Assessing mental flexibility: neuroanatomical and neuropsychological correlates of the Trail Making Test in elderly people

Neuropsychological profile associated with financial exploitation vulnerability in older adults without dementia

Objective: Reports of financial exploitation have steadily increased among older adults. Few studies have examined neuropsychological profiles for individuals vulnerable to financial exploitation, and existing studies have focused on susceptibility to scams, one specific type of financial exploitation. The current study therefore examines whether a general measure of financial exploitation vulnerability is associated with neuropsychological performance in a community sample. Methods: A sample (n = 116) of adults aged 50 or older without dementia completed a laboratory visit that measures physical and psychological functioning and a neuropsychological assessment, the Uniform Data Set-3 (UDS-3) and California Verbal Learning Test-II. Results: After covarying for demographics, current medical problems, financial literacy, and a global cognition screen, financial exploitation vulnerability was negatively associated with scores on the Multilingual Naming Test, Craft Story Recall and Delayed Recall, California Verbal Learning Test-II Delayed Recall and Recognition Discriminability, Phonemic Fluency, and Trails B. Financial exploitation vulnerability was not associated with performance on Digit Span, Semantic Fluency, Benson Complex Figure Recall, or Trails A. Conclusions: Among older adults without dementia, individuals at higher risk for financial exploitation demonstrated worse verbal memory, confrontation naming, phonemic fluency, and set-shifting. These tests are generally sensitive to Default Mode Network functioning and Alzheimer's Disease neuropathology. Longitudinal studies in more impaired samples are warranted to further corroborate and elucidate these relationships.

Measuring cognitive flexibility: A brief review of neuropsychological, self-report, and neuroscientific approaches

Cognitive flexibility involves dynamic processes that allow adaptation of our thinking and behavior in response to changing contextual demands. Despite a large consensus about its beneficial effects, cognitive flexibility is still poorly understood. In this mini review, we examined the main conceptualizations and approaches for assessing cognitive flexibility: (1) neuropsychological tasks, (2) self-report questionnaires, and (3) neuroscientific approaches. The reviewed evidence shows that the definition and assessment of cognitive flexibility are not unified within the field and suggests that a more consensual and consistent conceptualization and operationalization of this important concept is needed. We propose that an integrative behavior-brain-context approach can help advance our understanding of cognitive flexibility.

The impact of frontal lesions after mild to moderate traumatic brain injury on frontal network measures

To investigate the impact of frontal macro-structural lesions on intrinsic network measures, we examined brain network function during resting-state fMRI in patients with frontal lesions in the subacute phase after mild to moderate traumatic brain injury. Additionally, network function was related to neuropsychological performances. 17 patients with frontal lesions, identified on admission CT after mild to moderate trauma, were compared to 30 traumatic brain injury patients without frontal lesions and 20 healthy controls. Three months post-injury, we acquired fMRI scans and neuropsychological assessments (measuring frontal executive functions and information processing speed). Using independent component analysis, the activity of and connectivity between network components (largely located in the prefrontal cortex) and relations with neuropsychological measures were examined and compared across groups. The analysis yielded five predominantly frontal components: anterior and posterior part of the default mode network, left and right frontoparietal network and salience network. No significant differences concerning fMRI measures were found across groups. However, the frontal lesions group performed significantly worse on neuropsychological tests than the other two groups. Additionally, the frontal lesions group showed a significant positive association of stronger default mode network-salience network connectivity with better executive performances. Our findings suggest that, on fMRI level, frontal network measures are not largely affected by frontal lesions following a mild to moderate traumatic brain injury. Yet, patients with damage to the frontal structures did show poorer executive abilities which might to some degree be related to altered frontal network connectivity between the default mode network and salience network.

Mental flexibility depends on a largely distributed white matter network: Causal evidence from connectome-based lesion-symptom mapping

Mental flexibility (MF) refers to the capacity to dynamically switch from one task to another. Current neurocognitive models suggest that since this function requires interactions between multiple remote brain areas, the integrity of the anatomic tracts connecting these brain areas is necessary to maintain performance. We tested this hypothesis by assessing with a connectome-based lesion-symptom mapping approach the effects of white matter lesions on the brain's structural connectome and their association with performance on the trail making test, a neuropsychological test of MF, in a sample of 167 first unilateral stroke patients. We found associations between MF deficits and damage of i) left lateralized fronto-temporo-parietal connections and interhemispheric connections between left temporo-parietal and right parietal areas; ii) left cortico-basal connections; and iii) left cortico-pontine connections. We further identified a relationship between MF and white matter disconnections within cortical areas composing the cognitive control, default mode and attention functional networks. These results for a central role of white matter integrity in MF extend current literature by providing causal evidence for a functional interdependence among the regional cortical and subcortical structures composing the MF network. Our results further emphasize the necessity to consider connectomics in lesion-symptom mapping analyses to establish comprehensive neurocognitive models of high-order cognitive functions.

Neuronal properties of pyramidal cells in lateral prefrontal cortex of the aging rhesus monkey brain are associated with performance deficits on spatial working memory but not executive function

Age-related declines in cognitive abilities occur as early as middle-age in humans and rhesus monkeys. Specifically, performance by aged individuals on tasks of executive function (EF) and working memory (WM) is characterized by greater frequency of errors, shorter memory spans, increased frequency of perseverative responses, impaired use of feedback and reduced speed of processing. However, how aging precisely differentially impacts specific aspects of these cognitive functions and the distinct brain areas mediating cognition are not well understood. The prefrontal cortex (PFC) is known to mediate EF and WM and is an area that shows a vulnerability to age-related alterations in neuronal morphology. In the current study, we show that performance on EF and WM tasks exhibited significant changes with age, and these impairments correlate with changes in biophysical properties of layer 3 (L3) pyramidal neurons in lateral LPFC (LPFC). Specifically, there was a significant age-related increase in excitability of L3 LPFC pyramidal neurons, consistent with previous studies. Further, this age-related hyperexcitability of LPFC neurons was significantly correlated with age-related decline on a task of WM, but not an EF task. The current study characterizes age-related performance on tasks of WM and EF and provides insight into the neural substrates that may underlie changes in both WM and EF with age.

Binding objects to their spatiotemporal context: Age gradient and neuropsychological correlates of What-Where-When task performance

A number of recent studies have shown that the ability to accurately recall bound object and spatiotemporal aspects of an experienced event develops gradually in children and is greatly impaired in the elderly, reflecting developmental discontinuities in the integrity of the underlying medial temporal lobe network. Using a novel What-Where-When (WWW) visuospatial reconstruction task, the experiential memory performance of a group of healthy older adults (aged 60-80) was compared to that of a group of younger adults (aged 20-40). Both groups were equated on their general cognitive ability, their executive functioning, and on the presence of depression, anxiety, and stress symptomatology. As hypothesized, the performance of the older adults in the binding task was significantly lower, with younger participants recalling three times the amount of bound object and spatiotemporal triads than their older counterparts. Psychomotor speed was found to be lower in older adults and was the only neuropsychological index to significantly affect success on the WWW binding task. Based on this and other relevant studies, the selective associative memory impairment obtained using a non-verbal What-Where-When paradigm emerges as a marker for the detection of early pre-clinical signs of experiential memory pathology.

Patterns of structure-function association in normal aging and in Alzheimer's disease: Screening for mild cognitive impairment and dementia with ML regression and classification models

Background

The combined analysis of imaging and functional modalities is supposed to improve diagnostics of neurodegenerative diseases with advanced data science techniques.

Objective

To get an insight into normal and accelerated brain aging by developing the machine learning models that predict individual performance in neuropsychological and cognitive tests from brain MRI. With these models we endeavor to look for patterns of brain structure-function association (SFA) indicative of mild cognitive impairment (MCI) and Alzheimer's dementia.

Materials and methods

We explored the age-related variability of cognitive and neuropsychological test scores in normal and accelerated aging and constructed regression models predicting functional performance in cognitive tests from brain radiomics data. The models were trained on the three study cohorts from ADNI dataset-cognitively normal individuals, patients with MCI or dementia-separately. We also looked for significant correlations between cortical parcellation volumes and test scores in the cohorts to investigate neuroanatomical differences in relation to cognitive status. Finally, we worked out an approach for the classification of the examinees according to the pattern of structure-function associations into the cohorts of the cognitively normal elderly and patients with MCI or dementia.

