Diagnostic Accuracy of Memory Measures in Alzheimer's Dementia and Mild Cognitive Impairment: a Systematic Review and Meta-Analysis

Diagnostic and Prognostic Accuracy of the Cogstate Brief Battery and Auditory Verbal Learning Test in Preclinical Alzheimer's Disease and Incident Mild Cognitive Impairment: Implications for Defining Subtle Objective Cognitive Impairment

BACKGROUND

There are detectable cognitive differences in cognitively unimpaired (CU) individuals with preclinical Alzheimer's disease (AD).

OBJECTIVE

To determine whether cross-sectional performance on the Cogstate Brief Battery (CBB) and Auditory Verbal Learning Test (AVLT) could identify 1) CU participants with preclinical AD defined by neuroimaging biomarkers of amyloid and tau, and 2) incident mild cognitive impairment (MCI)/dementia.

METHOD

CU participants age 50+ were eligible if they had 1) amyloid (A) and tau (T) imaging within two years of their baseline CBB or 2) at least one follow-up visit. AUROC analyses assessed the ability of measures to differentiate groups. We explored the frequency of cross-sectional subtle objective cognitive impairment (sOBJ) defined as performance ≤-1 SD on CBB Learning/Working Memory Composite (Lrn/WM) or AVLT delayed recall using age-corrected normative data.

RESULTS

A+T+ (n = 33, mean age 79.5) and A+T- (n = 61, mean age 77.8) participants were older than A-T- participants (n = 146, mean age 66.3), and comparable on sex and education. Lrn/WM did not differentiate A + T+or A+T- from A-T- participants. AVLT differentiated both A+T+ and A+T- from A-T- participants; 45% of A+T+ and 25% of A+T- participants met sOBJ criteria. The follow-up cohort included 150 CU individuals who converted to MCI/dementia and 450 age, sex, and education matched controls. Lrn/WM and AVLT differentiated between stable and converter CU participants.

CONCLUSION

Among CU participants, AVLT helped differentiate A+T+ and A+T- from A-T- participants. The CBB did not differentiate biomarker subgroups, but showed potential for predicting incident MCI/dementia. Results inform future definitions of sOBJ.

Psychometric properties of Addenbrooke's Cognitive Examination III (ACE-III): An item response theory approach

The Addenbrooke's Cognitive Examination III is one of the most widely used tests to assess cognitive impairment. Although previous studies have shown adequate levels of diagnostic utility to detect severe impairment, it has not shown sensitivity to detect mild decline. The aim of this study was to evaluate the psychometric properties of Addenbrooke's Cognitive Examination III in a large sample of elderly people through Item Response Theory, due to the lack of studies using this approach. A cross-sectional study was conducted with 1164 people from the age of 60 upwards, of which 63 had a prior diagnosis of Alzheimer dementia. The results showed that, globally, the Addenbrooke's Cognitive Examination III possesses adequate psychometrics properties. Furthermore, the information function test shows that the subscales have different sensitivity to different levels of impairment. These results can contribute to determining patterns of cognitive deterioration for the adequate detection of different levels of dementia. An optimized version is suggested which may be an economic alternative in the applied field.

Breaking the Percent Memory Retention Ceiling using Bayesian Statistics

OBJECTIVES

Neuropsychological tests of episodic memory often include a measure of memory retention to facilitate the diagnosis of memory disorders. However, the traditional percent retention (PR) score has limited interpretability when smaller amounts of information are both initially learned and later recalled, creating a pseudo-ceiling effect. To improve psychometrics of PR, we investigated a scoring procedure that incorporates levels of certainty into estimates of memory retention based on learning level.

METHODS

Word-list recall data from adults with traumatic brain injury were modeled using a uniform prior in the Bayesian framework. From the resultant posterior probability distributions, we derived a measure referred to as retention probability (RPr), which distinguishes the retention of relatively good and poor learners. PR and RPr scores were compared on their distributional properties and associations with theoretically related memory measures.

RESULTS

Significant distributional differences between PR and RPr were observed. RPr removed the conspicuous ceiling of PR, resulting in stronger correlational and predictive relationships with other memory measures.

CONCLUSION

A Bayesian procedure for quantifying memory retention has psychometric advantages and potentially widespread applicability for measuring the change in behavioral features over time. Future directions are briefly discussed. A sample RPr calculator is provided for interactive exploration of the method.

Following H.N. over 21 years: recency change and reduced retention predict later impairment in memory, and recency ratio may combine both effects

The study follows an intellectually superior patient from initial subjective memory complaints to MCI and dementia over 21 years. Primary memory measures, process- and reliable change-measures from 12 assessments with the California Verbal Learning Test (CVLT) were analyzed as well as experimental measures of retrieval and Recency-Ratio (Rr) combining traditional recency measures with selective retrieval impairments of recency items.Recency change preceded normatively impaired memory by four years, and retention percentage by two years. Rr indicated risk for MCI conversion 13 years prior to receiving that diagnosis, and is an interesting measure for early detection of dementia in CVLT.

Diagnostic accuracy of the Cogstate Brief Battery for prevalent MCI and prodromal AD (MCI A+ T+ ) in a population-based sample

INTRODUCTION

This study evaluated the diagnostic accuracy of the Cogstate Brief Battery (CBB) for mild cognitive impairment (MCI) and prodromal Alzheimer's disease (AD) in a population-based sample.

METHODS

Participants included adults ages 50+ classified as cognitively unimpaired (CU, n = 2866) or MCI (n = 226), and a subset with amyloid (A) and tau (T) positron emission tomography who were AD biomarker negative (A-T-) or had prodromal AD (A+T+).

RESULTS

Diagnostic accuracy of the Learning/Working Memory Composite (Lrn/WM) for discriminating all CU and MCI was moderate (area under the curve [AUC] = 0.75), but improved when discriminating CU A-T- and MCI A+T+ (AUC = 0.93) and when differentiating MCI participants without AD biomarkers from those with prodromal AD (AUC = 0.86). Conventional cut-offs yielded lower than expected sensitivity for both MCI (38%) and prodromal AD (73%).

