The most frequently used tests for assessing executive functions in aging

Utility of a Short-Form Phonemic Fluency Task

OBJECTIVE

to establish a proof-of-concept and ascertain the reliability of an abbreviated 30-second (30s) phonemic fluency measure as a cognitive screening tool in older adults.

METHODS

in all, 201 English-speaking individuals with normal cognition (NC; n = 119) or cognitive impairment (CI; mild CI or dementia; n = 82) were administered a standard 60s phonemic fluency task (FAS/CFL) with discrete 30s intervals denoted.

RESULTS

for all letters, 30s trial scores significantly predicted 60s scores for the same letter, R2 = .7-.9, F(1, 200) = 850-915, p < .001. As with 60s total scores, 30s cumulative scores (for all three trials) were significantly different between NC and CI groups (p < .001). Receiver operating characteristic analyses showed that 30s total scores distinguished NC and CI groups as effectively (AUC = .675) as 60s total scores (AUC = .658).

CONCLUSIONS

these findings support the utility and reliability of a short-form phonemic fluency paradigm, as 30s performance reliably predicted 60s/trial totals and was equally accurate in distinguishing impaired/non-impaired groups.

Barriers to Early Progress in Adult Cochlear Implant Outcomes

OBJECTIVES

Adult cochlear implant (CI) recipients obtain varying levels of speech perception from their device. Adult CI users adapt quickly to their CI if they have no peripheral "bottom-up" or neurocognitive "top-down" limiting factors. Our objective here was to understand the influence of limiting factors on the progression of sentence understanding in quiet and in noise, initially and over time. We hypothesized that the presence of limiting factors, detected using a short test battery, would predictably influence sentence recognition with practical consequences. We aimed to validate the test battery by comparing the presence of limiting factors and the success criteria of >90% sentence understanding in quiet 1 month after activation.

DESIGN

The study was a single-clinic, cross-sectional, retrospective design incorporating 32 adult unilateral Nucleus CI users aged 27 to 90 years (mean = 70, SD = 13.5). Postoperative outcome was assessed through sentence recognition scores in quiet and in varying signal to noise ratios at 1 day, 1 to 2 months, and up to 2 years. Our clinic's standard test battery comprises physiological and neurocognitive measures. Physiological measures included electrically evoked compound action potentials for recovery function, spread of excitation, and polarity effect. To evaluate general cognitive function, inhibition, and phonological awareness, the Montreal Cognitive Assessment screening test, the Stroop Color-Word Test, and tests 3 and 4 of the French Assessment of Reading Skills in Adults over 16 years of age, respectively were performed. Physiological scores were considered abnormal, and therefore limiting, when total neural recovery periods and polarity effects, for both apical and basal electrode positions, were >1.65 SDs from the population mean. A spread of excitation of >6 electrode units was also considered limiting. For the neurocognitive tests, scores poorer than 1.65 SDs from published normal population means were considered limiting.

RESULTS

At 1 month, 13 out of 32 CI users scored ≥90% sentence recognition in quiet with no significant dependence on age. Subjects with no limiting peripheral or neurocognitive factors were 8.5 times more likely to achieve ≥90% score in quiet at 1 month after CI switch-on (p = 0.010). In our sample, we detected 4 out of 32 cases with peripheral limiting factors that related to neural health or poor electrode-neural interface at both apical and basal positions. In contrast, neurocognitive limiting factors were identified in 14 out of 32 subjects. Early sentence recognition scores were predictive of long-term sentence recognition thresholds in noise such that limiting factors appeared to be of continuous influence.

CONCLUSIONS

Both peripheral and neurocognitive processing factors affect early sentence recognition after CI activation. Peripheral limiting factors may have been detected less often than neurocognitive limiting factors because they were defined using sample-based criteria versus normal population-based criteria. Early performance was generally predictive of long-term performance. Understanding the measurable covariables that limit CI performance may inform follow-up and improve counseling. A score of ≥90% for sentence recognition in quiet at 1 month may be used to define successful progress; whereas, lower scores indicate the need for diagnostic testing and ongoing rehabilitation. Our findings suggest that sentence test scores as early as 1 day after activation can provide vital information for the new CI user and indicate the need for rehabilitation follow-up.

Predicting Learning: Understanding the Role of Executive Functions in Children's Belief Revision Using Bayesian Models

Recent studies suggest that learners who are asked to predict the outcome of an event learn more than learners who are asked to evaluate it retrospectively or not at all. One possible explanation for this "prediction boost" is that it helps learners engage metacognitive reasoning skills that may not be spontaneously leveraged, especially for individuals with still-developing executive functions. In this paper, we combined multiple analytic approaches to investigate the potential role of executive functions in elementary school-aged children's science learning. We performed an experiment that investigates children's science learning during a water displacement task where a "prediction boost" had previously been observed-children either made an explicit prediction or evaluated an event post hoc (i.e., postdiction). We then considered the relation of executive function measures and learning, which were collected following the main experiment. Via mixed effects regression models, we found that stronger executive function skills (i.e., stronger inhibition and switching scores) were associated with higher accuracy in Postdiction but not in the Prediction Condition. Using a theory-based Bayesian model, we simulated children's individual performance on the learning task (capturing "belief flexibility"), and compared this "flexibility" to the other measures to understand the relationship between belief revision, executive function, and prediction. Children in the Prediction Condition showed near-ceiling "belief flexibility" scores, which were significantly higher than among children in the Postdiction Condition. We also found a significant correlation between children's executive function measures to our "belief flexibility" parameter, but only for children in the Postdiction Condition. These results indicate that when children provided responses post hoc, they may have required stronger executive function capacities to navigate the learning task. Additionally, these results suggest that the "prediction boost" in children's science learning could be explained by increased metacognitive flexibility in the belief revision process.

Cognitive screening test for rehabilitation using spatiotemporal data extracted from a digital trail making test part-A

We investigated a newly developed digitized Trail Making Test using an iPad (iTMT) as a brief cognitive function screening test. We found that the iTMT part-A (iTMT-A) can estimate generalized cognitive function in rehabilitation inpatients examined using the Mini-Mental State Examination (MMSE). Forty-two hospitalized participants undergoing rehabilitation (rehab participants), 30 of whom had cerebral infarction/hemorrhage (stroke participants), performed the iTMT five times (first three times: iTMT-A; fourth: paper version of TMT-A; fifth: the inverse version of iTMT-A) and the MMSE once. Each iTMT-A trial's completion time was divided into the move and dwell times. A linear mixed model following post-hoc tests revealed that the completion time of the third and fourth iTMT-A was faster compared to that of the first iTMT-A, suggesting the presence of a learning effect. In the partial least squares (PLS) regression analysis, the coefficient of determination for estimating the MMSE score was increased by using the dwell and move times extracted from the repeated iTMT-A and the availability of TMT-B, even for subjects with low MMSE scores. These findings indicate that the dwell time of iTMT-A may be important for estimating cognitive function. The iTMT-A extracts significant factors temporally and spatially, and by incorporating the learning effect of repeated trials, it may be possible to screen cognitive and physical functions for rehabilitation patients.

PEMOCS: Evaluating the effects of a concept-guided, PErsonalised, MOtor-Cognitive exergame training on cognitive functions and gait in chronic Stroke-study protocol for a randomised controlled trial

BACKGROUND

Many stroke survivors remain with residual cognitive and motor impairments despite receiving timely acute and sub-acute rehabilitation. This indicates that rehabilitation following stroke should be continuous to meet the needs of individual stroke patients. Both cognitive and motor functions are essential for mastering daily life and, therefore, should be aimed at with rehabilitation. Exergames, motor-cognitive exercises performed using video games, are an auspicious method to train both motor and cognitive functions and at the same time may foster the long-term motivation for training. This study aims to assess the effect of concept-guided, personalised, motor-cognitive exergame training on cognitive and motor functions in chronic stroke survivors.

METHODS

This study is a single-blinded, randomised controlled trial. Assessments are performed at baseline, after a 12-week intervention, and at a 24-weeks follow-up. Chronic stroke patients (≥ 18 years old, ≥ 6 months post-stroke) able to stand for 3 min, independently walk 10 m, follow a two-stage command, and without other neurological diseases apart from cognitive deficits or dementia are included. Participants in the intervention group perform the exergame training twice per week for 30 (beginning) up to 40 (end) minutes additionally to their usual care programme. Participants in the control group receive usual care without additional intervention(s). Global cognitive functioning (total Montreal Cognitive Assessment (MoCA) score) is the primary outcome. Secondary outcomes include health-related quality of life, specific cognitive functions, single- and dual-task mobility, and spatiotemporal gait parameters. The target sample size for this trial is 38 participants. Linear mixed models with the post-outcome scores as dependent variables and group and time as fixed effects will be performed for analysis.

DISCUSSION

Superior improvements in global cognitive functioning and in the abovementioned secondary outcomes in the intervention group compared to the control group are hypothesised. The results of this study may guide future design of long-term rehabilitation interventions after stroke.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05524727). Registered on September 1, 2022.

