Verbal fluency as a screening tool for mild cognitive impairment

Risk factor of disability as new certification of long-term care needs in older Japanese adults with diabetes mellitus: A longitudinal study

AIM

This observational longitudinal study aimed to explore the risk factors for disabilities in older Japanese individuals with diabetes at a frailty clinic, an outpatient clinic specializing in comprehensive geriatric assessments for older patients.

METHODS

The outcome was the onset of disability as a new certification of long-term care needs in outpatients aged ≥65 years. Multivariable Cox regression analyses examined the independent associations between the onset of disability and the variables that reached significance in the bivariate analysis, after adjusting for age and sex, years of education, and certification of need for support.

RESULTS

A total of 182 participants (mean age 77.8 years, 59.9% female) were included in the study. During a mean follow-up period of 1070 days, 28 patients (15.4%) developed disabilities. Multivariable analysis showed that poor glycemic control (higher levels of glycosylated albumin and HbA1c), frailty as measured by the Clinical Frailty Scale (CFS), cognitive decline as assessed by the revised Hasegawa Dementia Scale (especially "5 object recall" and verbal fluency as assessed by the number of "vegetable names"), poor adherence to medications, and reduced muscle mass were significantly associated with the development of disability. Multivariable Cox regression analyses revealed independent and significant associations between the development of disability and HbA1c ≥7.5%, CFS ≥4, and generating vegetable names≤9.

CONCLUSION

In identifying older patients with diabetes who are at risk of developing disabilities, it may be useful to evaluate glycemic control, CFS, cognition, and medication adherence. Verbal fluency tests using vegetable names may serve as simple tools for assessing the risk of disability. Geriatr Gerontol Int 2024; 24: 1030-1038.

Semantic and phonemic verbal fluency tests: Normative data for the Turkish population

Semantic and phonemic verbal fluency tests are widely used neuropsychological assessments of executive functions and language skills and are easy to administer. The aim of this study was to determine the impact of age, education, and gender on semantic and phonemic verbal fluency tests and to establish normative data for Turkish adults aged between 18 and 86 years. The results revealed significant main effects of age and education on all subscores of verbal fluency tests. Furthermore, an interaction effect between age and education was observed on semantic fluency and letter K fluency scores. While no significant differences were found among the 18-29, 30-39, and 40-49 age groups in any of the subscores, performance on the tests decreased with increasing age. Significant differences were observed among all education groups in all subscores. No main or interaction effects of gender were found on any subscore. These normative data could prove useful in clinical and research settings for the assessment of cognitive impairment.

Evaluating factors influencing community readiness for post-mining environmental development strategies

This research delves into the complex factors that affect how ready a community is to embrace new environmental development strategies, which could significantly change the region's social and economic fabric. Using a structured questionnaire, exploratory factor analysis and logistic regression analysis, the study assesses how corporate practices in resource management, environmental governance, efforts to enhance community capabilities, and various demographic factors influence the community's willingness to adapt to change. Despite its intentions to benefit both the mining operations and the community, corporate resource management appears to have a paradoxical impact on the community's willingness to pursue new environmental paths. This negative impact can be attributed to the dependency it creates. Effective corporate resource management can lead to a community becoming heavily reliant on the stability and benefits provided by the mining company. This dependency fosters a sense of security and satisfaction with the status quo, making community members less inclined to explore or support new and potentially disruptive environmental strategies. The stability provided by the mine's resource management practices may inadvertently anchor the community to existing economic structures, reducing their impetus to seek alternative livelihoods or adapt to new socioeconomic conditions. However, it is essential to consider the limitations of this finding. One limitation is the potential bias in community perceptions, where immediate benefits from corporate resource management overshadow long-term considerations for sustainable development. Additionally, the context-specific nature of this study means that these findings may not be universally applicable to all mining communities.

A glimpse into the future: revealing the key factors for survival in cognitively impaired patients

Background

Drawing on prospective data from the National Health and Nutrition Examination Survey (NHANES), our goal was to construct and validate a 5-year survival prediction model for individuals with cognitive impairment (CI).

Methods

This study entailed a prospective cohort design utilizing information from the 2011-2014 NHANES dataset, encompassing individuals aged 40 years or older, with updated mortality status as of December 31, 2019. Predictive models within the derivation and validation cohorts were assessed using logistic proportional risk regression, column-line plots, and least absolute shrinkage and selection operator (LASSO) binomial regression models.

Results

The study enrolled a total of 1,439 participants (677 men, mean age 69.75 ± 6.71 years), with the derivation and validation cohorts consisting of 1,007 (538 men) and 432 (239 men) individuals, respectively. The 5-year mortality rate stood at 16.12% (n = 232). We devised a 5-item column-line graphical model incorporating age, race, stroke, cardiovascular disease (CVD), and blood urea nitrogen (BUN). The model exhibited an area under the curve (AUC) of 0.772 with satisfactory calibration. Internal validation demonstrated that the column-line graph model displayed strong discrimination, yielding an AUC of 0.733, and exhibited good calibration.

Conclusion

To sum up, our study successfully developed and internally validated a 5-item nomogram integrating age, race, stroke, cardiovascular disease, and blood urea nitrogen. This nomogram exhibited robust predictive performance for 5-year mortality in individuals with CI, offering a valuable tool for prognostic evaluation and personalized care planning.

Anxiety symptoms without depression are associated with cognitive control network (CNN) dysfunction: An fNIRS study

Anxiety is a common psychological disorder associated with other mental disorders, with depression being the most common comorbidity. Few studies have examined the neural mechanisms underlying anxiety after controlling for depression. This study aimed to explore whether there are differences in cortical activation in anxiety patients with different severities whose depression are normal. In the current study, depression levels were normal for 366 subjects-139 healthy subjects, 117 with mild anxiety, and 110 with major anxiety. Using the Hospital Anxiety and Depression Scale (HADS) and a verbal fluency task (VFT) to test subjects' anxiety and depression and cognitive function, respectively. A 53-channel guided near-infrared spectroscopic imaging technology (fNIRS) detected the concentration of oxyhemoglobin (oxy-Hb). Correlation analysis between anxiety severity and oxy-Hb concentration in the brain cortex was performed, as well as ANOVA analysis of oxy-Hb concentration among the three anxiety severity groups. The results showed that anxiety severity was significantly and negatively correlated with oxy-Hb concentrations in the left frontal eye field (lFEF) and in the right dorsolateral prefrontal area (rDLPFC). The oxy-Hb concentration in the lFEF and the rDLPFC were significantly lower in the major anxiety disorder group than that in the control group. This suggests that decreased cortical activity of the lFEF and rDLPFC may be neural markers of anxiety symptoms after controlling for depression. Anxiety symptoms without depression may be result from the dysfunction of the cognitive control network (CCN) which includes the lFEF and rDLPFC.

An examination of the clinical utility of phonemic fluency in healthy adults and adults with mild cognitive impairment

The Controlled Oral Word Association Test (COWAT) is a widely utilized measure of phonemic fluency. However, two issues remain: (1) whether demographic, cognitive variables, or version of test administered predict performance; (2) if the test is predictive of Mild Cognitive Impairment (MCI). Recent studies report that item-level analyses such as lexical frequency may be more sensitive to early cognitive change. The purpose of this study was to examine the clinical utility of the COWAT, considering both total correct words and the lexical frequency. Sixty-seven healthy adults and thirty-seven adults with MCI completed neuropsychological testing. Mann-Whitney U tests were used to determine if there was a difference in COWAT performance between groups. Elastic net regression models were used to assess whether variance in total scores/lexical frequencies can be predicted by demographics, test version, or diagnosis; which cognitive tests explained the variance in performance; and how total scores and lexical frequencies compared with other cognitive tests in predicting diagnosis. Overall, individuals with MCI produced fewer and higher frequency words. The variance in total correct words or lexical frequency was not explained by demographics, test version, or diagnosis. Total correct words was a more important predictor of diagnosis than lexical frequency.

