Free and cued selective reminding distinguishes Alzheimer's disease from vascular dementia

A remote digital memory composite to detect cognitive impairment in memory clinic samples in unsupervised settings using mobile devices

Remote monitoring of cognition holds the promise to facilitate case-finding in clinical care and the individual detection of cognitive impairment in clinical and research settings. In the context of Alzheimer's disease, this is particularly relevant for patients who seek medical advice due to memory problems. Here, we develop a remote digital memory composite (RDMC) score from an unsupervised remote cognitive assessment battery focused on episodic memory and long-term recall and assess its construct validity, retest reliability, and diagnostic accuracy when predicting MCI-grade impairment in a memory clinic sample and healthy controls. A total of 199 participants were recruited from three cohorts and included as healthy controls (n = 97), individuals with subjective cognitive decline (n = 59), or patients with mild cognitive impairment (n = 43). Participants performed cognitive assessments in a fully remote and unsupervised setting via a smartphone app. The derived RDMC score is significantly correlated with the PACC5 score across participants and demonstrates good retest reliability. Diagnostic accuracy for discriminating memory impairment from no impairment is high (cross-validated AUC = 0.83, 95% CI [0.66, 0.99]) with a sensitivity of 0.82 and a specificity of 0.72. Thus, unsupervised remote cognitive assessments implemented in the neotiv digital platform show good discrimination between cognitively impaired and unimpaired individuals, further demonstrating that it is feasible to complement the neuropsychological assessment of episodic memory with unsupervised and remote assessments on mobile devices. This contributes to recent efforts to implement remote assessment of episodic memory for case-finding and monitoring in large research studies and clinical care.

Brain reserve contributes to distinguishing preclinical Alzheimer's stages 1 and 2

BACKGROUND

In preclinical Alzheimer's disease, it is unclear why some individuals with amyloid pathologic change are asymptomatic (stage 1), whereas others experience subjective cognitive decline (SCD, stage 2). Here, we examined the association of stage 1 vs. stage 2 with structural brain reserve in memory-related brain regions.

METHODS

We tested whether the volumes of hippocampal subfields and parahippocampal regions were larger in individuals at stage 1 compared to asymptomatic amyloid-negative older adults (healthy controls, HCs). We also tested whether individuals with stage 2 would show the opposite pattern, namely smaller brain volumes than in amyloid-negative individuals with SCD. Participants with cerebrospinal fluid (CSF) biomarker data and bilateral volumetric MRI data from the observational, multi-centric DZNE-Longitudinal Cognitive Impairment and Dementia Study (DELCODE) study were included. The sample comprised 95 amyloid-negative and 26 amyloid-positive asymptomatic participants as well as 104 amyloid-negative and 47 amyloid-positive individuals with SCD. Volumes were based on high-resolution T2-weighted images and automatic segmentation with manual correction according to a recently established high-resolution segmentation protocol.

RESULTS

In asymptomatic individuals, brain volumes of hippocampal subfields and of the parahippocampal cortex were numerically larger in stage 1 compared to HCs, whereas the opposite was the case in individuals with SCD. MANOVAs with volumes as dependent data and age, sex, years of education, and DELCODE site as covariates showed a significant interaction between diagnosis (asymptomatic versus SCD) and amyloid status (Aß42/40 negative versus positive) for hippocampal subfields. Post hoc paired comparisons taking into account the same covariates showed that dentate gyrus and CA1 volumes in SCD were significantly smaller in amyloid-positive than negative individuals. In contrast, CA1 volumes were significantly (p = 0.014) larger in stage 1 compared with HCs.

CONCLUSIONS

These data indicate that HCs and stages 1 and 2 do not correspond to linear brain volume reduction. Instead, stage 1 is associated with larger than expected volumes of hippocampal subfields in the face of amyloid pathology. This indicates a brain reserve mechanism in stage 1 that enables individuals with amyloid pathologic change to be cognitively normal and asymptomatic without subjective cognitive decline.

A modified Cued Recall Test for detecting prodromal AD in adults with Down syndrome

Introduction

The development of valid methods to diagnose prodromal Alzheimer's disease (AD) in adults with Down syndrome (DS) is one of the many goals of the Alzheimer's Biomarkers Consortium-Down Syndrome (ABC-DS).

Methods

The diagnostic utility of a modified Cued Recall Test (mCRT) was evaluated in 332 adults with DS ranging from 25 to 81 years of age. Total recall was selected a priori, as the primary indicator of performance. Multiple regression and receiver-operating characteristic (ROC) analyses were used to compare diagnostic groups.

Results

Performance on the mCRT, as indicated by the total recall score, was highly sensitive to differences between diagnostic groups. ROC areas under the curve (AUCs) ranging from 0.843 to 0.955, were observed.

Discussion

The mCRT has strong empirical support for its use in clinical settings, as a valuable tool in studies targeting biomarkers of AD, and as a potential outcome measure in clinical trials targeting AD in this high-risk population.