Isolated cognitive impairment in people with multiple sclerosis: frequency, MRI patterns and its development over time

OBJECTIVES

To study the frequency of isolated (i.e., single-domain) cognitive impairments, domain specific MRI correlates, and its longitudinal development in people with multiple sclerosis (PwMS).

METHODS

348 PwMS (mean age 48 ± 11 years, 67% female, 244RR/52SP/38PP) underwent neuropsychological testing (extended BRB-N) at baseline and at five-year follow-up. At baseline, structural MRI was acquired. Isolated cognitive impairment was defined as a Z-score of at least 1.5 SD below normative data in one domain only (processing speed, memory, executive functioning/working memory, and attention). Multi-domain cognitive impairment was defined as being affected in ≥ 2 domains, and cognitively preserved otherwise. For PwMS with isolated cognitive impairment, MRI correlates were explored using linear regression. Development of isolated cognitive impairment over time was evaluated based on reliable change index.

RESULTS

At baseline, 108 (31%) PwMS displayed isolated cognitive impairment, 148 (43%) PwMS displayed multi-domain cognitive impairment. Most PwMS with isolated cognitive impairment were impaired on executive functioning/working memory (EF/WM; N = 37), followed by processing speed (IPS; N = 25), memory (N = 23), and attention (N = 23). Isolated IPS impairment was explained by a model of cortical volume and fractional anisotropy (adj. R2 = 0.539, p < 0.001); memory by a model with cortical volume and hippocampal volume (adj. R2 = 0.493, p = 0.002); EF/WM and attention were not associated with any MRI measure. At follow-up, cognitive decline was present in 11/16 (69%) of PwMS with isolated IPS impairment at baseline. This percentage varied between 18 and 31% of PwMS with isolated cognitive impairment in domains other than IPS at baseline.

CONCLUSION

Isolated cognitive impairment is frequently present in PwMS and can serve as a proxy for further decline, particularly when it concerns processing speed. Cortical and deep grey matter atrophy seem to play a pivotal role in isolated cognitive impairment. Timely detection and patient-tailored intervention, predominantly for IPS, may help to postpone further cognitive decline.

Effect of the duration of hypertension on white matter structure and its link with cognition

The relation between hypertension (HTN) and cognition has been reported inclusive results, which may be affected by disease duration. Our study aimed to examine the influence of HTN duration on cognition and its underlying white matter (WM) changes including macrostructural WM hyperintensities (WMH) and microstructural WM integrity. A total of 1218 patients aged ≥55 years with neuropsychological assessment and a subgroup of 233 people with imaging data were recruited and divided into 3 groups (short duration: <5 years, medium duration: 5-20 years, long duration: >20 years). We found that greater HTN duration was preferentially related to worse executive function (EF), processing speed (PS), and more severe WMH, which became more significant during long duration stage. The reductions in WM integrity were evident at the early stage especially in long-range association fibers and then scattered through the whole brain. Increasing WMH and decreasing integrity of specific tracts consistently undermined EF. Furthermore, free water imaging method greatly enhanced the sensitivity in detecting HTN-related WM alterations. These findings supported that the neurological damaging effects of HTN is cumulative and neuroimaging markers of WM at macro- and microstructural level underlie the progressive effect of HTN on cognition.

Exposure to Sedation and Analgesia Medications: Short-term Cognitive Outcomes in Pediatric Critical Care Survivors With Acquired Brain Injury

Background/Objective: Pediatric intensive care unit (PICU) survivors risk significant cognitive morbidity, particularly those with acquired brain injury (ABI) diagnoses. Studies show sedative and analgesic medication may potentiate neurologic injury, but few studies evaluate impact on survivor outcomes. This study aimed to evaluate whether exposures to analgesic and sedative medications are associated with worse neurocognitive outcome. Methods: A retrospective cohort study was conducted of 91 patients aged 8 to 18 years, undergoing clinical neurocognitive evaluation approximately 1 to 3 months after PICU discharge. Electronic health data was queried for sedative and analgesic medication exposures, including opioids, benzodiazepines, propofol, ketamine, and dexmedetomidine. Doses were converted to class equivalents, evaluated by any exposure and cumulative dose exposure per patient weight. Cognitive outcome was derived from 8 objective cognitive assessments with an emphasis on executive function skills using Principal Components Analysis. Then, linear regression was used to control for baseline cognitive function estimates to calculate a standardized residualized neurocognitive index (rNCI) z-score. Multivariable linear regression evaluated the association between rNCI and medication exposure controlling for covariates. Significance was defined as P < .05. Results: Most (n = 80; 88%) patients received 1 or more study medications. Any exposure and higher cumulative doses of benzodiazepine and ketamine were significantly associated with worse rNCI in bivariate analyses. When controlling for Medicaid, preadmission comorbid conditions, length of stay, delirium, and receipt of other medication classes, receipt of benzodiazepine was associated with significantly worse rNCI (β-coefficient = -0.48, 95% confidence interval = -0.88, -0.08). Conclusions: Exposure to benzodiazepines was independently associated with worse acute phase cognitive outcome using objective assessments focused on executive function skills when controlling for demographic and illness characteristics. Clinician decisions regarding medication regimens in the PICU may serve as a modifiable factor to improve outcomes. Additional inquiry into associations with long-term cognitive outcome and optimal medication regimens is needed.

Transcranial direct current stimulation combined with cognitive training improves decision making and executive functions in opioid use disorder: a triple-blind sham-controlled pilot study

Opioid use disorder (OUD) is a chronic disorder with a considerable amount of morbidity and mortality. Despite remarkable improvement achieved by maintenance programs, an array of treatment goals were still unmet. Mounting evidence suggests that transcranial Direct Current Stimulation (tDCS) improves decision making and cognitive functions in addictive disorders. tDCS paired with a decision making task was depicted to diminish impulsivity as well.

The present study aimed to assess the effect of tDCS combined with cognitive training (CT) in OUD for the first time.

In this triple-blind randomized sham-controlled pilot study, 38 individuals with OUD from the Buprenorphine-Naloxone Maintenance Therapy program were administered 20-minutes of 2 mA active/sham tDCS over the dorsolateral prefrontal cortex with concomitant cognitive training. A selected test battery evaluating decision making under risk and ambiguity as well as executive functions, verbal fluency and working memory was utilized before and after the intervention.

Greater improvements were observed in decision making under ambiguity (p = 0.016), set shifting ability and alternating fluency while no improvements were observed in decision making under risk in the active group, compared to sham.

Deficits of decision making and executive functions have a pivotal role in the perpetuation and the relapse of the OUD. Alleviation of these impairments brought tDCS/CT forth as an expedient neuroscientifically-grounded treatment option that merits further exploration in OUD, Trial registration: NCT05568251.

Feasibility, safety, and adherence of a remote physical and cognitive exercise protocol for older women

BACKGROUND

 Population aging and the consequences of social distancing after the COVID-19 pandemic make it relevant to investigate the feasibility of remote interventions and their potential effects on averting functional decline.

OBJECTIVE

 (1) To investigate the feasibility, safety, and adherence of a remote protocol involving physical and cognitive exercises for older women with normal cognition; (2) to examine its effects on cognitive and well-being variables.

METHODS

 Twenty-nine women (age ≥ 60 years old) were randomized into experimental group (EG; n = 15) and control group (CG; n = 14). The EG performed a 40-minute session of cognitive and physical exercises, and CG performed a 20-minute stretching session. Both groups performed 20 sessions via videoconference and 20 on YouTube twice a week. The Mini-Mental State Examination, Verbal Fluency Test, Digit Span (direct an inverse order), Geriatric Depression Scale (GDS), and Well-being Index (WHO-5) were applied in pre- and post-interventions by phone.

RESULTS

 Overall adherence was 82.25% in EG and 74.29% in CG. The occurrence of adverse events (mild muscle pain) was 33.3% in EG and 21.4% in CG. The EG improved verbal fluency and attention (p ≤ 0.05); both groups had improved depressive symptoms.

CONCLUSION

 The present study met the pre-established criteria for feasibility, safety, and adherence to the remote exercise protocol among older women. The results suggest that a combined protocol has more significant potential to improve cognitive function. Both interventions were beneficial in improving the subjective perception of well-being.

The assessment of executive function abilities in healthy and neurodegenerative aging-A selective literature review

Numerous studies have examined executive function (EF) abilities in cognitively healthy older adults and those living with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Currently, there are no standard accepted protocols for testing specific EFs; thus, researchers have used their preferred tool, which leads to variability in assessments of decline in a particular ability across studies. Therefore, there is a need for guidance as to the most sensitive tests for assessing EF decline. A search of the most current literature published between 2000 and 2022 on EF studies assessing cognitively healthy older adults and individuals living with MCI and AD was conducted using PubMed/Medline, PsycINFO, Embase, Web of Science, and Google Scholar. Emphasis was placed on the EF's dual-tasking, inhibition, shifting or switching, and working memory updating. Many tasks and their outcomes were reviewed. Of particular importance was the difference in outcomes for tasks applied to the same group of participants. These various EF assessment tools demonstrate differences in effectively identifying decline in EF ability due to the aging process and neurodegenerative conditions, such as MCI and AD. This review identifies various factors to consider in using particular EF tasks in particular populations, including task demand and stimuli factors, and also when comparing differing results across studies.

