability to recognize one's own symptoms. Although dementia with Lewy bodies (DLB) is the second most common degenerative dementia, there is little evidence of memory deficit awareness in this condition. The objectives of this research were to compare anosognosia between individuals with DLB and dementia due to Alzheimer's disease (AD) and to evaluate whether medial temporal atrophy, a marker of AD pathology, could help to explain different rates of anosognosia in DLB and dementia due to AD.

METHODS/DESIGN

This is a cross-sectional study that took place at the Memory Clinic of D'Or Institute for Research and Education (IDOR). Twenty individuals with DLB and 20 with dementia due to AD were included in this study. We assessed anosognosia for memory using an index derived from subjective memory complaints (using the Memory Complaint Questionnaire) and from the performance in memory neuropsychological testing (Rey Auditory Verbal Learning Test). Thirty-one participants also underwent brain Magnetic Resonance Imaging to evaluate hippocampal atrophy with a visual scale (MTA-score [medial temporal atrophy score]).

RESULTS

There was no significant difference between groups regarding age, years of education, sex or time of disease. Individuals with DLB had a higher index of anosognosia than dementia due to AD (2.92 and 1.87; p = 0.024), meaning worse awareness of memory deficits. MTA-score was slightly higher in dementia due to AD than in DLB, albeit without statistical significance.

CONCLUSION

Our study was the first to demonstrate that anosognosia for memory is worse in DLB than in dementia due to AD. This finding supports the hypothesis that anosognosia in DLB is a heterogeneous phenomenon.

The Cognitive Difficulties Scale (CDS): Psychometric Characteristics in a Clinical Referral Sample

OBJECTIVE

To evaluate the psychometric characteristics of the Cognitive Difficulties Scale (CDS), a 39-item Likert-type self-report instrument that requires a fifth grade reading level. The CDS is a popular instrument that has been shown to predict cognitive decline in older persons.

METHOD

Participants were 512 consecutive outpatient referrals (71% women, mean age 60.6, and education 14.6 years) for a neuropsychological examination in a memory disorders clinic as part of a broader neurodiagnostic workup for cognitive decline. A principal components analysis was followed by a varimax rotation (Kaiser). Factor scores were investigated in relation to multiple internal and external criteria including demographics, Cronbach's alpha, Digit Span, and Wechsler Memory Scale-IV Logical Memory (LM) and Visual Reproduction (VR), and Minnesota Multiphasic Personality Inventory (MMPI)-2 measures of depression, anxiety, somatic preoccupations, and thought disturbance.

RESULTS

Six dimensions of cognitive complaint emerged accounting for 64% of the variance: attention/concentration, praxis, prospective memory, speech problems, memory for people's names, and temporal orientation. The factors showed good internal consistency (alphas > .850). Correlations with Digit Span, LM, and VR were all nonsignificant. CDS scores were associated with MMPI-2 measures of anxiety, depression, somatic preoccupation, and thought disturbance. Percentiles and T-scores were derived for raw scores on the CDS and its six component subscales.

CONCLUSION

The CDS is a multidimensional measure of subjective cognitive complaints that provides clinicians with a psychometrically sound basis for deriving a profile with six subscale scores. The test has clinical utility and is a potentially useful tool in research involving age-related cognitive changes and meta-cognition.

Poor awareness of IADL deficits is associated with reduced regional brain volume in older adults with cognitive impairment

Performance of instrumental activities of daily living (IADLs) can become compromised in older adults with mild cognitive impairment (MCI). Patients' level of insight into their everyday functioning varies both amongst individuals and across domains assessed, with some individuals exhibiting complete unawareness of deficits. The current cross-sectional study examined the neuroanatomical substrates of self-awareness in order to help explain the variability in this phenomenon in older adults across a continuum of cognitive impairment. Eighty-five participants (ages 54-88, mean age = 73 years, 57% female, 89% Caucasian) diagnosed with MCI or mild probable dementia underwent structural magnetic resonance imaging. Level of self-awareness was assessed by calculating the discrepancy between objective and subjective performance across six IADLs (Financial Management, Driving, Grocery Shopping, Nutrition Evaluation, Medication Management, and Telephone Use). Over-estimation of current abilities occurred in 13-31% of the sample depending on which IADL was evaluated. Poor awareness was significantly related to reduced volume in the bilateral medial prefrontal cortex, middle and posterior cingulate cortex, right insular cortex, and cerebellum. No associations were found with total white matter lesion load. These findings were broadly consistent across all functional domains assessed, supporting the theory that cortical midline and cerebellar structures are involved in self-referential processing across a variety of different cognitive and behavioral skills. Longitudinal studies are needed to confirm this association.

Implementation of subjective cognitive decline criteria in research studies

INTRODUCTION

Subjective cognitive decline (SCD) manifesting before clinical impairment could serve as a target population for early intervention trials in Alzheimer's disease (AD). A working group, the Subjective Cognitive Decline Initiative (SCD-I), published SCD research criteria in the context of preclinical AD. To successfully apply them, a number of issues regarding assessment and implementation of SCD needed to be addressed.

METHODS

Members of the SCD-I met to identify and agree on topics relevant to SCD criteria operationalization in research settings. Initial ideas and recommendations were discussed with other SCD-I working group members and modified accordingly.

RESULTS

Topics included SCD inclusion and exclusion criteria, together with the informant's role in defining SCD presence and the impact of demographic factors.

DISCUSSION

Recommendations for the operationalization of SCD in differing research settings, with the aim of harmonization of SCD measurement across studies are proposed, to enhance comparability and generalizability across studies.

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.

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.

Altered neurochemical metabolites in Alzheimer's disease patients with unawareness of deficits

BACKGROUND

Unawareness of deficits is common and is associated with poor outcomes in Alzheimer's disease (AD); however, little is known about correlated neurobiochemical changes.