The Free and Cued Selective Reminding Test: Discriminative Values in a Naturalistic Cohort

Background: Neuropsychological assessment is still the basis for the first evaluation of patients with cognitive complaints. The Free and Cued Selective Reminding Test (FCSRT) generates several indices that could have different accuracy in the differential diagnosis between Alzheimer’s disease (AD) and other disorders. Objective: In a consecutive series of naturalistic patients, the accuracy of the FCSRT indices in differentiating patients with either mild cognitive impairment (MCI) due to AD or AD dementia from other competing conditions was evaluated. Methods: We evaluated the accuracy of the seven FCSRT indices in differentiating patients with AD from other competing conditions in 434 consecutive outpatients, either at the MCI or at the early dementia stage. We analyzed these data through the receiver operating characteristics curve, and we then generated the odds-ratio map of the two indices with the best discriminative value between pairs of disorders. Results: The immediate and the delayed free total recall, the immediate total recall, and the index of sensitivity of cueing were the most useful indices and allowed to distinguish AD from dementia with Lewy bodies and psychiatric conditions with very high accuracy. Accuracy was instead moderate in distinguishing AD from behavioral variant frontotemporal dementia, vascular cognitive impairment, and other conditions. Conclusion: By using odd-ratio maps and comparison-customized cut-off scores, we confirmed that the FCSRT represents a useful tool to characterize the memory performance of patients with MCI and thus to assist the clinician in the diagnosis process, though with different accuracy values depending on the clinical hypothesis.

Quantitative Gradient Echo MRI Identifies Dark Matter as a New Imaging Biomarker of Neurodegeneration that Precedes Tisssue Atrophy in Early Alzheimer's Disease

BACKGROUND

Currently, brain tissue atrophy serves as an in vivo MRI biomarker of neurodegeneration in Alzheimer's disease (AD). However, postmortem histopathological studies show that neuronal loss in AD exceeds volumetric loss of tissue and that loss of memory in AD begins when neurons and synapses are lost. Therefore, in vivo detection of neuronal loss prior to detectable atrophy in MRI is essential for early AD diagnosis.

OBJECTIVE

To apply a recently developed quantitative Gradient Recalled Echo (qGRE) MRI technique for in vivo evaluation of neuronal loss in human hippocampus.

METHODS

Seventy participants were recruited from the Knight Alzheimer Disease Research Center, representing three groups: Healthy controls [Clinical Dementia Rating® (CDR®) = 0, amyloid β (Aβ)-negative, n = 34]; Preclinical AD (CDR = 0, Aβ-positive, n = 19); and mild AD (CDR = 0.5 or 1, Aβ-positive, n = 17).

RESULTS

In hippocampal tissue, qGRE identified two types of regions: one, practically devoid of neurons, we designate as "Dark Matter", and the other, with relatively preserved neurons, "Viable Tissue". Data showed a greater loss of neurons than defined by atrophy in the mild AD group compared with the healthy control group; neuronal loss ranged between 31% and 43%, while volume loss ranged only between 10% and 19%. The concept of Dark Matter was confirmed with histopathological study of one participant who underwent in vivo qGRE 14 months prior to expiration.

CONCLUSION

In vivo qGRE method identifies neuronal loss that is associated with impaired AD-related cognition but is not recognized by MRI measurements of tissue atrophy, therefore providing new biomarkers for early AD detection.

The Cognitive and Language Profile of Dementia with Lewy Bodies

Dementia with Lewy bodies (DLB) is a major neurocognitive disorder (MNCD) that is primarily characterized by motor, cognitive, and behavioral symptoms. Although not dominant in the clinical portrait of DLB, impairments affecting language processing have been reported. It is sometimes challenging to differentiate DLB from Alzheimer’s disease and dementia associated with Parkinson’s disease in clinical practice. Therefore, a better comprehension of the typical clinical presentation of DLB may be useful to ease the medical diagnosis. In this article, current data on cognitive and language disorders in DLB are reported, with special attention paid to their primary or secondary functional origin. The main elements that should be considered for the neuropsychological and speech-language assessment of individuals with possible or proven DLB are also highlighted. Additional studies are needed, especially for language impairment, to obtain a more accurate portrait of the clinical presentation of DLB and characterize its progression.

A prospective multicenter assessor-blinded randomized controlled study to compare the efficacy of short versus long protocols of electroconvulsive therapy as an augmentation strategy to clozapine in patients with ultra-resistant schizophrenia (SURECT study)

Background

Although clozapine is the most effective antipsychotic drug for treatment-resistant schizophrenia, it leads to a poor or partial response in 40 to 70% of patients. Augmentation of clozapine with electroconvulsive therapy (ECT) is a highly effective and relatively safe treatment for these clozapine-resistant patients. However, parameters are not yet well specified, such as the optimal number of sessions, their frequency, and the relevance of maintenance ECT. Our objective is to compare the efficacy and tolerance between two protocols of combined ECT and clozapine treatment in patients with ultra-resistant schizophrenia (URS): a 6-month protocol (short protocol with 20 ECT sessions) and a 12-month protocol (long protocol with 40 ECT sessions).

Methods

Sixty-four patients with schizophrenia with persistent psychotic symptoms despite clozapine treatment will be enrolled in a prospective multicentric assessor-blinded randomized controlled trial. Patients will be randomly assigned to the short or the long protocol. The main outcome is the response rate assessed by the Positive and Negative Symptoms Scale (PANSS) 3 months after the end of the treatment in patients following the long protocol compared to those following the short protocol. The response was defined as a 30% reduction on the PANSS baseline. Clinical assessments (PANSS, BPRS, HAMD-21, YMRS, CGI, GAF, Modified Overt Aggression Scale (MOAS), and Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS)) and plasma clozapine concentration will be performed at baseline and at 2, 4, 6, 9, 12, and 15 months. Neuropsychological measures (MMSE, RL/RI-16, Doors test, D2 Test of Attention, Copy of the Rey-Osterrieth complex figure) will be performed at baseline and at 6 and 15 months.

Discussion

The aims of this research are to optimize protocols of combined ECT with clozapine in patients with URS and to offer specific recommendations for these patients’ care.

