The Behavioral and Cognitive Executive Disorders of Stroke: The GREFEX Study

Fiber connectivity density in subcortical stroke patients with behavioral dysexecutive symptoms

Subcortical stroke induces widespread connectivity changes between cortical and subcortical regions, which may underpin the ensuing behavioral dysexecutive symptoms. This study therefore investigated the cortical structural connectivity that were related to behavioral dysexecutive symptoms using fiber connectivity density (FiCD) mapping, an approach which combines white matter (WM) fiber tractography and cortex reconstruction. The relationships between cortical structural connectivity of significant clusters and its corresponding cortical thickness (CT), and clinical variables were also evaluated based on region-of-interest analysis. Sixty-four subcortical stroke patients with high-resolution T1-weighted imaging and diffusion tensor imaging were enrolled and the behavioral dysexecutive symptoms were assessed using the dysexecutive questionnaire. The FiCD of the left superior parietal gyrus was positively associated with cognitive executive processing (CTT1 time, r = 0.570, p = 0.047; CVFT total correct, r = 0.582, p = 0.047; CVFT total response, r = 0.605, p = 0.040). Similary, the FiCD of the right superior parietal gyrus was also positively associated with cognitive executive processing, (CTT1 time, r = 0.639, p = 0.034). Conversely, negative correlations were observed between the FiCD and CT of the right (r = -0.612 p = 0.045) superior parietal gyrus.

Poststroke action slowing increases with task complexity and is linked to broader brain recruitment

Despite its high prevalence, the mechanisms of slowing in stroke remain surprisingly poorly understood. Our objectives were (1) to determine the profile of slowing as a function of test complexity and (2) to examine the relationship between this complexity effect, test sensitivity and the recruitment of brain areas. The study focused on the 371 stroke patients and 581 controls of the GRECogVASC study assessed with eight time-limited tests: finger tapping, simple reaction time, line cancellation, Trail Making Test parts A and B, coding, and semantic and phonemic fluency tests. Action speed of patients was slower than that of controls (p = .0001); slowing worsened with test complexity (p = .0001) by 7.7% at each step of increasing complexity. The highest test sensitivity was observed (p = .0001) for more complex tests. The number of lesioned voxels associated with action speed increased with test complexity. The sensitivity of the tests roughly paralleled (p = .007) the volume of recruited brain areas. The individual slopes of action duration with test complexity correlated with the volume of lesion (p = .002), white matter hyperintensities (p = .0001) and parenchymal brain fraction (p = .0001). The effect of stroke on slowing is due both to small slowing on simple tests and to a general slowing of processing speed. The test sensitivity reflects the size of recruited brain network and its proportional vulnerability to lesion. In addition to their clinical implications, these results shed light on the organization of the systems that optimize action speed in humans.

Are we ready to cure post-stroke cognitive impairment? Many key prerequisites can be achieved quickly and easily

PURPOSE

Post-stroke (PS) cognitive impairment (CI) is frequent and its devastating functional and vital consequences are well known. Despite recent guidelines, they are still largely neglected. A large number of recent studies have re-examined the epidemiology, diagnosis, imaging determinants and management of PSCI. The aim of this update is to determine whether these new data answer the questions that are essential to reducing PSCI, the unmet needs, and steps still to be taken.

METHODS

Literature review of stroke unit-era studies examining key steps in the management of PSCI: epidemiology and risk factors, diagnosis (cognitive profile and assessments), imaging determinants (quantitative measures, voxelwise localization, the disconnectome and associated Alzheimer's disease [AD]) and treatment (secondary prevention, symptomatic drugs, rehabilitation and noninvasive brain stimulation) of PSCI.

FINDINGS

(1) the prevalence of PSCI of approximately 50% is probably underestimated; (2) the sensitivity of screening tests should be improved to detect mild PSCI; (3) comprehensive assessment is now well-defined and should include apathy; (4) easily available factors can identify patients at high risk of PSCI; (5) key imaging determinants are the location and volume of the lesion and the resulting disconnection, associated AD and brain atrophy; WMH, ePVS, microhemorrhages, hemosiderosis, and cortical microinfarcts may contribute to cognitive impairment but are more likely to be markers of brain vulnerability or associated AD that reduce PS recovery; (6) remote and online assessment is a promising approach for selected patients; (7) secondary stroke prevention has not been proven to prevent PSCI; (8) symptomatic drugs are ineffective in treating PSCI and apathy; (9) in addition to cognitive rehabilitation, the benefits of training platforms and computerized training are yet to be documented; (10) the results and the magnitude of improvement of noninvasive brain stimulation, while very promising, need to be substantiated by large, high-quality, sham-controlled RCTs.

DISCUSSION AND CONCLUSION

These major advances pave the way for the reduction of PSCI. They include (1) the development of more sensitive screening tests applicable to all patients and (2) online remote assessment; crossvalidation of (3) clinical and (4) imaging factors to (5) identify patients at risk, as well as (6) factors that prompt a search for associated AD; (7) the inclusion of cognitive outcome as a secondary endpoint in acute and secondary stroke prevention trials; and (8) the validation of the benefit of noninvasive brain stimulation through high-quality, randomized, sham-controlled trials. Many of these objectives can be rapidly and easily attained.

Mechanisms of Verbal Fluency Impairment in Stroke: Insights From "Strategic Indices" Derived From a Study of 337 Patients

Verbal fluency provides a unique index of the functional architecture of control functions because it reflects the interactions between executive processes and lower-level language processes. However, an evaluation of the number of correct words alone does not enable one to determine precisely which processes are impaired. This study investigates post-stroke fluency impairments, focusing on previously unexplored indices and their neuroanatomical correlates using voxel-based lesion symptom mapping (VLSM). In total, 337 patients and 851 controls performed letter and semantic fluency tests. Analyses included overall performance (correct responses) and strategic indices (errors, time course, frequency, switches, and cluster size). Stroke patients produced fewer correct responses, more rule-breaking errors, fewer words after 15″, fewer infrequent words, fewer switches, and smaller clusters in letter fluency. Switching was strongly associated with letter fluency, while clustering was more related to semantic fluency. VLSM identified left-hemisphere structures, particularly frontal tracts (e.g., anterior thalamic and frontostriatal tracts), associated with switching, and a smaller set of left-hemisphere structures linked to clustering. Conceptually, the findings suggest stroke-related fluency disorders primarily arise from impairments in executive strategic search, as indicated by switching impairments, with weaker impairment on lexicosemantic abilities. The rarity of rule-breaking and perseverative errors indicates that inhibition and working memory deficits do not significantly contribute to poor fluency. The patients' production of infrequent words and fluency worsened over time, although the precise contributions of the three core processes to these additional changes require further investigation. Our results highlight the importance of detailed fluency evaluations in stroke patients for optimized rehabilitation.