Results

In the healthy population, the global cognitive functioning slightly changes with age. It also remains stable across the disease course in the majority of cases. In healthy adults and patients with MCI or dementia, the trendlines of performance in digit symbol substitution test and trail making test converge at the approximated point of 100 years of age. According to the SFA pattern, we distinguish three cohorts: the cognitively normal elderly, patients with MCI, and dementia. The highest accuracy is achieved with the model trained to predict the mini-mental state examination score from voxel-based morphometry data. The application of the majority voting technique to models predicting results in cognitive tests improved the classification performance up to 91.95% true positive rate for healthy participants, 86.21%-for MCI and 80.18%-for dementia cases.

Conclusion

The machine learning model, when trained on the cases of this of that group, describes a disease-specific SFA pattern. The pattern serves as a "stamp" of the disease reflected by the model.

Association of Income with Post-Stroke Cognition and the Underlying Neuroanatomical Mechanism

OBJECTIVE

To investigate the association between income and post-stroke cognition at 3 months, and the underlying neuroanatomical mechanism.

METHODS

Patients with first-ever ischemic stroke were enrolled and analyzed. Baseline information on income and neuroimaging measurements with predictive values for post-stroke cognitive impairment (PSCI) were collected within 7 days of the admission. Three months after the index stroke, all participants underwent a detailed neuropsychological test battery. The associations between income and PSCI and between income and brain structural measurements were investigated.

RESULTS

A total of 294 patients were recruited for this study. Lower income was independently associated with poor cognitive performance on Stroop tests, Clinical Dementia Rating, Boston Naming Test, and Verbal Fluency Test. Regarding neuroimaging parameters, lower income was associated with a lower total brain volume (TBV)/total intracranial volume (TICV) ratio (p = 0.004).

CONCLUSIONS

Lower income is associated with an increased chance of post-stroke cognitive decline, particularly in executive function and language domains. Since global brain atrophy (measured by TBV/TICV ratio) is a strong predictor for PSCI, its correlation with income may help explain the neuroanatomical mechanism between income and post-stroke cognition.

Neuronal properties of pyramidal cells in lateral prefrontal cortex of the aging rhesus monkey brain are associated with performance deficits on spatial working memory but not executive function

Age-related declines in cognitive abilities occur as early as middle-age in humans and rhesus monkeys. Specifically, performance by aged individuals on tasks of executive function (EF) and working memory (WM) is characterized by greater frequency of errors, shorter memory spans, increased frequency of perseverative responses, impaired use of feedback and reduced speed of processing. However, how aging precisely differentially impacts specific aspects of these cognitive functions and the distinct brain areas mediating cognition are not well understood. The prefrontal cortex (PFC) is known to mediate EF and WM and is an area that shows a vulnerability to age-related alterations in neuronal morphology. In the current study, we show that performance on EF and WM tasks exhibited significant changes with age and these impairments correlate with changes in biophysical properties of L3 pyramidal neurons in lateral LPFC (LPFC). Specifically, there was a significant age-related increase in excitability of Layer 3 LPFC pyramidal neurons, consistent with previous studies. Further, this age-related hyperexcitability of LPFC neurons was significantly correlated with age-related decline on a task of WM, but not an EF task. The current study characterizes age-related performance on tasks of WM and EF and provides insight into the neural substrates that may underlie changes in both WM and EF with age.

Vascular feature as a modulator of the aging brain

The cerebral functional reorganization and declined cognitive function of aging might associate with altered vascular features. Here, we explored the altered cerebral hierarchical functional network of 2 conditions (task-free and naturalistic stimuli) in older adults and its relationship with vascular features (systemic microvascular and perfusion features, measured by magnetic resonance imaging) and behavior. Using cerebral gradient analysis, we found that compressive gradient of resting-state mainly located on the primary sensory-motor system and transmodal regions in aging, and further compress in these regions under the continuous naturalistic stimuli. Combining cerebral functional gradient, vascular features, and cognitive performance, the more compressive gradient in the resting-state, the worse vascular state, the lower cognitive function in older adults. Further modulation analysis demonstrated that both vascular features can regulate the relationship between gradient scores in the insula and behavior. Interestingly, systemic microvascular oxygenation also can modulate the relationship between cerebral gradient and cerebral perfusion. Furthermore, the less alteration of the compressive gradient with naturalistic stimuli came with lower cognitive function. Our findings demonstrated that the altered cerebral hierarchical functional structure in aging was linked with changed vascular features and behavior, offering a new framework for studying the physiological mechanism of functional connectivity in aging.

The Use of Executive Fluency Tasks to Detect Cognitive Impairment in Individuals with Subjective Cognitive Decline

OBJECTIVE

Although evidence has indicated that subjective cognitive decline (SCD) may be an early sign of Alzheimer's disease (AD), the objectification of cognitive impairment in SCD is challenging, mainly due to the lack of sensitivity in assessment tools. The present study investigated the potential contribution of two verbal fluency tasks with high executive processing loads to the identification of cognitive impairment in SCD.

METHODS

A total of 60 adults with SCD and 60 healthy controls (HCs) performed one free action (verb) fluency task and two fluency tasks with more executive processing load-an alternating fluency task and an orthographic constraint fluency task-and the results were compared.

RESULT

In the free action fluency task, the performance of the participants with SCD and the HCs was similar. However, HCs performed significantly better than SCD in the alternating fluency task, which required mental flexibility, and the orthographic constraint fluency task, which required inhibition.

DISCUSSION

The study findings suggest that verbal fluency tasks with high executive processing load could be useful in detecting cognitive deficits at the preclinical stage of AD. The inclusion of such tests in assessment batteries should be considered in order to improve the detection of subtle cognitive impairment in preclinical major neurocognitive disorder populations.

The relationship between clinical measures of cognitive function and grip strength in healthy older adults

BACKGROUND

Handgrip strength is considered a surrogate for musculoskeletal strength, however there is emerging evidence of an association with cognition. The specific neurocognitive attribute which best associates with grip strength is unknown.

METHODS

We performed a secondary analysis on baseline data in 49 healthy older adults. Grip strength was corrected for body mass index. Control independent variables included age, Montreal Cognitive Assessment, and Trails B. Experimental variables included a clinical measure of simple reaction time, and clinical and computerized go/no-go tasks. The clinical Go/No-Go measure was determined with ReacStick, a rod-shaped device which - when released by the examiner - requires the participant to decide within 390 ms whether to catch the device or let it fall to the ground.

RESULTS

Bivariate analysis demonstrated that age and all cognitive measures other than the computer go/no-go response accuracy related to grip strength. Multivariate analyses showed that following inclusion of the control variables, only ReacStick measures (reaction accuracy/simple reaction time) significantly predicted grip strength, explaining an additional 15.90% variance (p = 0.026). In contrast, computerized Go/No-Go accuracy (p = 0.391), response time variability (p = 0.463), and the control variables (p value range = 0.566-0.942) did not predict grip strength.

CONCLUSION

A short latency (< 390 ms) visuomotor Go/No-Go task independently predicted over 15% of grip strength variance, whereas a slower screen-based Go/No-Go task did not. These findings support the notion that declining grip strength likely reflects sub-clinical brain changes as well as musculoskeletal dysfunction, possibly explaining the potent relationships between grip strength, disability, chronic disease, and mortality.

Effect of human probiotics on memory, psychological and biological measures in elderly: A study protocol of bi-center, double-blind, randomized, placebo-controlled clinical trial (CleverAge Biota)

Background

Gut microbiota may influence brain functions. Therefore, we prepared a study protocol for a double-blind, crossover, randomized clinical trial to determine the complex effects of human probiotics on memory, psychological, and biological measures in the elderly.

Methods

We selected eligible participants using an effective electronic questionnaire containing the inclusion and exclusion criteria and a brief electronic cognitive test. One-third of the respondents with the worst cognitive scores on the electronic test are randomized to group A, starting with a 3-month probiotic intervention, and to group B, starting with a placebo. In a crossover design, both groups change their intervention/placebo status after 3 months for the next 3 months. Participants refusing longer personal assessments due to the COVID-19 pandemic were randomly allocated to one of two subgroups assessed online. Participants in both groups are matched in age, education, gender, and cognitive scores on electronic testing at baseline. At three time points, participants are assessed using a neuropsychological battery, self-report measures of mood, a physical fitness test, blood, urine, and stool samples, and actigraphy. A subset of participants also provided their biological samples and underwent the neuropsychological battery in an extended testing phase 3 months after study termination to find out the long-term effect of the intervention.

Discussion

This is the first trial to address the comprehensive effects of human probiotics on memory and many other measures in the elderly. We assume that the probiotic group will have better outcomes than the placebo group after the first and second trimesters. We expect that the probiotic effect will persist for the next 3 months. These study's findings will contribute to an interesting area of how to improve memory, psychological and biological and other factors naturally and will examine the importance of probiotics for overall health in the elderly.