Trial registration

ClinicalTrials.gov NCT03542903. Registered on May 31, 2018. Id RCB: 2017-A02657-46

Brief Cognitive Tests for Distinguishing Clinical Alzheimer-Type Dementia From Mild Cognitive Impairment or Normal Cognition in Older Adults With Suspected Cognitive Impairment

BACKGROUND

The accuracy and harms of brief cognitive tests for identifying clinical Alzheimer-type dementia (CATD) are uncertain.

PURPOSE

To summarize evidence on accuracy and harms of brief cognitive tests for CATD in older adults with suspected cognitive impairment.

DATA SOURCES

Electronic bibliographic databases (from inception to November 2019) and systematic review bibliographies.

STUDY SELECTION

English-language, controlled observational studies in older adults that evaluated the accuracy of brief cognitive tests (standalone tests; memory, executive function, and language tests; and brief multidomain batteries) for distinguishing CATD from mild cognitive impairment (MCI) or normal cognition as defined by established diagnostic criteria. Studies with low or medium risk of bias (ROB) were analyzed.

DATA EXTRACTION

Two reviewers rated ROB. One reviewer extracted data; the other verified extraction accuracy.

DATA SYNTHESIS

Fifty-seven studies met analysis criteria. Many brief, single cognitive tests were highly sensitive and specific for distinguishing CATD from normal cognition. These included standalone tests (clock-drawing test, median sensitivity 0.79 and specificity 0.88 [8 studies]; Mini-Mental State Examination, 0.88 and 0.94 [7 studies]; Montreal Cognitive Assessment, 0.94 and 0.94 [2 studies]; and Brief Alzheimer Screen, 0.92 and 0.97 [1 study]), memory tests (list delayed recall, 0.89 and 0.94 [5 studies]), and language tests (category fluency, 0.92 and 0.89 [9 studies]). Accuracy was lower in distinguishing mild CATD from normal cognition and distinguishing CATD from MCI. No studies reported on testing harms.

LIMITATIONS

Studies were small. Few test metrics were evaluated by multiple studies. Few studies directly compared different tests, scores, cut points, or test combinations.

CONCLUSION

Many brief, single cognitive tests accurately distinguish CATD from normal cognition in older adults but are less accurate in distinguishing mild CATD from normal cognition or CATD from MCI. No studies reported on testing harms.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (PROSPERO: CRD42018117897).

Associations of Widowhood and β-Amyloid With Cognitive Decline in Cognitively Unimpaired Older Adults

IMPORTANCE

To reduce the rising incidence of clinical impairment due to Alzheimer disease, it is essential to define older adults at highest risk. Widowhood may be an unrecognized factor contributing to accelerated clinical progression along the Alzheimer disease pathway among cognitively unimpaired older adults.

OBJECTIVE

To determine whether widowhood status and level of brain β-amyloid (ie, the Alzheimer disease pathologic protein) are additively or interactively associated with cognitive decline among cognitively unimpaired older adults.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, 257 married, widowed, and unmarried (ie, never married, divorced, or separated) participants from the Harvard Aging Brain Study longitudinal cohort underwent baseline evaluation of neocortical β-amyloid levels using Pittsburgh compound B positron emission tomography and 4 annual cognitive assessments. Data were collected from September 2010 to February 2017 and analyzed from July 2018 to July 2019.

MAIN OUTCOMES AND MEASURES

Cognitive performance was measured using the Preclinical Alzheimer Cognitive Composite.

RESULTS

Of the 257 participants, 153 (59.5%) were women, and the mean (SD) age was 73.5 (6.1) years; 145 participants (56.4%) were married (66 [45.5%] women), 77 (30.0%) were unmarried (56 [72.7%] women), and 35 (13.6%) were widowed (31 [88.6%] women). Compared with married participants, widowed participants demonstrated worsening cognitive performance after adjusting for age, sex, socioeconomic status, depression, and β-amyloid levels (β = -0.11; 95% CI, -0.19 to -0.04; P = .002) with no difference observed between married and unmarried participants. Furthermore, widowed participants with higher baseline β-amyloid levels exhibited steeper cognitive decline (β = -0.22; 95% CI, -0.42 to -0.03; P = .02), indicating both independent and interactive associations of β-amyloid levels and widowhood with cognition. In a secondary model using dichotomous β-amyloid-marital status groupings, the rate of cognitive decline among widowed participants with high β-amyloid was nearly 3 times faster than among married participants with high β-amyloid (widowed, high β-amyloid: β, -0.33; 95% CI, -0.46 to -0.19; P < .001; married, high β-amyloid: β, -0.12; 95% CI, -0.18 to -0.01; P < .001).

CONCLUSIONS AND RELEVANCE

In a sample of cognitively unimpaired older adults, being widowed was associated with accelerated β-amyloid-related cognitive decline during 3 years. Cognitively unimpaired, widowed older adults were particularly susceptible to Alzheimer disease clinical progression, emphasizing the need for increased research attention and evidenced-based interventions for this high-risk group.

Social Engagement and Amyloid-β-Related Cognitive Decline in Cognitively Normal Older Adults

OBJECTIVE

Public health recommendations promote social engagement to reduce risk of cognitive decline and dementia. The objective of this study was to evaluate the longitudinal associations of social engagement and cognition in cognitively normal older adults with varying levels of neocortical amyloid-β, the Alzheimer's disease (AD) pathologic marker.