DISCUSSION

Clinical utility of the CBB for detecting MCI in a population-based sample is lower than expected. Caution is needed when using currently available CBB normative data for clinical interpretation.

Mayo Normative Studies: Regression-Based Normative Data for the Auditory Verbal Learning Test for Ages 30-91 Years and the Importance of Adjusting for Sex

OBJECTIVE

Rey's Auditory Verbal Learning Test (AVLT) is a widely used word list memory test. We update normative data to include adjustment for verbal memory performance differences between men and women and illustrate the effect of this sex adjustment and the importance of excluding participants with mild cognitive impairment (MCI) from normative samples.

METHOD

This study advances the Mayo's Older Americans Normative Studies (MOANS) by using a new population-based sample through the Mayo Clinic Study of Aging, which randomly samples residents of Olmsted County, Minnesota, from age- and sex-stratified groups. Regression-based normative T-score formulas were derived from 4428 cognitively unimpaired adults aged 30-91 years. Fully adjusted T-scores correct for age, sex, and education. We also derived T-scores that correct for (1) age or (2) age and sex. Test-retest reliability data are provided.

RESULTS

From raw score analyses, sex explained a significant amount of variance in performance above and beyond age (8-10%). Applying original age-adjusted MOANS norms to the current sample resulted in significantly fewer-than-expected participants with low delayed recall performance, particularly in women. After application of new T-scores adjusted only for age, even in normative data derived from this sample, these age-adjusted T-scores showed scores <40 T occurred more frequently among men and less frequently among women relative to T-scores that also adjusted for sex.

CONCLUSIONS

Our findings highlight the importance of using normative data that adjust for sex with measures of verbal memory and provide new normative data that allow for this adjustment for the AVLT.

Dual-Task Exercise to Improve Cognition and Functional Capacity of Healthy Older Adults

Background

It has been suggested that physical inactivity and lack of stimulating cognitive activity are the two most significant modifiable risk factors to impair cognitive function. Although many studies that investigated the cognitive effects of physical exercise and cognitive stimuli in dual-task conditions showed improved cognitive performance, others have not confirmed these findings. The main aim of the present work is to analyze the effects of a dual-task multimodal physical exercise training, at moderate intensity, and cognitive stimulation on cognitive and physical function in healthy older adults.

Methods

This clinical trial was registered on the Brazilian Registry of Clinical Trials (RBR-9zrx3d). Here we tested the effects of a dual-task multimodal physical exercise training, at moderate intensity, on cognitive and physical function and quality of life in community dwelling older adults. The training protocol included 24 group sessions, 2/week, per 75 min. Cognition was assessed using CANTAB automated neuropsychological tests and Functional Capacity to Exercise tests. Performance was compared from baseline to post intervention and to a non-exercise control group using Mixed Linear Model for repeated measures.

Results

Control (CG) and dual-task (DTEx) groups progressed differentially over time on performance of episodic memory, sustained visual attention, functional mobility, cardiorespiratory fitness, lower limbs strength resistance, agility, quality of life and dual-task performance with significant improved DTEx performance. Control group did not show any significant changes on these tests except for showing a reduction in dual-task performance.

Conclusion

We suggest that the dual-task combination of multisensory cognitive stimulation and multimodal moderate physical exercise training, twice a week, may be adopted as an effective program to reduce progression of age-related cognitive decline and improve physical fitness and quality of life on healthy older adults.

Clinical Trial Registration

Brazilian Registry of Clinical Trials: https://ensaiosclinicos.gov.br/rg/RBR-9zrx3d -UTN code: U1111-1233-6349.

Four-year trajectories of episodic memory decline in mid-late life by living arrangements: a cross-national comparison between China and England

BACKGROUND

There is mixed evidence on the association between living arrangements and mid-late life cognition, which may be due to distinct familial arrangements and preferences between populations. To address such heterogeneity, we assessed these associations in China and England.

METHODS

Four-year trajectories of episodic memory scores (0-20, word recall test) by living arrangements (living with partner only, living with partner and children/grandchildren, living with no partner but with children/grandchildren, and living alone) were estimated using latent growth curve modelling for men and women aged 50+ from China (n=12 801) and England (n=10 964).

RESULTS

After adjusting for baseline socioeconomic, health behaviours and health covariates, worse baseline memory was found in Chinese adults living with no partner but with children/grandchildren and in Chinese women living with partner and children/grandchildren, compared with those living with partner only. Better baseline memory was associated with living alone in English women. A faster memory decline was found in Chinese men living with no partner but with children/grandchildren (-0.122 word/year, 95% CI -0.213 to -0.031), as well as in English women living with children/grandchildren with (-0.114, 95% CI -0.180 to -0.049) or without (-0.118, 95% CI -0.209 to -0.026) a partner, and those living alone (-0.075, 95% CI -0.127 to -0.024). No differences at baseline nor over follow-up were found between English men in different living arrangements.

CONCLUSION

Overall, our findings did not confirm the protective effects of co-residence with children/grandchildren, nor the detrimental effects of living alone on mid-late life cognition in China and England.

Akt and calcium-permeable AMPA receptor are involved in the effect of pinoresinol on amyloid β-induced synaptic plasticity and memory deficits

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative disorders characterized by memory deficits. Although no drug has given promising results, synaptic dysfunction-modulating agents might be considered potential candidates for alleviating this disorder. Pinoresinol, a lignan found in Forsythia suspensa, is a memory-enhancing agent with excitatory synaptic activation. In the present study, we tested whether pinoresinol reduces learning and memory and excitatory synaptic deficits in an amyloid β (Aβ)-induced AD-like mouse model. Pinoresinol enhanced hippocampal long-term potentiation (LTP) through calcium-permeable AMPA receptor, which was mediated by Akt activation. Moreover, pinoresinol ameliorated LTP deficits in amyloid β (Aβ)-treated hippocampal slices via Akt signaling. Oral administration of pinoresinol ameliorated Aβ-induced memory deficits without sensory dysfunction. Moreover, AD-like pathology, including neuroinflammation and synaptic deficit, were ameliorated by pinoresinol administration. Collectively, pinoresinol may be a good candidate for AD therapy by modulating synaptic functions.