Clinical trial registration

[clinicaltrials.gov], identifier [NCT05051501].

Higher levels of neuroticism in older adults predict lower executive functioning across time: the mediating role of perceived stress

Neuroticism has been associated with individual differences across multiple cognitive functions. Yet, the literature on its specific association with executive functions (EF) in older adults is scarce, especially using longitudinal designs. To disentangle the specific influence of neuroticism on EF and on coarse cognitive functioning in old adulthood, respectively, we examined the relationship between neuroticism, the Trail Making Test (TMT) and the Mini-Mental State Examination (MMSE) in a 6-year longitudinal study using Bayesian analyses. Data of 768 older adults (M age = 73.51 years at Wave 1) were included in a cross-lagged analysis. Results showed no cross-sectional link between neuroticism and TMT performance at Wave 1 and no longitudinal link between neuroticism at Wave 1 and MMSE at Wave 2. However, neuroticism at Wave 1 predicted TMT performance at Wave 2, indicating that the more neurotic participants were, the lower they performed on the TMT six years later. Additional analyses showed that this relation was fully mediated by participants' perceived stress. Our results suggest that the more neurotic older adults are the more stress they may perceive six years later, which in turn negatively relates to their EF. In sum, this study demonstrates that neuroticism may lead to lower EF in older age across six years. It further suggests older adults' perceived stress as mediator, thereby providing novel insights into the mechanisms underlying this relation. Possible intervention approaches to counter these effects are discussed.

Life-course socioeconomic conditions and cognitive performance in older adults: a cross-cohort comparison

OBJECTIVES

Socioeconomic disadvantage predicts the level of cognitive performance in old age, but findings have been mixed for trajectories of performance. This study examined associations between life-course socioeconomic conditions, including social mobility, and cognitive performance assessed in terms of level and change, across multiple cognitive domains in two independent cohorts of older adults.

METHODS

Data were from two Swiss population-based cohorts: CoLaus|PsyCoLaus (N = 1210, mean age 72 years) and Vivre/Leben/Vivere (N = 993, mean age 75 years). Verbal fluency, processing speed, cognitive flexibility, memory, and global cognitive performance were assessed at two time points, each spaced 6 years apart. Associations between socioeconomic conditions (father's occupation, parental education, own education, own occupation, household income, and social mobility) and cognitive performance were examined within each cohort, and using pooled data. Covariates included health behaviors, comorbidities, and depressive symptoms.

RESULTS

Across cohorts, socioeconomic disadvantage predicted a lower level of performance across different cognitive domains, including processing speed, verbal fluency, and memory. Moreover, individuals who experienced life-course socioeconomic disadvantage performed worse than those who experienced upward social mobility. Associations between socioeconomic disadvantage and cognitive decline were less consistent.

CONCLUSION

Life-course socioeconomic conditions predict performance level across different cognitive domains, and, to a lesser extent, performance trajectories.

Effects of aging on functional connectivity in a neurodegenerative risk cohort: resting state versus task measurement using near-infrared spectroscopy

Changes in functional brain organization are considered to be particularly sensitive to age-related effects and may precede structural cognitive decline. Recent research focuses on aging processes determined by resting state (RS) functional connectivity (FC), but little is known about differences in FC during RS and cognitive task conditions in elderly participants. The purpose of this study is to compare FC within and between the cognitive control (CCN) and dorsal attention network (DAN) at RS and during a cognitive task using functional near-infrared spectroscopy (fNIRS). In a matched, neurodegenerative high-risk cohort comprising early (n = 98; 50–65 y) and late (n = 98; 65–85 y) elder subjects, FC was measured at RS and during performance of the Trail Making Test (TMT) via fNIRS. Both, under RS and task conditions our results revealed a main effect for age, characterized by reduced FC for late elder subjects within the left inferior frontal gyrus. During performance of the TMT, negative correlations of age and FC were confirmed in various regions of the CCN and DAN. For the whole sample, FC of within-region connections was elevated, while FC between regions was decreased at RS. The results confirm a reorganization of functional brain connectivity with increasing age and cognitive demands.

Cingulo-opercular and frontoparietal control network connectivity and executive functioning in older adults

Executive function is a cognitive domain that typically declines in non-pathological aging. Two cognitive control networks that are vulnerable to aging-the cingulo-opercular (CON) and fronto-parietal control (FPCN) networks-play a role in various aspects of executive functioning. However, it is unclear how communication within these networks at rest relates to executive function subcomponents in older adults. This study examines the associations between CON and FPCN connectivity and executive function performance in 274 older adults across working memory, inhibition, and set-shifting tasks. Average CON connectivity was associated with better working memory, inhibition, and set-shifting performance, while average FPCN connectivity was associated solely with working memory. CON region of interest analyses revealed significant connections with classical hub regions (i.e., anterior cingulate and anterior insula) for each task, language regions for verbal working memory, right hemisphere dominance for inhibitory control, and widespread network connections for set-shifting. FPCN region of interest analyses revealed largely right hemisphere fronto-parietal connections important for working memory and a few temporal lobe connections for set-shifting. These findings characterize differential brain-behavior relationships between cognitive control networks and executive function in aging. Future research should target these networks for intervention to potentially attenuate executive function decline in older adults.

Digitally generated Trail Making Test data: Analysis using hidden Markov modeling

The Trail Making Test (TMT) is a neuropsychological test used to assess cognitive dysfunction. The TMT consists of two parts: TMT-A requires connecting numbers 1 to 25 sequentially; TMT-B requires connecting numbers 1 to 12 and letters A to L sequentially, alternating between numbers and letters. We propose using a digitally recorded version of TMT to capture cognitive or physical functions underlying test performance. We analyzed digital versions of TMT-A and -B to derive time metrics and used Bayesian hidden Markov models to extract additional metrics. We correlated these derived metrics with cognitive and physical function scores using regression. On both TMT-A and -B, digital metrics associated with graphomotor processing test scores and gait speed. Digital metrics on TMT-B were additionally associated with episodic memory test scores and grip strength. These metrics provide additional information of cognitive state and can differentiate cognitive and physical factors affecting test performance.

A Link between Handgrip Strength and Executive Functioning: A Cross-Sectional Study in Older Adults with Mild Cognitive Impairment and Healthy Controls

Older adults with amnestic mild cognitive impairment (aMCI) who in addition to their memory deficits also suffer from frontal-executive dysfunctions have a higher risk of developing dementia later in their lives than older adults with aMCI without executive deficits and older adults with non-amnestic MCI (naMCI). Handgrip strength (HGS) is also correlated with the risk of cognitive decline in the elderly. Hence, the current study aimed to investigate the associations between HGS and executive functioning in individuals with aMCI, naMCI and healthy controls. Older, right-handed adults with amnestic MCI (aMCI), non-amnestic MCI (naMCI), and healthy controls (HC) conducted a handgrip strength measurement via a handheld dynamometer. Executive functions were assessed with the Trail Making Test (TMT A&B). Normalized handgrip strength (nHGS, normalized to Body Mass Index (BMI)) was calculated and its associations with executive functions (operationalized through z-scores of TMT B/A ratio) were investigated through partial correlation analyses (i.e., accounting for age, sex, and severity of depressive symptoms). A positive and low-to-moderate correlation between right nHGS (rp (22) = 0.364; p = 0.063) and left nHGS (rp (22) = 0.420; p = 0.037) and executive functioning in older adults with aMCI but not in naMCI or HC was observed. Our results suggest that higher levels of nHGS are linked to better executive functioning in aMCI but not naMCI and HC. This relationship is perhaps driven by alterations in the integrity of the hippocampal-prefrontal network occurring in older adults with aMCI. Further research is needed to provide empirical evidence for this assumption.

The Diagnostic Value of Language Screening in Primary Progressive Aphasia: Validation and Application of the Sydney Language Battery

PURPOSE

The three variants of primary progressive aphasia (PPA) differ in clinical presentation, underlying brain pathology, and clinical course, which stresses the need for early differentiation. However, brief cognitive tests that validly distinguish between all PPA variants are lacking. The Sydney Language Battery (SYDBAT) is a promising screening instrument that can be used as a first step in a comprehensive neuropsychological assessment to distinguish PPA subtypes, but evidence on its validity and reliability is to date limited. In the current study, the validation and diagnostic value of the SYDBAT are described for discriminating PPA subtypes as well as distinguishing PPA from mild cognitive impairment (MCI) or Alzheimer's dementia (AD).