Split-half reliability estimates of an online card sorting task in a community sample of young and elderly adults

Executive function is vital for normal social, cognitive, and motor functions. Executive function decline due to aging increases the risk of disability and falls in older adults, which has become an urgent public health issue. Fast and convenient neuropsychological tools are thus needed to identify high-risk groups as early as possible to conduct a timely intervention. Card sorting tasks, such as Wisconsin Card Sorting Task (WCST) and its variants, are popular tools for measuring executive function. This study investigated the reliability of an open-source, self-administered, online, short-version card sorting task with a sample of young (n = 107, 65 females, age: M = 30.1 years, SD = 5.5 years) and elderly Chinese (n = 113, 53 females, age: M = 64.0 years, SD = 6.7 years). We developed an automated scoring and visualization procedure following the recent recommendations on scoring perseverative responses to make the results comparable to the standardized WCST. Reliability estimates of commonly used measures were calculated using the split-half method. All task indices' reliabilities were reasonably good in both old and young groups except for "failure-to-maintain-set." Elderly Chinese adults showed compromised task performance on all measures compared with the young Chinese adults at the group level. The R script of automated scoring and estimation of reliability is publicly available.

Heart Rate Variability and Cognition: A Narrative Systematic Review of Longitudinal Studies

BACKGROUND

Heart rate variability (HRV) is a reliable and convenient method to assess autonomic function. Cross-sectional studies have established a link between HRV and cognition. Longitudinal studies are an emerging area of research with important clinical implications in terms of the predictive value of HRV for future cognition and in terms of the potential causal relationship between HRV and cognition. However, they have not yet been the objective of a systematic review. Therefore, the aim of this systematic review was to investigate the association between HRV and cognition in longitudinal studies.

METHODS

The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Embase, PsycINFO and PubMed databases were searched from the earliest available date to 26 June 2023. Studies were included if they involved adult human subjects and evaluated the longitudinal association between HRV and cognition. The risk of bias was assessed with the Newcastle-Ottawa Scale for Cohort Studies. The results were presented narratively.

RESULTS

Of 14,359 records screened, 12 studies were included in this systematic review, with a total of 24,390 participants. Two thirds of the studies were published from 2020 onwards. All studies found a longitudinal relationship between HRV and cognition. There was a consistent association between higher parasympathetic nervous system (PNS) activity and better cognition, and some association between higher sympathetic nervous system activity and worse cognition. Also, higher PNS activity persistently predicted better executive functioning, while data on episodic memory and language were more scant and/or controversial.

CONCLUSIONS

Our results support the role of HRV as a biomarker of future cognition and, potentially, as a therapeutic target to improve cognition. They will need confirmation by further, more comprehensive studies also including unequivocal non-HRV sympathetic measures and meta-analyses.

Does serum neurofilament light help predict accelerated cognitive ageing in unimpaired older adults?

Introduction

Neurofilament light (NfL) is a blood biomarker of neurodegeneration. While serum NfL levels have been demonstrated to increase with normal ageing, the relationship between serum NfL levels and normal age-related changes in cognitive functions is less well understood.

Methods

The current study investigated whether cross-sectional serum NfL levels measured by single molecule array technology (Simoa®) mediated the effect of age on cognition, measured by a battery of neuropsychological tests administered biannually for 8 years, in a cohort of 174 unimpaired older adults (≥50 years) from the Tasmanian Healthy Brain Project. Mediation analysis was conducted using latent variables representing cognitive test performance on three cognitive domains - episodic memory, executive function, and language (vocabulary, comprehension, naming). Cognitive test scores for the three domains were estimated for each participant, coincident with blood collection in 2018 using linear Bayesian hierarchical models.

Results

Higher serum NfL levels were significantly positively associated with age (p < 0.001 for all domains). Cognitive test scores were significantly negatively associated with age across the domains of executive function (p < 0.001), episodic memory (p < 0.001) and language (p < 0.05). However, serum NfL levels did not significantly mediate the relationship between age and cognitive test scores across any of the domains.

Discussion

This study adds to the literature on the relationship between serum NfL levels and cognition in unimpaired older adults and suggests that serum NfL is not a pre-clinical biomarker of ensuing cognitive decline in unimpaired older adults.

ETMT: A Tool for Eye-Tracking-Based Trail-Making Test to Detect Cognitive Impairment

The growing number of people with cognitive impairment will significantly increase healthcare demand. Screening tools are crucial for detecting cognitive impairment due to a shortage of mental health experts aiming to improve the quality of life for those living with this condition. Eye tracking is a powerful tool that can provide deeper insights into human behavior and inner cognitive processes. The proposed Eye-Tracking-Based Trail-Making Test, ETMT, is a screening tool for monitoring a person's cognitive function. The proposed system utilizes a fuzzy-inference system as an integral part of its framework to calculate comprehensive scores assessing visual search speed and focused attention. By employing an adaptive neuro-fuzzy-inference system, the tool provides an overall cognitive-impairment score, allowing psychologists to assess and quantify the extent of cognitive decline or impairment in their patients. The ETMT model offers a comprehensive understanding of cognitive abilities and identifies potential deficits in various domains. The results indicate that the ETMT model is a potential tool for evaluating cognitive impairment and can capture significant changes in eye movement behavior associated with cognitive impairment. It provides a convenient and affordable diagnosis, prioritizing healthcare resources for severe conditions while enhancing feedback to practitioners.

Awareness of Disease and Its Domains in Young-onset and Late-onset Dementia: The Role of Executive Function

INTRODUCTION

Executive function (EF) involves a general cognitive process linked to strategic organization and control of complex goal-oriented tasks. In young-onset dementia (YOD), especially Alzheimer's disease, the symptoms that stand out in the initial stage are deficits in attention, visual-spatial function, praxis, and language. The present study aims to investigate what components of EF differ in young and late-onset dementia (LOD) and its impact on awareness and its domains.

METHODS

Using a cross-sectional design, we included 44 people with YOD and 70 with LOD. We assessed awareness and its domains, cognition, dementia severity, EF, functionality, and neuropsychiatric symptoms.

RESULTS

The YOD group was more impaired in general cognition ( P =0.017) and had a worse performance in Wechsler Digit Span Backward (DSB) ( P =0.007) and Phonemic fluency task (FAS) ( P =0.046) tests. In the LOD group, deficits in EF had a greater impact on awareness and on most domains (awareness total score, cognitive functioning and health condition, functional activity impairments and social function).

CONCLUSIONS

Our study findings support the heterogeneity of awareness, not only with regard to the difference between the domains and the measures of EF, but also to the groups studied.

Effects of a biomechanical-based Tai Chi program on gait and posture in people with Parkinson's disease: study protocol for a randomized controlled trial

BACKGROUND

Parkinson's disease (PD) is associated with changes in gait and posture, which increases the rate of falls and injuries in this population. Tai Chi (TC) training enhances the movement capacity of patients with PD. However, the understanding of the effect of TC training on gait and postural stability in PD is lacking. This study aims to examine the effect of biomechanical-based TC training on dynamic postural stability and its relationship with walking performance.

METHODS/DESIGN

A single-blind, randomized control trial of 40 individuals with early-stage PD was conducted (Hoehn and Yahr stages 1 to 3). Patients with PD will be randomly assigned to either the TC or control group. The TC group will participate in a biomechanical-based TC training program that is formed based on the movement analysis of TC and will be practiced thrice a week for 12 weeks. The control group will be required to engage in at least 60 min of regular physical activity (PA) on their own for three times per week for 12 weeks. The primary and secondary outcomes will be assessed at baseline and at 6 and 12 weeks after commencing the study protocol. The primary outcome measures will include dynamic postural stability indicated by the center of mass and center of pressure separation distance and clearance distance of the heel and toe measured during fixed-obstacle crossing. The secondary measures are gait speed, cadence, step length during level surface walking (simple task), and fixed-obstacle crossing (challenging task). The Unified Parkinson's Disease Rating Scale, single leg-stance test with eyes open and closed, and three cognitive scores (Stroop Test, Trail Making Test Part B, and the Wisconsin Card Sorting Test) were also employed.

DISCUSSION

This protocol could lead to the development of a biomechanics TC training program for the improvement of gait and postural stability among individuals with PD. The program could enhance the understanding of the effect of TC training on gait and postural stability and could help improve or preserve the postural stability, self-confidence, and active participation in social activities of the participants, thus enhancing their overall quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04644367. Registered on 25 November 2020.