METHODS

Proton magnetic resonance spectroscopy was used to examine neurobiochemical correlates of unawareness of deficits as assessed by the Dementia Deficit Scale in 36 patients with AD. Magnetic resonance spectroscopy spectra were acquired from the anterior cingulate area and right orbitofrontal area. Concentrations of N-acetyl-aspartate (NAA), total creatine, and other neurometabolites were calculated.

RESULTS

Nineteen (52.8%) participants had relative unawareness of deficits. This condition was negatively correlated with NAA/creatine in the anterior cingulate area (β = -0.36, p = 0.025) and positively correlated with NAA/creatine in the right orbitofrontal area (β = 0.41, p = 0.009) after controlling for dementia severity.

CONCLUSIONS

These findings suggest unawareness of deficits in AD was associated with the altered neurochemical metabolites in the anterior cingulate area and right orbitofrontal area. However, the two areas might have opposite neuronal functions in unawareness of deficits.

Consciência do déficit na doença de Alzheimer: diferenças entre os domínios cognitivo e funcional

OBJETIVOS: Revisar sistematicamente desenhos de estudo, instrumentos de avaliação e fatores relacionados ao comprometimento dos domínios cognitivo e funcional da consciência do déficit em pessoas com doença de Alzheimer (DA). MÉTODO: Pesquisa nas bases de dados PubMed e ISI de estudos sobre consciência do déficit na DA publicados entre 2008 e 2013. As palavras-chave utilizadas foram: "dementia", "Alzheimer", "awareness", "awareness of memory" e "awareness of functioning", "deficits", "cognition". RESULTADOS: Os 10 artigos selecionados utilizaram os conceitos "falta de consciência do déficit", "anosognosia", "insight", "falta de consciência das dificuldades cognitivas" e "consciência limitada das deficiências". A etiologia do comprometimento da consciência do déficit foi relacionada a fatores biológicos como gravidade clínica da doença, associações neuroanatômicas, alterações neuropsiquiátricas e fatores psicológicos e sociais. O desenho de estudo mais utilizado foi o corte transversal. No domínio cognitivo, a memória e as funções executivas foram as duas principais funções investigadas. No domínio funcional, foram encontradas associações com a disfunção executiva, declínio da interação social, depressão e a influência do desempenho ocupacional. CONCLUSÕES: As distintas hipóteses etiológicas, a operacionalização variável do conceito e a falta de instrumentos de avaliação padronizados impossibilitam a obtenção de resultados homogêneos. Essas dificuldades comprometem a compreensão e a investigação dos domínios cognitivo e funcional.

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.

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.

Medial prefrontal functional connectivity--relation to memory self-appraisal accuracy in older adults with and without memory disorders

It is tentatively estimated that 25% of people with early Alzheimer's disease (AD) show impaired awareness of disease-related changes in their own cognition. Research examining both normative self-awareness and altered awareness resulting from brain disease or injury points to the central role of the medial prefrontal cortex (MPFC) in generating accurate self-appraisals. The current project builds on this work - examining changes in MPFC functional connectivity that correspond to impaired self-appraisal accuracy early in the AD time course. Our behavioral focus was self-appraisal accuracy for everyday memory function, and this was measured using the Memory Function Scale of the Memory Awareness Rating Scale - an instrument psychometrically validated for this purpose. Using regression analysis of data from people with healthy memory (n=12) and people with impaired memory due to amnestic mild cognitive impairment or early AD (n=12), we tested the hypothesis that altered MPFC functional connectivity - particularly with other cortical midline structures and dorsolateral prefrontal cortex - explains variation in memory self-appraisal accuracy. We spatially constrained (i.e., explicitly masked) our regression analyses to those regions that work in conjunction with the MPFC to evoke self-appraisals in a normative group. This empirically derived explicit mask was generated from the result of a psychophysiological interaction analysis of fMRI self-appraisal task data in a separate, large group of cognitively healthy individuals. Results of our primary analysis (i.e., the regression of memory self-appraisal accuracy on MPFC functional connectivity) were generally consistent with our hypothesis: people who were less accurate in making memory self-appraisals showed attenuated functional connectivity between the MPFC seed region and proximal areas within the MPFC (including subgenual anterior cingulate cortex), bilateral dorsolateral prefrontal cortex, bilateral caudate, and left posterior hippocampus. Contrary to our expectations, MPFC functional connectivity with the posterior cingulate was not significantly related to accuracy of memory self-appraisals. Results reported here corroborate findings of variable memory self-appraisal accuracy during the earliest emergence of AD symptoms and reveal alterations in MPFC functional connectivity that correspond to impaired memory self-appraisal.

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.

Development and validation of the Memory Orientation Screening Test (MOST™): A better screening test for dementia

OBJECTIVES

Accurate, economical identification of cognitive impairment would increase dementia detection and improve care of older patients.

DESIGN

Analysis of archival neuropsychological data combined 3-word recall, time orientation, list memory, and clock drawing into the Memory Orientation Screening Test (MOST ™). The MOST was compared with Folstein Mini Mental State Examination (MMSE) and Mini-Cog to detect dementia presence and severity, and convergence with standardized neuropsychological tests. Internal consistency, retest reliabilities, completion likelihood, and time costs were calculated.

RESULTS

The MOST was significantly more sensitive than MMSE or Mini-Cog, twice as accurate as MMSE for identifying mild dementia, better correlated with standardized memory tests, more reliable over time, and minimally related to depression.

CONCLUSIONS

The MOST is routinely administered in less than 5 minutes by a medical assistant, more accurately identifies dementia and severity than current screening tests, and emulates longer memory testing, making it valuable for Annual Wellness Visits and many applied clinical settings.