METHOD

Forty-five patients with PPA (13 with semantic PPA, 20 with logopenic PPA, and 12 with nonfluent/agrammatic PPA), 25 MCI patients, 13 AD patients, and 50 cognitively unimpaired controls were included in this study. Both patients and controls completed the SYDBAT-NL (Dutch version). Performance on and predictive ability of the four subtests (i.e., Naming, Word Comprehension, Repetition, and Semantic Association) were assessed. In addition, construct validity and internal consistency were examined.

RESULTS

Different SYDBAT performance patterns were found across PPA and non-PPA patient groups. While a discriminant function analysis based on SYDBAT subtest scores could predict PPA subtype with 78% accuracy, it was more difficult to disentangle PPA from non-PPA patients based on SYDBAT scores alone. For assisting in clinical interpretation, simple rules were set up and translated into a diagnostic decision tree for subtyping PPA, which was capable of diagnosing a large proportion of the cases. Satisfying validity and reliability measures were found.

CONCLUSIONS

The SYDBAT is an easy-to-use and promising screen for assessing single-word language processes, which may contribute to the differential diagnostic process of PPA and the assessment of language impairment in MCI and AD. It can be easily implemented for initial screening of patients in a memory clinic.

Switching attention deficits in post-stroke individuals with different aphasia types

BACKGROUND

Previous studies have shown that individuals with aphasia have impairments in switching attention compared to healthy controls. However, there is insufficient information about the characteristics of switching attention within one task and whether attention deficits vary depending on aphasia type and lesion location. We aimed to address these knowledge gaps by investigating characteristics of switching attention within one type of task in participants with different types of aphasia and distinct lesion sites.

METHOD

Forty individuals with post-stroke aphasia (20 with non-fluent aphasia and frontal lobe damage, and 20 with fluent aphasia and temporal lobe damage) and 20 neurologically healthy age-matched individuals performed an attention switching task. They listened to sequences of high-pitched and low-pitched tones that were presented to them one by one, tallied them separately, and, at the end of each sequence, had to say how many high- and low-pitched tones they had heard.

RESULTS

Participants with aphasia performed significantly worse on the task compared to healthy controls, and the performance of two aphasia groups also differed. Specifically, individuals with both aphasia types made more errors than healthy individuals, and the participants with non-fluent aphasia responded more slowly than controls, while reaction times of the participants with fluent aphasia did not differ significantly from those of controls. Also, the two groups of participants with aphasia differed significantly in accuracy, with individuals in the non-fluent group making more errors.

CONCLUSIONS

The data demonstrated that people with different types of aphasia have distinct impairments in switching attention. Since cognitive deficits impact language performance, this information is important for differentially addressing their language problems and selecting more specific and optimal rehabilitation programs that target different underlying mechanisms.

Verbal intelligence is a more robust cross-sectional measure of cognitive reserve than level of education in healthy older adults

BACKGROUND

Cognitive reserve is most commonly measured using socio-behavioural proxy variables. These variables are easy to collect, have a straightforward interpretation, and are widely associated with reduced risk of dementia and cognitive decline in epidemiological studies. However, the specific proxies vary across studies and have rarely been assessed in complete models of cognitive reserve (i.e. alongside both a measure of cognitive outcome and a measure of brain structure). Complete models can test independent associations between proxies and cognitive function in addition to the moderation effect of proxies on the brain-cognition relationship. Consequently, there is insufficient empirical evidence guiding the choice of proxy measures of cognitive reserve and poor comparability across studies.

METHOD

In a cross-sectional study, we assessed the validity of 5 common proxies (education, occupational complexity, verbal intelligence, leisure activities, and exercise) and all possible combinations of these proxies in 2 separate community-dwelling older adult cohorts: The Irish Longitudinal Study on Ageing (TILDA; N = 313, mean age = 68.9 years, range = 54-88) and the Cognitive Reserve/Reference Ability Neural Network Study (CR/RANN; N = 234, mean age = 64.49 years, range = 50-80). Fifteen models were created with 3 brain structure variables (grey matter volume, hippocampal volume, and mean cortical thickness) and 5 cognitive variables (verbal fluency, processing speed, executive function, episodic memory, and global cognition).

RESULTS

No moderation effects were observed. There were robust positive associations with cognitive function, independent of brain structure, for 2 individual proxies (verbal intelligence and education) and 16 composites (i.e. combinations of proxies). Verbal intelligence was statistically significant in all models. Education was significant only in models with executive function as the cognitive outcome variable. Three robust composites were observed in more than two-thirds of brain-cognition models: the composites of (1) occupational complexity and verbal intelligence, (2) education and verbal intelligence, and (3) education, occupational complexity, and verbal intelligence. However, no composite had larger average effects nor was more robust than verbal intelligence alone.

CONCLUSION

These results support the use of verbal intelligence as a proxy measure of CR in cross-sectional studies of cognitively healthy older adults.

Impaired Set-Shifting from Dorsal Stream Disconnection: Insights from a European Series of Right Parietal Lower-Grade Glioma Resection

Simple Summary

Awake surgery with cognitive monitoring has increasingly been implemented to preserve brain networks and functionality. More recently, not only surgery in the left but also in the right hemisphere, i.c., the parietal lobe, was associated with potential risk for deficits in cognitive functions, such as cognitive flexibility. We describe an explorative pilot study in an international consortium within clinical care as usual. Careful interpretation of our findings indicates that disconnection of the lateral part of the dorsal stream correlated with impaired set-shifting. More importantly, it illustrates the need for international collaboration on neuropsychological tests and methodologies to improve our understanding of white matter networks at risk during awake surgery.

Abstract

Awake surgery with cognitive monitoring has increasingly been implemented to preserve brain networks and functionality. More recently, not only surgery in the left but also in the right hemisphere, i.c., the parietal lobe, was associated with potential risk for deficits in cognitive functions, such as cognitive flexibility. In this explorative pilot study, we compare cognitive performance more than three months after surgery with baseline measurements and explore the association between cognitive decline and subcortical tracts that may have been severed during surgery in the right hemisphere. Twenty-two patients who underwent surgery for a right parietal low-grade glioma were assessed pre- and postoperatively using the Trail Making Test and the Stroop task to administer set-shifting abilities and inhibition. Volume measurements and lesion–symptom mapping analyses were performed on postoperative MRI scans. Careful interpretation of the results shows a change in TMT performance and not on the Stroop Task when the lateral part of the arcuate fasciculus is damaged, indicating that disconnection of the lateral part of the dorsal stream might be correlated specifically with impaired set-shifting and not with inhibition. More importantly, this study underlines the need for international concertation to allow larger studies to increase power and perform more detailed analyses.

Trail Making Test Performance Using a Touch-Sensitive Tablet: Behavioral Kinematics and Electroencephalography

The Trail Making Test (TMT) is widely used to probe brain function and is performed with pen and paper, involving Parts A (linking numbers) and B (alternating between linking numbers and letters). The relationship between TMT performance and the underlying brain activity remains to be characterized in detail. Accordingly, sixteen healthy young adults performed the TMT using a touch-sensitive tablet to capture enhanced performance metrics, such as the speed of linking movements, during simultaneous electroencephalography (EEG). Linking and non-linking periods were derived as estimates of the time spent executing and preparing movements, respectively. The seconds per link (SPL) was also used to quantify TMT performance. A strong effect of TMT Part A and B was observed on the SPL value as expected (Part B showing increased SPL value); whereas the EEG results indicated robust effects of linking and non-linking periods in multiple frequency bands, and effects consistent with the underlying cognitive demands of the test.

Engagement in Cognitively Stimulating Activities Mediates the Relationship between Openness and Attention/Executive Functions, but Not Memory in Older Adults

OBJECTIVE

Openness has a positive association with cognitive functioning and engagement in cognitively stimulating activities (CSA). Older adults who engage in more CSA tend to show greater preservation of their cognitive skills; thus, we examined whether: higher Openness would be associated with higher attention/executive functions (AEF) and verbal memory; and CSA would mediate the relationship between Openness and AEF, as well as verbal memory.

METHOD

477 community-dwelling older adults (65+ years) were included in the current cross-sectional study. Composite variables of AEF (TMT-A&B, COWAT, and DSST) and verbal memory (RBANS immediate and delayed verbal memory subtasks) were included. Openness was assessed via the Big-5 Inventory and CSA with the Leisure Activity Questionnaire.