Post-stroke outcome prediction based on lesion-derived features

Stroke-induced deficits result from both focal structural damage and widespread network disruption. This study investigated whether simulated measures of network disruption, derived from structural lesions, could predict functional impairments in stroke patients. We extracted four lesion-derived feature sets: lesion masks, probabilistic structural disconnection maps (pSDMs), structural and indirectly estimated functional connectivity strengths between brain regions, and topological properties of functional and structural brain networks to predict motor, executive, and processing speed deficits in 340 S patients, employing PCA-based ridge regression with leave-one-out cross validation. The findings revealed that both structural disconnection map patterns and lesion masks were strong predictors of functional deficits. Lesion masks exhibited superior predictive performance relative to unthresholded pSDMs. Furthermore, applying a probability threshold to the pSDMs - retaining only disconnections present in a sufficient proportion of healthy subjects - significantly improved predictive performance. For motor deficits, thresholded SDMs (tSDMs) with thresholds of 0.9 and 0.5 produced the highest R2 values, 0.95 for left motor deficits and 0.69 for right motor deficits, respectively. In the case of executive function and processing speed, the highest R2 values were 0.58 and 0.64, achieved with tSDM thresholds of 0.3 and 0.5, respectively. Connectome-based features exhibited lower R2 values, with structural connection strength alterations showing stronger associations with post-stroke scores compared to changes in functional connectivity. Nodal parameters (degree and clustering coefficient) had lower explanatory power than the SDM features and lesion masks. Our findings underscore the effectiveness of lesion masks and thresholded SDMs in predicting post-stroke deficits. This study contributes to the growing body of evidence supporting the reliability of simulated structural networks as a complementary approach to lesion patterns and structural disconnection in predicting post-stroke outcomes.

Poststroke cognitive outcome is better accounted for by white matter abnormalities automated segmentation than visual analysis

BACKGROUND AND AIMS

The association between white matter abnormalities (WMA) and cognitive decline previously reported in poststroke patients has been mainly documented using visual scales. However, automated segmentation of WMA provides a precise determination of the volume of WMA. Nonetheless, it is rarely used in the stroke population and its potential advantage over visual scales is still unsettled. The objective of this study was to examine whether automated segmentation of WMA provides a better account than the visual Fazekas and Wahlund scales of the decline in executive functions and processing speed in stroke patients.

METHODS

The analyses were conducted on the 358 patients of the GRECogVASC cohort with an MRI performed at six months poststroke in the Amiens center. WMA were visually analyzed using the Fazekas (subcortical abnormalities) and Wahlund scales. Segmentation was performed using LST (3.0.3). Following preliminary studies to determine the optimal segmentation threshold, we examined the relationship between cognitive status and WMA volume computed at each threshold using receiver operating characteristic (ROC) curves. Finally, we assessed the ability of both Fazekas and Wahlund visual scores and WMA volume to account for cognitive scores by using a bivariate Pearson correlation analysis, comparing correlation coefficients with the Fisher transformation and repeating correlation analysis after adjustment for the lesion volume.

RESULTS

Increasing the threshold led to an underestimation of WMA (P=0.0001) (significant for a threshold ≥0.2) and an improvement in correct rejection of signal changes in the stroke cavity (P=0.02) (significant for a threshold ≤0.5), susceptibility artifacts (P=0.002) (significant for a threshold ≤0.6), and corticospinal degeneration (P=0.03) (significant for a threshold ≤0.5). WMA volume decreased with increasing threshold (P=0.0001). Areas under the curve (AUC) did not differ according to the threshold (processing speed: P=0.85, executive cognitive functions: P=0.7). Correlation coefficients between cognitive scores and WMA were higher for WMA volume than the Fazekas (processing speed: Z=-3.442, P=0.001; executive functions: Z=-2.751, P=0.006) and Wahlund scores (processing speed: Z=-3.615, P=0.0001; executive functions: Z=-2.769, P=0.006). Adjustment for lesion volume did not alter the correlations with WMA volume (processing speed: r=-0.327 [95%CI: -0.416; -0.223], P=0.0001; executive functions: r=-0.262 [95%CI: -0.363; -0.150], P=0.0001).

CONCLUSION

This study shows that WMA volume assessed by automated segmentation provides a better account of cognitive disorders than visual analysis. This should favor its wider use to refine imaging determinants of poststroke cognitive disorders.

The pattern of cortical thickness associated with executive dysfunction in MCI and SCC: The MEMENTO cohort

BACKGROUND

The association between the pattern of cortical thickness (CT) and executive dysfunction (ED) in mild cognitive impairment (MCI) and subjective cognitive complaints (SCC) is still poorly understood. We aimed to investigate the association between CT and ED in a large French cohort (MEMENTO) of 2323 participants with MCI or SCC.

METHODS

All participants with available CT and executive function data (verbal fluency and Trail Making Test [TMT]) were selected (n=1924). Linear regressions were performed to determine relationships between executive performance and the brain parenchymal fraction (BPF) and CT using FreeSurfer.

RESULTS

The global executive function score was related to the BPF (sß: 0.091, P<0.001) and CT in the right supramarginal (sß: 0.060, P=0.041) and right isthmus cingulate (sß: 0.062, P=0.011) regions. Literal verbal fluency was related to the BPF (sß: 0.125, P<0.001) and CT in the left parsorbitalis region (sß: 0.045, P=0.045). Semantic verbal fluency was related to the BPF (sß: 0.101, P<0.001) and CT in the right supramarginal region (sß: 0.061, P=0.042). The time difference between the TMT parts B and A was related to the BPF (sß: 0.048, P=0.045) and CT in the right precuneus (sß: 0.073, P=0.019) and right isthmus cingulate region (sß: 0.054, P=0.032).

CONCLUSIONS

In a large clinically based cohort of participants presenting with either MCI or SCC (a potential early stage of Alzheimer's disease [AD]), ED was related to the BPF and CT in the left pars orbitalis, right precuneus, right supramarginal, and right isthmus cingulate regions. This pattern of lesions adds knowledge to the conventional anatomy of ED and could contribute to the early diagnosis of AD.

Digital tools to support technology-enabled budget management in people with acquired brain injury: a rapid review

People with acquired brain injuries (ABI) face financial challenges that affect their daily lives. Managing finances is a crucial activity that can help avoid social isolation. However, this task becomes difficult for people with ABI because of their cognitive impairments. Recent advances in digital technology can help people with ABI manage their finances more effectively. This study aims to identify and describe available digital tools that can help ABI in budget management, and identify their effectiveness, barriers and facilitators to implementation. To address this issue, we conducted a rapid review of academic databases followed by a modified Google/Google Scholar search to identify the digital tools to support budgeting tasks (DBT) used and tested by people with ABI. Our rapid review included only two articles on the use of DBT. The first study showed that common portable electronic devices were acceptable and desirable as memory and organisational aids for people with ABI. The second study documented the development of a DBT and the perception of users (research participants) who found it appealing and user-friendly. However, for both articles, the technologies used are outdated and lack information on barriers and facilitators to using DBT. In conclusion, this literature review revealed that digital technologies have the potential to support budget management in people with ABI, but technology needs to be made available on the market to benefit the users. Further research and development are needed to create new ways to help people with brain injuries manage their budgets.