Whole body vibration therapy and cognitive functions: a systematic review

Whole Body Vibration has been found to induce physiological changes in human subjects, improving their neuromuscular, respiratory and cardiovascular functions. Evidence from animal research prove that whole-body vibration appears to induce changes in molecular and cellular levels to alter cognitive functions in mice. There is evolving evidence for a potential value of whole body vibration in improving cognition and preventing the development of age-related cognitive disorders in humans. However, literature on the biological consequences of whole-body vibration on the human brain is scanty. If so, gathering the available evidences would help decide the possibility of designing appropriate whole-body vibration protocols to extend its application to induce neurocognitive enhancement and optimize its effects. Therefore, a systematic review of the literature was performed, consulting the ProQuest, MEDLINE and Scopus bibliographic databases, to summarize the available scientific evidence on the effects of whole-body vibration on cognitive functions in adults. Results of the review suggest that whole-body vibration therapy enhances a wide spectrum of cognitive functions in adults although there isn't enough evidence available yet to be able to design a standardized protocol to achieve optimum cognitive enhancement.

The association between subjective cognitive decline and trajectories of objective cognitive decline: Do social relationships matter?

OBJECTIVES

We examine the association between subjective cognitive decline (SCD) and the trajectories of objective cognitive decline (OCD); and the extent to which this association is moderated by social relationships.

METHODS

Data come from waves 10 (2010) through 14 (2018) of the Health and Retirement Study, a nationally representative panel survey of individuals aged 50 and above in the United States. OCD is measured using episodic memory, and overall cognition. SCD is assessed using a baseline measure of self-rated memory. Social relationships are measured by social network size and perceived positive and negative social support. Growth curve models estimate the longitudinal link between SCD and subsequent OCD trajectories and the interactions between SCD and social relationship variables on OCD.

RESULTS

SCD is associated with subsequent OCD. A wider social network and lower perceived negative support are linked to slower decline in memory, and overall cognition. None of the social relationship variables, however, moderate the link between SCD and future OCD.

CONCLUSION

Knowing that SCD is linked to subsequent OCD is useful because at SCD stage, deficits are more manageable relative to those at subsequent stages of OCD. Future work on SCD and OCD should consider additional dimensions of social relationships.

Genome-wide association study of executive function in a multi-ethnic cohort implicates LINC01362: Results from the northern Manhattan study

Executive function is a cognitive domain with sizable heritability representing higher-order cognitive abilities. Genome-wide association studies (GWAS) of executive function are sparse, particularly in populations underrepresented in medical research. We performed a GWAS on a composite measure of executive function that included measures of mental flexibility and reasoning using data from the Northern Manhattan Study, a racially and ethnically diverse cohort (N = 1077, 69% Hispanic, 17% non-Hispanic Black and 14% non-Hispanic White). Four SNPs located in the long intergenic non-protein coding RNA 1362 gene, LINC01362, on chromosome 1p31.1, were significantly associated with the composite measure of executive function in this cohort (top SNP rs2788328, ß = 0.22, p = 3.1 × 10-10). The associated SNPs have been shown to influence expression of the tubulin tyrosine ligase like 7 gene, TTLL7 and the protein kinase CAMP-activated catalytic subunit beta gene, PRKACB, in several regions of the brain involved in executive function. Together, these findings present new insight into the genetic underpinnings of executive function in an understudied population.

Does peak expiratory flow moderate trajectories of cognitive function among individuals with lung diseases? A longitudinal analysis of the National Health and Aging Trends Study

INTRODUCTION

Impaired cognitive function can co-exist in chronic respiratory diseases. However, it is not clear if peak expiratory flow (PEF) impacts changes in cognitive function. Our objective was to explore whether peak expiratory flow moderates trajectories of memory, visuospatial abilities, and executive function in individuals with chronic respiratory diseases.

METHODS

This was an analysis of individuals with lung diseases from the National Health and Aging Trends Study. Multivariable-adjusted generalized linear mixed models were used to estimate trajectories of immediate and delayed recall, and clock drawing over a 10-year follow-up. The interaction between PEF and time were plotted using sex-specific values for peak expiratory flow at 10th, 50th and 90th percentiles.

RESULTS

In females, interactions of time-by-PEF were found for both immediate (n = 489, t = 2.73, p<0.01) and delayed recall (n = 489, t = 3.38, p<0.01). Females in the 10th vs. 90th percentile of PEF declined in immediate recall at 0.14 vs. 0.065 words/year, and 0.17 vs. 0.032 words/year for delayed recall. Among males, recall declined linearly over 10 years (immediate recall: n = 296, t = -3.08, p < 0.01; delayed recall: n = 292, t = -2.46, p = 0.02), with no interaction with PEF. There were no time-by-PEF interactions nor declines over time in clock drawing scores in both sexes (females: n = 484, t = 0.25, p = 0.81; males: n = 291, t = -0.61, p = 0.55).

CONCLUSION

Females with the lowest PEF values experienced the greatest rates of decline in immediate and delayed recall over 10 years of follow-up, whereas males experienced similar declines in memory outcomes across all levels of PEF. Clock drawing scores remained stable over 10 years in both sexes.

Cross-cultural adaptation of the web-based executive functioning questionnaire for Brazilian sample (Webexec-BR)

The Web-based Executive Functioning Questionnaire (Webexec) is a brief scale developed to assess executive functions via online format. It has been used in different contexts, but its adaptation to other cultures is still restricted. This study aimed to perform a cross-cultural adaptation of the Webexec for a Brazilian sample considering the psychometric properties of the scale. This study used a sample of 295 Brazilian participants, with a mean age equal to 20.69 (SD = 6.030). This is a longitudinal study with reapplication of the scale six weeks after the test phase. Classical and contemporary methods were applied to analyze the psychometric properties of the Webexec. The results showed that the scale presented excellent psychometric properties for the Brazilian version, considering validity evidence based on the content and internal structure of Webexec, as well as reliability and precision. However, it is considered that other relational and experimental studies should be carried out with a larger sample size and for different population groups.

White matter hyperintensities and longitudinal cognitive decline in cognitively normal populations and across diagnostic categories: A meta-analysis, systematic review, and recommendations for future study harmonization

INTRODUCTION

The primary aim of this paper is to improve the clinical interpretation of white matter hyperintensities (WMHs) and provide an overarching summary of methodological approaches, allowing researchers to design future studies targeting current knowledge gaps.

METHODS

A meta-analysis and systematic review was performed investigating associations between baseline WMHs and longitudinal cognitive outcomes in cognitively normal populations, and populations with mild cognitive impairment (MCI), Alzheimer's disease (AD), and stroke.

RESULTS

Baseline WMHs increase the risk of cognitive impairment and dementia across diagnostic categories and most consistently in MCI and post-stroke populations. Apolipoprotein E (APOE) genotype and domain-specific cognitive changes relating to strategic anatomical locations, such as frontal WMH and executive decline, represent important considerations. Meta-analysis reliability was assessed using multiple methods of estimation, and results suggest that heterogeneity in study design and reporting remains a significant barrier.

DISCUSSION

Recommendations and future directions for study of WMHs are provided to improve cross-study comparison and translation of research into consistent clinical interpretation.

Education bias in typical brief cognitive tests used for the detection of dementia in elderly population with low educational level: a critical review

Dementia is a significant decline in cognition that interfere with independent, daily functioning. Dementia is a syndrome caused by a myriad and include primary neurologic, neuropsychiatric, and medical conditions. It has been projected that the prevalence of dementia will triple in the elderly population by the year 2050. Despite the benefits of early diagnosis, there is an effective under-detection of around 62% of people with mild cognitive impairment (MCI) or dementia. One of the factors associated with this problem is that diagnostic techniques are affected by the educational level of those evaluated. This is an important aspect to consider in the use of brief cognitive tests for the detection of dementia. This review presents and critically analyzes the available evidence regarding the effect of educational level on the diagnostic utility of three of the most widely used tools in the clinical setting: the Mini-mental Test Examination (MMSE), the Montreal Cognitive Assessment (MoCA), and the Addenbrooke's Cognitive Examination (ACE). Previous evidence shows that the tasks that require reading, writing, calculation, phonological fluency, and visuoconstruction are affected by educational level. These results lead to discourage the use of these tests in older people with less than 6 years of schooling. The development of brief cognitive tests appropriate for people with a low educational level is recommended. We posit that adequate cognitive tests should not consider tasks or items that resemble characteristics of academic contexts and should be more analogous to daily activities situations.

The Impact of Anticholinergic Use for Overactive Bladder on Cognitive Changes in Adults with Normal Cognition, Mild Cognitive Impairment, or Dementia

Background

Few studies have addressed whether anticholinergic (AC) medications for overactive bladder (OAB) cause cognitive decline in individuals with existing cognitive impairment, and whether the APOE ε4 gene increases this risk.

Objective

To determine whether OAB AC use is associated with a clinically relevant change in cognitive measures among adults with normal and abnormal cognition.

Design setting and participants

This was a retrospective cohort study using data from the National Alzheimer's Coordinating Center. Patients were enrolled at specialized centers in the USA between 2005 and 2019. Patients with existing OAB AC use, missing APOE ε4 status, and confounding neurologic diagnoses were excluded. New users of an OAB AC were matched 1:1 to patients not taking an OAB AC using propensity scores.