Symptoms of traumatic encephalopathy syndrome are common in the US general population

There are no validated criteria for diagnosing chronic traumatic encephalopathy, or traumatic encephalopathy syndrome, in a living person. The purpose of this study is to examine symptom reporting resembling the research criteria for traumatic encephalopathy syndrome in men and women from the US general population. This is a retrospective analysis of publicly available data from a cross-sectional epidemiological study. The National Comorbidity Survey Replication was designed to examine the prevalence and correlates of mental disorders in the USA. The study included a nationally representative sample of 9282 adults (4139 men and 5143 women). An in-person interview and survey were conducted in the homes of men and women from the general population. The study was conducted with participants residing in New York City, Los Angeles, Chicago, Philadelphia, Detroit, San Francisco, Washington DC, Dallas/Fort Worth, Houston, Boston, Nassau-Suffolk NY, St. Louis, Pittsburgh, Baltimore, Minneapolis and Atlanta. Symptoms from the research criteria for the diagnosis of traumatic encephalopathy syndrome were applied to men and women in the general population and in sub-groups of people with health problems and mental health problems. A small percentage of the US general population met symptom criteria for traumatic encephalopathy syndrome (6.6–11.9%, depending on the definition applied). People with chronic pain were much more likely to meet criteria (i.e. 14.8–30.5%), and two out of three people who have experienced suicidality in the past year met symptom criteria for traumatic encephalopathy syndrome (65.2–72.2%). The majority of women with a mood disorder and chronic pain met criteria (62.7–89.8%). This is the largest study, to date, examining the aspects of the research criteria for the diagnosis of traumatic encephalopathy syndrome in the general population, and the first study to examine these criteria in women. This study has important clinical and public health implications. The potential rate for misdiagnosing traumatic encephalopathy syndrome in adults who are experiencing chronic pain, idiopathic mental health problems or both is high.

Preliminary Validation of the Triana Test: A New Story Recall Test Based on Emotional Material

OBJECTIVE

To first validate the diagnostic accuracy of the "Triana Test," a new story recall test based on emotional material.

METHOD

A phase I study of validation. We included 55 patients with amnestic Mild Cognitive Impairment and 69 healthy controls, diagnosed according to the "Memory Associative Test of the district of Seine-Saint-Denis" (TMA-93), and matched by age, gender, and educational level. The Triana Test's diagnostic accuracy was calculated by ROC curve analysis and Spearman correlations estimated its convergent validity with a hippocampal memory test, the Free and Cued Selective Reminding Test with Immediate Recall (FCSRT+IR).

RESULTS

The "Triana Test" immediate and delayed recalls showed adequate diagnostic accuracy (AUC ≥ 0,74). The delayed free recall showed the highest diagnostic accuracy (AUC = 0.86). Correlations with the FCSRT+IR were moderate to strong.

CONCLUSIONS

The "Triana Test" demonstrated accuracy for discriminating amnestic Mild Cognitive Impairment patients from healthy controls and convergent validity with the FCSRT+IR.

Episodic Memory and Verbal Fluency Tasks: Normative Data from Nine Nationally Representative Samples

OBJECTIVE

This study aims to generate country-specific norms for two episodic memory tasks and a verbal fluency test among middle-aged and older adults using nationally representative data from nine low-, middle-, and high-income countries.

METHOD

Data from nine countries in Africa, Asia, Europe, and Latin America were analyzed (n = 42,116; aged 50 years or older). Episodic memory was assessed with the word list memory (three trials of immediate recall) and word list recall (delayed recall). Verbal fluency was measured through the animal naming task. Multiple linear regression models with country-specific adjustments for gender, age, education, and residential area were carried out.

RESULTS

Both age and education showed high influence on test performance (i.e. lower cognitive performance with increasing age and decreasing years of education, respectively), while the effect of sex and residential area on cognitive function was neither homogeneous across countries nor across cognitive tasks.

CONCLUSIONS

Our study provided sex-, age-, education-, and residential area-specific regression-based norms that were obtained from one of the largest normative study worldwide on verbal recall and fluency tests to date. Findings derived from this study will be especially useful for clinicians and researchers based at countries where cognitive norms are limited.

REDD1 Is Involved in Amyloid β-Induced Synaptic Dysfunction and Memory Impairment

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by neurological dysfunction, including memory impairment, attributed to the accumulation of amyloid β (Aβ) in the brain. Although several studies reported possible mechanisms involved in Aβ pathology, much remains unknown. Previous findings suggested that a protein regulated in development and DNA damage response 1 (REDD1), a stress-coping regulator, is an Aβ-responsive gene involved in Aβ cytotoxicity. However, we still do not know how Aβ increases the level of REDD1 and whether REDD1 mediates Aβ-induced synaptic dysfunction. To elucidate this, we examined the effect of Aβ on REDD1-expression using acute hippocampal slices from mice, and the effect of REDD1 short hairpin RNA (shRNA) on Aβ-induced synaptic dysfunction. Lastly, we observed the effect of REDD1 shRNA on memory deficit in an AD-like mouse model. Through the experiments, we found that Aβ-incubated acute hippocampal slices showed increased REDD1 levels. Moreover, Aβ injection into the lateral ventricle increased REDD1 levels in the hippocampus. Anisomycin, but not actinomycin D, blocked Aβ-induced increase in REDD1 levels in the acute hippocampal slices, suggesting that Aβ may increase REDD1 translation rather than transcription. Aβ activated Fyn/ERK/S6 cascade, and inhibitors for Fyn/ERK/S6 or mGluR5 blocked Aβ-induced REDD1 upregulation. REDD1 inducer, a transcriptional activator, and Aβ blocked synaptic plasticity in the acute hippocampal slices. REDD1 inducer inhibited mTOR/Akt signaling. REDD1 shRNA blocked Aβ-induced synaptic deficits. REDD1 shRNA also blocked Aβ-induced memory deficits in passive-avoidance and object-recognition tests. Collectively, these results demonstrate that REDD1 participates in Aβ pathology and could be a target for AD therapy.