Architecture and anatomy of executive processes: evidence from verbal fluency and Trail Making Test in 2009 stroke patients

OBJECTIVES

The few voxel-wise lesion-symptom mapping (VLSM) studies aimed at identifying the anatomy of executive function are limited by the absence of a model and by small populations. Using Trail Making Test (TMT) and verbal fluency and a model of their architectures, our objective was to identify the key structures underlying two major executive processes, set-shifting and strategic word search.

METHODS

We applied a validated VLSM analysis to harmonized cognitive and imaging data from 2009 ischemic stroke patients as a part of the Meta VCI Map consortium. All contrast analyses used an adjusted threshold with 2000 Freedman-Lane permutations (p ≤ 0.05).

RESULTS

The TMT parts A and B were associated with structures involved in visual-spatial processing, the motor system, the frontal lobes, and their subcortical connections. Set-shifting depended on the left dorsomedial frontal region. Both semantic and phonemic fluency tests depended on verbal output abilities and processing speed with similar slopes in different languages. The strategic search process depended on Broca's area, F2 and related tracts, temporal and deep regions. Lastly, the lesion map of set-shifting did not overlap with those of strategic word search processes.

INTERPRETATION

Our results identify the anatomical substrates of two main executive processes, revealing that they represent only a specific subpart of previously reported structures. Finally, our results indicate that executive functions depend on several specific, anatomically separable executive processes mainly operating in various parts of the frontal lobes.

Determinants of cognitive dysfunction in adults with sickle cell-related stroke or suspected neurological morbidity

ABSTRACT

The prognosis of sickle cell disease (SCD) in adults is determined primarily by damage to targeted organs such as the brain. Cognitive dysfunction in SCD is a common chronic neurological manifestation, but studies remain mostly descriptive in adults. The objective of this study was to better characterize the cognitive profile and the association between cognitive dysfunction and brain lesions. We included adult patients with SCD referred for a neurological assessment. An adapted battery of neuropsychological tests was used to assess cognitive deficits. Brain or arterial abnormalities were assessed using brain magnetic resonance imaging/magnetic resonance angiography and a cervical and transcranial Doppler ultrasound. The cognitive profile of 96 patients was characterized by deficits in processing speed (58%), short-term memory (34%), and working memory (24%). Brain infarcts were found in 56% of patients and intracranial vasculopathy in 49%. Twenty percent of patients had no brain abnormalities. Processing speed dysfunction was associated with territorial infarcts (odds ratio [OR], 3.1; P = .03) and education outside of France (OR, 4.7; P = .02). Short-term memory dysfunction was associated with territorial infarcts (OR, 3.4; P = .01) and a low educational level (OR, 8.2; P = .01). Working memory dysfunction was associated with a low educational level (OR, 4.3; P = .05) and vasculopathy (OR, 3.7; P = .03). Cognitive dysfunction appears to be a hallmark sign of SCD, particularly for adults with sickle cell-related stroke or suspected neurological morbidity. Assessment of such dysfunction could be used in longitudinal follow-up and clinical trials.

Adult norms for the decision-making MindPulse Digital Test

We present adult normalized data for MindPulse (MP), a new tool evaluating attentional and executive functioning (AEF) in decision-making. We recruited 722 neurotypical participants (18-80 years), with 149 retested. The MP test includes three tasks: Simple Reaction Time (SRT), Go/No-go, and complex Go/No-go, involving perceptual components, motor responses, and measurements of reaction time (RT) and correctness. We compare responses, evaluating 14 cognitive indices (including new composite indices to describe AEF: Executive Speed and Reaction to Difficulty). We adjust for age/sex effects, introduce a difficulty scale, and consider standard deviations, aberrant times, and Spearman Correlation for speed-accuracy balance. Wilcoxon unpaired rank test is used to assess sex effects, and linear regression is employed to assess the age linear dependency model on the normalized database. The study demonstrated age and sex effects on RTs, in all three subtests, and the ability to correct it for individual results. The test showed excellent validity (Cronbach Alpha for the three subtasks is 92, 87, 95%) and high internal consistency (p < 0.001 for each subtask significantly faster than the more complex subtask) of the MP across the wide age range. Results showed correlation within the three RT parts of the test (p < .001 for each) and the independence of SRT, RD, and ES indices. The Retest effect was lower than intersubject variance, showing consistency over time. This study highlights the MP test's strong validity on a homogeneous, large adult sample. It emphasizes assessing AEF and Reaction to Difficulty dynamically with high sensitivity.

Profiles of executive functioning following traumatic brain injury and stroke using the assessment of participation and executive functions: combined cross-sectional and longitudinal designs

OBJECTIVES

The Assessment of Participation and Executive Functions (A-PEX) evaluates executive functioning through daily participation in complex daily activities. This study examines its ability to discriminate between executive functioning profiles post-traumatic brain injury and post-stroke and its sensitivity to changes.

DESIGN

Cross-sectional with a longitudinal component.

PATIENTS

Adults with post-traumatic brain injury (n = 28) and post-stroke (n = 26) in a rehabilitation facility.

METHODS

Patients were administered the A-PEX, Multiple Errands Test-Hospital version and Color Trail Test at 2 time-points 1 month apart. The Montreal Cognitive Assessment was administered at the first time-point, and Executive Functions Performance Test's Internet-based Bill Payment subtest at the second. The analysis used Mann-Whitney and Wilcoxon signed-rank tests.

RESULTS

The stroke group's A-PEX scores were higher than the traumatic brain injury group's at the first time-point (p < 0.05). No differences were found in the other assessments. Within-group differences in both groups were significant in the A-PEX (-3.7 < r < - 2.3, p < 0.05) and Multiple Errands Test-Hospital version (-3.4 < r < -3.3, p < 0.01).

CONCLUSION

The A-PEX may provide valuable information about the uniqueness of executive functioning profiles and patients' progress.

Neuroimaging determinants of cognitive impairment in the memory clinic: how important is the vascular burden?

While neurodegenerative and vascular neurocognitive disorder (NCD) often co-occur, the contribution of vascular lesions, especially stroke lesions identified on MRI, to global cognition in a real-life memory clinic population remains unclear. The main objective of this retrospective study was to determine NCD neuroimaging correlates: the GM atrophy pattern and vascular lesions (especially stroke lesion localization by voxel-based lesion-symptom mapping, VLSM) in a memory clinic. We included 336 patients with mild or major NCD who underwent cerebral MRI and a neuropsychological assessment. The GM atrophy pattern (obtained by voxel-based morphometry, VBM) and the stroke lesion localization (obtained by VLSM) associated with G5 z-score (a global cognitive score), were included as independent variables with other neuroimaging and clinical indices in a stepwise linear regression model. The mean age was 70.3 years and the mean MMSE score 21.3. On MRI, 75 patients had at least one stroke lesion. The G 5 z-score was associated with GM density in the pattern selected by the VBM analysis (R2 variation = 0.166, p < 0.001) and the presence of a stroke lesion in the region selected by the VSLM analysis (mainly in the right frontal region; R2 variation = 0.018, p = 0.008). The interaction between the two factors was insignificant (p = 0.374). In conclusion, in this first study combining VBM and VLSM analysis in a memory clinic, global cognition was associated with a specific GM atrophy pattern and the presence of a stroke lesion mainly in the right frontal region.