Intervention

New use of oxybutynin, tolterodine, solifenacin, trospium, darifenacin, or fesoterodine.

Outcome measurements and statistical analysis

The outcome was a change in cognitive function, measured as a ≥1-point increase on the Clinical Dementia Rating (CDR) instrument or a ≥3-point decrease on the Mini-Mental State Examination (MMSE). Conditional logistic regression with odds ratios (ORs) was conducted. We also tested for APOE ε4 effect modification.

Results and limitations

Among 18 835 eligible patients, 782 matched pairs were identified. The most common OAB ACs were oxybutynin (38%) and tolterodine (23%). There was no significant increase in the risk of a clinically relevant cognitive decline among OAB AC users (CDR: OR 1.38, 95% confidence interval [CI] 0.93-2.05; p = 0.11, MMSE: OR 1.06, 95% CI 0.79-1.43; p = 0.70). There was no significant interaction between APOE ε4 status and OAB AC use for the CDR (p = 0.38) or MMSE (p = 0.95) outcomes. Users of oxybutynin or tolterodine had numerically higher odds of a change on the CDR test (OR 1.65, 95% CI 0.98-2.77) that was close to statistical significance (p = 0.06). Limitations include the inability to determine medication dose or duration, and residual confounding.

Conclusions

OAB AC use was not associated with a significant change in cognitive function among individuals with normal and abnormal cognition. Further research is necessary to determine if oxybutynin and tolterodine are significantly more likely to cause cognitive decline.

Patient summary

Use of a specific class of overactive bladder medication was not associated with negative changes in brain function among patients with either normal or abnormal function. A genetic risk factor for Alzheimer's disease did not predispose individuals to cognitive decline when taking these drugs. Two of the drugs (oxybutynin and tolterodine) may lead to a higher risk of cognitive decline in comparison to other drugs, and this needs further research.

Which motor-cognitive abilities underlie the digital Trail-Making Test? Decomposing various test scores to detect cognitive impairment in Parkinson's disease-Pilot study

Since Parkinson's disease (PD) is a heterogeneous disorder with symptoms, such as tremors, gait and speech disturbances, or memory loss, individualized diagnostics are needed to optimize treatment. In their current form, the typical paper-pencil methods traditionally used to track disease progression are too coarse to capture the subtleties of clinical phenomena. For this reason, digital biomarkers that capture, for example, motor function, cognition, and behavior using apps, wearables, and tracking systems are becoming increasingly established. However, given the high prevalence of cognitive impairment in PD, digital cognitive biomarkers to predict mental progression are important in clinical practice. This pilot study aimed to identify those components of our digital version of the TMT (dTMT) that allow discrimination between PD patients with and without cognitive deficits. A total of 30 healthy control (age 66.3 ± 8.61) and 30 participants with PD (age 68.3 ± 9.66) performed the dTMT using a touch-sensitive tablet to capture enhanced performance metrics, such as the speed between and inside circles. The decomposition of cognitive abilities based on integrating additional variables in the dTMT revealed that the Parkinson's disease group was significantly more sensitive to parameters of inhibitory control. In contrast, the mild cognitive impairment group was sensitive to parameters of cognitive flexibility and working memory. The dTMT allows objective, ecologically valid, and long-term cognitive and fine-motor performance tracking, suggesting its potential as a digital biomarker in neurodegenerative disorders.

Cognitive impairment, childhood trauma, sedentary behaviour, and elevated C-reactive protein levels in major affective disorders

Elevated C-reactive protein (CRP) levels were associated with cognitive decline, sedentary behaviour, and childhood trauma in patients with major affective disorders. This study aims to examine the association of peripheral CRP levels, cognitive function, childhood trauma, sedentary behaviour, and quality of life in individuals with major affective disorders, including bipolar disorder (BD), major depressive disorder (MDD), and individuals without mood disorders (controls). We included outpatients with BD (n = 42), MDD (n = 27), and healthy controls (n = 40). All participants were assessed by a questionnaire, structured clinical interview, and the following scales: international physical activity questionnaire, childhood trauma questionnaire, 17-item Hamilton Depression Rating Scale (HDRS₁₇), and World Health Organization Quality of Life instrument, brief version (WHOQOL-BREF). Other measures were included: hs-CRP levels, anthropometric measures, and cognitive tests (Trail-making test part A and part B, Stroop test, phonemic verbal fluency test, and semantic verbal fluency test). Our results indicated that BD outpatients were less significantly physically active on leisure domain than controls. Levels of hs-CRP ≥ 5 mg/L were significantly linked with a history of childhood sexual abuse and childhood physical abuse, as well as worse neurocognitive performance in major depressive disorders, mainly in BD. There was a significant negative correlation between Trail-making part B score and WHOQOL-BREF total score. The findings support the hypothesis that levels of hs-CRP ≥ 5 mg/L may be a possible predictor of cognitive dysfunction, childhood sexual abuse and sedentary behaviour in major affective disorders.

The relationship between executive function, neurodevelopmental disorder traits, and academic achievement in university students

Difficulties with executive function have often been identified in individuals with various neurodevelopmental disorders such as Autism Spectrum Disorder (ASD), Attention-Deficit Hyperactivity Disorder (ADHD), and Developmental Co-ordination Disorder (DCD). Additionally, in childhood and adolescence, executive functioning is an important predictor of academic achievement. However, less research has explored these relationships in adult students, and those with a high level of neurodevelopmental disorder traits but no clinical diagnosis. Therefore, the current study aimed to assess whether ASD, ADHD, and DCD traits can predict academic achievement in university students, and whether traits of these neurodevelopmental conditions moderate the relationship between executive function and academic achievement. Both neurotypical students and those with a clinical diagnosis of a neurodevelopmental disorder were able to participate, with the majority being neurotypical. Participants completed four self-report questionnaires and provided a measure of academic achievement based on their university assignment results. Traits of ASD, ADHD, and DCD alone did not predict achievement, however, traits of ADHD and DCD significantly moderated the relationship between executive function and academic achievement. ASD traits did not significantly moderate this relationship. Implications and suggestions for future research are also discussed.

Effect of Modified Bifrontotemporal Electroconvulsive Therapy on Executive Function in Patients With Psychiatric Illness: A Longitudinal Observational Study

OBJECTIVE

The study was conducted to compare the pre-electroconvulsive therapy (ECT) and post-ECT status of the executive functions of patients and report any deficits found at long-term follow-up. The secondary objective of the study was to compare the performance at executive function tests after ECT with patient characteristics and ECT parameters.

METHODOLOGY

In a prospective longitudinal observational study, 50 patients in the age group of 18 to 65 years who were receiving modified bifrontotemporal ECT for the first time and admitted in psychiatry ward of a tertiary care hospital from July 2015 to June 2016 were assessed for executive functions using a neuropsychological battery consisting of digit span forward, digit span backward, spatial span forward, spatial span backward, phonemic verbal fluency test, semantic verbal fluency test, Stroop test, and Wisconsin Card Sorting Test, a day before ECT and then followed up at 3 and 6 months.

RESULTS

Patients' score improved on all the tests of executive function at 3-month follow-up and was significant for some tests. Improvement was sustained for all the tests 6 months after ECT. Number of years of formal education of patients before illness significantly influenced patients' performance on most of the executive function tests after ECT. Younger age of the patient positively influenced patients' performance on digit span forward and backwards and semantic verbal fluency.

CONCLUSIONS

There are no executive function deficits 3 to 6 months after brief pulse modified ECT with bilateral electrode placement. A higher premorbid education level is associated with better performance on executive functions after ECT.

The age differences and effect of mild cognitive impairment on perceptual-motor and executive functions

It is unclear whether the decline in executive function (EF) and perceptual-motor function (PMF) found in older adults with mild cognitive impairment (MCI) is the result of a normal aging process or due to MCI. This study aimed to determine age-related and MCI-related cognitive impairments of the EF and PMF. The EF and PMF were investigated across four groups of 240 participants, 60 in each group, including early adult, middle adult, older adult, and older adult with probable MCI. The EF, working memory, inhibition, and cognitive flexibility were evaluated using digit span backward tasks, the Stroop color-word test, and the modified switching verbal fluency test, respectively. The PMF, visual perception, visuoconstructional reasoning, and perceptual-motor coordination were evaluated using the clock reading test, stick design test, and stick catching test, respectively. Group differences were found for all subdomains of EF and PMF (p < 0.05), except for perceptual-motor coordination, indicating that this subdomain could be maintained in older adults and was not affected by MCI. For the age difference, working memory, cognitive flexibility, visual perception, and visuoconstructional reasoning remained stable across middle adults and started to decline in older adults, while cognitive inhibition began to decrease in middle adults and it further declined in older adults. To control the confounding effect of education level, the results showed that only cognitive flexibility was further decreased in older adults with probable MCI compared to those without MCI (p < 0.05). In conclusion, cognitive inhibition decreased earlier in middle adults, whereas EF and PMF started to decline in older adults. Cognitive flexibility was the only MCI-sensitive cognitive function.