Predementia constructs: Mild cognitive impairment or mild neurocognitive disorder? A narrative review

BACKGROUND

Predementia is a heuristic umbrella concept to classify older adults with cognitive impairment who do not suffer dementia. Many diagnostic entities have been proposed to address this concept, but most of them have not had widespread acceptance.

AIMS

To review clinical definitions, epidemiologic data (prevalence, incidence) and rate of conversion to dementia of the main predementia constructs, with special interest in the two most frequently used: mild cognitive impairment (MCI) and minor neurocognitive disorder (miNCD).

METHODS

We have selected in three databases (MEDLINE, Web of Science and Google scholar) the references from inception to 31 December 2019 of relevant reviews, population and community-based surveys, and clinical series with >500 participants and >3 years follow-up as the best source of evidence.

MAIN RESULTS

The history of predementia constructs shows that MCI is the most referred entity. It is widely recognized as a clinical syndrome harbinger of dementia of several etiologies, mainly MCI due to Alzheimer's disease. The operational definition of MCI has shortcomings: vagueness of its requirement of "preserved independence in functional abilities" and others. The recent miNCD construct presents analogous difficulties. Current data indicate that it is a stricter predementia condition, with lower prevalence than MCI, less sensitivity to cognitive decline and, possibly, higher conversion rate to dementia.

CONCLUSIONS

MCI is a widely employed research and clinical entity. Preliminary data indicate that the clinical use of miNCD instead of MCI requires more scientific evidence. Both approaches have common limitations that need to be addressed.

Association of glial and neuronal degeneration markers with Alzheimer's disease cerebrospinal fluid profile and cognitive functions

BACKGROUND

Neuroinflammation has gained increasing attention as a potential contributing factor in the onset and progression of Alzheimer's disease (AD). The objective of this study was to examine the association of selected cerebrospinal fluid (CSF) inflammatory and neuronal degeneration markers with signature CSF AD profile and cognitive functions among subjects at the symptomatic pre- and early dementia stages.

METHODS

In this cross-sectional study, 52 subjects were selected from an Icelandic memory clinic cohort. Subjects were classified as having AD (n = 28, age = 70, 39% female, Mini-Mental State Examination [MMSE] = 27) or non-AD (n = 24, age = 67, 33% female, MMSE = 28) profile based on the ratio between CSF total-tau (T-tau) and amyloid-β_1-42 (Aβ₄₂) values (cut-off point chosen as 0.52). Novel CSF biomarkers included neurofilament light (NFL), YKL-40, S100 calcium-binding protein B (S100B) and glial fibrillary acidic protein (GFAP), measured with enzyme-linked immunosorbent assays (ELISAs). Subjects underwent neuropsychological assessment for evaluation of different cognitive domains, including verbal episodic memory, non-verbal episodic memory, language, processing speed, and executive functions.

RESULTS

Accuracy coefficient for distinguishing between the two CSF profiles was calculated for each CSF marker and test. Novel CSF markers performed poorly (area under curve [AUC] coefficients ranging from 0.61 to 0.64) compared to tests reflecting verbal episodic memory, which all performed fair (AUC > 70). LASSO regression with a stability approach was applied for the selection of CSF markers and demographic variables predicting performance on each cognitive domain, both among all subjects and only those with a CSF AD profile. Relationships between CSF markers and cognitive domains, where the CSF marker reached stability selection criteria of > 75%, were visualized with scatter plots. Before calculations of corresponding Pearson's correlations coefficients, composite scores for cognitive domains were adjusted for age and education. GFAP correlated with executive functions (r = - 0.37, p = 0.01) overall, while GFAP correlated with processing speed (r = - 0.68, p < 0.001) and NFL with verbal episodic memory (r = - 0.43, p = 0.02) among subjects with a CSF AD profile.

CONCLUSIONS

The novel CSF markers NFL and GFAP show potential as markers for cognitive decline among individuals with core AD pathology at the symptomatic pre- and early stages of dementia.

Validation of the Brief Assessment of Impaired Cognition and the Brief Assessment of Impaired Cognition Questionnaire for identification of mild cognitive impairment in a memory clinic setting

OBJECTIVES

The aim of this study was to validate the Brief Assessment of Impaired Cognition (BASIC) and the Brief Assessment of Impaired Cognition Questionnaire (BASIC-Q) for identification of mild cognitive impairment (MCI) in a memory clinic setting.

METHODS

A total of 163 sociodemographically matched patients (MCI, n = 42, and dementia, n = 121) and 83 control participants were included in the study. Two instruments were validated: (a) BASIC, including the components self-report, informant report, and two brief cognitive tests, and (b) BASIC-Q, including the components self-report, informant report, and orientation. BASIC can be administered in 5 minutes and BASIC-Q in less than 5 minutes.

RESULTS

A high discriminative validity for MCI vs control participants was found for both BASIC (sensitivity 0.86, specificity 0.89) and BASIC-Q (sensitivity 0.88, specificity 0.88). In comparison, the MMSE had low sensitivity (0.61) and moderate specificity (0.72). All components of BASIC and BASIC-Q contributed significantly to differentiate MCI from control participants. The components of BASIC and BASIC-Q also contributed significantly to differentiate MCI from dementia, except for self-report, which was identical in the two groups.

CONCLUSIONS

Both BASIC and BASIC-Q are brief, valid, and effective instruments for identification of patients with possible MCI in a memory clinic setting. Further cross-validation of the instruments in a general practice or primary care setting is needed.