Dual-task versus single-task gait rehabilitation after stroke: the protocol of the cognitive-motor synergy multicenter, randomized, controlled superiority trial (SYNCOMOT)

BACKGROUND

Gait disorders and cognitive impairments are prime causes of disability and institutionalization after stroke. We hypothesized that relative to single-task gait rehabilitation (ST GR), cognitive-motor dual-task (DT) GR initiated at the subacute stage would be associated with greater improvements in ST and DT gait, balance, and cognitive performance, personal autonomy, disability, and quality of life in the short, medium and long terms after stroke.

METHODS

This multicenter (n=12), two-arm, parallel-group, randomized (1:1), controlled clinical study is a superiority trial. With p<0.05, a power of 80%, and an expected loss to follow-up rate of 10%, the inclusion of 300 patients will be required to evidence a 0.1-m.s-1 gain in gait speed. Trial will include adult patients (18-90 years) in the subacute phase (0 to 6 months after a hemispheric stroke) and who are able to walk for 10 m (with or without a technical aid). Registered physiotherapists will deliver a standardized GR program (30 min three times a week, for 4 weeks). The GR program will comprise various DTs (phasic, executive function, praxis, memory, and spatial cognition tasks during gait) in the DT (experimental) group and gait exercises only in the ST (control) group. The primary outcome measure is gait speed 6 months after inclusion. The secondary outcomes are post-stroke impairments (National Institutes of Health Stroke Scale and the motor part of the Fugl-Meyer Assessment of the lower extremity), gait speed (10-m walking test), mobility and dynamic balance (timed up-and-go test), ST and DT cognitive function (the French adaptation of the harmonization standards neuropsychological battery, and eight cognitive-motor DTs), personal autonomy (functional independence measure), restrictions in participation (structured interview and the modified Rankin score), and health-related quality of life (on a visual analog scale). These variables will be assessed immediately after the end of the protocol (probing the short-term effect), 1 month thereafter (the medium-term effect), and 5 months thereafter (the long-term effect).

DISCUSSION

The main study limitation is the open design. The trial will focus on a new GR program applicable at various stages after stroke and during neurological disease.

TRIAL REGISTRATION

NCT03009773 . Registered on January 4, 2017.

Poststroke apathy: Major role of cognitive, depressive and neurological disorders over imaging determinants

Apathy occurs in approximately one third of people after stroke. Despite its frequency and functional consequences, the determinants of apathy have only been partially defined. The major difficulty lies in disentangling the reduction in activity due to apathy itself from those secondary to comorbidities, such as depression, sensorimotor deficits, and cognitive impairment. Here, we aimed to examine the prevalence of apathy, identify confounding sources of hypoactivity, and define its neuroimaging determinants using multivariate voxel lesion symptom-mapping (mVLSM) analyses. We assessed apathy in a subgroup (n = 325, mean age: 63.8 ± 10.5 years, 91.1% ischemic stroke) of the GRECogVASC cohort using the validated Behavioral Dysexecutive Syndrome Inventory, interpreted using GREFEX criteria, as well as confounding factors (depression, anxiety, severity of the neurological deficit, and gait disorders). mVLSM analysis was used to define neuroimaging determinants and was repeated after controlling for confounding factors. Apathy was present for 120 patients (36.9%, 95% CI: 31.7-42.2). Stepwise linear regression identified three factors associated with apathy: depressive symptoms (R² = .3, p = .0001), cognitive impairment (R² = .015, p = .02), and neurological deficit (R² = .110, p = .0001). Accordingly, only 9 (7.5%) patients had apathy without a confounding factor, i.e., isolated apathy. In conventional VLSM analysis, apathy was associated with a large number of subcortical lesions that were no longer considered after controlling for confounding factors. Strategic site analysis identified five regions associated with isolated apathy: the F3 orbitalis pars, left amygdala, left thalamus, left pallidum, and mesencephalon. mVLSM analysis identified four strategic sites associated with apathy: the right corticospinal tract (R² = .11; p = .0001), left frontostriatal tract (R² = .11; p = .0001), left thalamus (R² = .04; p = .0001), and left amygdala (R² = .01; p = .013). These regions remained significant after controlling for confounding factors but explained a lower amount of variance. These findings indicate that poststroke apathy is more strongly associated with depression, neurological deficit, and cognitive impairment than with stroke lesions locations, at least using VLSM analysis.

Poststroke action slowing: Motor and attentional impairments and their imaging determinants. Evidence from lesion-symptom mapping, disconnection and fMRI activation studies

BACKGROUND AND OBJECTIVES

Although action slowing is the main cognitive impairment in stroke survivors, its mechanisms and determinants are still poorly understood. The objectives of the present study were to determine the mechanisms of post-stroke action slowing (using validated, highly specific simple reaction time (SRT) and tapping tests) and identify its imaging determinants (using multivariate lesion-symptom mapping (mLSM)).

METHODS

Action speed in the GRECogVASC cohort was assessed using finger tapping and SRT tests performed with both hands and analyzed using previously validated indices. Imaging determinants were identified using validated mLSM analyses and disconnection analysis and compared to those of an fMRI activation meta-analytic database.

RESULTS

Both the tapping time and SRT were 10.7% slower for the 394 patients (p = 0.0001) than for the 786 controls, without a group × test interaction (p = 0.2). The intra-individual distribution curve was characterized by a rightward shift with an unaltered attentional peak. The mLSM analyses showed tapping to be associated with lesions in the frontostriatal tract (p = 0.0007). The SRT was associated with lesions in the frontostriatal tract (p = 0.04) and the orbital part of F3 (p = 0.0001). The SRT-tapping index was associated with lesions in the orbital part of F3 (p = 0.0001). All lesions were located in the right hemisphere only and were responsible for the disconnection of several structures involved in motor preparation, initiation, and speed. A comparison with fMRI activation meta-analytic data highlighted mostly the same regions, including the orbital part of F3, the ventral and dorsal parts of F1, and the premotor and cingulate regions in the right hemisphere.

DISCUSSION

Our results confirm the marked impairment of action speed in stroke and show that the primary mechanism is motor slowing and that it is related to lesions in the right frontostriatal tract. A deficit in sustained alertness accounted for action slowing in the subgroup with lesions in the right orbital part of F3. Our SRT and mLSM results were in accordance with the fMRI activation data. Thus, stroke induces slowing in the broad network associated with SRT tasks by disrupting the frontostriatal tract and, to a lesser extent, other sites involved in attention.