Aging and Olfactory Training: A Scoping Review

Background and Objectives

Decreased olfactory function commonly occurs alongside the aging process. Research suggests olfactory training (OT) has the potential to improve olfactory and cognitive function in individuals with and without olfactory dysfunction. The degree to which these benefits extend into older age and among those with cognitive impairment (i.e., people with dementia and mild cognitive impairment) is less clear. The purpose of the current review was to investigate the extent to which OT affects olfactory function, cognition, and well-being among older people.

Research Design and Methods

A scoping review of the literature was conducted in PubMed, Embase, EbscoHost, and SCOPUS. Articles were considered eligible for original research studies with human populations, included adults aged 55 and older, performed any type of OT, and included a form of olfactory testing. The data from the included studies were synthesized and presented narratively.

Results

A total of 23 studies were included. The results suggest that OT provides multiple benefits to older adults, including those with cognitive impairment. Particularly, OT was associated with measurable changes in olfactory function, improved cognitive function, specifically semantic verbal fluency and working memory, reduced depressive symptoms, and protection from cognitive decline.

Discussion and Implications

The findings suggest that benefits from OT extend beyond changes in olfactory function and include improved cognitive function, amelioration of depressive symptoms, and protection from cognitive decline. Future research is needed across specific participant groups, including those with differentiated types of dementia, to investigate the olfactory and cognitive benefits of OT.

Clinical validity of the Italian adaptation of the Uniform Data Set Neuropsychological Test Battery (I-UDSNB) in Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND

The identification and staging of Alzheimer's Disease (AD) represent a challenge, especially in the prodromal stage of Mild Cognitive Impairment (MCI), when cognitive changes can be subtle. Worldwide efforts were dedicated to select and harmonize available neuropsychological instruments. In Italy, the Italian Network of Neuroscience and Neuro-Rehabilitation has promoted the adaptation of the Uniform Data Set Neuropsychological Test Battery (I-UDSNB), collecting normative data from 433 healthy controls (HC). Here, we aimed to explore the ability of I-UDSNB to differentiate between a) MCI and HC, b) AD and HC, c) MCI and AD.

METHODS

One hundred thirty-seven patients (65 MCI, 72 AD) diagnosed after clinical-neuropsychological assessment, and 137 HC were included. We compared the I-UDSNB scores between a) MCI and HC, b) AD and HC, c) MCI and AD, with t-tests. To identify the test(s) most capable of differentiating between groups, significant scores were entered in binary logistic and in stepwise regressions, and then in Receiver Operating Characteristic curve analyses.

RESULTS

Two episodic memory tests (Craft Story and Five Words test) differentiated MCI from HC subjects; Five Words test, Semantic Fluency (vegetables), and TMT-part B differentiated AD from, respectively, HC and MCI.

CONCLUSIONS

Our findings indicate that the I-UDSNB is a suitable tool for the harmonized and concise assessment of patients with cognitive decline, showing high sensitivity and specificity for the diagnosis of MCI and AD.

Psychometric Evaluation of a Tablet-Based Tool to Detect Mild Cognitive Impairment in Older Adults: Mixed Methods Study

BACKGROUND

With the rapid aging of the global population, the prevalence of mild cognitive impairment (MCI) and dementia is anticipated to surge worldwide. MCI serves as an intermediary stage between normal aging and dementia, necessitating more sensitive and effective screening tools for early identification and intervention. The BrainFx SCREEN is a novel digital tool designed to assess cognitive impairment. This study evaluated its efficacy as a screening tool for MCI in primary care settings, particularly in the context of an aging population and the growing integration of digital health solutions.

OBJECTIVE

The primary objective was to assess the validity, reliability, and applicability of the BrainFx SCREEN (hereafter, the SCREEN) for MCI screening in a primary care context. We conducted an exploratory study comparing the SCREEN with an established screening tool, the Quick Mild Cognitive Impairment (Qmci) screen.

METHODS

A concurrent mixed methods, prospective study using a quasi-experimental design was conducted with 147 participants from 5 primary care Family Health Teams (FHTs; characterized by multidisciplinary practice and capitated funding) across southwestern Ontario, Canada. Participants included health care practitioners, patients, and FHT administrative executives. Individuals aged ≥55 years with no history of MCI or diagnosis of dementia rostered in a participating FHT were eligible to participate. Participants were screened using both the SCREEN and Qmci. The study also incorporated the Geriatric Anxiety Scale-10 to assess general anxiety levels at each cognitive screening. The SCREEN's scoring was compared against that of the Qmci and the clinical judgment of health care professionals. Statistical analyses included sensitivity, specificity, internal consistency, and test-retest reliability assessments.

RESULTS

The study found that the SCREEN's longer administration time and complex scoring algorithm, which is proprietary and unavailable for independent analysis, presented challenges. Its internal consistency, indicated by a Cronbach α of 0.63, was below the acceptable threshold. The test-retest reliability also showed limitations, with moderate intraclass correlation coefficient (0.54) and inadequate κ (0.15) values. Sensitivity and specificity were consistent (63.25% and 74.07%, respectively) between cross-tabulation and discrepant analysis. In addition, the study faced limitations due to its demographic skew (96/147, 65.3% female, well-educated participants), the absence of a comprehensive gold standard for MCI diagnosis, and financial constraints limiting the inclusion of confirmatory neuropsychological testing.

CONCLUSIONS

The SCREEN, in its current form, does not meet the necessary criteria for an optimal MCI screening tool in primary care settings, primarily due to its longer administration time and lower reliability. As the number of digital health technologies increases and evolves, further testing and refinement of tools such as the SCREEN are essential to ensure their efficacy and reliability in real-world clinical settings. This study advocates for continued research in this rapidly advancing field to better serve the aging population.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/25520.

Validity, feasibility, and effectiveness of a voice-recognition based digital cognitive screener for dementia and mild cognitive impairment in community-dwelling older Chinese adults: A large-scale implementation study

INTRODUCTION

We investigated the validity, feasibility, and effectiveness of a voice recognition-based digital cognitive screener (DCS), for detecting dementia and mild cognitive impairment (MCI) in a large-scale community of elderly participants.

METHODS

Eligible participants completed demographic, cognitive, functional assessments and the DCS. Neuropsychological tests were used to assess domain-specific and global cognition, while the diagnosis of MCI and dementia relied on the Clinical Dementia Rating Scale.

RESULTS

Among the 11,186 participants, the DCS showed high completion rates (97.5%) and a short administration time (5.9 min) across gender, age, and education groups. The DCS demonstrated areas under the receiver operating characteristics curve (AUCs) of 0.95 and 0.83 for dementia and MCI detection, respectively, among 328 participants in the validation phase. Furthermore, the DCS resulted in time savings of 16.2% to 36.0% compared to the Mini-Mental State Examination (MMSE) and Montral Cognitive Assessment (MoCA).

DISCUSSION

This study suggests that the DCS is an effective and efficient tool for dementia and MCI case-finding in large-scale cognitive screening.

HIGHLIGHTS

To our best knowledge, this is the first cognitive screening tool based on voice recognition and utilizing conversational AI that has been assessed in a large population of Chinese community-dwelling elderly. With the upgrading of a new multimodal understanding model, the DCS can accurately assess participants' responses, including different Chinese dialects, and provide automatic scores. The DCS not only exhibited good discriminant ability in detecting dementia and MCI cases, it also demonstrated a high completion rate and efficient administration regardless of gender, age, and education differences. The DCS is economically efficient, scalable, and had a better screening efficacy compared to the MMSE or MoCA, for wider implementation.