Longitudinal Study of Cognitive Functioning in Adults with Juvenile Idiopathic Arthritis

Objective: To prospectively evaluate possible decline of cognitive functions in adult patients with juvenile idiopathic arthritis (JIA) and identify associated factors. Patients and methods: We performed a 24-month prospective observational study of adults (≥16 years) with JIA. The primary outcome measure was decline in cognitive function defined as a worsening of ≥2 points on the scales of the subsets administered to evaluate the different cognitive areas using the Wechsler Adult Intelligence Scale (WAIS) after 24 months: attention/concentration (digit span); verbal function (vocabulary); visual-spatial organization (block design); working memory (letter-number sequencing); and problem solving (similarities). Other variables included average inflammatory activity using C-reactive protein and composite activity indexes, comorbidity, and treatment. Logistic regression was performed to identify factors associated with cognitive decline. Results: The study population comprised 52 patients with JIA. Of these, 15 (28.8%) had cognitive decline at V24. The most affected functions were working memory (17.3%), attention/concentration (9.6%), verbal function (7.7%), visual-spatial organization (7.7%), and problem solving (3.8%). There were no significant differences in the median direct or scale scores for the cognitive functions evaluated between V0 and V24 for the whole sample. The factors associated with cognitive decline in patients with JIA were average C-reactive protein (OR [95% CI], 1.377 [1.060–1.921]; p = 0.039), depression (OR [95% CI], 3.691 [1.294–10.534]; p = 0.015), and treatment with biologics (OR [95% CI], 0.188 [0.039–0.998]; p = 0.046). Conclusion: Cognitive decline was detected in almost one third of adults with JIA after 24 months of follow-up. Systemic inflammatory activity in JIA patients was related to cognitive decline. Patients treated with biologics had a lower risk of decline in cognitive functions.

Postsecondary Education and Late-life Cognitive Outcomes Among Black and White Participants in the Project Talent Aging Study: Can Early-life Cognitive Skills Account for Educational Differences in Late-life Cognition?

BACKGROUND

Higher education consistently predicts improved late-life cognition. Racial differences in educational attainment likely contribute to inequities in dementia risk. However, few studies of education and cognition have controlled for prospectively measured early-life confounders or evaluated whether the education late-life cognition association is modified by race/ethnicity.

METHODS

Among 2343 Black and White Project Talent Aging Study participants who completed telephone cognitive assessments, we evaluated whether the association between years of education and cognition (verbal fluency, memory/recall, attention, and a composite cognitive measure) differed by race, and whether these differences persisted when adjusting for childhood factors, including the cognitive ability.

RESULTS

In fully adjusted linear regression models, each additional year of education was associated with higher composite cognitive scores for Black [β=0.137; 95% confidence interval (CI)=0.068, 0.206] and White respondents (β=0.056; CI=0.034, 0.078) with an interaction with race ( P =0.03). Associations between education and memory/recall among Black adults (β=0.036; CI=-0.037, 0.109) and attention among White adults (β=0.022; CI=-0.002, 0.046) were nonsignificant. However, there were significant race-education interactions for the composite ( P =0.03) and attention measures ( P <0.001) but not verbal fluency ( P =0.61) or memory/recall ( P =0.95).

CONCLUSION

Education predicted better overall cognition for both Black and White adults, even with stringent control for prospectively measured early-life confounders.

Epidemiology of body dysmorphic disorder among adolescents: A study of their cognitive functions

BACKGROUND

Body dysmorphic disorder (BDD) is characterized by a preoccupation with an imagined defect in one's appearance. In case of a slight physical anomaly, the person would experience an excessive concern. This disorder causes cognitive dysfunction.

PURPOSE

The aim of this study was to examine epidemiology of body dysmorphic disorder among students at secondary schools of the first and second stage in Shiraz, Iran. It also compares executive functions in students with BDD to healthy students.

METHODS

The Body Dysmorphic Disorder Questionnaire (BDDQ), Stroop Color and Word Test (SCWT),Wisconsin Card Sorting Test (WCST), Tower of London test (ToL), and Trail Making Test (TMT) were measured in participants with BDD (N = 52; M_age  = 16.20; SD = 1.03) and healthy control group (N = 52; M_age  = 15.91; SD = 0.96).

RESULTS

The frequency of BDD was significantly higher in women than men (14.8% vs. 6.8%), and its prevalence was 10.4% in total. There was a significant difference between the two groups of students concerning attentional set-shifting, inhibition of cognitive interference, visual-spatial searching, and sequencing, but not problem-solving tasks.

CONCLUSIONS

Students with BDD have cognitive deficits, which need to be addressed in cognitive rehabilitation.

Psychometric Properties of the Revised Dysexecutive Questionnaire in a Non-clinical Population

Aims

The aim of this study was to assess the psychometric properties of the revised self-rated version of the Dysexecutive Questionnaire (DEX-R) within a non-clinical sample.

Methods

The study was hosted online, with 140 participants completing the DEX-R, GAD-2 and PHQ-2. Sixty participants also completed the FrSBe, with 99 additionally completing the DEX-R again 3 weeks later. Correlations with demographic factors and symptoms of anxiety and depression were conducted. Rasch and factor analysis were also used to explore underlying subconstructs.

Results

The DEX-R correlated highly with the FrSBe, indicating sound concurrent validity. Internal consistency, split-half reliability and test-retest reliability were excellent. Age and symptoms of depression and anxiety correlated with DEX-R scores, with older age associated with less dysexecutive problems. The Rasch analysis confirmed the multidimensionality of the rating scale, and a three-factor structure was found relating to activation-self-regulatory, cognitive and social-emotional processes. Frequencies of responses on DEX-R items varied, many were not fully endorsed indicating specific relevance of most but not all items to patients.

Conclusion

Interpretations of DEX-R ratings of dysexecutive problems should consider mood and individual variation. Systematic comparison of DEX-R responses between healthy and clinical groups could help identify a suitable cut off for dysexecutive symptoms.

Executive Functions in Alzheimer’s Disease: A Systematic Review

Background: In Alzheimer’s disease, in addition to memory, attention has been given to cognitive testing due to its interface and connection with memory. Objective: The aim of this study is to take a global view of executive functions and place the concept within the theoretical framework of Alzheimer’s disease dementia, verifying their role in the cognitive functioning of the human mind, as well as how they are compromised in this pathology. Methods: An initial search was carried out in databases such as PubMed, ScienceDirect, and Web of Science. The guiding question presented at the end of the introduction was elaborated from the PICO/PIO/PEO strategy. The selected articles, therefore, answered the guiding question, were made available in full, and published in the period from 2000 to 2020. Studies without specific methodology and which correlated with other diseases or other types of dementia were excluded. To meet the objective, an integrative literature review was adopted. Results: The results indicate that, although the tests to verify the performance of cognitive functions have their limitations, they bring some evidence that they have been compromised, especially when analyzed periodically during the development of dementia. Conclusion: It is concluded that there is an interference of executive functions in function of Alzheimer’s and that memory and attention are the most evident in this type of dementia.

A scoping review of near infrared spectroscopy studies employing a verbal fluency task in bipolar disorder

BACKGROUND

Deficits in cognitive functioning, including attention, memory, and executive functions, along with impairments in language production, are present in patients with bipolar disorder (BD) patients during mood phases, but also during euthymia.Verbal fluency tasks (VFTs), being able to evaluate integrity of a wide range of cognitive domains and represent, can be used to screen for these disturbances. Neuroimaging studies, including Near-InfraRed Spectroscopy (NIRS), have repeatedly showed widespread alterations in the prefrontal and temporal cortex during the performance of VFTs in BD patients. This review aims to summarize the results of NIRS studies that evaluated hemodynamic responses associated with the VFTs in prefrontal and temporal regions in BD patients.

METHODS

We performed a scoping review of studies evaluating VFT-induced activation in prefrontal and temporal regions in BD patients, and the relationship between NIRS data and various clinical variables.

RESULTS

15 studies met the inclusion criteria. In BD patients, compared to healthy controls, NIRS studies showed hypoactivation of the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex and anterior temporal regions. Moreover, clinical variables, such as depressive and social adaptation scores, were negatively correlated with hemodynamic responses in prefrontal and temporal regions, while a positive correlation were reported for measures of manic symptoms and impulsivity.

LIMITATIONS

The heterogeneity of the studies in terms of methodology, study design and clinical characteristics of the samples limited the comparability of the findings.

CONCLUSIONS

Given its non-invasiveness, good time-resolution and no need of posturalconstraint, NIRS technique could represent a useful tool for the evaluation of prefrontal and temporal haemodynamic correlates of cognitive performances in BD patients.