METHOD

477 community-dwelling older adults (65+ years) were included in the current cross-sectional study. Composite variables of AEF (TMT-A&B, COWAT, and DSST) and verbal memory (RBANS verbal memory subtasks) were included. Openness was assessed via the Big-5 Inventory and CSA with the Leisure Activity Questionnaire.

RESULTS

Linear regressions indicated a significant positive association between Openness and AEF (β = .09, p < .01), but not verbal memory (β = .06, p = .06). A significant partial mediation was demonstrated between Openness, CSA, and AEF (c: β = .08, p < .05, 95%CI = .02-.14; c': β = .02, 95%CI = .01-.03). The mediation of Openness, CSA, and verbal memory was not significant (c: β = .06, p > .05, 95%CI = .01-.11; c': β = .00, 95%CI = -.01-.01).

CONCLUSIONS

The association between Openness and AEF, but not verbal memory, was partially mediated by CSA in healthy older adults. The findings suggest that those who are more open to and highly engaged in CSA may have a later in life advantage in preserving their AEF abilities.

Digital trail making test-black and white: Normal vs MCI

OBJECTIVE

Trail Making Test-Black and White (TMT-B&W) was developed to assess the cognition of patients with mild cognitive impairment (MCI), dementia, and Alzheimer's disease. Collection and analysis of test results have been limited due to scoring time and efforts required from both administrators and patients during and after taking the test. To increase efficiency and reducing scoring time, a computer version touchscreen-based digital trail making test-black and white (dTMT-B&W) was developed on Android and it was administered on MCI versus cognitively normal controls (NC) participants. The current study examines the sensitivity of newly developed computer version dTMT-B&W on NC and MCI subjects.

METHOD

dTMT-B&W was developed using MIT app inventor software, a web-based integrated development environment (IDE) with the Android development tools that are used to build fully functional applications for smartphones and tablets. A total of 44 participants were included, comprised of 22 NC and 22 MCI. The dTMT-TMT-B&W was administered to all NC and MCI subjects.

RESULT

dTMT-B&W was designed to be as consistent with the pen-paper TMT-B&W (ppTMT-B&W) where the application is a standalone installation. dTMT-B&W is divided into two parts (Part-A and Part-B), in which the subject attempts to connect black and white numbered circles sequentially as quickly as possible, while still maintaining accuracy. Similarly, the paper-based TMT-B&W requires the subject to connect black and white numbered circles in ascending order, except on a sheet of paper rather than a tablet. dTMT-B&W successfully distinguished NC from MCI subjects.

CONCLUSION

dTMT-B&W is an Android application that was successfully developed to be as consistent as possible with the original pen-paper TMT-B&W to establish equal concurrent validity, with some improved features embedded into the design and dTMT-B&W revealed a significant correlation with frontal executive function and this can help in early diagnosing subjects with MCI among NC subjects.

Reaction Time and Visible White Matter Lesions in Subcortical Ischemic Vascular Cognitive Impairment

Slowed behavioral reaction time is associated with pathological brain changes, including white matter lesions, the common clinical characteristic of subcortical ischemic vascular cognitive impairment (SIVCI). In the present study, reaction time (RT) employing Trails B of the Trail Making Test, with responses capped at 300 s, was investigated in SIVCI (n = 27) compared to cognitively healthy aging (CH) (n = 26). RT was significantly slowed in SIVCI compared to CH (Cohen’s d effect size = 1.26). Furthermore, failure to complete Trails B within 300 s was also a characteristic of SIVCI although some ostensibly cognitively healthy older adults also failed to complete within this time limit. Within the SIVCI group, RT did not differ significantly with respect to whether the patients were classified as having moderate/severe or mild, periventricular white matter changes visible on their diagnostic CT/MRI scans. This, together with the high degree of overlap in RT between the two SIVCI subgroups, raises the possibility that using visible ratings scales in isolation may lead to the underestimation of disease level.

White matter hyperintensities at critical crossroads for executive function and verbal abilities in small vessel disease

The presence of white matter lesions in patients with cerebral small vessel disease (SVD) is among the main causes of cognitive decline. We investigated the relation between white matter hyperintensity (WMH) locations and executive and language abilities in 442 SVD patients without dementia with varying burden of WMH. We used Stroop Word Reading, Stroop Color Naming, Stroop Color‐Word Naming, and Category Fluency as language measures with varying degrees of executive demands. The Symbol Digit Modalities Test (SDMT) was used as a control task, as it measures processing speed without requiring language use or verbal output. A voxel‐based lesion–symptom mapping (VLSM) approach was used, corrected for age, sex, education, and lesion volume. VLSM analyses revealed statistically significant clusters for tests requiring language use, but not for SDMT. Worse scores on all tests were associated with WMH in forceps minor, thalamic radiations and caudate nuclei. In conclusion, an association was found between WMH in a core frontostriatal network and executive‐verbal abilities in SVD, independent of lesion volume and processing speed. This circuitry underlying executive‐language functioning might be of potential clinical importance for elderly with SVD. More detailed language testing is required in future research to elucidate the nature of language production difficulties in SVD.

Breast cancer post-surgical impact on women´s quality of life during chemotherapy treatment: A structural equation modelling approach

OBJECTIVE

Breast cancer is an important public health problem that is increasing in incidence, being a stressor with a negative impact on women's quality of life. This study is focused on the evaluation of temporal precursors (one month before) of women's quality of life undergoing chemotherapy, considering post-surgical personal, clinical, cognitive and neuropsychophysiological factors, according to the Transactional Stress and Coping Model.

METHODS

This longitudinal study included 112 patients with breast cancer. Data were collected in two different moments: before and during the adjuvant chemotherapy. Structural equation modelling was used to support a theoretically based model in which some antecedent factors impact patients' long-term quality of life through a set of mediators.

RESULTS

The associations of breast symptoms, body image and sexual functioning with psychological distress and quality of life were totally mediated by illness perceptions, while the associations of working memory with psychological distress and quality of life were totally mediated by self-efficacy for coping. Patients with greater psychological distress showed higher levels of nadir cortisol.

CONCLUSIONS

Results showed the importance of assessing patients' perceptions of their illness, prior to chemotherapy, as well as promoting more self-efficacy for coping, in order to improve women's emotional state and quality of life.

Is Methylphenidate Beneficial and Safe in Pharmacological Cognitive Enhancement?

Nootropics are drugs used to either treat or benefit cognition deficits. Among this class, methylphenidate is a popular agent, which acts through indirect dopaminergic and noradrenergic agonism and, therefore, is proposed to enhance performance in catecholamine-dependent cognitive domains such as attention, memory and prefrontal cortex-dependent executive functions. However, investigation into the efficacy of methylphenidate as a cognitive enhancer has yielded variable results across all domains, leading to debate within the scientific community surrounding its off-label use in healthy individuals seeking scholaristic benefit or increased productivity. Through analysis of experimental data and methodological evaluation, it is apparent that there are dose-, task- and domain-dependent considerations surrounding the use of methylphenidate in healthy individuals, whereby tailored dose administration is likely to provide benefit on an individual basis dependent on the domain of cognition in which benefit is required. Additionally, it is apparent that there are subjective effects of methylphenidate, which may increase user productivity irrespective of cognitive benefit. Whilst there is not extensive study in healthy older adults, it is plausible that there are dose-dependent benefits to methylphenidate in older adults in selective cognitive domains that might improve quality of life and reduce fall risk. Methylphenidate appears to produce dose-dependent benefits to individuals with attention-deficit/hyperactivity disorder, but the evidence for benefit in Parkinson's disease and schizophrenia is inconclusive. As with any off-label use of pharmacological agents, and especially regarding drugs with neuromodulatory effects, there are inherent safety concerns; epidemiological and experimental evidence suggests there are sympathomimetic, cardiovascular and addictive considerations, which might further restrict their use within certain demographics.

Exploring the Predictive Ability of the Motor-Free Visual Perception Test (MVPT) and Trail Making Test (TMT) for On-Road Driving Performance

IMPORTANCE

Resuming driving after a change in functional ability is challenging for patients with a neurological condition. Although a combination of assessment tools has been suggested for use in driving evaluation, resources and availability of tools have been a problem.

OBJECTIVE

To examine the predictive ability of two commonly used tools, the Motor-Free Visual Perception Test (MVPT) and the Trail Making Test, Parts A and B (TMTA and TMTB), on on-road driving performance.

DESIGN

Retrospective chart review of 82 patient charts between 2015 and 2016.

SETTING

Local rehabilitation hospital.

PARTICIPANTS

Eighty-two patients with a primary neurological diagnosis (general neurological condition, n = 13; spinal cord injury, n = 11; stroke, n = 58).