Verbal fluency patterns associated with the amnestic conversion from mild cognitive impairment to dementia

Patients with amnestic mild cognitive impairment (aMCI) are at a higher risk of converting to Alzheimer's disease. The aim of this study was to examine the potential use of Verbal Fluency (VF) measures as markers for predicting the conversion to dementia. At baseline, 61 aMCI, aged 65 to 80 years, underwent a comprehensive neuropsychological assessment, including phonemic (PVF) and semantic verbal fluency (SVF) tasks. After 18 months, 14 individuals with aMCI had progressed to a diagnosis of dementia. The findings revealed that aMCI-converter group had lower Mini Mental State Examination and Rey Auditory Verbal Learning Task scores than aMCI-no converter and produced fewer clusters in both VF tasks and a lower number of switches in PVF at baseline (p < 0.05). According to receiver operating characteristic curve analysis, the number of clusters in PVF had the highest predictive value (AUC = 0.80) with a threshold of 5.510 for identifying aMCI-converter at baseline. Additionally, participants with higher levels of education exhibited more clusters and switches in VF tasks (p < 0.05). These results suggest that qualitative measures of VF could serve as neuropsychological markers for predicting cognitive decline in individuals with aMCI. Furthermore, the study highlights the potential influence of the education level on cognitive performance in neuropsychological tasks.

Intelligent digital tools for screening of brain connectivity and dementia risk estimation in people affected by mild cognitive impairment: the AI-Mind clinical study protocol

More than 10 million Europeans show signs of mild cognitive impairment (MCI), a transitional stage between normal brain aging and dementia stage memory disorder. The path MCI takes can be divergent; while some maintain stability or even revert to cognitive norms, alarmingly, up to half of the cases progress to dementia within 5 years. Current diagnostic practice lacks the necessary screening tools to identify those at risk of progression. The European patient experience often involves a long journey from the initial signs of MCI to the eventual diagnosis of dementia. The trajectory is far from ideal. Here, we introduce the AI-Mind project, a pioneering initiative with an innovative approach to early risk assessment through the implementation of advanced artificial intelligence (AI) on multimodal data. The cutting-edge AI-based tools developed in the project aim not only to accelerate the diagnostic process but also to deliver highly accurate predictions regarding an individual's risk of developing dementia when prevention and intervention may still be possible. AI-Mind is a European Research and Innovation Action (RIA H2020-SC1-BHC-06-2020, No. 964220) financed between 2021 and 2026. First, the AI-Mind Connector identifies dysfunctional brain networks based on high-density magneto- and electroencephalography (M/EEG) recordings. Second, the AI-Mind Predictor predicts dementia risk using data from the Connector, enriched with computerized cognitive tests, genetic and protein biomarkers, as well as sociodemographic and clinical variables. AI-Mind is integrated within a network of major European initiatives, including The Virtual Brain, The Virtual Epileptic Patient, and EBRAINS AISBL service for sensitive data, HealthDataCloud, where big patient data are generated for advancing digital and virtual twin technology development. AI-Mind's innovation lies not only in its early prediction of dementia risk, but it also enables a virtual laboratory scenario for hypothesis-driven personalized intervention research. This article introduces the background of the AI-Mind project and its clinical study protocol, setting the stage for future scientific contributions.

Micronutrients, Frailty, and Cognitive Impairment: Design and Preliminary Results from the CogLife 2.0 Study

Background

Among preventive strategies against dementia, nutrition is considered a powerful one and the recently established "nutritional cognitive neuroscience of aging" is a highly active research field.

Objective

The present study was designed to deeply characterize older adults across the continuum from cognitive integrity to mild cognitive impairment (MCI) and better elucidate the prognostic role of lipophilic micronutrients within their lipidomic signature.

Methods

123 participants older than 65 years across the continuum from cognitive integrity to MCI were included [49 with subjective cognitive impairment, 29 women, 72.5±5.4 years, 26 MCI, 9 women, 74.5±5.8 years and 50 without cognitive impairment, 21 women, 70.8±4.3 years]. All participants underwent neuropsychological and nutritional examination as well as comprehensive geriatric assessment with calculation of the Multidimensional Prognostic Index (MPI) as a proxy of frailty and biological age and blood withdrawal for the analyses of lipophilic micronutrients, metabolomics and oxylipidomics. One year after the evaluation, same tests are ongoing.

Results

After adjustment for age, sex, daily fruit and vegetable intake and cholesterol, we found a significant positive correlation between lutein and the number of correct words in category fluency (p = 0.016).

Conclusions

This result supports the importance of carotenoids as robust biomarkers of cognitive performance independent of the nutritional status and frailty of the participants, as the entire present study collective was robust (MPI 0-0.33). The complete analyses of the metabolome and the oxylipidome will hopefully shed light on the metabolic and prognostic signature of cognitive decline in the rapidly growing population at risk of frailty.

Exploring Verbal Fluency Strategies among Individuals with Normal Cognition, Amnestic and Non-Amnestic Mild Cognitive Impairment, and Alzheimer's Disease

Background and Objectives: The present study explored the utilization of verbal fluency (VF) cognitive strategies, including clustering, switching, intrusions, and perseverations, within both semantic (SVF) and phonemic (PVF) conditions, across a continuum of neurocognitive decline, spanning from normal cognitive ageing (NC) to mild cognitive impairment (MCI) and its subtypes, amnestic (aMCI) and non-amnestic (naMCI), as well as AD. Materials and Methods: The study sample was derived from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD) cohort. The sample included 1607 NC individuals, 146 with aMCI (46 single-domain and 100 multi-domain), 92 with naMCI (41 single-domain and 51 multi-domain), and 79 with AD. Statistical analyses, adjusting for sex, age, and education, employed multivariate general linear models to probe differences among these groups. Results: Results showed that AD patients exhibited poorer performance in switching in both VF tasks and SVF clustering compared to NC. Similarly, the aMCI group performed worse than the NC in switching and clustering in both tasks, with aMCI performing similarly to AD, except for SVF switching. In contrast, the naMCI subgroup performed similarly to those with NC across most strategies, surpassing AD patients. Notably, the aMCI subgroup's poor performance in SVF switching was mainly due to the subpar performance of the multi-domain aMCI subgroup. This subgroup was outperformed in switching in both VF tasks by the single-domain naMCI, who also performed better than the multi-domain naMCI in SVF switching. No significant differences emerged in terms of perseverations and intrusions. Conclusions: Overall, these findings suggest a continuum of declining switching ability in the SVF task, with NC surpassing both aMCI and AD, and aMCI outperforming those with AD. The challenges in SVF switching suggest executive function impairment associated with multi-domain MCI, particularly driven by the multi-domain aMCI.

Handgrip strength, physical activity and incident mild cognitive impairment and dementia

OBJECTIVE

We analyzed the mediating role of handgrip strength in the association between moderate to vigorous physical activity and incident mild cognitive impairment and dementia.

METHODS

We used prospective data from 14 European countries participating in the Survey of Health, Ageing, and Retirement in Europe. 19,686 participants free of dementia and mild cognitive impairment (64.9 ± 8.7 years) were followed up for a mean of 10.2 years. Moderate to vigorous physical activity was self-reported, and handgrip strength was assessed with a dynamometer. Mild cognitive impairment was defined as 1.5 standard deviations below the mean of the standardized global cognition score, while dementia was determined by physician diagnosis. Gender, age, country, education, presence of chronic diseases, depressive symptoms, limitations in activities of daily living, body mass index, and baseline cognitive levels were used as covariates. Cox proportional hazards as well as mediation models were used.

RESULTS

Moderate to vigorous physical activity for at least 1 day per week was independently associated with lower incident mild cognitive impairment (HR: 0.85; 95%CI: 0.74-0.98). A 10 % increase in handgrip strength was associated a 6 % lower hazard for incident mild cognitive impairment (0.94; 0.92-0.97) and 5 % lower hazard for incident dementia (0.95; 0.93-0.98). Handgrip strength partly mediated the association of moderate to vigorous physical activity with mild cognitive impairment (Coefficient: 0.03; 95%CI: 0.01-0.05; 17.9 %).