Venous stroke–a stroke subtype that should not be ignored

Based on the etiology, stroke can be classified into ischemic or hemorrhagic subtypes, which ranks second among the leading causes of death. Stroke is caused not only by arterial thrombosis but also by cerebral venous thrombosis. Arterial stroke is currently the main subtype of stroke, and research on this type has gradually improved. Venous thrombosis, the particular type, accounts for 0.5–1% of all strokes. Due to the lack of a full understanding of venous thrombosis, as well as its diverse clinical manifestations and neuroimaging features, there are often delays in admission for it, and it is easy to misdiagnose. The purpose of this study was to review the pathophysiology mechanisms and clinical features of arterial and venous thrombosis and to provide guidance for further research on the pathophysiological mechanism, clinical diagnosis, and treatment of venous thrombosis. This review summarizes the pathophysiological mechanisms, etiology, epidemiology, symptomatology, diagnosis, and treatment heterogeneity of venous thrombosis and compares it with arterial stroke. The aim is to provide a reference for a comprehensive understanding of venous thrombosis and a scientific understanding of various pathophysiological mechanisms and clinical features related to venous thrombosis, which will contribute to understanding the pathogenesis of intravenous stroke and provide insight into diagnosis, treatment, and prevention.

Walking speed at the acute and subacute stroke stage: A descriptive meta-analysis

Gait disorders are one of the leading patient complaints at the sub-acute stroke stage (SSS) and a main determinant of disability. Walking speed (WS) is a major vital and functional index, and the Ten-Meter Walk Test is considered the gold standard after stroke. Based on a systematic review of the literature, studies published between January 2000 and November 2021 were selected when WS was reported (ten-meter walk test for short distance and/or 6-min walking distance for long distance) within 6 months following a first ischemic and/or hemorrhagic stroke (SSS) in adults prior to receiving specific walking rehabilitation. Following PRISMA guidelines, a meta-analysis was conducted on two kinds of WS: the principal criterion focused on short-distance WS (ten-meter walking test) and the secondary criteria focused on long-distance WS (6-min test) and meta-regressions to study the association of WS with balance, cognitive disorders and autonomy. Nine studies comprising a total of 939 data on post-stroke patients were selected. The weighted average age was 61 years [95% IC [55-67] and males represented 62% ± 2.7 of patients [57-67]. Average short-distance WS was 0.36 ± 0.06 m.s-1 [95% CI (0.23-0.49)]. Average long-distance WS was 0.46 ± 0.1 m.s-1 [95% CI (0.26-0.66)]. The funnel plot revealed asymmetry of publication bias and high heterogeneity of the nine studies (I 2 index 98.7% and Q-test p < 0.0001). Meta-regressions of secondary endpoints could not be performed due to a lack of study data. At the SSS, WS would be lower than data in general population published in literature, but above all, lower than the WS required for safe daily autonomy and community ambulation after stroke. WS must be a priority objective of stroke rehabilitation to increase walking function but also for survival, autonomy, social participation and health-related quality of life.

Determinants of Disability at 6 Months After Stroke: the GRECogVASC Study

BACKGROUND

The present study aimed at determining the contributions of background disorders responsible for participation restriction as indexed by a structured interview for the modified Rankin scale (mRS-SI).

METHODS

A subset of 256 patients was assessed at 6 months after stroke using the National Institutes of Health Stroke Scale (NIHSS), gait score, comprehensive cognitive battery (yielding a global cognitive Z-score), behavioral dysexecutive disorders (DDs), anxiety and depressive symptoms, epilepsy, and headache. Following bivariate analyses, determinants of participation restriction were selected using ordinal regression analysis with partial odds.

RESULTS

Poststroke participation restriction (mRS-SI >1) was observed in 59% of the patients. In bivariate analyses mRS-SI was associated with prestroke mRS-SI, 6-month NIHSS score, gait score, global cognitive Z-score, behavioral DDs, and presence of anxiety and depression (p=0.0001, all) (epilepsy: p=0.3; headache: p=0.7). After logistic regression analysis, the NIHSS score was associated with increasing mRS-SI grades (p=0.00001). Prestroke mRS-SI (p=0.00001), behavioral DDs (p=0.0008) and global cognitive Z-score (p=0.01) were associated with both mRS-SI>1 and mRS-SI>2. In addition, the gait score was associated with mRS-SI >2 (p=0.00001). This model classified 85% of mRS-SI correctly (p=0.001). Structural equation modeling showed the contributions of gait limitation (standardized coefficient (SC): 0.68, p=0.01), prestroke mRS-SI (SC: 0.41, p=0.01), severity of neurological impairment (SC: 0.16, p=0.01), global cognitive Z-score (SC: -0.14, p=0.05), and behavioral DDs (SC: 0.13, p=0.01).

CONCLUSION

These results provide a statistical model of weights of determinants responsible for poststroke participation restriction and highlight a new independent determinant: behavioral DDs.

Long-term neuropsychiatric symptoms in spontaneous intracerebral haemorrhage survivors

OBJECTIVE

Neuropsychiatric (NP) symptoms are prominent features of cognitive decline, but they have been understudied in patients with spontaneous intracerebral haemorrhage (ICH). In ICH survivors, we aimed at assessing NP symptoms prevalence and profiles, and their influence on long-term outcomes.

METHODS

We analysed data from consecutive 6-month ICH survivors enrolled in the Prognosis of Intracerebral Haemorrhage study. We performed NP evaluation using the Neuropsychiatric Inventory Questionnaire. Patients underwent long-term clinical follow-up after ICH (median follow-up time 7.2 years, IQR 4.8-8.2).

RESULTS

Out of 560 patients with ICH, 265 survived at 6 months. NP evaluation 6 months after ICH was feasible in 202 patients. NP symptoms were present in 112 patients (55%), and in 36 out of 48 patients (75%) with post-ICH dementia. Affective symptoms were present in 77 patients (38%), followed by vegetative symptoms (52 patients, 26%) and hyperactivity (47 patients, 23%). Apathy and hyperactivity were associated with post-ICH dementia and cerebral amyloid angiopathy MRI profile (all p<0.05). Apathy and hyperactivity prevailing over affective symptoms at 6-month follow-up were associated with higher risks of developing new-onset dementia (HR 5.40; 95% CI 2.27 to 12.84), while presence or severity of NP symptoms were not.

CONCLUSION

NP symptoms were present in more than half of 6-month ICH survivors, with higher prevalence and severity in patients with post-ICH dementia. Distinctive NP profile might be associated to cognitive status and inform on long-term dementia risk.

A Novel Perspective on the Proactive and Reactive Controls of Executive Function in Chronic Stroke Patients

Objectives

To investigate the proactive and reactive control process when executing a complex task in patients with stroke. Proactive control is the preparatory process before the target stimulus, whereas reactive control is an imperative resolution of interference after the target stimulus.

Methods

In total, 17 patients with chronic stroke and 17 healthy individuals were recruited. The proactive and reactive control of executive function was assessed by the task-switching paradigm and the AX version of the Continuous Performance Task (AX-CPT). The general executive function was assessed by Color Trial Test (CTT) and Stroop Test. The behavioral data of the task-switching paradigm were analyzed by a three-way repeated-measures ANOVA, and the AX-CPT data were analyzed by two-way repeated-measures ANOVA.