Autonomic function in amnestic and non-amnestic mild cognitive impairment: spectral heart rate variability analysis provides evidence for a brain-heart axis

Mild cognitive impairment (MCI) is a heterogeneous syndrome with two main clinical subtypes, amnestic (aMCI) and non-amnestic (naMCI). The analysis of heart rate variability (HRV) is a tool to assess autonomic function. Cognitive and autonomic processes are linked via the central autonomic network. Autonomic dysfunction entails several adverse outcomes. However, very few studies have investigated autonomic function in MCI and none have considered MCI subtypes or the relationship of HRV indices with different cognitive domains and structural brain damage. We assessed autonomic function during an active orthostatic challenge in 253 oupatients aged ≥ 65, [n = 82 aMCI, n = 93 naMCI, n = 78 cognitively normal (CN), neuropsychologically tested] with power spectral analysis of HRV. We used visual rating scales to grade cerebrovascular burden and hippocampal/insular atrophy (HA/IA) on neuroimaging. Only aMCI showed a blunted response to orthostasis. Postural changes in normalised low frequency (LF) power and in the LF to high frequency ratio correlated with a memory test (positively) and HA/IA (negatively) in aMCI, and with attention/executive function tests (negatively) and cerebrovascular burden (positively) in naMCI. These results substantiate the view that the ANS is differentially impaired in aMCI and naMCI, consistently with the neuroanatomic substrate of Alzheimer's and small-vessel subcortical ischaemic disease.

Composite cognitive and functional measures for early stage Alzheimer's disease trials

INTRODUCTION

Composite scales have been advanced as primary outcomes in early stage Alzheimer's disease trials, and endorsed by the U.S. Food and Drug Administration (FDA) for pivotal trials. They are generally composed of several neurocognitive subscales and may include clinical and functional activity scales.

METHODS

We summarized the development of 12 composite scales intended as outcomes for clinical trials and assessed their characteristics.

RESULTS

Composite scales have been constructed from past observational and clinical trial databases by selecting components of individual neuropsychological tests previously used in clinical trials. The atheoretical approaches to combining scales into a composite scale that have often been used risk omitting clinically important measures and so may include redundant, irrelevant, or noncontributory tests. The deliberate combining of neurocognitive scales with functional activity scales provides arbitrary weightings that also may be clinically irrelevant or obscure change in a particular domain. Basic psychometric information is lacking for most of the composites.

DISCUSSION

Although composite scales are desirable for pivotal clinical trials because they, in principle, provide for a single, primary outcome combining neurocognitive and/or functional domains, they have substantial limitations, including their common derivations, inattention to basic psychometric principles, redundancy, absence of alternate forms, and, arguably, the inclusion of functional measures in some. In effect, any currently used composite is undergoing validation through its use in a trial. The assumption that a composite, by its construction alone, is more likely than an individual measure to detect an effect from any particular drug and that the effect is more clinically relevant or valid has not been demonstrated.

Cognitive and neuropsychological examination of the elderly

Neuropsychological assessment plays a prominent role in the evaluation and care of patients with neurodegenerative diseases throughout the dynamic course of disease. As a biomarker of disease, neuropsychological measurement can distinguish normal from pathologic aging processes. Further, neuropsychological data can help distinguish and classify underlying pathologies in dementing diseases, augmenting imaging and biofluid markers in this area. Neuropsychological data can predict increased or reduced risk for dementia conferred by multiple factors, and describe disease trajectory in affected individuals. Cognitive evaluation can also estimate and address functional outcomes that are most important to patients and their loved ones and that are clinically relevant to diagnostic staging. In informing intervention and patient care needs, areas of cognitive weakness highlight targets for support/intervention, while areas of cognitive strength can be capitalized upon to modify the clinical course of disease. These functions can be accomplished through the complementary use of brief screening tools and comprehensive test batteries. However, for neuropsychological data to serve these functions, it is critical to understand neuropsychological test properties and nondisease factors that can account for variance in test performance. This chapter concludes with directions for future research.

Enhanced diagnostic accuracy for neurocognitive disorders: a revised cut-off approach for the Montreal Cognitive Assessment

Background

The Montreal Cognitive Assessment (MoCA) has good sensitivity for mild cognitive impairment, but specificity is low when the original cut-off (25/26) is used. We aim to revise the cut-off on the German MoCA for its use in clinical routine.

Methods

Data were analyzed from 496 Memory Clinic outpatients (447 individuals with a neurocognitive disorder; 49 with cognitive normal findings) and from 283 normal controls. Cut-offs were identified based on (a) Youden’s index and (b) the 10th percentile of the control group.

Results

A cut-off of 23/24 on the MoCA had better correct classification rates than the MMSE and the original MoCA cut-off. Compared to the original MoCA cut-off, the cut-off of 23/24 points had higher specificity (92% vs 63%), but lower sensitivity (65% vs 86%). Introducing two separate cut-offs increased diagnostic accuracies with 92% specificity (23/24 points) and 91% sensitivity (26/27 points). Scores between these two cut-offs require further examinations.

Conclusions

Using two separate cut-offs for the MoCA combined with scores in an indecisive area enhances the accuracy of cognitive screening.