CONCLUSIONS

Physical activity is independently associated with a lower incidence of mild cognitive impairment.

Normative Data for Single-Letter Controlled Oral Word Association Test in Older White Australians and Americans, African-Americans, and Hispanic/Latinos

Background

The Controlled Oral Word Association Test (COWAT) is a commonly used measure of verbal fluency. While a normal decline in verbal fluency occurs in late adulthood, significant impairments may indicate brain injury or diseases such as Alzheimer's disease. Normative data is essential to identify when test performance falls below expected levels based on age, gender, and education level.

Objective

This study aimed to establish normative performance data on single-letter COWAT for older community-dwelling adults.

Methods

Over 19,000 healthy men and women, without a diagnosis of dementia or a Modified Mini-Mental State Examination score below 77/100, were recruited for the ASPREE trial. Neuropsychological assessments, including the COWAT with letter F, were administered at study entry.

Results

Median participant age was 75 years (range 65-98), with 56.5% being women. The majority of participants had 9-11 years of education in Australia and over 12 years in the U.S. The COWAT performance varied across ethno-racial groups and normative data were thus presented separately for 16,335 white Australians, 1,084 white Americans, 896 African-Americans, and 316 Hispanic/Latinos. Women generally outperformed men in the COWAT, except for Hispanic/Latinos. Higher education levels consistently correlated with better COWAT performance across all groups, while the negative association with age was weaker.

Conclusions

This study provides comprehensive normative data for the COWAT stratified by ethno-racial groups in Australia and the U.S., considering age, gender, and education level. These norms can serve as reference standards for screening cognitive impairments in older adults in both clinical and research settings.

Cognitive Performance in Asymptomatic Elderly People with Hepatitis C: The Role of Education

BACKGROUND

Neurotropism of the hepatitis C virus (HCV) can be the source of subtle neuropsychological symptoms in non-cirrhotic patients. Age is a risk factor for cognitive impairment (CI). Thus, asymptomatic elderly people who carry HCV might be at a greater risk of CI. Education can influence test performance.

OBJECTIVES

(1) To verify whether elderly people with HCV performed poorer than controls on cognitive tests. (2) To analyze how education affects performance. (3) To verify whether the extent of the effect of education on performance depends on the group (HCV vs. controls) and the type of cognitive test.

METHODS

Asymptomatic HCV carriers older than 60 years (n = 41) were matched with 41 corresponding controls. All participants performed the following tests: Mini-Cog, Mini Mental State Examination, clock drawing test (CDT), and verbal fluency.

RESULTS

(1) There were no significant differences in cognitive performance between the two groups. (2) Higher education was always associated with better performance. (3) There was a significant group difference in the slopes of the regression lines between years of education and CDT performance. No differences were found for the other three tests.

CONCLUSION

Considering the scores on the CDT, the rate of improvement in performance when schooling increases is higher in HCV carriers.

Meta-analysis of Controlled Oral Word Association Test (COWAT) FAS performance in amnestic mild cognitive impairment and cognitively unimpaired older adults

Findings from several studies have shown that amnestic mild cognitive impairment (aMCI) older adults have significantly lower performance on phonemic fluency tasks relative to cognitively unimpaired (CU) older adults. These findings suggest that nonmemory domains, such as executive function, are impacted in aMCI. As Alzheimer's disease (AD) research has shifted toward identifying and characterizing preclinical AD, there is a need to identify subtle but significant cognitive changes that are below the threshold for clinical impairment. The aim of this meta-analysis was to examine phonemic fluency differences between aMCI and CU older adults. Data from 18 studies were included in this analysis that found that aMCI individuals' phonemic fluency performance was approximately seven points lower than CU individuals (Δ = -7.31, 95% CI [-9.10, -5.52], z = -8.01, p < 0.001), which represents a medium effect size of (g = 0.61, 95% CI [0.46, 0.76], z = 7.90, p < 0.001). Normative conversion of the aMCI groups' raw scores showed that all were in the normal range of performance. The findings of this meta-analysis demonstrate that significant subclinical deficits in phonemic fluency can be present in aMCI. This should prompt greater use of phonemic fluency tasks in outcome measures for observational and intervention studies.

Meta-Analysis of Animal Fluency Performance in Amnestic Mild Cognitive Impairment and Cognitively Unimpaired Older Adults

Animal fluency is a commonly used neuropsychological measure that is used in the diagnosis of amnestic mild cognitive impairment (aMCI) and Alzheimer disease. Although most individuals with aMCI have clinically normal scores on this test, several studies have shown that aMCI individuals' performance is significantly lower than that of cognitively unimpaired (CU) individuals. The aim of this meta-analysis was to characterize the effect size of animal fluency performance differences between aMCI and CU individuals. Literature search with search terms used were: "animal fluency and mild cognitive impairment," "semantic fluency and mild cognitive impairment," "category fluency and mild cognitive impairment." Both the standardized mean difference and the raw mean difference were derived from random effects analyses. Demographically adjusted z-scores for animal fluency performance for the aMCI groups were obtained to determine normative performance. Nineteen studies were included in the analysis. The standardized mean difference for animal fluency performance between CU and aMCI was 0.89 (95% confidence interval: [0.73; 1.04], P <0.001), I2 =70.3% [52.7%; 81.4%], which reflects a large effect size with moderate heterogeneity. The raw mean difference was -4.08 [-4.75; -3.38], P <0.001. The mean animal fluency z-score for aMCI groups was in the Low Average range (z=-0.77). This study found a substantial difference in animal fluency performance between aMCI and CU individuals. The aMCI groups' normative performance did not fall into the impaired range, indicating that there are important subclinical differences in animal fluency performance that may inform the design of cognitive end points for Alzheimer's disease prevention trials.

Language Differences Among Individuals with Normal Cognition, Amnestic and Non-Amnestic MCI, and Alzheimer's Disease

OBJECTIVE

To investigate differences in language performance among older adults with normal cognition (CN), mild cognitive impairment (MCI), and Alzheimer's disease (ad). Owing to the conflicting literature concerning MCI, discrepancies between amnestic (aMCI) and non-amnestic MCI (naMCI) were explored in greater detail.

METHOD

The study sample was drawn from the older (>64 years) HELIAD cohort. Language performance was assessed via semantic and phonemic fluency, confrontation naming, verbal comprehension, verbal repetition as well as a composite language index. Age, sex, and education adjusted general linear models were used to quantify potential pairwise differences in language performance.

RESULTS

The present analysis involved 1607 participants with CN, 146 with aMCI [46 single and 100 multi-domain aMCI], 92 with naMCI [41 single and 51 multi-domain naMCI], and 79 with ad. The mean age and education of our predominantly female (60%) participants were 73.82 (±5.43) and 7.98 (±4.93) years, respectively. MCI individuals performed between those with CN and ad, whereas participants with aMCI performed worse compared to those with naMCI, especially in the semantic fluency and verbal comprehension tasks. Discrepancies between the aMCI and naMCI groups were driven by the exquisitely poor performance of multi-domain aMCI subgroup.

CONCLUSIONS

Overall, individuals could be hierarchically arranged in a continuum of language impairment with the CN individuals constituting the healthy reference and naMCI, aMCI, ad patients representing gradually declining classes in terms of language performance. Exploration of language performance via separation of single from multi-domain naMCI provided a potential explanation for the conflicting evidence of previous research.

Language dysfunction correlates with cognitive impairments in older adults without dementia mediated by amyloid pathology

Background

Previous studies have explored the application of non-invasive biomarkers of language dysfunction for the early detection of Alzheimer's disease (AD). However, language dysfunction over time may be quite heterogeneous within different diagnostic groups.