Results

For efficiency scores in the task-switching paradigm, trial (repeat vs. switch) × group (stroke or control group) interaction effect was significant. Post-hoc analysis on trial × group effect showed a significant between-trial difference in accuracy rates in the repeat trial in the control group regardless of 100 or 50% validity. For the AX-CPT, the main effects of condition and group on response time were statistically significant. The interaction effect of condition (AY or BX) × group (stroke or control group) was also significant. Post-hoc analysis for condition × group indicated that the stroke group had a significantly longer response time in the BX condition than the control group and longer completion time in CTT2 and larger word interference for completion time in the Stroop test than the control cohort.

Conclusions

Post-stroke survivors showed deficits in the performance of proactive control but not in the performance of reactive control. Deficits in proactive control may be related to the impairment of working memory. Interventions that focus on proactive control may result in improved clinical outcomes.

Long-term anxiety in spontaneous intracerebral haemorrhage survivors

Background. Although anxiety is common in several neurological conditions, it has been poorly investigated after spontaneous intracerebral haemorrhage (ICH).

Aims. In consecutive ICH survivors, we assessed the long-term prevalence of anxiety and its clinical and radiological determinants.

Methods. Using the Hospital Anxiety and Depression scale (HADS), we evaluated ICH survivors enrolled in the prospective, single-centre Prognosis of Intracerebral Hemorrhage (PITCH) study. The prevalence of anxiety (defined as a HADS-anxiety subscale score > 7) was evaluated at three time points (1-2, 3-5, and 6-8 years after ICH), along with neurological symptoms severity, functional disability, and cognitive impairment scores. Clinical and radiological characteristics associated with anxiety were evaluated in univariate and multivariable models.

Results. Of 560 patients with spontaneous ICH, 255 were alive 1 year later, 179 of whom completed the HADS questionnaire and were included in the study. Thirty-one patients (17%; 95% confidence interval [CI] 12-23) had anxiety 1-2 years, 38 (27%; 95% CI 19-34) 3-5 years, and 18 (21%; 95% CI 12-30) 6-8 years after ICH. In patients with anxiety, the prevalence of associated depressive symptoms was 48.4% 1-2 years, 60.5% 3-5 years, and 55.5% 6-8 years after ICH. Among clinical and radiological baseline characteristics, only lobar ICH location was significantly associated with anxiety 1-2 years after ICH (odds ratio 2.8; 95% CI 1.2-6.5). Anxiety was not associated with concomitant neurological symptoms severity, functional disability, or cognitive impairment.

Conclusions. Anxiety is frequent in ICH survivors, often in association with depressive symptoms, even many years after the index event.

Random number generation and the ability of mentally reconstructing context in patients with organic amnesia

Studies investigating amnesic patients have shown the involvement of the medial temporal lobe during working memory (WM) tasks, especially when multiple items or features have to be associated. However, so far, no study has examined the relationship between episodic memory and WM components in patients with amnesia for comprehensive neuropsychological evaluation.

Objective

The objective of this study was to investigate whether the null retention relates to deficits in the episodic buffer (EB) or the central executive (CE) components of WM.

Methods

This study included 15 amnesic patients with mixed etiologies and 13 matched healthy controls. These 15 amnesic patients with mixed etiologies were divided into two subgroups: NUL subgroup (n=7) patients whose raw score was 0 (zero) on the Logical Memory delayed recall test and MOR subgroup (n=8) patients who recalled at least 1 item. The EB was assessed by complex span tasks, and the CE was assessed by random number generation (RNG) test.

Results

EB tasks were impaired in both subgroups compared with controls. RNG was impaired in NUL (p=0.03), but not in MOR (p=0.99), subgroup.

Conclusions

CE impairment hampers the retrieval mode action, preventing it from initiating the mental reconstruction of the context in which the to-be-remembered information was presented minutes ago.

What do people respond to when rating executive function? - a cognitive interviewing investigation of BRIEF-A informant ratings in severe aphasia

PURPOSE

Executive dysfunction is common in persons with severe aphasia. Assessing these functions in this population is challenging. Informant ratings, such as the BRIEF-A, might be a useful alternative to neuropsychological tests. However, research has shown weak relationships between tests and ratings. The aim of this study was to understand how significant others of people with severe aphasia interpret and respond to questions about executive function in the informant report version of BRIEF-A.

METHODS

Eleven significant others were interviewed about a subset of the BRIEF-A items, using cognitive interviewing. Interviews were subjected to thematic analysis.

RESULTS

There was variation in the interpretation of the items of BRIEF-A which frequently corrupted the items' relation to what it was intended to measure. Further, informants wavered between considering the person with aphasias' ability or actual performance and many had lowered their expectations. The language problems caused by the aphasia affected the validity of some items.

CONCLUSIONS

The quantitative results of BRIEF-A informant ratings should be interpreted with caution, since it is unclear to what extent the responses represent executive function. The use of informant ratings does not solve the problem with aphasia being a confounding factor in assessment of executive function.IMPLICATIONS FOR REHABILITATIONAssessing executive function in people with severe aphasia is important but challenging.Quantitative results of informant ratings of executive function, such as BRIEF-A, in this population should be interpreted with caution, since it is unclear to what extent the ratings represent executive function.Using informant ratings does not solve the problem of the aphasia being a confounding factor, since the aphasia impacts on the validity of some of the items.

Microstructural degeneration and cerebrovascular risk burden underlying executive dysfunction after stroke

Executive dysfunction affects 40% of stroke patients, but is poorly predicted by characteristics of the stroke itself. Stroke typically occurs on a background of cerebrovascular burden, which impacts cognition and brain network structural integrity. We used structural equation modelling to investigate whether measures of white matter microstructural integrity (fractional anisotropy and mean diffusivity) and cerebrovascular risk factors better explain executive dysfunction than markers of stroke severity. 126 stroke patients (mean age 68.4 years) were scanned three months post-stroke and compared to 40 age- and sex-matched control participants on neuropsychological measures of executive function. Executive function was below what would be expected for age and education level in stroke patients as measured by the organizational components of the Rey Complex Figure Test, F(3,155) = 17, R2 = 0.25, p < 0.001 (group significant predictor at p < 0.001) and the Trail-Making Test (B), F(3,157) = 3.70, R2 = 0.07, p < 0.01 (group significant predictor at p < 0.001). A multivariate structural equation model illustrated the complex relationship between executive function, white matter integrity, stroke characteristics and cerebrovascular risk (root mean square error of approximation = 0.02). Pearson's correlations confirmed a stronger relationship between executive dysfunction and white matter integrity (r = - 0.74, p < 0.001), than executive dysfunction and stroke severity (r = 0.22, p < 0.01). The relationship between executive function and white matter integrity is mediated by cerebrovascular burden. White matter microstructural degeneration of the superior longitudinal fasciculus in the executive control network better explains executive dysfunction than markers of stroke severity. Executive dysfunction and incident stroke can be both considered manifestations of cerebrovascular risk factors.