METHODS

Two hundred seventeen men and women, age 63-89 underwent assessments for social engagement and cognitive performance at baseline and 3 years later using the Community Healthy Activities Model Program for Seniors questionnaire and the Preclinical Alzheimer Cognitive Composite (PACC). Amyloid-β was measured using Pittsburgh compound B-PET. Multivariable regression models estimated main and interactive effects of baseline social engagement and amyloid-β on cognitive change. Reciprocal models estimated main and interactive effects of baseline cognitive performance and amyloid-β on change in social engagement.

RESULTS

Baseline social engagement was associated with PACC change as a modifier but not as a main effect. Lower baseline social engagement was associated with greater amyloid-β-related PACC decline, while higher baseline social engagement was associated with relative preservation of PACC scores (β = 0.05, p = 0.03). Reciprocally, lower baseline PACC score was associated with decline in social engagement score (β = 1.1, p = 0.02). This association was not modified by amyloid-β, and there was no direct association of amyloid-β with change in social engagement.

CONCLUSIONS

Low social engagement may be a marker of neurocognitive vulnerability in older adults who are cognitively normal but have evidence of AD pathophysiologic change. Understanding changes in social engagement in older adults may lead to earlier diagnosis of AD and advances in evidence-based prevention and treatment.

How many patients are eligible for disease-modifying treatment in Alzheimer's disease? A French national observational study over 5 years

OBJECTIVE

We aimed to study the epidemiology of the prodromal and mild stages of Alzheimer's disease (AD) patients who are eligible for clinical trials with disease-modifying therapies.

SETTINGS

We analysed two large complementary databases to study the incidence and characteristics of this population on a nationwide scope in France from 2014 to 2018. The National Alzheimer Database contains data from 357 memory centres and 90 private neurologists. Data from 2014 to 2018 have been analysed.

PARTICIPANTS

Patients, 50-85 years old, diagnosed with AD who had an Mini-Mental State Exam (MMSE) score of ≥20 were included. We excluded patients with mixed and non-AD neurocognitive disorders.

PRIMARY OUTCOME MEASURE

Descriptive statistics of the population of interest was the primary measure.

RESULTS

In the National Alzheimer Database, 550 198 patients were assessed. Among them, 72 174 (13.1%) were diagnosed with AD and had an MMSE ≥20. Using corrections for specificity of clinical diagnosis of AD, we estimated that about 50 000 (9.1%) had a prodromal or mild AD. In the combined electronic clinical records database of 11 French expert memory centres, a diagnosis of prodromal or mild AD, certified by the use of cerebrospinal fluid AD biomarkers, could be established in 195 (1.3%) out of 14 596 patients.

CONCLUSIONS

AD was not frequently diagnosed at a prodromal or mild dementia stage in France in 2014 to 2018. Diagnosis rarely relied on a pathophysiological marker even in expert memory centres. National databases will be valuable to monitor early stage AD diagnosis efficacy in memory centres when a disease-modifying treatment becomes available.

Lateral parietal contributions to memory impairment in posterior cortical atrophy

Objective

Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterised by progressive impairment in visuospatial and perceptual function. Recent findings show that memory functioning can also be compromised early in the course of disease. In this study, we investigated the neural basis of memory impairment in PCA, and hypothesised that correlations would be observed with parietal cortex rather than classic medial temporal memory structures.

Methods

Eighteen PCA patients, 15 typical Alzheimer's disease (tAD) patients and 21 healthy controls underwent memory testing with the Rey Auditory Verbal Learning Test (RAVLT) word list and MRI. Voxel-based morphometry (VBM) was used to identify regions in the parietal and medial temporal lobes that correlated with memory performance.

Results

Compared with controls, PCA patients were impaired at learning, immediate and delayed recall and recognition of the RAVLT. Learning rate and immediate recall was significantly better in PCA compared to tAD, whereas there was no difference in delayed recall. Recognition memory also was not statistically different between patient groups, but PCA patients made significantly more false positive errors than tAD patients. VBM analysis in the PCA patients revealed a significant correlation between total learning and grey matter density in the right supramarginal gyrus, right angular gyrus and left postcentral gyrus. The left post central gyrus also significantly correlated with immediate and delayed recall and with recognition memory. No correlations were detected in the medial temporal lobe.

Conclusions

The findings provide novel evidence that early verbal memory impairment is frequently observed in PCA, and is associated with damage to lateral parietal structures. The results have implications for the diagnosis and management of PCA.

•

PCA patients were impaired in learning, recall and recognition memory.

•

Deficits were evident in the early stages of disease.

•

Memory impairment was associated with damage to lateral parietal structures.

•

No correlations were detected in the medial temporal lobe.

Comparison of Computerized and Paper-and-Pencil Memory Tests in Detection of Mild Cognitive Impairment and Dementia: A Systematic Review and Meta-analysis of Diagnostic Studies

OBJECTIVES

To compare the diagnostic performance of computerized and paper-and-pencil memory tests in detection of mild cognitive impairment (MCI) and dementia.

DESIGN

Diagnostic studies comparing computerized or paper-and-pencil memory tests with the standard diagnostic criterion for MCI or dementia were identified from OVID databases. The primary outcome was the diagnostic performance of memory tests for detection of MCI, and detection of dementia was the secondary outcome. Risk of bias and reporting quality in included studies was assessed.

SETTING AND PARTICIPANTS

Participants with MCI and dementia in any kind of setting.

MEASURES

Bivariate random-effects models were used to combine the diagnostic performance of memory tests and presented with a summary receiver-operating characteristic curve.