A Comparison Between the Performances of Verbal and Nonverbal Fluency Tests in Discriminating Between Mild Cognitive Impairments and Alzheimer’s Disease Patients and Their Brain Morphological Correlates

Background and Purpose

Methods

Results

Conclusions

Violence, neurocognitive function and clinical correlates in patients with schizophrenia

BACKGROUND

Schizophrenia patients with violent behavior are a severe public health concern, but the correlates of this violent behavior are unknown. Additionally, the relationship between neurocognitive function and violent behavior in Chinese patients with schizophrenia has not yet been investigated.

METHODS

A total of 337 schizophrenia inpatients were recruited. The Positive and Negative Syndrome Scale (PANSS) was used to assess psychopathological symptoms. Neurocognitive functioning was evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).

RESULTS

The percentage of violent behavior was 10.4% in patients with schizophrenia. Patients with violent behavior had higher PANSS-positive, excited, and total subscale scores than patients who did not show violent behavior. Patients with violent behavior also had lower RBANS language, semantic fluency, and total subscale scores. Gender (OR = 0.066∼0.819, p = 0.023), illness duration (OR = 0.876∼0.971, p = 0.002), smoking (OR = 1.127∼2.950, p = 0.014), the PANSS positive subscale (OR = 1.050∼1.197, p = 0.001), and the RBANS language subscale (OR = 0.927∼0.987, p = 0.005) significantly contributed to the development of violent behavior in schizophrenia patients.

CONCLUSION

Our findings revealed that cognitive and clinical assessments should be considered in comprehensive assessments of future risks of violence in schizophrenia patients.

Central nervous system physiology

This is the second chapter of the series on the use of clinical neurophysiology for the study of movement disorders. It focusses on methods that can be used to probe neural circuits in brain and spinal cord. These include use of spinal and supraspinal reflexes to probe the integrity of transmission in specific pathways; transcranial methods of brain stimulation such as transcranial magnetic stimulation and transcranial direct current stimulation, which activate or modulate (respectively) the activity of populations of central neurones; EEG methods, both in conjunction with brain stimulation or with behavioural measures that record the activity of populations of central neurones; and pure behavioural measures that allow us to build conceptual models of motor control. The methods are discussed mainly in relation to work on healthy individuals. Later chapters will focus specifically on changes caused by pathology.

Initial Adaptation of the General Cognitive Assessment Battery by Cognifit™ for Bulgarian Older Adults

BACKGROUND

Online neuropsychological assessment batteries may facilitate the screening of cognitive functions in older adults and could be useful for early diagnosis and detection of cognitive impairments.

OBJECTIVE

The primary aim of this study was to assess the psychometric qualities of an online multi-domain cognitive assessment battery (General Cognitive Assessment Battery (GCAB) by Cognifit™) applied for the first time in Bulgaria.

METHODS

A total of 20 healthy older adults (6 male and 14 female, aged 60-82) completed the GCAB as well as the Mini-Mental State Examination (MMSE) and the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery. Descriptive statistics were used to describe the demographic characteristics of the sample and the scores on the GCAB and the CERAD battery. The internal consistency of the GCAB was evaluated using item analysis and measured with Cronbach's alpha. The concurrent validity of the GCAB was assessed with respect to the CERAD using Spearman's r after verifying the linear relationship between the GCAB and CERAD scores.

RESULTS

The GCAB showed good concurrent validity when compared with the corresponding CERAD tests. The correlation coefficients ranged from 0.67 for working memory to 0.47 for short-term auditory memory. We found very good reliability of the GCAB, with the inter-class correlation coefficient higher than 0.8 for all cognitive domains. There were no significant correlations between MMSE and GCAB scores.

CONCLUSION

The GCAB was found to be valid for the cognitive screening of Bulgarian healthy older adults and may provide an adequate assessment of their cognitive status. The GCAB showed good concurrent validity when compared with the CERAD battery, measuring similar cognitive constructs. Further work is necessary to explore its validity and reliability.

Inhibitory control training in healthy and highly educated older adults

Executive function training is considered a promising tool for delaying the natural effects of aging on cognition. However, there are still few studies that propose a unimodal intervention with a focus on inhibitory control, and none of them has studied the effect of this type of intervention on older adults (OA).

OBJECTIVE

The aim of this study is to investigate the benefits of inhibitory control training in healthy OA by comparing the two assessment time points, namely, before and after training.

METHODS

Twenty-seven participants were included after interview and checking the inclusion criteria. The training was based on the stop-signal paradigm and carried out in 21 sessions.

RESULTS

Participants performed better after training by reducing the false alarm error rate (i.e., for stop-signal trials), reducing omission error rate, showing an increase in hit rate, Go response time (i.e., for go-signal trials), stop-signal response time, and showing a decrease in the level of anxiety. The executive function training had no significant impact on the scores obtained in the complementary neuropsychological tests.

CONCLUSIONS

These results are consistent with previous studies that support the viability and effectiveness of cognitive intervention for executive functions in OA and suggest a positive effect of the intervention, which may be related to the learning experience of a new and challenging task.

Executive functions and functional impairment in Latin seniors suffering from depression

Functional impairment (FI) relates to the condition of executive functions (EFs). While EFs become affected by age and educational level (EL). Seniors suffering from depression (SSDs) on the other hand show EF-related deficiencies; however, there is hardly any literature available regarding their relationship with FI in Latin SSDs, who usually have low ELs.

OBJECTIVE

To verify the relationship between EFs and FI in SSDs of Latin origins, by controlling the effects associated with age and educational level.

METHODOLOGY

Cross-sectional study, of cases and controls, conducted on a nonprobability sample, made up of 102 self-sufficient SSDs and 142 control subjects over age 50, monolinguals of Latin origin (Chileans), all assessed by means of a battery of assessments such as: Geriatric Depression Scale, Addenbrook's Cognitive Assessment III, Trail making Tests A and B, STROOP word-color test, and semantic and phonological verbal fluency tests. A domain of composite EFs was established with standardized Chilean population scores, where age and educational levels were controlled. A simple linear regression analysis was conducted to determine the relationship between EFs and FI in SSDs.

RESULTS

Upon controlling age and educational levels, EFs explained an FI variance of 3.9% in SSDs; depression explained an EF variance of 3.2%, and 3.7% of FI.

CONCLUSION

The results of the present study highlight the importance of a timely intervention when it comes to geriatric depression, considering the negative effect it has over the executive functions and the functionality of seniors.

Effects of Chinese Mind-Body Exercises on Executive Function in Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis

Chinese mind-body exercises (CMBEs) are positively associated with executive function (EF), but their effects on EF, from synthesized evidence using systematic and meta-analytic reviews, have not been conducted. Therefore, the present systematic review with meta-analysis attempted to determine whether CMBEs affect EF and its sub-domains, as well as how exercise, sample, and study characteristics moderate the causal relationship between CMBEs and EF in middle-aged and older adults. Seven electronic databases were searched for relevant studies published from the inception of each database through June 2020 (PubMed, Web of Science, Embase, Cochrane Controlled Trials Register, Wanfang, China National Knowledge Infrastructure, and Weipu). Randomized controlled trials with at least one outcome measure of CMBEs on EF in adults of mean age ≥ 50 years with intact cognition or mild cognitive impairment (MCI) and with or without chronic diseases were included. A total of 29 studies (N = 2,934) ultimately were included in this study. The results indicated that CMBEs improved overall EF (Standardized Mean Differences = 0.28, 95% CI 0.12, 0.44), as well as its sub-domains of working memory and shifting. The beneficial effects of CMBEs on EF occurred regardless of type (Tai Chi, Qigong), frequency of group classes (≤2 time, 3-4 time, ≥5 times), session time (≤45 min, 46-60 min), total training time (≥150 to ≤300 min, >300 min), and length of the CMBEs (4-12 week, 13-26 week, and >26 week), in addition to that more frequent participation in both group classes and home practice sessions (≥5 times per week) resulted in more beneficial effects. The positive effects of CMBEs on EF were also demonstrated, regardless of participants mean age (50-65 years old, >65 years old), sex (only female, both), and cognitive statuses (normal, MCI, not mentioned), health status (with chronic disease, without chronic disease), as well as training mode (group class, group class plus home practice) and study language (English, Chinese). This review thus suggests that CMBEs can be used as an effective method with small to moderate and positive effects in enhancing EF, and that more frequent group classes and home practice sessions may increase these effects. However, certain limitations, including strictly design studies, limited ES (effect size) samples for specific variables, and possible biased publications, required paying particular attention to, for further exploring the effects of CMBEs on EF.

Executive Function and Physical Function Among Community-Dwelling Egyptian Older Adults

BACKGROUND

The ongoing scientific debate regarding the association between physical function and cognitive impairment has focused mainly on global cognitive performance rather than specific cognitive functions tests and the importance of recognition of its associations and any factors that could play a role later in the prevention of such decline.

OBJECTIVE

This study examined the association between physical function, using handgrip strength (HGS) and Timed Up-and-Go test (TUGT), and executive function (EF), using Clock Drawing Test (CDT), among community-dwelling Egyptian elderly.