OUTCOMES AND MEASURES

MVPT, TMTA, and TMTB.

RESULTS

Among the patients, 36 passed and 46 failed the on-road evaluation. The TMTA and TMTB scores were significantly different between those who passed or failed the on-road evaluation. Logistic regression analyses revealed that the TMTB completion time was the only significant predictor of on-road driving performance (for the all-patient model, 66% prediction accuracy, -2 log-likelihood [LL] = 93.47, exp β = 0.98; for the stroke-only model, 76% prediction accuracy, -2LL = 59.61, exp β = 0.97).

CONCLUSIONS AND RELEVANCE

Our findings suggest that the TMTB is a better predictor of on-road driving performance for patients with a neurological condition than the MVPT. The findings shed light on the importance of selecting proper tools when assessing driving performance. Future prospective studies with a wider array of predictive variables are recommended to support the present findings.

WHAT THIS ARTICLE ADDS

Occupational therapists should revisit the use of the MVPT in driving assessment and consider multiple assessment tools when evaluating and predicting driving performance.

Functional magnetic resonance imaging of the trail-making test in older adults

The trail-making test (TMT) is a popular neuropsychological test, which is used extensively to measure cognitive impairment associated with neurodegenerative disorders in older adults. Behavioural performance on the TMT has been investigated in older populations, but there is limited research on task-related brain activity in older adults. The current study administered a naturalistic version of the TMT to a healthy older-aged population in an MRI environment using a novel, MRI-compatible tablet. Functional MRI was conducted during task completion, allowing characterization of the brain activity associated with the TMT. Performance on the TMT was evaluated using number of errors and seconds per completion of each link. Results are reported for 36 cognitively healthy older adults between the ages of 52 and 85. Task-related activation was observed in extensive regions of the bilateral frontal, parietal, temporal and occipital lobes as well as key motor areas. Increased age was associated with reduced brain activity and worse task performance. Specifically, older age was correlated with decreased task-related activity in the bilateral occipital, temporal and parietal lobes. These results suggest that healthy older aging significantly affects brain function during the TMT, which consequently may result in performance decrements. The current study reveals the brain activation patterns underlying TMT performance in a healthy older aging population, which functions as an important, clinically-relevant control to compare to pathological aging in future investigations.

Standardising Dementia Diagnosis Across Linguistic and Educational Diversity: Study Design of the Indian Council of Medical Research-Neurocognitive Tool Box (ICMR-NCTB)

OBJECTIVES

While the burden of dementia is increasing in low- and middle-income countries, there is a low rate of diagnosis and paucity of research in these regions. A major challenge to study dementia is the limited availability of standardised diagnostic tools for use in populations with linguistic and educational diversity. The objectives of the study were to develop a standardised and comprehensive neurocognitive test battery to diagnose dementia and mild cognitive impairment (MCI) due to varied etiologies, across different languages and educational levels in India, to facilitate research efforts in diverse settings.

METHODS

A multidisciplinary expert group formed by Indian Council of Medical Research (ICMR) collaborated towards adapting and validating a neurocognitive test battery, that is, the ICMR Neurocognitive Tool Box (ICMR-NCTB) in five Indian languages (Hindi, Bengali, Telugu, Kannada, and Malayalam), for illiterates and literates, to standardise diagnosis of dementia and MCI in India.

RESULTS

Following a review of existing international and national efforts at standardising dementia diagnosis, the ICMR-NCTB was developed and adapted to the Indian setting of sociolinguistic diversity. The battery consisted of tests of cognition, behaviour, and functional activities. A uniform protocol for diagnosis of normal cognition, MCI, and dementia due to neurodegenerative diseases and stroke was followed in six centres. A systematic plan for validating the ICMR-NCTB and establishing cut-off values in a diverse multicentric cohort was developed.

CONCLUSIONS

A key outcome was the development of a comprehensive diagnostic tool for diagnosis of dementia and MCI due to varied etiologies, in the diverse socio-demographic setting of India.

Role of stress, age and adjuvant therapy in the cognitive function of patients with breast cancer

According to data largely obtained from retrospective studies, it has been postulated that chemotherapy exerts an aggravating effect on the cognitive function of patients with breast cancer. Potential individual factors related to the effects of chemotherapy on cognitive function have been indicated, such as age-related cognitive dysfunction and stress. Elderly patients differ from non-elderly patients as regards higher cognitive related comorbidities, such as dementia, as well as regarding lower stress levels, indicating that 'chemobrain' may differentially affect these two age groups. The aim of this review was to discuss the effects of stress and chemotherapy on cognitive dysfunction and identify any potential age-related differences in patients with breast cancer treated with adjuvant chemotherapy. For this purpose, a systematic review of the literature was carried out on the PubMed, Scopus and Web of Science databases. The inclusion criteria were original articles published in peer-reviewed journals, elderly and non-elderly patients with breast cancer, reporting on stress and at least one cognitive parameter pre- and/or post-treatment. Eight studies met the preset criteria and were further analyzed. In total, the data of 1,253 women were included, of whom 800 patients with breast cancer were treated with surgery only, systemic treatment only, or both. Although all the studies included a non-elderly breast cancer patient subpopulation, only two of the studies included patients over 65 years of age. All studies indicated a statistically significant association of stress with various domains of cognitive dysfunction in patients, as shown by either self-completed questionnaires, neuropsychological testing or both. An age over 60 years was linked to fewer cognitive difficulties mediated by lower levels of stress. Thus, the evidence supports the association of stress with cognitive deficits in patients with breast cancer, regardless of the type of cancer-related treatment. Therefore, stress should be appropriately addressed. However, further research is required to investigate the association of stress with cognitive function in elderly patients with breast cancer.

Individual differences in cognitive processes underlying Trail Making Test-B performance in old age: The Lothian Birth Cohort 1936

The Trail Making Test Part B (TMT-B) is commonly used as a brief and simple neuropsychological assessment of executive dysfunction. The TMT-B is thought to rely on a number of distinct cognitive processes that predict individual differences in performance. The current study examined the unique and shared contributions of latent component variables in a large cohort of older people. Five hundred and eighty-seven healthy, community-dwelling older adults who were all born in 1936 were assessed on the TMT-B and multiple tasks tapping cognitive domains of visuospatial ability, processing speed, memory and reading ability. Firstly, a first-order measurement model examining independent contributions of the four cognitive domains was fitted; a significant relationship between TMT-B completion times and processing speed was found (β = −0.610, p < .001). Secondly, a bifactor model examined the unique influence of each cognitive ability when controlling for a general cognitive factor. Importantly, both a general cognitive factor (g; β = −0.561, p < .001) and additional g-independent variance from processing speed (β = −0.464, p < .001) contributed to successful TMT-B performance. These findings suggest that older adults' TMT-B performance is influenced by both general intelligence and processing speed, which may help understand poor performance on such tasks in clinical populations.

•

Speed and general cognitive ability (g) contribute to Trail Making completion times.

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Faster processing speed was associated with faster completion times.

•

Higher g was a strong contributor to faster completion times.

•

Visuospatial and crystallized ability did not uniquely contribute to completion times.

•

Memory did not independently contribute to completion times.

Aberrant resting-state oscillatory brain activity in Parkinson's disease patients with visual hallucinations: An MEG source-space study

To gain insight into possible underlying mechanism(s) of visual hallucinations (VH) in Parkinson's disease (PD), we explored changes in local oscillatory activity in different frequency bands with source-space magnetoencephalography (MEG). Eyes-closed resting-state MEG recordings were obtained from 20 PD patients with hallucinations (Hall+) and 20 PD patients without hallucinations (Hall-), matched for age, gender and disease severity. The Hall+ group was subdivided into 10 patients with VH only (unimodal Hall+) and 10 patients with multimodal hallucinations (multimodal Hall+). Subsequently, neuronal activity at source-level was reconstructed using an atlas-based beamforming approach resulting in source-space time series for 78 cortical and 12 subcortical regions of interest in the automated anatomical labeling (AAL) atlas. Peak frequency (PF) and relative power in six frequency bands (delta, theta, alpha1, alpha2, beta and gamma) were compared between Hall+ and Hall-, unimodal Hall+ and Hall-, multimodal Hall+ and Hall-, and unimodal Hall+ and multimodal Hall+ patients. PF and relative power per frequency band did not differ between Hall+ and Hall-, and multimodal Hall+ and Hall- patients. Compared to the Hall- group, unimodal Hall+ patients showed significantly higher relative power in the theta band (p = 0.005), and significantly lower relative power in the beta (p = 0.029) and gamma (p = 0.007) band, and lower PF (p = 0.011). Compared to the unimodal Hall+, multimodal Hall+ showed significantly higher PF (p = 0.007). In conclusion, a subset of PD patients with only VH showed slowing of MEG-based resting-state brain activity with an increase in theta activity, and a concomitant decrease in beta and gamma activity, which could indicate central cholinergic dysfunction as underlying mechanism of VH in PD. This signature was absent in PD patients with multimodal hallucinations.