RESULTS

A total of 58 studies with 18,450 participants with mean age ranging from 55 to 84 years were included. For the verbal memory tests on patients with MCI, computerized tests showed diagnostic accuracy of 0.89 sensitivity (95% confidence interval [CI] 0.69-0.97) and 0.82 specificity (95% CI 0.70-0.90), whereas paper-and-pencil tests showed diagnostic accuracy of 0.86 sensitivity (95% CI 0.82-0.90) and 0.82 specificity (95% CI 0.76-0.86). For the visual memory tests on MCI patients, computerized tests showed diagnostic accuracy of 0.79 sensitivity (95% CI 0.71-0.84) and 0.80 specificity (95% CI 0.71-0.86), whereas paper-and-pencil tests showed diagnostic accuracy of 0.80 sensitivity (95% CI 0.67-0.89) and 0.68 specificity (95% CI 0.51-0.81). The findings were also comparable to those with dementia.

CONCLUSIONS/IMPLICATIONS

Both verbal and visual computerized memory tests showed comparable diagnostic performance to the paper-and-pencil tests. Computerized cognitive tests show a great potential to use as an alternative to paper-and-pencil tests. When the records can be digitalized, long-term monitoring of cognitive function will be feasible for better management of dementia.

The Association between Montreal Cognitive Assessment Memory Scores and Hippocampal Volume in a Neurodegenerative Disease Sample

Despite widespread use, there have been few investigations into the neuroanatomical correlates of the Montreal Cognitive Assessment (MoCA). In a sample of 138 consecutive patients presenting with cognitive complaints, we report significant correlations between lower MoCA memory scores and smaller hippocampal volumes (r = 0.36–0.41, p < 0.001). We also report that the newly devised memory index score, designed to better capture encoding deficits than the standard delayed recall score, was not significantly better for predicting hippocampal volume. These initial results suggest that poor performance on the MoCA’s memory section should prompt further evaluation for hippocampal atrophy.

Episodic Memory Dysfunction in Behavioral Variant Frontotemporal Dementia: A Clinical And FDG-PET Study

BACKGROUND

Episodic memory disturbance is still considered as an exclusion criterion for behavioral variant frontotemporal dementia (bvFTD), but growing evidence suggests that memory can be impaired.

OBJECTIVE

Our main purposes were to assess episodic memory in a group of bvFTD patients comparatively with Alzheimer's disease (AD) patients, and analyze the relationship between episodic memory and brain metabolism measured using positron emission tomography imaging with 18F-fluorodeoxyglucose (FDG-PET).

METHODS

Twenty-six bvFTD, 29 AD, and 24 healthy controls were included. Episodic memory was assessed by the Free and Cued Selective Reminding Test (FCSRT), which controls for effective encoding and measures memory consolidation processing. All participants underwent FDG-PET brain scans to provide data for voxel-based brain mapping analysis.

RESULTS

Half of bvFTD patients had a deficit of total, free delayed, and total free delayed recall as severe as AD patients (amnestic-FTD). The other half had FCSRT scores similar to controls (non-amnestic-FTD). Imaging analyses revealed that amnestic-FTD showed bilateral lower metabolism than non-amnestic-FTD in anterior parahippocampal and inferior temporal gyri. Additionally, FCSRT total and total delayed scores were inversely correlated with parahippocampal metabolism in both bvFTD and AD. Besides, bvFTD showed an inverse association among FCSRT and inferior temporal metabolism.

CONCLUSIONS

Our findings support that bvFTD could present a genuine amnesia affecting storage and consolidation abilities, which involves structures implicated in the Papez circuit, as occurs in AD, and also inferior temporal regions. These results contribute to understanding the mechanisms underpinning memory dysfunction in bvFTD, and may be relevant to further revisions of the current diagnostic criteria.

Assessment of free and cued recall in Alzheimer's disease and vascular and frontotemporal dementia with 24-item Grober and Buschke test

Alzheimer's disease (AD), vascular dementia (VaD) and frontotemporal dementia (FTD) are the most common forms of dementia. It is well known that memory deficits in AD are different from those in VaD and FTD, especially with respect to cued recall. The aim of this clinical study was to compare the memory performance in 15 AD, 10 VaD and 9 FTD patients and 20 normal controls by means of a 24-item Grober-Buschke test [8]. The patients' groups were comparable in terms of severity of dementia. We considered free and total recall (free plus cued) both in immediate and delayed recall and computed an Index of Sensitivity to Cueing (ISC) [8] for immediate and delayed trials. We assessed whether cued recall predicted the subsequent free recall across our patients' groups. We found that AD patients recalled fewer items from the beginning and were less sensitive to cueing supporting the hypothesis that memory disorders in AD depend on encoding and storage deficit. In immediate recall VaD and FTD showed a similar memory performance and a stronger sensitivity to cueing than AD, suggesting that memory disorders in these patients are due to a difficulty in spontaneously implementing efficient retrieval strategies. However, we found a lower ISC in the delayed recall compared to the immediate trials in VaD than FTD due to a higher forgetting in VaD.

Exploring anterograde memory: a volumetric MRI study in patients with mild cognitive impairment

BACKGROUND

The aim of this volumetric study was to explore the neuroanatomical correlates of the Free and Cued Selective Reminding Test (FCSRT) and the Delayed Matching-to-Sample-48 items (DMS-48), two tests widely used in France to assess verbal and visual anterograde memory. We wanted to determine to what extent the two tests rely on the medial temporal lobe, and could therefore be predictive of Alzheimer's disease, in which pathological changes typically start in this region.