METHODS

A cross-sectional study was conducted in 5 social clubs in Cairo, Egypt and included a sample of 136 elderly males and females aged≥55 years old. All participants had their physical function assessed using TUGT, and measurement of HGS using a pneumatic hand-held dynamometer. Assessment of EF using CDT was also done.

RESULTS

Higher CDT scores were significantly associated with both better HGS, and lower TUGT (OR = 3.77, and 0.65 respectively). This persisted even after adjustment for age and gender (OR = 2.56, and 0.71 respectively) and after further adjustment for weight, systolic blood pressure, education, smoking, hyperlipidemia, hypothyroidism, and physical activity (O.R. = 4.79, and 0.76 respectively). Adjustment for both male and female genders showed an association between physical (HGS and TUGT) and EF was stronger among men.

CONCLUSION

A strong association between CDT score and both of HGS and TUGT was found among the studied sample. Higher HGS and lower TUGT was significantly associated with better performance in the CDT. This association is stronger in males than in females for both HGS and TUGT.

Executive function and high ambiguity perceptual discrimination contribute to individual differences in mnemonic discrimination in older adults

Mnemonic discrimination deficits, or impaired ability to discriminate between similar events in memory, is a hallmark of cognitive aging, characterised by a stark age-related increase in false recognition. While individual differences in mnemonic discrimination have gained attention due to potential relevance for early detection of Alzheimer's disease, our understanding of the component processes that contribute to variability in task performance across older adults remains limited. The present investigation explores the roles of representational quality, indexed by perceptual discrimination of objects and scenes with overlapping features, and strategic retrieval ability, indexed by standardised tests of executive function, to mnemonic discrimination in a large cohort of older adults (N=124). We took an individual differences approach and characterised the contributions of these factors to performance under Forced Choice (FC) and Yes/No (YN) recognition memory formats, which place different demands on strategic retrieval. Performance in both test formats declined with age. Accounting for age, individual differences in FC memory performance were best explained by perceptual discrimination score, whereas YN memory performance was best explained by executive functions. A linear mixed model and dominance analyses confirmed the relatively greater importance of perceptual discrimination over executive functioning for FC performance, while the opposite was true for YN. These findings highlight parallels between perceptual and mnemonic discrimination in aging, the importance of considering demands on executive functions in the context of mnemonic discrimination, and the relevance of test format for modulating the impact of these factors on performance in older adults.

What is the contribution of executive functions to communicative-pragmatic skills? Insights from aging and different types of pragmatic inference

The role of executive functions in supporting the pragmatics of communication has been extensively examined in clinical populations, but is still under-explored in healthy aging. In this study we addressed the role of executive skills, including inhibition, working memory, and cognitive flexibility, in older adults' communicative-pragmatic abilities. Pragmatics was extensively assessed by measuring the understanding of figurative language, narrative texts, humor, and implicatures. A hierarchical regression analysis using composite scores evidenced a global effect of executive functions on communicative-pragmatic abilities, beyond demographic and theory of mind aspects. More fine-grained analyses showed that working memory was the strongest predictor of all pragmatic tasks. Specifically, comprehending narratives and humor seemed to capitalize primarily upon working memory, whereas figurative language and implicatures relied on working memory and to some extent cognitive flexibility. Conversely, inhibition did not stand out as a robust predictor of pragmatics. We argue that working memory allows for the simultaneous consideration of multiple pieces of information needed for pragmatic inferencing, and that only once working memory has played its role other executive aspects, such as cognitive flexibility and inhibition, might come into play. Overall, this study highlights the diverse role of executive skills in pragmatics in aging, and more generally contributes to shed light on pragmatic competence in older adults.

Virtual reality assessment of daily life executive functions in mood disorders: associations with neuropsychological and functional measures

BACKGROUND

Mood disorders are often accompanied by cognitive difficulties that impede patients' functional capacity. However, neuropsychological tests provide limited insight into patients' ability to tackle daily life cognitive challenges. To address this challenge, we investigated the sensitivity and validity of the Jansari assessment of Executive Functions (JEF©) virtual reality test in patients with mood disorders and its associations with functional capacity.

METHODS

In total, 21 patients with bipolar disorder or unipolar disorder in full or partial remission and 29 healthy control participants were recruited for the study. Participants attended one test session during which they underwent diagnostic assessments, mood ratings and assessments with JEF©, a battery of standard neuropsychological tests (RAVLT, Trial Making A and B, Fluency tests, letter-number sequencing and RBANS digit span and coding tests) and functional capacity measures (UPSA-B and FAST).

RESULTS

Patients showed impaired executive functions on JEF© compared to the control group. Relative to the control group, patients were also impaired on neuropsychological sub-composite scores of executive function, verbal memory and processing speed as well as on a global cognition composite score. In addition, JEF© scores predicted performance on a global cognition composite based on neuropsychological tests, and a performance-based measure of functional capacity.

LIMITATIONS

This study had a relatively small sample size and included a mixed group of patients with unipolar or bipolar disorder.

CONCLUSIONS

JEF© is a sensitive and valid measure of daily life executive impairments in patients with mood disorders that is associated with functional capacity.

The trail-making-test: Comparison between paper-and-pencil and computerized versions in young and healthy older adults

One of the key challenges in assessing cognitive performance is to detect not only apparent impairment but to also pick up on subtle differences. Computerized tests benefit especially from the acquisition of fine-grained outcome measures. However, the equivalency of paper-based and computerized tests cannot be assumed. The Trail-Making-Test is a paper-pencil cognitive assessment tool (ppTMT) that has been used in many research studies to evaluate visuomotor abilities and mental flexibility. A digital version of the extended TMT (including a condition measuring fine motor speed) called the dTMT has been developed. This study aims to test (1) reliability, (2) equivalence, and (3) agreement of the ppTMT and dTMT. A total of 53 healthy individuals aged 19 to 82 years of age (22 men, 31 women; mean age 42.2, SD = 22.8) completed three trials per ppTMT and dTMT condition. Part M involves following a predefined path, Part A links numbers randomly distributed in space, in ascending order, and Part B alternates between linking numbers and letters. dTMT scores were highly reproducible, correlated strongly with paper-pencil administered durations, and discriminated young from older adults. Measures of reliability, sensitivity, and clinical meaning for dTMT scores were favorable compared with ppTMT-based testing. Our findings support the comparability of TMT-indices in computerized assessments. While many digital biomarker efforts are in progress (e.g., neurodegenerative disorders), the dTMT sets itself apart through its high sensitivity, the alternate forms, and the additional component measures. In this light, it could serve as a starting point for an early diagnostic tool.

Meta-Analysis on the Effectiveness of Virtual Reality Cognitive Training (VRCT) and Computer-Based Cognitive Training (CBCT) for Individuals with Mild Cognitive Impairment (MCI)

This meta-analysis aims to assess the effectiveness of virtual reality cognitive training (VRCT) and conventional computer-based cognitive training (CBCT) in five specific cognitive domains (i.e., global cognitive function (GCF), memory (Mem), executive function (EF), language (Lang) and visuospatial skills (VS)) of individuals with mild cognitive impairment. A total of 320 studies were yielded from five electronic databases. Eighteen randomized controlled trials met the PRISMA criteria, with 10 related to VRCT and 8 related to CBCT. A random-effect model was used in determining the main effect of cognitive training in five specific cognitive domains. VRCT provided the largest effect size on VS and Lang while the smallest on EF. CBCT provided the largest effect size on Mem and Lang while the smallest on EF. VRCT and CBCT generate an opposite effect on VS. VRCT outweighs CBCT in treatment effectiveness of GCF, EF, Lang and VS. More immersive and interactive experiences in VRCT may help individuals with MCI better engage in real-life experiences, which supports skill generalization and reduces external distractions. CBCT tends to improve Mem but no definite conclusions can be made. Further investigation with more stringent research design and specific protocol are required to reach consensus about the optimum intervention regime.

Do cognitive training applications improve executive function in children with adverse childhood experiences? A pilot study

Executive function (EF) is comprised of inhibitory control, working memory and cognitive flexibility, core components which more complex skills and abilities develop from, including problem solving, reasoning and planning. Adverse childhood experiences (ACE) negatively impact the development of these skills and in turn life outcomes. This pilot-study explores the use of computerized cognitive training applications (CCTA) (software-based training programs) in school, to improve these skills in children aged 6-11 with ACE. A pre-post-test, between-subject experimental design using an experimental and a placebo-control group was used. The control group were matched to the experimental group by prior academic attainment level and age. A one-way multivariate analysis of covariance (MANCOVA) assessed changes in EF across two time-points between the experimental and the control group. Both groups of participants were selected based on an ACE parent-report questionnaire score of 4+ (n = 32). EF was measured using the Behavior Rating Inventory of Executive Function (BRIEF), assessing far-transfer of training to behavioral measures of EF. Results show CCTA had a significant positive impact on executive function, particularly on working memory. This small-scale pilot study presents exciting directions for future research into the role of CCTA in order to confirm conclusions drawn.