Effects of MitraClip on cognitive and psychological function in heart failure patients: the sicker the better

Purpose

Cognitive impairment and reduced quality of life is a common condition in patients with heart failure (HF). Percutaneous mitral valve repair using (PMVR) MitraClip (MC) has emerged as a promising interventional tool, reducing all-cause mortality and hospitalization as well as increasing cognitive functioning and quality of life. However, the benefit of HF patients with severely depressed cognitive functioning remains unknown.

Methods

We assessed cognitive functioning (figural memory—FGT, executive function—TOL, TMT B), psychosocial functioning (depression—PHQ-9, quality of life—SF36), and clinical parameters (echocardiography, 6-min walk test distance, and cardiac biomarkers) 1 day before (t0) and 6 weeks after (t1) MC intervention in HF patients (n = 40). First, paired sample t tests were conducted to uncover improvements in cognitive functioning post-MC intervention. Second, the COGBAT Norm-sample, a representative age-matched healthy sample, was used to compare participants’ individual scores. Third, bivariate linear regressions were calculated for all key predictors of the detected improvements in cognitive functioning post-MC intervention (t1–t0).

Results

Following the MC intervention, we found significant improvements in figural memory, executive functioning, and psychosocial functioning. Most of the patients with depressed executive functioning before the MC intervention showed post-intervention test scores within the normal range (> 50th percentile; t0 22.5% vs. t1 60%) as compared to the normative COGBAT sample. Regression analyses revealed that lower baseline scores in planning ability before the MC intervention (t0) were associated with greater planning ability (TOL; B = − 0.78, 95% CI − 1.04 to − 0.53), figural memory (FGT; B = − 0.26, 95% CI − 0.44 to − 0.07), and cognitive flexibility (TMT B; B = − 0.36, 95% CI − 0.50 to − 0.23) improvement post-MC intervention (t1–t0). Psychosocial functioning and age were not associated with these improvements.

Conclusions

Patients with depressed executive functioning showed the greatest benefit from the MC intervention regarding cognitive functioning. Age and psychological functioning seem less important for cognitive performance improvements post-MC intervention. Hence, severely depressed cognitive functioning in patients is not a contraindication for PMVR using MitraClip.

Structural white matter networks in myotonic dystrophy type 1

The myriad of neuropsychiatric manifestations reported in myotonic dystrophy type 1 may have its origin in alterations of complex brain network interactions at the structural level. In this study, we tested the hypothesis that altered white matter microstructural integrity and network organisation were present in a cohort of individuals with DM1 compared to unaffected controls, which was expected to be associated with CNS related disease manifestations of DM1. We performed a cross-sectional neuropsychological assessment and brain MRI in 25 myotonic dystrophy type 1 (DM1) patients and 26 age, sex and educational level matched unaffected controls. Patients were recruited from the Dutch cohort of the OPTIMISTIC study, a concluded trial which had included ambulant, genetically confirmed DM1 patients who were severely fatigued. We applied graph theoretical analysis on structural networks derived from diffusion tensor imaging (DTI) data and deterministic tractography to determine global and local network properties and performed group-wise comparisons. Furthermore, we analysed the following variables from structural MRI imaging: semi-quantitative white matter hyperintensity load andwhite matter tract integrity using tract-based spatial statistics (TBSS). Structural white matter networks in DM1 were characterised by reduced global efficiency, local efficiency and strength, while the network density was compatible to controls. Other findings included increased white matter hyperintensity load, and diffuse alterations of white matter microstructure in projection, association and commissural fibres. DTI and network measures were associated (partial correlations coefficients ranging from 0.46 to 0.55) with attention (d2 Test), motor skill (Purdue Pegboard test) and visual-constructional ability and memory (copy subtest of the Rey-Osterrieth Complex Figure Test). DTI and network measures were not associated with clinical measures of fatigue (checklist individual strength, fatigue subscale) or apathy (apathy evaluation scale - clinician version). In conclusion, our study supports the view of brain involvement in DM1 as a complex network disorder, characterised by white matter network alterations that may have relevant neuropsychological correlations. This work was supported by the European Community's Seventh Framework Programme (FP7/2007-2013; grant agreement n° 305,697) and the Marigold Foundation.

Improving precision in neuropsychological assessment: Bridging the gap between classic paper-and-pencil tests and paradigms from cognitive neuroscience

OBJECTIVE

In cognitive neuroscience, well-controlled and highly specific paradigms have been developed to measure cognitive processes over the last decades, often using computer-assisted presentation and response registration. This approach is in contrast with the traditional paper-and-pencil tests used in clinical neuropsychology, which typically assess cognitive function in a less specific manner, often even at the level of a cognitive domain. As a result, important aspects of cognitive (dys)function may be missed during a neuropsychological assessment. This paper focuses on the main challenges that need to be overcome in order to successfully integrate experimental paradigms from cognitive neuroscience into the clinical practice of neuropsychologists.

METHOD

Six challenges are discussed: (i) experimental paradigms are often lengthy and may be overly specific; (ii) technical limitations even today hamper their application in clinics; (iii) the psychometric properties of methods used in cognitive neuroscience are under-examined or poor; (iv) many paradigms from cognitive neuroscience rely on reaction times rather than accuracy, limiting their use in the many brain-injured patients with processing speed deficits; (v) the predictive and ecological validity of these paradigms often unclear; (vi) technological progress (e.g. Moore's law) seriously affects the continuous availability of experimental computerized assessment methods.

CONCLUSION

Both cognitive neuroscientists and clinical neuropsychologists should work together to develop and validate novel paradigms for use in clinical assessments that are platform-independent, reliable and valid, user friendly and easy to use in clinical practice.

Differences in road-crossing decisions between healthy older adults and patients with Alzheimer's disease

INTRODUCTION

This study investigated the differences in road-crossing behavior among healthy older adults and patients with Alzheimer's disease (AD).

METHOD

Twelve pedestrians with mild AD and 24 age-, gender-, and education-matched controls were examined with a battery of cognitive, visual, and motor tests. Using a simulated two-lane, one-way road-crossing situation, we determined the remaining time and safety margin for each participant in traffic situations involving different vehicle speeds (40 km/h vs. 60 km/h vs. 80 km/h), time gaps (5 s vs. 7 s vs. 9 s), and time of day (dusk vs. midday).

RESULTS

We found that patients with AD were more vulnerable to traffic crash while crossing the road than healthy older adults (Odds Ratio = 2.50, P < 0.05). Compared with healthy older adults, patients with AD were more severely affected by daylight conditions, faster vehicle speed, and shorter time gap. Participants in both groups had a significantly higher risk of unsafe crossing behavior if they had lower scores on the Mini-Mental State Examination (MMSE), Complex Figure Test - recall (CFT-Recall), Trail Making Test (TMT) B-A, Useful Field of View (UFOV) - total, and Visual Form Discrimination (VFD). We also found that when given a long enough time gap (9 s), patients with AD and healthy older adults used similar safe road-crossing behaviors, independent of other factors.

PRACTICAL APPLICATIONS

These results provide important suggestions for road design for patients with AD and healthy older adults during road-crossing.