METHODS

We analysed data from a cohort of 138 patients with mild cognitive impairment participating in a longitudinal multicentre clinical research study. Verbal memory was assessed using the FCSRT and visual recognition memory was evaluated using the DMS-48. Performances on these two tests were correlated to local grey matter atrophy via structural MRI using voxel-based morphometry.

RESULTS

Our results confirm the existence of a positive correlation between the volume of the medial temporal lobe and the performance on the FCSRT, prominently on the left, and the performance on the DMS-48, on the right, for the whole group of patients (family-wise error, P < 0.05). Interestingly, this region remained implicated only in the subgroup of patients who had deficient scores on the cued recall of the FCSRT, whereas the free recall was associated with prefrontal aspects. For the DMS-48, it was only implicated for the group of patients whose performances declined between the immediate and delayed trial. Conversely, temporo-parietal cortices were implicated when no decline was observed. Within the medial temporal lobe, the parahippocampal gyrus was prominently involved for the FCSRT and the immediate trial of the DMS-48, whereas the hippocampus was solely involved for the delayed trial of the DMS-48.

CONCLUSIONS

The two tests are able to detect an amnestic profile of the medial temporal type, under the condition that the scores remain deficient after the cued recall of the FCSRT or decline on the delayed recognition trial of the DMS-48. Strategic retrieval as well as perceptual/attentional processes, supported by prefrontal and temporo-parietal cortices, were also found to have an impact on the performances. Finally, the implication of the hippocampus appears time dependent, triggered by a longer delay than the parahippocampus, rather than determined by the sense of recollection or the encoding strength associated with the memory trace.

O Procedimento Selective Reminding na Avaliação da Memória e Aprendizagem: Um Levantamento de Estudos Brasileiros

RESUMO Os pesquisadores têm à sua disposição uma variedade de métodos que auxiliam a compreensão dos processos de memória e aprendizagem. O presente artigo tem como objetivo revisitar o procedimento de recordação seletiva, apresentando suas características e variações, e realizar um levantamento de estudos brasileiros que fizeram uso do mesmo. São apresentadas as diferenças entre a recordação seletiva e o procedimento padrão em tarefas de aprendizagem por recordação livre. Constatou-se que, no Brasil, além de diferentes tarefas, são utilizadas formas de aplicações distintas do procedimento. A utilização da recordação seletiva apresenta relevância no estudo da memória e da aprendizagem, em especial na busca pela diferenciação entre as dificuldades normais de memórias e os déficits patológicos dessa função cognitiva.

Improvement of encoding and retrieval in normal and pathological aging with word-picture paradigm

OBJECTIVES

During the aging process, there is a progressive deficit in the encoding of new information and its retrieval. Different strategies are used in order to maintain, optimize or diminish these deficits in people with and without dementia. One of the classic techniques is paired-associate learning (PAL), which is based on improving the encoding of memories, but it has yet to be used to its full potential in people with dementia. In this study, our aim is to corroborate the importance of PAL tasks as instrumental tools for creating contextual cues, during both the encoding and retrieval phases of memory. Additionally, we aim to identify the most effective form of presenting the related items.

METHOD

Pairs of stimuli were shown to healthy elderly people and to patients with moderate and mild Alzheimer's disease. The encoding conditions were as follows: word/word, picture/picture, picture/word, and word/picture.

RESULTS

Associative cued recall of the second item in the pair shows that retrieval is higher for the word/picture condition in the two groups of patients with dementia when compared to the other conditions, while word/word is the least effective in all cases.

CONCLUSION

These results confirm that PAL is an effective tool for creating contextual cues during both the encoding and retrieval phases in people with dementia when the items are presented using the word/picture condition. In this way, the encoding and retrieval deficit can be reduced in these people.

Selective Reminding and Free and Cued Selective Reminding in Mild Cognitive Impairment and Alzheimer Disease

The Selective Reminding Test (SRT) and the Free and Cued Selective Reminding Test (FCSRT) are multitrial memory tests that use a common "selective reminding" paradigm that aims to facilitate learning by presenting only the missing words from the previous recall trial. While in the FCSRT semantic cues are provided to elicit recall, in the SRT, participants are merely reminded of the missing items by repeating them. These tests have been used to assess age-related memory changes and to predict dementia. The performance of healthy elders on these tests has been compared before, and results have shown that twice as many words were retrieved from long-term memory in the FCSRT compared with the SRT. In this study, we compared the tests' properties and their accuracy in discriminating amnestic mild cognitive impairment (aMCI; n = 20) from Alzheimer disease (AD; n = 18). Patients with AD performed significantly worse than patients with aMCI on both tests. The percentage of items recalled during the learning trials was significantly higher for the FCSRT in both groups, and a higher number of items were later retrieved, showing the benefit of category cueing. Our key finding was that the FCSRT showed higher accuracy in discriminating patients with aMCI from those with AD.

Screening older Latinos for dementia in the primary care setting

The purpose was to compare the Spanish language picture version of the Free and Cued Selective Reminding Test with Immediate Recall (pFCSRT+IR) and the Mini Mental State Exam (MMSE) in identifying very mild dementia among Spanish speaking Latino patients. The tests and an independent diagnostic assessment were administered to 112 Latino patients free of medically diagnosed dementia from an urban primary care clinic. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to examine differences in the operating characteristics of the pFCSRT+IR and the MMSE. Cut scores were manipulated to equate sensitivities (specificities) at clinically relevant values to compare differences in specificities (sensitivities) using the Pearson Chi Square test. Youden's index was used to select the optimal cut scores. Twenty-four of the 112 primary care patients (21%) received a research dementia diagnosis, indicating a substantial burden of unrecognized dementia. MMSE scores but not free recall scores were associated with years of education in patients free of dementia. AUC was significantly higher for free recall than for MMSE. Free recall performed significantly better than the MMSE in sensitivity and in specificity. Using optimal cut scores, patients with impaired free recall were 10 times more likely to have dementia than patients with intact recall, and patients with impaired MMSE scores were 4.5 times more likely to have dementia than patients with intact scores. These results suggest that the Spanish language pFCSRT+IR may be an effective tool for dementia screening in educationally diverse Latino primary care populations.