Method

Patient demographics and clinical data were retrieved from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database for the participants without dementia who had measures of cerebrospinal fluid (CSF) biomarkers and language dysfunction. We analyzed the effect of longitudinal neuropathological and clinical correlates in the pathological process of semantic fluency and confrontation naming. The mediation effects of AD biomarkers were also explored by the mediation analysis.

Result

There were 272 subjects without dementia included in this analysis. Higher rates of decline in semantic fluency and confrontation naming were associated with a higher risk of progression to MCI or AD, and a greater decline in cognitive abilities. Moreover, the rate of change in semantic fluency was significantly associated with Aβ deposition, while confrontation naming was significantly associated with both amyloidosis and tau burden. Mediation analyses revealed that both confrontation naming and semantic fluency were partially mediated by the Aβ aggregation.

Conclusion

In conclusion, the changes in language dysfunction may partly stem from the Aβ deposition, while confrontation naming can also partly originate from the increase in tau burden. Therefore, this study sheds light on how language dysfunction is partly constitutive of mild cognitive impairment and dementia and therefore is an important clinical predictor.

Lower semantic fluency scores and a phonemic-over-semantic advantage predict abnormal CSF P-tau181 levels in Aβ + patients within the Alzheimer's disease clinical spectrum

BACKGROUND

The present study aimed to determine whether patients with mild cognitive impairment (MCI) and dementia due to Alzheimer's disease (AD), semantic verbal fluency (SVF), and the semantic-phonemic discrepancy (SPD) could predict abnormal cerebrospinal fluid (CSF) phosphorylated tau (P-tau₁₈₁) and total tau (T-tau) levels.

METHODS

Phonemic verbal fluency (PVF) and SVF scores of N = 116 Aβ-positive patients with either MCI due to AD (N = 39) or probable AD dementia (ADD; N = 77) were retrospectively collected. The SPD was computed by subtracting PVF scores from SVF ones (positive and negative values corresponding to a semantic and phonemic advantage, respectively). Patients were cognitively phenotyped via a thorough test battery and profiled according to the amyloidosis/tauopathy/neurodegeneration (ATN) framework via CSF analyses. Two separate sets of logistic regressions were run to predict normal vs. abnormal P-tau₁₈₁ and T-tau levels by encompassing as predictors SVF + PVF and SPD and covarying for demographic, disease-related features, and cognitive profile.

RESULTS

Lower SVF, but not PVF, scores, as well as a greater phonemic advantage (i.e., negative SPD values), predicted abnormal CSF P-tau₁₈₁ levels (p ≤ .01). Moreover, lower SVF scores were selectively predictive of abnormal CSF T-tau levels too (p = .016), while the SPD was not.

DISCUSSION

SVF and the SPD are able to predict tauopathy across the AD spectrum, thus supporting their status of valid, and sufficiently specific, cognitive markers of AD.

The Role of Silence in Verbal Fluency Tasks - A New Approach for the Detection of Mild Cognitive Impairment

OBJECTIVE

Most recordings of verbal fluency tasks include substantial amounts of task-irrelevant content that could provide clinically valuable information for the detection of mild cognitive impairment (MCI). We developed a method for the analysis of verbal fluency, focusing not on the task-relevant words but on the silent segments, the hesitations, and the irrelevant utterances found in the voice recordings.

METHODS

Phonemic ('k', 't', 'a') and semantic (animals, food items, actions) verbal fluency data were collected from healthy control (HC; n = 25; M_age = 67.32) and MCI (n = 25; M_age = 71.72) participants. After manual annotation of the voice samples, 10 temporal parameters were computed based on the silent and the task-irrelevant segments. Traditional fluency measures, based on word count (correct words, errors, repetitions) were also employed in order to compare the outcome of the two methods.

RESULTS

Two silence-based parameters (the number of silent pauses and the average length of silent pauses) and the average word transition time differed significantly between the two groups in the case of all three semantic fluency tasks. Subsequent receiver operating characteristic (ROC) analysis showed that these three temporal parameters had classification abilities similar to the traditional measure of counting correct words.

CONCLUSION

In our approach for verbal fluency analysis, silence-related parameters displayed classification ability similar to the most widely used traditional fluency measure. Based on these results, an automated tool using voiced-unvoiced segmentation may be developed enabling swift and cost-effective verbal fluency-based MCI screening.

Is there a link between heart rate variability and cognitive decline? A cross-sectional study on patients with mild cognitive impairment and cognitively healthy controls

BACKGROUND

Given that, up to date, there is no effective strategy to treat dementia, a timely start of interventions in a prodromal stage such as mild cognitive impairment (MCI) is considered an important option to lower the overall societal burden. Although autonomic functions have been related to cognitive performance, both aspects have rarely been studied simultaneously in MCI.

OBJECTIVE

The aim of the present study was to investigate cardiac autonomic control in older adults with and without MCI.

METHODS

Cardiac autonomic control was assessed by means of heart rate variability (HRV) at resting state and during cognitive tasks in 22 older adults with MCI and 29 healthy controls (HCs). Resting HRV measurement was performed for 5 minutes during a sitting position. Afterwards, participants performed three PC-based tasks to probe performance in executive functions and language abilities (i.e., Stroop, N-back, and a verbal fluency task).

RESULTS

Participants with MCI showed a significant reduction of HRV in the frequency-domain (high frequency power) and nonlinear indices (SD2, D2, and DFA1) during resting state compared to HCs. Older individuals with MCI exhibited decreases in RMSSD and increases in DFA1 from resting state to Stroop and N-back tasks, reflecting strong vagal withdrawal, while this parameter remained stable in HCs.

CONCLUSION

The results support the presence of autonomic dysfunction at the early stage of cognitive impairment. Heart rate variability could help in the prediction of cognitive decline as a noninvasive biomarker or as a tool to monitor the effectiveness of therapy and prevention of neurodegenerative diseases.

Sözel Akıcılık Testleri, Alzheimer Hastalığı klinik ölçütlerine göre evrelenmiş demans ve HKB ayrımında yarar sağlayabilir

Demans tarama ve tanısı için klinik pratikte sıklıkla kısa tarama testleri kullanılmaktadır. Mini Mental Durum Testi (MMDT) en sık kullanılan testlerin başında gelmektedir. MMDT’nin demans için duyarlı olduğu bilinmektedir. Ancak, sağlıklı yaşlanma ile demans arasında bir geçiş evresi olarak kabul edilen Hafif Kognitif Bozukluk (HKB)’un ayırt edilmesinde ve Alzheimer Hastalığı tipi demans (AHD) ile HKB’nin ayırıcı tanısında MMDT çoğu zaman yeterli olmamaktadır. Kısa sürede uygulanabilen sözel akıcılık testleri (semantik ve fonemik) MMDT’ye alternatif ya da MMDT ile kullanıldığında HKB ve AH’nin erken evreleri için tanısal doğruluğu daha yüksek bir tarama testi elde edilebilir. Bu çalışmanın amacı MMDT, semantik ve fonemik akıcılık testlerinin ROC eğrisi analizleri ile belirlenen duyarlılık, özgüllük ve kesme puanı değerlerinin sunulmasıdır. Çalışmaya yaş-eğitim-cinsiyet açısından uyumlu 72 sağlıklı birey, 72 HKB ve 72 AHD’li birey dahil edilmiştir. Çalışmanın bulguları MMDT’nin sağlıklı bireyleri ayırt etmede semantik ve fonemik akıcılıktan daha güçlü olduğunu, ancak HKB ve AH ayrımında özgüllüğünün semantik akıcılıktan düşük olduğunu göstermektedir. Tanı doğruluğunun artırılması için kısa zamanda uygulanabilen sözel akıcılık testlerinin, özellikle semantik akıcılık testinin klinik pratiğe eklenmesi yararlı olabilir.

Elevated serum uric acid is associated with cognitive improvement in older American adults: A large, population-based-analysis of the NHANES database

Background

The many studies revealing a connection between serum uric acid (SUA) and dementia have reported conflicting results. This study sought to investigate the relations between SUA and cognitive function in older adults.