Convolution neural network-based Alzheimer's disease classification using hybrid enhanced independent component analysis based segmented gray matter of T2 weighted magnetic resonance imaging with clinical valuation

In recent times, accurate and early diagnosis of Alzheimer's disease (AD) plays a vital role in patient care and further treatment. Predicting AD from mild cognitive impairment (MCI) and cognitive normal (CN) has become popular. Neuroimaging and computer-aided diagnosis techniques are used for classification of AD by physicians in the early stage. Most of the previous machine learning techniques work on handpicked features. In the recent days, deep learning has been applied for many medical image applications. Existing deep learning systems work on raw magnetic resonance imaging (MRI) images and cortical surface as an input to the convolution neural network (CNN) to perform classification of AD. AD affects the brain volume and changes the gray matter texture. In our work, we used 1820 T2-weighted brain magnetic resonance volumes including 635 AD MRIs, 548 MCI MRIs, and 637 CN MRIs, sliced into 18,017 voxels. We proposed an approach to extract the gray matter from brain voxels and perform the classification using the CNN. A Gaussian filter is used to enhance the voxels, and skull stripping algorithm is used to remove the irrelevant tissues from enhanced voxels. Then, those voxels are segmented by hybrid enhanced independent component analysis. Segmented gray matter is used as an input to the CNN. We performed clinical valuation using our proposed approach and achieved 90.47% accuracy, 86.66% of recall, and 92.59% precision.

Accuracy of verbal fluency tests in the discrimination of mild cognitive impairment and probable Alzheimer's disease in older Spanish monolingual individuals

The main objetive was to analyze the accuracy of different verbal fluency tests (VFTs) in discriminating cognitively healthy subjects from individuals with mild cognitive impairment (MCI) and probable Alzheimer's disease (AD) in a cohort of older Spanish speaking adults. As a result, we aimed to identify the VFT that best predicts conversion from MCI to probable AD. 287 subjects: 170 controls (HC), 90 stable MCI and 27 patients with MCI that evolved into probable AD (MCI-AD) were assessed with a neuropsychological battery test and five VFTs. The animal fluency test produced the best differentiation of HC from MCI (p < .001), of HC from MCI-AD (p < .001) and of MCI from MCI-AD converters (p < .001), with sensitivities 98.8%, 98.8% and 75.6%, respectively. Logistic regression showed that the animal fluency test (p < 0.001) appears to be the most useful and neuropsychological VFT to predict conversion to probable dementia.

Quantifying memory deficits in amnestic mild cognitive impairment

INTRODUCTION

In the present study, we use the item-specific deficit approach (ISDA), a method for characterizing memory deficits in list-learning, to portray the memory deficits in amnestic mild cognitive impairment (aMCI).

METHODS

We applied the ISDA to compare memory performance of patients with aMCI and healthy controls in encoding, consolidation, and retrieval using the Free and Cued Selective Reminding Test.

RESULTS

The results revealed clear differences in recall performance between patients with aMCI and controls. When analyzing the ISDA deficit indices, the results revealed a prominent encoding deficit, followed by a consolidating deficit. A greater sensitivity for the encoding index confirmed that a difficulty with encoding information plays a major role in explaining the episodic memory deficits experienced by patients with aMCI.

DISCUSSION

The present study applying the ISDA reveals great sensitivity and specificity of the encoding deficit index when identifying aMCI. As aMCI constitutes a risk factor to develop Alzheimer's disease, the current findings also confirm the need to concentrate on encoding deficits as an early diagnostic sign of cognitive decline.

A Guide to Conducting a Meta-Analysis with Non-Independent Effect Sizes

Conventional meta-analytic procedures assume that effect sizes are independent. When effect sizes are not independent, conclusions based on these conventional procedures can be misleading or even wrong. Traditional approaches, such as averaging the effect sizes and selecting one effect size per study, are usually used to avoid the dependence of the effect sizes. These ad-hoc approaches, however, may lead to missed opportunities to utilize all available data to address the relevant research questions. Both multivariate meta-analysis and three-level meta-analysis have been proposed to handle non-independent effect sizes. This paper gives a brief introduction to these new techniques for applied researchers. The first objective is to highlight the benefits of using these methods to address non-independent effect sizes. The second objective is to illustrate how to apply these techniques with real data in R and Mplus. Researchers may modify the sample R and Mplus code to fit their data.

Inter-method and anatomical correlates of episodic memory tests in the Alzheimer's Disease spectrum

Background

Episodic memory impairments have been described as initial clinical findings in the Alzheimer’s Disease (AD) spectrum, which could be associated with the presence of early hippocampal dysfunction. However, correlates between performances in neuropsychological tests and hippocampal volumes in AD were inconclusive in the literature. Divergent methods to assess episodic memory have been depicted as a major source of heterogeneity across studies.

Methods

We examined correlates among performances in three different delayed-recall tasks (Rey-Auditory Verbal-Learning Test–RAVLT, Logical Memory and Visual Reproduction subtests from the Wechsler Memory Scale) and fully-automated volumetric measurements of the hippocampus (estimated using Neuroquant^®) of 83 older subjects (47 controls, 27 Mild Cognitive Impairment individuals and 9 participants with Dementia due to AD).

Results

Inter-method correlations of episodic memory performances were at most moderate. Scores in the RAVLT predicted up to 48% of variance in HOC (Hippocampal Occupancy Score) among subjects in the AD spectrum.

Discussion

Tests using different stimuli (verbal or visual) and presenting distinct designs (word list, story or figure learning) may assess divergent aspects in episodic memory, with heterogeneous anatomical correlates.

Conclusions

Different episodic memory tests might not assess the same construct and should not be used interchangeably. Scores in RAVLT may correlate with the presence of neurodegeneration in AD.

Anticholinergic/sedative drug burden predicts worse memory acquisition in older racially/ethnically diverse patients with type 2 diabetes mellitus

OBJECTIVE

Anticholinergic/sedative drug use, measured by the Drug Burden Index (DBI), is linked to cognitive impairment in older adults. Yet, studies on the DBI's association with neuropsychological functioning are lacking, especially in underserved groups at increased risk of cognitive impairment. We examined cross-sectional relationships between total DBI (DBI_T ) and an age-adjusted analogue (Adj DBI_T ) with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in diverse adults with type 2 diabetes mellitus (T2DM). Based on results of a prior study, we anticipated higher DBIs would be associated with worse memory at older ages.