Development and Validation of a Comprehensive Neuropsychological and Language Rehabilitation for Stroke Survivors: A Home-Based Caregiver-Delivered Intervention Program

CONTEXT

Aphasia is a major disabling condition after a stroke that profoundly affects the quality of life of stroke survivors (SS) and their caregivers. Comprehensive neuropsychological rehabilitation has emerged as a complementary intervention that helps in improving the associated cognitive and psychological deficits and quality of life following a brain injury. A standardized, simple, and easy to administer intervention that can be delivered as a home-based intervention can assist in faster recovery.

AIMS

To describe the development, validation, and feasibility of a home-based, caregiver-delivered comprehensive neuropsychological and language rehabilitation for SS.

METHODS AND MATERIAL

A culture-specific picture and task-based 8-week training workbook and manual were developed based on extensive review and focused group discussions. This intervention targeted areas of language (comprehension, fluency, and naming) and cognition (working memory, attention and concentration, executive functioning, and response inhibition). It was standardized on 40 healthy controls (HC) and 15 SS. Before recruitment, written informed consent was obtained from each patient, their primary caregiver, and the HCs.

RESULTS

All tasks were found to be effective in discriminating the performance of SS from the HC. The performance of the HC with respect to the errors and the time taken for each task was used for the hierarchical arrangement of the tasks. The developed intervention was later validated on 15 SS where they significantly improved in the pre-post assessment of language functioning (P < 0.001), quality of life (P < 0.001), and depression (P < 0.001).

CONCLUSIONS

This intervention can be feasible to administer as a home-based intervention and may help to alleviate language and neuropsychological complaints after stroke in low-literate or mixed-cultural populations. Further, large sample size studies are recommended.

Association Between Behavioral Dysexecutive Syndrome and the Health-Related Quality of Life Among Stroke Survivors

AIM

Behavioral dysexecutive syndrome (BDES) is one common neuropsychiatric comorbidity after stroke. Despite evidences suggesting the adverse effect of BDES on the survivors' outcome, little is known about the association between BDES and the health-related quality of life (HRQoL) among stroke survivors and how BDES impacts the HRQoL. This study aimed to address these questions.

METHODS

This study included 219 patients with acute ischemic stroke consecutively admitted to a regional hospital in Hong Kong. BDES was defined as a Chinese version of the Dysexecutive Questionnaire (DEX) score of ≥20 assessed at three months after stroke. The HRQoL was assessed with the Chinese version of the Stroke-Specific Quality of Life (SSQoL) questionnaire encompassing 12 domains. Multivariate linear regression models were employed to examine the association between BDES symptoms and the SSQoL total and domain scores. Structural equation model (SEM) was further constructed to delineate the linking pathways linking BDES and the HRQoL.

RESULTS

The study sample compromised mainly older patients with mild to moderate ischemic stroke. Compared with patients without BDES, those with BDES exhibited poorer performances regarding with the summarized SSQoL (226.2 ± 18.8 vs. 200.3 ± 29.8, p < 0.001) and almost all domains. The BDES symptoms were independently contributed to the whole HRQoL (SSQoL total score) (β = -0.20, p = 0.002), specifically to the domains in personality (β = -0.34, p < 0.001), language (β = -0.22, p = 0.01), and work/productivity (β = -0.32, p < 0.001), after adjusting demographic and clinical characteristics in linear models. The impacts of the BDES symptoms on the HRQoL were mainly explained by the indirect path mediated by depression and anxiety (path coefficient = -0.27, p < 0.05) rather than physical disability, while the resting was elucidated by the path directly linking BDES to the HRQoL (path coefficient = -0.17, p < 0.05).

CONCLUSION

The present study preliminarily demonstrated a potential association between BDES and a lower level of the HRQoL, predominantly in domains of personality, language, and work/productivityafter acute ischemic stroke. This study also offered insights into the underlying mechanisms linking BDES and the HRQoL, implicating that integrative psychological therapies were urged to achieve better HRQoL after stroke.

Prevalence and Clinical Correlates of Poststroke Behavioral Dysexecutive Syndrome

Background

Behavioral dysexecutive syndrome (BDES) is a common phenomenon following stroke. To date, research has focused mainly on individual behavioral symptoms rather than a more comprehensive characterization of goal‐directed behavior in stroke survivors. This cross‐sectional study evaluated the prevalence and clinical correlates of BDES in Hong Kong stroke survivors.

Methods and Results

A total of 369 stroke survivors were recruited from a regional hospital at 3 months after their index stroke. Patients’ demographic and clinical characteristics were extracted from a comprehensive stroke database. BDES was measured with the Chinese version of the Dysexecutive Questionnaire. Four neurocognitive batteries assessed domains of cognitive executive functions. The prevalence of BDES 3 months poststroke was 18.7%. At that time point, the Hospital Anxiety Depression Scale and Mini‐Mental State Examination scores and the presence of depression were significant predictors of BDES in a multivariate logistic regression analysis. These parameters remained significant predictors of the Dysexecutive Questionnaire score in a linear stepwise regression analysis and together accounted for 28.5% of the variance. Current depression was predictive of the Dysexecutive Questionnaire score in patients with BDES, with a variance of 9.7%. Furthermore, compared with the non‐BDES group, patients with BDES exhibited poor performance‐based executive function in the Chinese version of the Frontal Assessment Battery and color trails, arrow, and category fluency tests.

Conclusions

Symptoms of anxiety, current depression, and global cognitive function may be independent predictors of the presence and severity of BDES 3 months poststroke. Stroke survivors with BDES exhibit poor executive functioning, including goal maintenance and semantic memory.

Neuroimaging Determinants of Poststroke Cognitive Performance

Background and Purpose- We aimed to define the neuroimaging determinants of poststroke cognitive performance and their relative contributions among a spectrum of magnetic resonance imaging markers, including lesion burden and strategic locations. Methods- We prospectively included patients with stroke from the GRECogVASC study (Groupe de Réflexion pour l'Évaluation Cognitive Vasculaire) who underwent 3-T magnetic resonance imaging and a comprehensive standardized battery of neuropsychological tests 6 months after the index event. An optimized global cognitive score and neuroimaging markers, including stroke characteristics, cerebral atrophy markers, and small vessel diseases markers, were assessed. Location of strategic strokes was determined using a specifically designed method taking into account stroke size and cerebral atrophy. A stepwise multivariable linear regression model was used to identify magnetic resonance imaging determinants of cognitive performance. Results- Data were available for 356 patients (mean age: 63.67±10.6 years; 326 [91.6%] of the patients had experienced an ischemic stroke). Six months poststroke, 50.8% of patients presented with a neurocognitive disorder. Strategic strokes (right corticospinal tract, left antero-middle thalamus, left arcuate fasciculus, left middle frontal gyrus, and left postero-inferior cerebellum; R²=0.225; P=0.0001), medial temporal lobe atrophy ( R²=0.077; P=0.0001), total brain tissue volume ( R²=0.028; P=0.004), and stroke volume ( R²=0.013; P=0.005) were independent determinants of cognitive performance. Strategic strokes accounted for the largest proportion of the variance in the cognitive score (22.5%). The white matter hyperintensity burden, brain microbleeds, and dilated perivascular spaces were not independent determinants. Conclusions- Optimized global cognitive score and combined approach of both quantitative measures related to structure loss and qualitative measures related to the presence of strategic lesion are required to improve the determination of structure-function relationship of cognitive performance after stroke.