Materials and methods

The sample was 2,767 American adults aged ≥60 years from the National Health and Nutrition Examination Survey 2011-2014. Cognitive performance was evaluated by the Consortium to Establish a Registry for Alzheimer's Disease test, animal fluency test, digit symbol substitution test, and composite z-score. Multivariate linear regression analyses were conducted to estimate the association between SUA and cognitive function.

Results

SUA level and cognitive function were significantly, positively correlated. Age significantly correlated with the association between SUA and cognitive function.

Conclusion

These findings support a connection between SUA and cognition, showing a positive link between SUA and cognitive scores among older American adults. We contend that a slight rise in uric acid within the normal range is advantageous for enhanced cognition. To confirm the precise dose-time-response relation, more tests will be needed.

Subjective cognitive decline in Brazil: Prevalence and association with dementia modifiable risk factors in a population-based study

Introduction

Subjective cognitive decline (SCD) may be an early symptom of Alzheimer's disease. We aimed to estimate the prevalence of SCD in Brazil and its association with dementia modifiable risk factors.

Methods

We used data of 8138 participants from the Brazilian Longitudinal Study of Aging (ELSI-Brazil), a population-based study that included clinical and demographic variables of individuals across the country. We calculated the prevalence of SCD and its association with dementia modifiable risk factors.

Results

We found that the prevalence of SCD in Brazil was 29.21% (28.22%-30.21%), varying according to region, sex, and age. SCD was strongly associated with hearing loss, low education, psychological distress, Brown/Pardo and Black races.

Discussion

The prevalence of SCD in Brazil is higher than in high-income countries. Brown/Black races and dementia modifiable risk factors were associated with SCD. Public strategies that target SCD may help mitigate the incidence of dementia.

Neuropsychological impairment in post-COVID condition individuals with and without cognitive complaints

One of the most prevalent symptoms of post-COVID condition is cognitive impairment, which results in a significant degree of disability and low quality of life. In studies with large sample sizes, attention, memory, and executive function were reported as long-term cognitive symptoms. This study aims to describe cognitive dysfunction in large post-COVID condition individuals, compare objective neuropsychological performance in those post-COVID condition individuals with and without cognitive complaints, and identify short cognitive exams that can differentiate individuals with post-COVID symptoms from controls. To address these aims, the Nautilus project was started in June 2021. During the first year, we collected 428 participants' data, including 319 post-COVID and 109 healthy controls (18-65 years old) from those who underwent a comprehensive neuropsychological battery for cognitive assessment. Scores on tests assessing global cognition, learning and long-term memory, processing speed, language and executive functions were significantly worse in the post-COVID condition group than in healthy controls. Montreal Cognitive Assessment, digit symbol test, and phonetic verbal fluency were significant in the binomial logistic regression model and could effectively distinguish patients from controls with good overall sensitivity and accuracy. Neuropsychological test results did not differ between those with and without cognitive complaints. Our research suggests that patients with post-COVID conditions experience significant cognitive impairment and that routine tests like the Montreal Cognitive Assessment, digit symbol, and phonetic verbal fluency test might identify cognitive impairment. Thus, the administration of these tests would be helpful for all patients with post-COVID-19 symptoms, regardless of whether cognitive complaints are present or absent.

STUDY REGISTRATION

www.ClinicalTrials.gov, identifiers NCT05307549 and NCT05307575.

Applying ACE-III, M-ACE and MMSE to Diagnostic Screening Assessment of Cognitive Functions within the Polish Population

The research aims to compare the accuracy of the mini-mental state examination (MMSE), the Addenbrooke's cognitive examination III (ACE-III) and the mini-Addenbrooke's cognitive examination (M-ACE) within the Polish population. The model comprised several stages: the features of each test were compared; the shifts in result categorisations between the norm and below the norm were analysed; a third category-mild cognitive impairment (MCI)-was included. Additionally, particular ACE-III domains that scored below domain-specific norm thresholds were analysed to establish the potential early predictors of dementia. All tests correlated to a high and very high degree-cf. MMSE and ACE-III (r = 0.817; p < 0.001), MMSE and M-ACE (r = 0.753; p < 0.001), ACE-III and M-ACE (r = 0.942; p < 0.001). The area under the ROC curve for the ACE-III diagnostic variable had a high value (AUC = 0.920 ± 0.014). A cut-off point of 81 points was suggested for ACE-III; the M-ACE diagnostic variable had an equally high value (AUC = 0.891 ± 0.017). A cut-off point of 20 points was suggested. A significant decrease in the mean score values for people who scored norm or below the norm under ACE-III, as compared to the MMSE results for norm (p < 0.0001), occurred for speech fluency (which decreased by 26.4%). The tests in question are characterised by high sensitivity and specificity. Targeted ACE-III seems best recommended for use in specialised diagnostic centres, whereas M-ACE appears to be a better suited diagnostic alternative for primary health care centres in comparison to MMSE.

Reduced white matter venous density on MRI is associated with neurodegeneration and cognitive impairment in the elderly

High-resolution susceptibility weighted imaging (SWI) provides unique contrast to small venous vasculature. The conspicuity of these mesoscopic veins, such as deep medullary veins in white matter, is subject to change from SWI venography when venous oxygenation in these veins is altered due to oxygenated blood susceptibility changes. The changes of visualization in small veins shows potential to depict regional changes of oxygen utilization and/or vascular density changes in the aging brain. The goal of this study was to use WM venous density to quantify small vein visibility in WM and investigate its relationship with neurodegenerative features, white matter hyperintensities (WMHs), and cognitive/functional status in elderly subjects (N = 137). WM venous density was significantly associated with neurodegeneration characterized by brain atrophy (β = 0.046± 0.01, p < 0.001), but no significant association was found between WM venous density and WMHs lesion load (p = 0.3963). Further analysis of clinical features revealed a negative trend of WM venous density with the sum-of-boxes of Clinical Dementia Rating and a significant association with category fluency (1-min animal naming). These results suggest that WM venous density on SWI can be used as a sensitive marker to characterize cerebral oxygen metabolism and different stages of cognitive and functional status in neurodegenerative diseases.

Training professional caregivers to screen for report of cognitive changes in persons with intellectual disability

Introduction

By age 60, 60% of adults with Down syndrome (DS) have dementia. Detecting dementia in persons with intellectual disability (ID) can be challenging because their underlying cognitive impairment can confound presentation of dementia symptoms and because adults with ID may have difficulty reporting symptoms. The National Task Group Early Detection Screen for Dementia (NTG-EDSD) was developed to aid detection of report of cognitive impairment in adults with ID. We implemented an educational curriculum using the NTG-EDSD and evaluated the impact of the intervention on professional caregivers' self-assessed capacity to identify persons with ID and dementia.

Methods

We held five in-person training sessions for professional caregivers of persons with ID, partnering with various managed care organizations and social services agencies. We assessed knowledge and attitudes at baseline; immediately after training; and 1 week, 1 month, and 6 months after training.

Results

A total of 154 direct care workers, case managers, health-care providers, and other social services staff attended the trainings. Satisfaction with the NTG-EDSD training was high; 94% of attendees agreed or strongly agreed that they could use the NTG-EDSD with their clients. After training, attendees reported a marked increase in confidence in their ability to track various health circumstances and detect functional decline in their clients, although some gains were not sustained over time. As a result of the training, one managed care organization made the NTG-EDSD a standard part of its assessment of adults with DS starting at age 40.

Discussion

Social services and health-care professionals can learn to document signs of cognitive decline in adults with ID using the NTG-EDSD. Attendees were highly satisfied with the training, experienced an increase in confidence in their care of persons with ID, and found the NTG- EDSD feasible to use. Because not all gains were sustained over time, booster trainings may be necessary.