METHODS

One hundred five adults with T2DM (age = 57 ± 9 years, 65% female, 62% Black, 27% Hispanic/Latino, Hb_A1c = 7.8 ± 1.8) participated. Although memory outcomes were normally distributed, DBI_T values were positively skewed. Spearman correlations assessed their bivariate relationships with RBANS. Adjusting for comorbidities, polypharmacy, Hb_A1c , and education, we tested the moderating effect of age on DBI-RBANS associations at mean ±1 standard deviations of age.

RESULTS

One third of the participants endorsed current sedative/anticholinergic use. Mean DBI_T was 0.385, and mean Adj DBI_T was 0.393 (ranges = 0.00-4.22). Drug burden negatively correlated with RBANS Immediate Memory (DBI_T r_s = -0.237, P = .013; Adj DBI_T r_s = -0.239, P = .014) but no other indices. There was a significant DBI*Age interaction; the negative effect of drug burden on Immediate Memory was significant for ages greater than or equal to 55 years old.

CONCLUSIONS

Sedative/anticholinergic drug exposure was prevalent in these diverse T2DM patients. Adjusting for covariates, greater drug burden was associated with worse memory acquisition among older adults only. Prospective studies should examine these relationships over time and assess whether dementia biomarkers affect the interaction.

Visual Object Discrimination Impairment as an Early Predictor of Mild Cognitive Impairment and Alzheimer's Disease

OBJECTIVE

Detection of cognitive impairment suggestive of risk for Alzheimer's disease (AD) progression is crucial to the prevention of incipient dementia. This study was performed to determine if performance on a novel object discrimination task improved identification of earlier deficits in older adults at risk for AD.

METHOD

In total, 135 participants from the 1Florida Alzheimer's Disease Research Center [cognitively normal (CN), Pre-mild cognitive impairment (PreMCI), amnestic mild cognitive impairment (aMCI), and dementia] completed a test of object discrimination and traditional memory measures in the context of a larger neuropsychological and clinical evaluation.

RESULTS

The Object Recognition and Discrimination Task (ORDT) revealed significant differences between the PreMCI, aMCI, and dementia groups versus CN individuals. Moreover, relative risk of being classified as PreMCI rather than CN increased as an inverse function of ORDT score.

DISCUSSION

Overall, the obtained results suggest that a novel object discrimination task improves the detection of very early AD-related cognitive impairment, increasing the window for therapeutic intervention. (JINS, 2019, 25, 688-698).

Visual memory tests enhance the identification of amnestic MCI cases at greater risk of Alzheimer's disease

OBJECTIVES

To investigate whether amnestic mild cognitive impairment (aMCI) identified with visual memory tests conveys an increased risk of Alzheimer's disease (risk-AD) and if the risk-AD differs from that associated with aMCI based on verbal memory tests.

PARTICIPANTS

4,771 participants aged 70.76 (SD = 6.74, 45.4% females) from five community-based studies, each a member of the international COSMIC consortium and from a different country, were classified as having normal cognition (NC) or one of visual, verbal, or combined (visual and verbal) aMCI using international criteria and followed for an average of 2.48 years. Hazard ratios (HR) and individual patient data (IPD) meta-analysis analyzed the risk-AD with age, sex, education, single/multiple domain aMCI, and Mini-Mental State Examination (MMSE) scores as covariates.

RESULTS

All aMCI groups (n = 760) had a greater risk-AD than NC (n = 4,011; HR range = 3.66 - 9.25). The risk-AD was not different between visual (n = 208, 17 converters) and verbal aMCI (n = 449, 29 converters, HR = 1.70, 95%CI: 0.88, 3.27, p = 0.111). Combined aMCI (n = 103, 12 converters, HR = 2.34, 95%CI: 1.13, 4.84, p = 0.023) had a higher risk-AD than verbal aMCI. Age and MMSE scores were related to the risk-AD. The IPD meta-analyses replicated these results, though with slightly lower HR estimates (HR range = 3.68, 7.43) for aMCI vs. NC.

CONCLUSIONS

Although verbal aMCI was most common, a significant proportion of participants had visual-only or combined visual and verbal aMCI. Compared with verbal aMCI, the risk-AD was the same for visual aMCI and higher for combined aMCI. Our results highlight the importance of including both verbal and visual memory tests in neuropsychological assessments to more reliably identify aMCI.

Studying the Manifold Structure of Alzheimer's Disease: A Deep Learning Approach Using Convolutional Autoencoders

Many classical machine learning techniques have been used to explore Alzheimer's disease (AD), evolving from image decomposition techniques such as principal component analysis toward higher complexity, non-linear decomposition algorithms. With the arrival of the deep learning paradigm, it has become possible to extract high-level abstract features directly from MRI images that internally describe the distribution of data in low-dimensional manifolds. In this work, we try a new exploratory data analysis of AD based on deep convolutional autoencoders. We aim at finding links between cognitive symptoms and the underlying neurodegeneration process by fusing the information of neuropsychological test outcomes, diagnoses, and other clinical data with the imaging features extracted solely via a data-driven decomposition of MRI. The distribution of the extracted features in different combinations is then analyzed and visualized using regression and classification analysis, and the influence of each coordinate of the autoencoder manifold over the brain is estimated. The imaging-derived markers could then predict clinical variables with correlations above 0.6 in the case of neuropsychological evaluation variables such as the MMSE or the ADAS11 scores, achieving a classification accuracy over 80% for the diagnosis of AD.

Cognitive Performance among Cognitively Healthy Adults Aged 30-100 Years

Background/Aims

To detect cognitive decline in older adults, measures of verbal fluency and verbal memory are widely used. Less is known about performance in these measures in younger persons or according to education level and gender. We investigated cognitive performance according to age, education and gender among cognitively healthy adults aged 30–100 years.

Methods

The study population comprised 4,174 cognitively healthy persons participating in the nationally representative Finnish Health 2011 survey. Cognitive assessment included verbal fluency, word list memory, word list recall and word list savings from the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery.