Theoretical Modeling of Cognitive Dysfunction in Schizophrenia by Means of Errors and Corresponding Brain Networks

The current evidence of cognitive disturbances and brain alterations in schizophrenia does not provide the plausible explanation of the underlying mechanisms. Neuropsychological studies outlined the cognitive profile of patients with schizophrenia, that embodied the substantial disturbances in perceptual and motor processes, spatial functions, verbal and non-verbal memory, processing speed and executive functioning. Standardized scoring in the majority of the neurocognitive tests renders the index scores or the achievement indicating the severity of the cognitive impairment rather than the actual performance by means of errors. At the same time, the quantitative evaluation may lead to the situation when two patients with the same index score of the particular cognitive test, demonstrate qualitatively different performances. This may support the view why test paradigms that habitually incorporate different cognitive variables associate weakly, reflecting an ambiguity in the interpretation of noted cognitive constructs. With minor exceptions, cognitive functions are not attributed to the localized activity but eventuate from the coordinated activity in the generally dispersed brain networks. Functional neuroimaging has progressively explored the connectivity in the brain networks in the absence of the specific task and during the task processing. The spatio-temporal fluctuations of the activity of the brain areas detected in the resting state and being highly reproducible in numerous studies, resemble the activation and communication patterns during the task performance. Relatedly, the activation in the specific brain regions oftentimes is attributed to a number of cognitive processes. Given the complex organization of the cognitive functions, it becomes crucial to designate the roles of the brain networks in relation to the specific cognitive functions. One possible approach is to identify the commonalities of the deficits across the number of cognitive tests or, common errors in the various tests and identify their common "denominators" in the brain networks. The qualitative characterization of cognitive performance might be beneficial in addressing diffuse cognitive alterations presumably caused by the dysconnectivity of the distributed brain networks. Therefore, in the review, we use this approach in the description of standardized tests in the scope of potential errors in patients with schizophrenia with a subsequent reference to the brain networks.

Genetic contributions to Trail Making Test performance in UK Biobank

The Trail Making Test (TMT) is a widely used test of executive function and has been thought to be strongly associated with general cognitive function. We examined the genetic architecture of the TMT and its shared genetic aetiology with other tests of cognitive function in 23 821 participants from UK Biobank. The single-nucleotide polymorphism-based heritability estimates for trail-making measures were 7.9% (part A), 22.4% (part B) and 17.6% (part B-part A). Significant genetic correlations were identified between trail-making measures and verbal-numerical reasoning (r_g>0.6), general cognitive function (r_g>0.6), processing speed (r_g>0.7) and memory (r_g>0.3). Polygenic profile analysis indicated considerable shared genetic aetiology between trail making, general cognitive function, processing speed and memory (standardized β between 0.03 and 0.08). These results suggest that trail making is both phenotypically and genetically strongly associated with general cognitive function and processing speed.

Convergent Results from Neuropsychology and from Neuroimaging in Patients with Mild Cognitive Impairment

BACKGROUND/AIMS

To investigate the correspondence between neuropsychological single measures and variation in fludeoxyglucose positron emission tomography (FDG PET) glucose metabolism and magnetic resonance imaging (MRI) cortical thickness in mild cognitive impairment (MCI) patients.

METHODS

Forty-two elderly controls and 73 MCI subjects underwent FDG PET and MRI scanning. Backward regression analyses with PET and MRI regions were used as dependent variables, while Rey Auditory Verbal Memory Test (RAVLT) recall, Trail Making Test B (TMT B), and a composite test score (RAVLT learning and immediate recall, TMT A, COWAT, and letter-number sequencing) were used as predictor variables.

RESULTS

The composite score predicted variation in cortical metabolism; supplementary analyses showed that TMT B was significantly correlated with PET metabolism as well. RAVLT and TMT B were significant predictors of variation in MRI cortical thickness.

CONCLUSION

Our results indicate that RAVLT and TMT B are sensitive to variation in Alzheimer disease neuroimaging markers.

Cognitive Impairment Is Reflected by an Increased Difference between Real and Imagined Timed Up and Go Test Performance

BACKGROUND

Recent research suggests using an imaginary version of the Timed Up and Go test (TUG) for a first assessment of cognitive impairment. By using the time difference between a real (TUGr) and an imagined (TUGi) TUG task, the objective of this study was to examine the effect of cognitive impairment on motor imagery ability.

METHODS

Fifty-two participants (mean age 69.3 ± 4.0 years) with mild cognitive impairment or subjective cognitive impairment were included in this study. The time difference between the TUGr and the TUGi was used as the main outcome. The Trail Making Test part B (TMT B), the ratio between TMT A and TMT B, and the Montreal Cognitive Assessment (MoCA) battery were the main independent variables.

RESULTS

The difference between TUGr and TUGi performance time and the TMT B performance time increased with decreasing cognitive function (p < 0.01). There was no relationship between TUGr and TUGi performance time and TMT B/A ratio. There were significant correlations between TUG time differences and the MoCA score (r = -0.489, p < 0.01), the TMT B (r = 0.364, p < 0.01), and the TMT B/A ratio (r = 0.377, p < 0.01).

CONCLUSION

The combination of TUGr and TUGi may have added value in assessing cognitive impairment, which is a possible pre-stage of dementia.

Neurocognitive, emotional and neuroendocrine correlates of exposure to sexual assault in women

BACKGROUND

Survivors of sexual assault are vulnerable to long-term negative psychological and physical health outcomes, but few studies have investigated changes in cognition, emotional processing and brain function in the early stages after sexual assault. We used a multimodal approach to identify the cognitive and emotional correlates associated with sexual assault in women.

METHODS

Twenty-seven female survivors of sexual assault were included within 4 weeks of the traumatic event, and they were compared with 20 age-matched controls. Participants underwent functional MRI while performing cognitive/emotional tasks (n-back, emotional go/no-go, mental imagery). We also measured diurnal salivary cortisol and conducted neuropsychological assessments of attention and memory abilities.

RESULTS

Relative to the control group, the survivors group had lower levels of morning cortisol and showed attentional deficits. We observed no between-group differences in brain activation during the n-back or mental imagery tasks. During the emotional go/no-go task, however, the survivors group showed a lack of deactivation in the dorsal anterior cingulate cortex when processing emotional material, relative to neutral material. Exploratory analyses in the survivors group indicated that symptom severity was negatively associated with cerebellar activation when positive emotional (happy) content interfered with response inhibition, and positively associated with cerebellar activation when thinking of positive (happy) memories.

LIMITATIONS

The small sample size was the main limitation of this study.

CONCLUSION

Dysfunctions in the dorsal anterior cingulate cortex and the cerebellum may represent early functional brain modifications that alter higher cognitive processes when emotional material is involved.

Processing speed and the relationship between Trail Making Test-B performance, cortical thinning and white matter microstructure in older adults

Part B of the Trail Making Test (TMT-B) is widely used as a quick and easy to administer measure of executive dysfunction. The current study investigated the relationships between TMT-B performance, brain volumes, cortical thickness and white matter water diffusion characteristics in a large sample of older participants, before and after controlling for processing speed. Four hundred and eleven healthy, community-dwelling older adults who were all born in 1936 were assessed on TMT-B, 5 tests of processing speed, and provided contemporaneous structural and diffusion MRI data. Significant relationships were found between slower TMT-B completion times and thinner cortex in the frontal, temporal and inferior parietal regions as well as the Sylvian fissure/insula. Slower TMT-B completion time was also significantly associated with poorer white matter microstructure of the left anterior thalamic radiation, and the right uncinate fasciculus. The majority of these associations were markedly attenuated when additionally controlling for processing speed. These data suggest that individual differences in processing speed contribute to the associations between TMT-B completion time and the grey and white matter structure of older adults.

Predictive Value of Traditional Measures of Executive Function on Broad Abilities of the Cattell–Horn–Carroll Theory of Cognitive Abilities

The neuropsychological construct of executive functions (EFs), and the psychometric Cattell–Horn–Carroll (CHC) theory of cognitive abilities are both approaches that attempt to describe cognitive functioning. The coherence between EF and CHC abilities has been mainly studied using factor-analytical techniques. Through multivariate regression analysis, the current study now assesses the integration of these latent constructs in clinical assessment. The predictive power of six widely used executive tasks on five CHC measures (crystallized and fluid intelligence, visual processing, short-term memory, and processing speed) is examined. Results indicate that executive tasks—except for the Stroop and the Tower of London—predict overall performance on the intelligence tests. Differentiation in predicting performance between the CHC abilities is limited, due to a high shared variance between these abilities. It is concluded that executive processes such as planning and inhibition have a unique variance that is not well-represented in intelligence tests. Implications for the use of EF tests and operationalization of CHC measures in clinical practice are discussed.

The relationship between autobiographical memory, cognition, and emotion in older adults: a review

Over the past 30 years, the concept of "autobiographical memory" has been highlighted in numerous behavioral and neuroanatomical studies. Importantly, episodic autobiographical memory, an aspect of autobiographical memory, has been shown to decrease with age but can be improved by training. Autobiographical memory is deeply associated with the default mode network (especially posterior cingulate cortex and medial prefrontal cortex), which is particularly interesting in the context of better understanding the relationship between autobiographical memory, cognition, and emotion in older adults. This article provides an overview of the behavioral and neuroanatomical characteristics of autobiographical memory, as well as its relationship with the default mode network, cognition, emotion, and aging. This article also provides an overall review of autobiographical memory training.