A Validation Study of the Hong Kong Brief Cognitive Test for Screening Patients with Mild Cognitive Impairment and Alzheimer’s Disease

Background: The Hong Kong Brief Cognitive Test (HKBC), a brief instrument designed to screen for cognitive impairment in older adults, has been validated in Cantonese-speaking populations and has shown better performance than the Mini-Mental State Examination (MMSE) in detecting both mild and major neurocognitive disorder (NCD). Objective: This study aimed to validate the HKBC for detecting patients with amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD) in a Mandarin-speaking Chinese population. Methods: Two hundred forty-eight patients with aMCI, 67 patients with mild AD and 306 healthy controls (HCs) were recruited for this study and completed both the HKBC and the MMSE. The performance of the HKBC and MMSE in distinguishing patients with aMCI from HCs and distinguishing patients with AD from patients with aMCI was compared in the whole population and in age- and education-stratified subgroups. Results: The optimal HKBC cutoff score for distinguishing patients with aMCI from HCs was 23, and the optimal cutoff for distinguishing patients with AD from patients with aMCI was 17. The HKBC significantly outperformed the MMSE at differentiating patients with aMCI from HCs in the whole population (z = 12.38, p <  0.01) and all subgroups stratified by age or education. Regarding the discrimination of patients with AD from patients with aMCI, the HKBC showed better performance than the MMSE in the oldest subgroup (z = 2.18, p = 0.03). Conclusion: The HKBC is a sensitive and specific screening tool for detecting aMCI and AD in the Chinese population across age groups and educational levels.

Multitask Versus Multicomponent Training on Cognitive and Motor Functions in Persons With Mild Cognitive Impairment: A Randomized Trial

This study aims to compare the effects of multitask (MTT; multiple tasks performed simultaneously) and multicomponent training (MCT; various types of exercise performed sequentially) on processing speed, cognitive functions, gait speed, and balance functions in persons with mild cognitive impairment. Forty-two persons with mild cognitive impairment were randomly allocated to MTT (n = 21) or MCT (n = 21). Outcome measures included processing speed, cognitive functions (attention and executive functions), single-task gait speed, dual-task gait speed (DTGS-Arithmetic and DTGS-Verbal), and balance functions. Processing speed (except inhibition), cognitive functions, gait speed, and balance functions improved in the MTT and MCT groups following training, with no significant differences between the groups in processing speed or cognitive functions. The MCT group improved more on single-task gait speed (F = 15.097; p = .000; r = .270) and DTGS (DTGS-Arithmetic; F = 10.594; p = .002; r = .214), while the MTT group improved more on balance functions (F = 4.366; p = .043; r = .101). MTT and MCT strategies can be used to improve cognitive and physical outcomes in persons with mild cognitive impairment.

Animals in multidimensional space: Interpreting coordinates throughout lexical-semantic features in mild cognitive impairment and control subjects

INTRODUCTION

Semantic verbal fluency is a useful neuropsychological tool since it involves language and executive abilities that can be impaired in patients with neurodegenerative diseases in comparison to healthy controls. The present study explores retrieve and executive control processes using traditional quantitative and qualitative raw scores and examines the utility of multidimensional scaling combined with linear regression to provide new insights about the underlying semantic network in mild cognitive impairment and in healthy older adults.

METHOD

A total of 165 Spanish older adults, 81 patients and 84 controls, were assessed in different cognitive domains and evoked animal names in one minute. Group differences on fluency raw scores were first explored. Regressions using tests to predict groups' fluency scores were also performed. The 12 animals that had been produced more frequently were selected to perform a multidimensional scaling analysis for each group. Four features related to animal names were extracted from normative studies and then were used as predictors in linear regression to provide an interpretation of the resulting dimensions' coordinates.

RESULTS

Patients performed worse on memory and naming and produced a shorter list of animals than controls. In controls, naming and visual memory explained a small part of variance related to the total of animals produced and to the number of switches. Both groups exhibited similar semantic maps.

CONCLUSIONS

Results suggest that patients' map is influenced by words with a dense associative neighborhood that were acquired at an early age, whereas in controls none of the predictors explained dimensions.

Magnetoencephalography resting-state correlates of executive and language components of verbal fluency

Verbal fluency (VF) is a heterogeneous cognitive function that requires executive as well as language abilities. The purpose of this study was to elucidate the specificity of the resting state MEG correlates of the executive and language components. To this end, we administered a VF test, another verbal test (Vocabulary), and another executive test (Trail Making Test), and we recorded 5-min eyes-open resting-state MEG data in 28 healthy participants. We used source-reconstructed spectral power estimates to compute correlation/anticorrelation MEG clusters with the performance at each test, as well as with the advantage in performance between tests, across individuals using cluster-level statistics in the standard frequency bands. By obtaining conjunction clusters between verbal fluency scores and factor loading obtained for verbal fluency and each of the two other tests, we showed a core of slow clusters (delta to beta) localized in the right hemisphere, in adjacent parts of the premotor, pre-central and post-central cortex in the mid-lateral regions related to executive monitoring. We also found slow parietal clusters bilaterally and a cluster in the gamma 2 and 3 bands in the left inferior frontal gyrus likely associated with phonological processing involved in verbal fluency.

Left Frontotemporal Region Plays a Key Role in Letter Fluency Task-Evoked Activation and Functional Connectivity in Normal Subjects: A Functional Near-Infrared Spectroscopy Study

Letter fluency task (LFT) is a tool that measures memory, executive function, and language function but lacks a definite cutoff value to define abnormalities. We used the optical signals of functional near-infrared spectroscopy (fNIRS) to study the differences in power and connectivity between the high-functioning and low-functioning participants while performing three successive LFTs, as well as the relationships between the brain network/power and LFT performance. We found that the most differentiating factor between these two groups was network topology rather than activation power. The high-functional group (7 men and 10 women) displayed higher left intra-hemispheric global efficiency, nodal strength, and shorter characteristic path length in the first section. They then demonstrated a higher power over the left Broca's area than the right corresponding area in the latter two sections. The low-LFT group (9 men and 11 women) displayed less left-lateralized connectivity and activation power. LFT performance was only related to the network topology rather than the power values, which was only presented in the low-functioning group in the second section. The direct correlation between power and connectivity primarily existed in the inter-hemispheric network, with the timing relationship also seeming to be present. In conclusion, the high-functioning group presented more prominent left-lateralized intra-hemispheric network connectivity and power activation, particularly in the Broca's area. The low-functioning group seemed to prefer using other networks, like the inter-hemispheric, rather than having a single focus on left intra-hemispheric connectivity. The network topology seemed to better reflect the LFT performance than did the power values.

A voice recognition-based digital cognitive screener for dementia detection in the community: Development and validation study

INTRODUCTION

To facilitate community-based dementia screening, we developed a voice recognition-based digital cognitive screener (digital cognitive screener, DCS). This proof-of-concept study aimed to investigate the reliability, validity as well as the feasibility of the DCS among community-dwelling older adults in China.

METHODS

Eligible participants completed demographic, clinical, and the DCS. Diagnosis of mild cognitive impairment (MCI) and dementia was made based on the Montreal Cognitive Assessment (MoCA) (MCI: MoCA < 23, dementia: MoCA < 14). Time and venue for test administration were recorded and reported. Internal consistency, test-retest reliability and inter-rater reliability were examined. Receiver operating characteristic (ROC) analyses were conducted to examine the discriminate validity of the DCS in detecting MCI and dementia.

RESULTS

A total of 103 participants completed all investigations and were included in the analysis. Administration time of the DCS was between 5.1-7.3 min. No significant difference (p > 0.05) in test scores or administration time was found between 2 assessment settings (polyclinic or community center). The DCS showed good internal consistency (Cronbach's alpha = 0.73), test-retest reliability (Pearson r = 0.69, p < 0.001) and inter-rater reliability (ICC = 0.84). Area under the curves (AUCs) of the DCS were 0.95 (0.90, 0.99) and 0.77 (0.67, 086) for dementia and MCI detection, respectively. At the optimal cut-off (7/8), the DCS showed excellent sensitivity (100%) and good specificity (80%) for dementia detection.