Review of brief cognitive tests for patients with suspected dementia

BACKGROUND

As the population ages, it is increasingly important to use effective short cognitive tests for suspected dementia. We aimed to review systematically brief cognitive tests for suspected dementia and report on their validation in different settings, to help clinicians choose rapid and appropriate tests.

METHODS

Electronic search for face-to-face sensitive and specific cognitive tests for people with suspected dementia, taking ≤ 20 minutes, providing quantitative psychometric data.

RESULTS

22 tests fitted criteria. Mini-Mental State Examination (MMSE) and Hopkins Verbal Learning Test (HVLT) had good psychometric properties in primary care. In the secondary care settings, MMSE has considerable data but lacks sensitivity. 6-Item Cognitive Impairment Test (6CIT), Brief Alzheimer's Screen, HVLT, and 7 Minute Screen have good properties for detecting dementia but need further validation. Addenbrooke's Cognitive Examination (ACE) and Montreal Cognitive Assessment are effective to detect dementia with Parkinson's disease and Addenbrooke's Cognitive Examination-Revised (ACE-R) is useful for all dementias when shorter tests are inconclusive. Rowland Universal Dementia Assessment scale (RUDAS) is useful when literacy is low. Tests such as Test for Early Detection of Dementia, Test Your Memory, Cognitive Assessment Screening Test (CAST) and the recently developed ACE-III show promise but need validation in different settings, populations, and dementia subtypes. Validation of tests such as 6CIT, Abbreviated Mental Test is also needed for dementia screening in acute hospital settings.

CONCLUSIONS

Practitioners should use tests as appropriate to the setting and individual patient. More validation of available tests is needed rather than development of new ones.

The free and cued selective reminding test distinguishes frontotemporal dementia from Alzheimer's disease

Memory impairment is often present in frontotemporal dementia (FTD) as a result of an inefficient use of learning strategies, sometimes leading to a misdiagnosis of Alzheimer's disease (AD). The Free and Cued Selective Reminding Test (FCSRT) is a memory test that controls attention and acquisition, by providing category cues in the learning process. The main goal of this study was to show the usefulness of the FCSRT in the distinction between behavioral (bv-) FTD and AD. Three matched subgroups of participants were considered: bv-FTD (n = 32), AD (n = 32), and a control group of healthy adults (n = 32). Results proved that while AD patients exhibited an overall impairment in FCSRT, bv-FTD subjects showed to benefit more from the controlled learning through category cues. AD patients were 25 times more likely to have an impaired FCSRT. The FCSRT has shown its utility in the distinction between bv-FTD and AD, therefore increasing the diagnostic accuracy.

EFNS-ENS Guidelines on the diagnosis and management of disorders associated with dementia

BACKGROUND AND OBJECTIVES

The last version of the EFNS dementia guidelines is from 2007. In 2010, the revised guidelines for Alzheimer's disease (AD) were published. The current guidelines involve the revision of the dementia syndromes outside of AD, notably vascular cognitive impairment, frontotemporal lobar degeneration, dementia with Lewy bodies, corticobasal syndrome, progressive supranuclear palsy, Parkinson's disease dementia, Huntington's disease, prion diseases, normal-pressure hydrocephalus, limbic encephalitis and other toxic and metabolic disorders. The aim is to present a peer-reviewed evidence-based statement for the guidance of practice for clinical neurologists, geriatricians, psychiatrists and other specialist physicians responsible for the care of patients with dementing disorders. It represents a statement of minimum desirable standards for practice guidance.

METHODS

The task force working group reviewed evidence from original research articles, meta-analyses and systematic reviews, published by June 2011. The evidence was classified (I, II, III, IV) and consensus recommendations graded (A, B, or C) according to the EFNS guidance. Where there was a lack of evidence, but clear consensus, good practice points were provided.

RESULTS AND CONCLUSIONS

New recommendations and good practice points are made for clinical diagnosis, blood tests, neuropsychology, neuroimaging, electroencephalography, cerebrospinal fluid (CSF) analysis, genetic testing, disclosure of diagnosis, treatment of behavioural and psychological symptoms in dementia, legal issues, counselling and support for caregivers. All recommendations were revised as compared with the previous EFNS guidelines. The specialist neurologist together with primary care physicians play an important role in the assessment, interpretation and treatment of symptoms, disability and needs of dementia patients.