Results

Total variance in the cognitive test performance explained by age, education and gender varied from 12.3 to 31.2%. A decreasing trend in cognitive performance existed in all subtests by advancing age, with differences appearing between 50 and 55 years. Persons with the highest-education level performed best for all measures. For the participants < 55 years, education explained part of the variance, while age and gender did not.

Conclusions

When assessing cognition, age and education should be accounted for in more detail in research and clinical practice. Additionally, the cohort effect and its potential impact on the renewal cycle of future normative values for cognitive tests should be considered.

Multiple oral ulcers caused by incorrect use of oral bisphosphonate in a patient with dementia: A case report

It is not widely known that incorrect use of oral bisphosphonates (BPs), such as chewing the medication, can cause oral ulcers. An 83-year-old woman with dementia was referred to our clinic with multiple oral ulcers. Blood and histopathological examinations were inconclusive. Further questioning revealed that the patient chewed the oral BP, resulting in oral ulceration. Patients with loss of cognitive function, such as dementia, are at risk of oral ulcers caused by incorrect use of BPs.

Neuropsychological case report of MCI reversion at one-year follow-up

This report presents the neuropsychological profile of an older gentleman diagnosed with single-domain mild cognitive impairment (MCI) at baseline who reverted to normal cognitive functioning at 1-year follow-up. The case highlights important considerations for assessing and diagnosing MCI in clinical settings in the context of sizeable reversion rates that have been reported extensively in the literature. A 72-year-old gentleman presented to our Neuropsychology Clinic with subjective memory complaints. Per recommendation, the patient returned for follow-up testing 1-year later. A clinical interview, comprehensive battery of neuropsychological tests, and mood questionnaires were administered during both evaluations. At baseline, DSM-5 Mild Neurocognitive Disorder consistent with single-domain amnestic MCI was diagnosed based on several impaired scores on the California Verbal Learning Test, 2nd version (CVLT-II) and collateral report of subtle decline in functioning. At follow-up, all cognitive performances fell within normal limits. The patient no longer met criteria for Mild Neurocognitive Disorder. The present case study highlights important considerations when assessing and diagnosing MCI in the clinical setting. Repeat testing in clinical settings is underscored by the sizeable rate of MCI reversion reported in the literature. Important diagnostic and feedback considerations are discussed.

The Face-Name Associative Memory Test as a Tool for Early Diagnosis of Alzheimer's Disease

One current challenge for neuropsychologists is to design assessment methods capable of detecting cognitive deficits in the early or preclinical phases of Alzheimer's disease (AD). The objective of this paper is to review the studies that have explored the use of the Face-Name Associative Memory Exam (FNAME) as a test for early diagnosis of AD. Studies looking at correlations between performance on the FNAME test and biomarkers in healthy people and studies comparing healthy controls and people with mild cognitive impairment are reviewed. These studies are based on the evidence that AD's pathological process begins years before the most visible clinical manifestations. We conclude that the FNAME test may be a valuable tool for early diagnosis but that some important questions remain to be resolved in future research.

Alterations to task positive and task negative networks during executive functioning in Mild Cognitive Impairment

Poor executive functioning increases risk of decline in Mild Cognitive Impairment (MCI). Executive functioning can be conceptualized within the framework of working memory. While some components are responsible for maintaining representations in working memory, the central executive is involved in the manipulation of information and creation of new representations. We aimed to examine the neural correlates of these components of working memory using a maintenance working memory and visuospatial reasoning task. Twenty-five patients with amnestic MCI and 19 elderly controls (EC) completed functional MRI during reasoning and maintenance working memory tasks. In MCI, maintenance working memory was associated with hypoactivation of right frontoparietal regions and hyperactivation of left prefrontal cortex, coupled with attenuation of default mode network (DMN) relative to EC. During reasoning, MCI showed hypoactivation of parietal regions, coupled with attenuation of anterior DMN and increased deactivation of posterior DMN relative to EC. Comparing the reasoning task to the maintenance working memory task yields the central executive. In MCI, the central executive showed hypoactivation of right parietal lobe and increased deactivation of posterior DMN compared to EC. Consistent with prior work on executive functioning, MCI show different neural circuitry during visuospatial reasoning, including changes to both task positive frontoparietal regions, as well as to deactivation patterns within the DMN. Both hyperactivation of task positive networks and increased deactivation of DMN may be compensatory.

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MCI show changes to task positive & negative networks during executive functioning.

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MCI show hypoactivation of parietal cortex & attenuation of medial PFC deactivation.

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Hypoactivation occurs in regions vulnerable to AD pathology.

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MCI show hyperactivation of left PFC & more deactivation of posterior DMN.

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These activity increases correlate with stronger cognition and may be compensatory.

External validation of change formulae in neuropsychology with neuroimaging biomarkers: A methodological recommendation and preliminary clinical data

OBJECTIVE

Within neuropsychology, a number of mathematical formulae (e.g. reliable change index, standardized regression based) have been used to determine if change across time has reliably occurred. When these formulae have been compared, they often produce different results, but 'different' results do not necessarily indicate which formulae are 'best.' The current study sought to further our understanding of change formulae by comparing them to clinically relevant external criteria (amyloid deposition and hippocampal volume).

METHOD

In a sample of 25 older adults with varying levels of cognitive intactness, participants were tested twice across one week with a brief cognitive battery. Seven different change scores were calculated for each participant. An amyloid PET scan (to get a composite of amyloid deposition) and an MRI (to get hippocampal volume) were also obtained.

RESULTS

Deviation-based change formulae (e.g. simple discrepancy score, reliable change index with or without correction for practice effects) were all identical in their relationship to the two neuroimaging biomarkers, and all were non-significant. Conversely, regression-based change formulae (e.g. simple and complex indices) showed stronger relationships to amyloid deposition and hippocampal volume.

CONCLUSIONS

These results highlight the need for external validation of the various change formulae used by neuropsychologists in clinical settings and research projects. The findings also preliminarily suggest that regression-based change formulae may be more relevant than deviation-based change formulae in this context.