CONCLUSION

The DCS is a feasible, reliable and valid digital dementia screening tool for older adults. The applicability of the DCS in a larger-scale community-based screening stratified by age and education levels warrants further investigation.

Gait Kinematic and Kinetic Characteristics of Older Adults With Mild Cognitive Impairment and Subjective Cognitive Decline: A Cross-Sectional Study

Background

Older adults with mild cognitive impairment (MCI) have slower gait speed and poor gait performance under dual-task conditions. However, gait kinematic and kinetic characteristics in older adults with MCI or subjective cognitive decline (SCD) remain unknown. This study was designed to explore the difference in gait kinematics and kinetics during level walking among older people with MCI, SCD, and normal cognition (NC).

Methods

This cross-sectional study recruited 181 participants from July to December 2019; only 82 met the inclusion criteria and consented to participate and only 79 completed gait analysis. Kinematic and kinetic data were obtained using three-dimensional motion capture system during level walking, and joint movements of the lower limbs in the sagittal plane were analyzed by Visual 3D software. Differences in gait kinematics and kinetics among the groups were analyzed using multivariate analysis of covariance (MANCOVA) with Bonferroni post-hoc analysis. After adjusting for multiple comparisons, the significance level was p < 0.002 for MANCOVA and p < 0.0008 for post-hoc analysis.

Results

Twenty-two participants were MCI [mean ± standard deviation (SD) age, 71.23 ± 6.65 years], 33 were SCD (age, 72.73 ± 5.25 years), and 24 were NC (age, 71.96 ± 5.30 years). MANCOVA adjusted for age, gender, body mass index (BMI), gait speed, years of education, diabetes mellitus, and Geriatric Depression Scale (GDS) revealed a significant multivariate effect of group in knee peak extension angle (F = 8.77, p < 0.0001) and knee heel strike angle (F = 8.07, p = 0.001) on the right side. Post-hoc comparisons with Bonferroni correction showed a significant increase of 5.91° in knee peak extension angle (p < 0.0001) and a noticeable decrease of 6.21°in knee heel strike angle (p = 0.001) in MCI compared with NC on the right side. However, no significant intergroup difference was found in gait kinetics, including dorsiflexion, plantar flexion, knee flexion, knee extension, hip flexion, and hip extension(p > 0.002).

Conclusion

An increase of right knee peak extension angle and a decrease of right knee heel strike angle during level walking were found among older adults with MCI compared to those with NC.

Functional Connectivity and Compensation of Phonemic Fluency in Aging

Neural compensatory mechanisms associated with broad cognitive abilities have been studied. However, those associated with specific cognitive subdomains (e.g., verbal fluency) remain to be investigated in healthy aging. Here, we delineate: (a) neural substrates of verbal (phonemic) fluency, and (b) compensatory mechanisms mediating the association between these neural substrates and phonemic fluency. We analyzed resting-state functional magnetic resonance imaging from 133 right-handed, cognitively normal individuals who underwent the Controlled Oral Word Association Test (COWAT) to record their phonemic fluency. We evaluated functional connectivity in an established and extended language network comprising Wernicke, Broca, thalamic and anti-correlated modules. (a) We conducted voxel-wise multiple linear regression to identify the brain areas associated with phonemic fluency. (b) We used mediation effects of cognitive reserve, measured by the Wechsler Adult Intelligence Scale—Information subtest, upon the association between functional connectivity and phonemic fluency tested to investigate compensation. We found that: (a) Greater functional connectivity between the Wernicke module and brain areas within the anti-correlated module was associated with better performance in phonemic fluency, (b) Cognitive reserve was an unlikely mediator in younger adults. In contrast, cognitive reserve was a partial mediator of the association between functional connectivity and phonemic fluency in older adults, likely representing compensation to counter the effect of aging. We conclude that in healthy aging, higher performance in phonemic fluency at older ages could be attributed to greater functional connectivity partially facilitated by higher cognitive reserve, presumably reflecting compensatory mechanisms to minimize the effect of aging.

Individual Differences in Hemodynamic Responses Measured on the Head Due to a Long-Term Stimulation Involving Colored Light Exposure and a Cognitive Task: A SPA-fNIRS Study

When brain activity is measured by neuroimaging, the canonical hemodynamic response (increase in oxygenated hemoglobin ([O2Hb]) and decrease in deoxygenated hemoglobin ([HHb]) is not always seen in every subject. The reason for this intersubject-variability of the responses is still not completely understood. This study is performed with 32 healthy subjects, using the systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) approach. We investigate the intersubject variability of hemodynamic and systemic physiological responses, due to a verbal fluency task (VFT) under colored light exposure (CLE; blue and red). Five and seven different hemodynamic response patterns were detected in the subgroup analysis of the blue and red light exposure, respectively. We also found that arterial oxygen saturation and mean arterial pressure were positively correlated with [O2Hb] at the prefrontal cortex during the CLE-VFT independent of the color of light and classification of the subjects. Our study finds that there is substantial intersubject-variability of cerebral hemodynamic responses, which is partially explained by subject-specific systemic physiological changes induced by the CLE-VFT. This means that both subgroup analyses and the additional assessment of systemic physiology are of crucial importance to achieve a comprehensive understanding of the effects of a CLE-VFT on human subjects.

Assessing within-task verbal fluency performance: the utility of individual time intervals in predicting incident mild cognitive impairment

The current study aimed to determine whether word generation performance on individual within-task 20-second time intervals predicted conversion to Mild Cognitive Impairment (MCI) status. Longitudinal data (Mean follow-up=2.95±1.64 years) was collected from cognitively-healthy community-dwelling older adults (N=344; %female=56.1). Performance on letter and semantic fluency tasks was divided into three consecutive within-task 20-second intervals. Incident MCI status (n=50) was determined via established diagnostic case conference. Fully adjusted Cox proportional-hazards regression models revealed that greater word production on semantic fluency across all time intervals significantly predicted a reduced risk of incident MCI [0-20 seconds (HR=0.906, p=0.002), 21-40 seconds (HR=0.904, p=0.02), and 41-60 seconds (HR=0.892, p=0.017)]. Conversely, on letter fluency, greater word production within the 41-60 second time interval only was significantly associated with reduced risk of incident MCI (HR=0.886, p=0.002). Overall, the clinical use of within-interval performance is supported given evidence of predictive sensitivity and ease of administration.

Cognitive predictors of self-awareness in patients with acquired brain injury along neuropsychological rehabilitation

Previous research has identified a critical role of executive function and memory in self-awareness, a metacognitive capacity often impaired in acquired brain injury. Through this observational study, we aimed to explore the effect of cognitive rehabilitation on the predictive value of these variables, as also whether any of them can predict the level of self-awareness once the cognitive rehabilitation is completed. 69 patients underwent a neuropsychological assessment, including self-awareness, at admission to and discharge from a cognitive rehabilitation process. Regression analysis was performed at these two moments and a third one was conducted to evaluate whether any of the variables at admission predicted the level of self-awareness at discharge. Verbal fluency was found to be the best predictor of self-awareness, both at admission and discharge. In addition, inhibition and cognitive flexibility, as well as episodic memory, appeared as significant predictors of post-rehabilitation self-awareness. Finally, verbal fluency was revealed as the unique pre-rehabilitation predictor of subsequent level of self-awareness following rehabilitation. While post-acute self-awareness is predicted by non-specific executive measures, the cognitive improvement putatively induced by neuropsychological rehabilitation reveals the contribution of more specific executive and memory functions. Importantly, pre-rehabilitation verbal fluency scores predicted the level of self-awareness after cognitive rehabilitation.