Awareness of memory deficits in early stage Huntington's disease

Patients with Huntington's disease (HD) are often described as unaware of their motor symptoms, their behavioral disorders or their cognitive deficits, including memory. Nevertheless, because patients with Parkinson's disease (PD) remain aware of their memory deficits despite striatal dysfunction, we hypothesize that early stage HD patients in whom degeneration predominates in the striatum can accurately judge their own memory disorders whereas more advanced patients cannot. In order to test our hypothesis, we compared subjective questionnaires of memory deficits (in HD patients and in their proxies) and objective measures of memory dysfunction in patients. Forty-six patients with manifest HD attending the out-patient department of the French National Reference Center for HD and thirty-three proxies were enrolled. We found that HD patients at an early stage of the disease (Stage 1) were more accurate than their proxies at evaluating their own memory deficits, independently from their depression level. The proxies were more influenced by patients' functional decline rather than by patients' memory deficits. Patients with moderate disease (Stage 2) misestimated their memory deficits compared to their proxies, whose judgment was nonetheless influenced by the severity of both functional decline and depression. Contrasting subjective memory ratings from the patients and their objective memory performance, we demonstrate that although HD patients are often reported to be unaware of their neurological, cognitive and behavioral symptoms, it is not the case for memory deficits at an early stage. Loss of awareness of memory deficits in HD is associated with the severity of the disease in terms of CAG repeats, functional decline, motor dysfunction and cognitive impairment, including memory deficits and executive dysfunction.

Suitability of neuropsychological tests in patients with vascular dementia (VaD)

The concept of vascular dementia (VaD) has evolved with the introduction of vascular cognitive impairment (VCI). VaD patients show predominantly frontal cognitive deficits. The executive area is particularly affected, while memory deficits are less frequent in patients with VaD than patients with AD. Several neuropsychological tests are available for the diagnosis and differentiation of dementias, but there are currently no tests developed specifically for VaD. We proposed to evaluate various neuropsychological tests, on the basis of evidence from different studies, in order to clarify the utility of the neuropsychological assessment in vascular dementia.

From Morris Water Maze to computer tests in the prediction of Alzheimer's disease

BACKGROUND

Spatial navigation performance in the Hidden Goal Task (HGT), a real-space human analogue of the Morris Water Maze, can identify amnestic mild cognitive impairment (aMCI) patients with memory impairment of the hippocampal type, a known indicator of incipient Alzheimer's disease (AD).

OBJECTIVE

Contrast results from computer versus real-space versions of the HGT.

METHODS

A total of 42 aMCI patients were clinically and neuropsychologically classified into: (1) memory impairment of the hippocampal type--the hippocampal aMCI (HaMCI; n = 10) and (2) isolated retrieval impairment--the nonhippocampal aMCI (NHaMCI; n = 32). Results were compared to the control (n = 28) and AD (n = 21) groups.

RESULTS

The HaMCI group, although similar to the NHaMCI group with respect to overall cognitive impairment, performed poorer on the computer version of the HGT and yielded parallel results to the real-space version. The two versions were strongly correlated.

CONCLUSIONS

Both versions of the HGT can reliably identify aMCI with pronounced memory impairment of the hippocampal type. The computer version of the HGT may be a useful, relatively inexpensive screening tool for early detection of individuals at a high risk of AD.

Longitudinal analysis of cognitive performances and structural brain changes in late-life bipolar disorder

OBJECTIVES

Cross-sectional studies in bipolar disorder (BD) suggested the presence of cognitive deficits and subtle magnetic resonance imaging (MRI) changes in limbic areas that may persist at euthymic stages. Whether or not cognitive and MRI changes represent stable attributes of BD or evolve with time is still matter of debate. To address this issue, we performed a 2-year longitudinal study including detailed neuropsychological and magnetic resonance imaging (MRI) analyses of 15 euthymic older BD patients and 15 controls.

METHODS

Neuropsychological evaluation concerned working memory, episodic memory, processing speed, and executive functions. MRI analyses included voxel-based morphometry (VBM) analysis of gray matter including region of interest (ROI) analysis and tract-based spatial statistics (TBSS) analysis of white matter of diffusion tensor imaging derived fractional anisotropy (FA).

RESULTS

BD patients displayed significantly lower performances in processing speed and episodic memory but not in working memory and executive functions compared to controls. However, BD patients did not differ from controls in the mean trajectory of cognitive changes during the 2 years follow-up. In the same line, longitudinal gray matter (VBM, ROI) and white matter (TBSS FA) changes did not differ between BD patients and controls.

CONCLUSION

The lack of distinction between BD patients and controls in respect to the 2-year changes in cognition and MRI findings supports the notion that this disorder does not have a significant adverse impact on cognitive and brain aging. From this point of view, the present results convey a message of hope for patients suffering from BD.

Free and cued selective reminding identifies very mild dementia in primary care

The Free and Cued Selective Reminding Test (FCSRT) is used widely to identify very mild dementia; 3 alternative scoring procedures have been proposed based on free recall, total recall, and cue efficiency. We compared the predictive validity of these scoring procedures for the identification of very mild prevalent dementia (CDR=0.5), of incident dementia, and for distinguishing Alzheimer Disease (AD) and nonAD dementias. We tested 244 elderly African American and White primary care patients at 18 month intervals using a screening neuropsychologic battery that included the FCSRT and a comprehensive diagnostic neuropsychologic battery. Median follow-up was 2.6 years. Dementia diagnoses were assigned using standard criteria without access to the results of the screening battery. There were 50 prevalent and 28 incident dementia cases. At scores selected to provide specificities of 90%, free recall was more sensitive to incident and prevalent dementia than the other 2 measures. Patients with impaired free recall were 15 times more likely to have a prevalent dementia and their risk of future dementia was 4 times higher than patients with intact free recall. Neither race nor education affected prediction although older patients were at increased risk of future dementia. Total recall was more impaired in AD dementia than in nonAD dementias. The results indicate that using the FCSRT, free recall is the best measure for detecting prevalent dementia and predicting future dementia. Total recall impairment supports the diagnosis of AD rather than nonAD dementia.