Who should undergo a comprehensive cognitive assessment after a stroke? A cognitive risk score

OBJECTIVE

To validate the ability of a specifically developed cognitive risk score to identify patients at risk of poststroke neurocognitive disorders (NCDs) who are eligible for a comprehensive cognitive assessment.

METHODS

After assessing 404 patients (infarct 91.3%) in the Groupe de Réflexion pour l'Evaluation Cognitive VASCulaire (GRECogVASC) cross-sectional study with the National Institute of Neurological Disorders and Stroke-Canadian Stroke Network battery 6 months after stroke, we used multivariable logistic regression and bootstrap analyses to determine factors associated with NCDs. Independent, internally validated factors were included in a cognitive risk score.

RESULTS

Cognitive impairment was present in 170 of the 320 patients with a Rankin Scale score ≥1. The backward logistic regression selected 4 factors (≥73% of the permutations): NIH Stroke Scale score on admission ≥7 (odds ratio [OR] 2.73, 95% confidence interval [CI] 1.29-4.3, p = 0.005), multiple strokes (OR 3.78, 95% CI 1.6-8, p = 0.002), adjusted Mini-Mental State Examination (MMSEadj) score ≤27 (OR 6.69, 95% CI 3.9-11.6, p = 0.0001), and Fazekas score ≥2 (OR 2.34, 95% CI 1.3-4.2, p = 0.004). The cognitive risk score computed with these 4 factors provided good calibration, discrimination (overoptimism-corrected C = 0.793), and goodness of fit (Hosmer-Lemeshow test p = 0.99). A combination of Rankin Scale score ≥1, cognitive risk score ≥1, and MMSEadj score ≥21 selected 230 (56.9%) of the 404 patients for a comprehensive assessment. This procedure yielded good sensitivity (96.5%) and moderate specificity (43%; positive predictive value 0.66, negative predictive value 0.91) and was more accurate (p ≤ 0.03 for all) than the sole use of screening tests (MMSE or Montréal Cognitive Assessment).

CONCLUSION

The GRECogVASC cognitive risk score comprises 4 easily documented factors; this procedure helps to identify patients at risk of poststroke NCDs who must therefore undergo a comprehensive assessment.

CLINICALTRIALSGOV IDENTIFIER

NCT01339195.

Dysexecutive disorders and their diagnosis: A position paper

Although executive function disorders are among the most prevalent cognitive impairments a consensus on diagnostic criteria has yet to be reached. With a view to harmonizing these criteria, the present position paper (i) focuses on the main dysexecutive disorders, (ii) examines recent approaches in both the behavioral and cognitive domains, (iii) defines diagnostic boundaries for frontal syndrome, (iv) reports on the frequency and profile of the executive function disorders observed in the main brain diseases, and (v) proposes an operationalization of diagnostic criteria. Future work must define the executive processes involved in human adaptive behavior, characterize their impairment in brain diseases, and improve the management of these conditions (including remediation strategies and rehabilitation).

Cognitive Sequelae of Unruptured and Ruptured Intracranial Aneurysms and their Treatment: Modalities for Neuropsychological Assessment

BACKGROUND

Cognitive sequelae frequently follow subarachnoid hemorrhage (SAH) and include deficits across multiple domains of executive function. This factor affects overall functional outcomes negatively, especially in younger patients. Several clinical correlates predict development and severity of cognitive dysfunction after SAH. Hypothetical mechanisms of cognitive dysfunction in the absence of radiographic lesion include cerebral hypoperfusion and blood breakdown products, resulting in perturbed interneuronal communication and network synchrony, excitotoxicity, and altered microRNA expression.

METHODS

The PubMed database was searched for articles discussing cognitive outcomes in patients with unruptured and ruptured intracranial aneurysmal disease, sequelae of treatment, and modalities for neuropsychologic testing.

RESULTS

Treatment of unruptured intracranial aneurysms, although capable of preventing SAH, comes with its own set of complications and may also affect cognitive function. Neuropsychological tests such as the Montreal Cognitive Assessment, Mini-Mental Status Examination, and others have proved useful in evaluating cognitive decline. Studies using functional neurologic imaging modalities have identified regions with altered activation patterns during various cognitive tasks. The sum of research efforts in this field has provided useful insights and an initial understanding of cognitive dysfunction after aneurysm treatment and SAH that should prove useful in guiding and rendering future investigations more fruitful.

CONCLUSIONS

Development of finer and more sensitive neuropsychological tests in evaluating the different domains of cognitive function after aneurysm treatment and SAH in general will be useful in accurately determining outcomes after ictus and comparing efficacy of different therapeutic strategies.

Prevalence of Poststroke Neurocognitive Disorders Using National Institute of Neurological Disorders and Stroke-Canadian Stroke Network, VASCOG Criteria (Vascular Behavioral and Cognitive Disorders), and Optimized Criteria of Cognitive Deficit

BACKGROUND AND PURPOSE

The prevalence of poststroke neurocognitive disorder (NCD) has yet to be accurately determined. The primary objective of the present study was to optimize operationalization of the criterion for NCD by using an external validity criterion.

METHODS

The GRECOG-VASC cohort (Groupe de Réflexion pour l'Évaluation Cognitive Vasculaire) of 404 stroke patients with cerebral infarct (91.3%) or hemorrhage (18.7%) was assessed 6 months poststroke and 1003 healthy controls, with the National Institute of Neurological Disorders and Stroke-Canadian Stroke Network standardized battery. Three dimensions of the criterion for cognitive impairment were systematically examined by using the false-positive rate as an external validity criterion. Diagnosis of mild and major NCD was based on the VASCOG criteria (Vascular Behavioral and Cognitive Disorders). The mechanisms of functional decline were systematically assessed.

RESULTS

The optimal criterion for cognitive impairment was the shortened summary score (ie, averaged performance for action speed, executive functions, and language) because it was associated with the highest (P=0.0001) corrected true-positive rate (43.5%) and a false-positive rate ≤5%. Using this criterion, the mean (95% confidence interval) prevalence of poststroke NCD was 49.5% (44.6-54.4), most of which corresponded to mild NCD (39.1%; 95% confidence interval, 34.4-43.9) rather than dementia (10.4%; 95% confidence interval, 7.4-13.4).

CONCLUSIONS

This study is the first to have optimized the operationalization of the criterion for poststroke cognitive impairment. It documented the prevalence of poststroke NCD in the GRECOG-VASC cohort and showed that mild cognitive impairment accounts for 80% of the affected patients. Finally, the method developed in the present study offers a means of harmonizing the diagnosis of NCD.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01339195.

Baseline Vascular Cognitive Impairment Predicts the Course of Apathetic Symptoms After Stroke: The CASPER Study

OBJECTIVE

To examine the influence of vascular cognitive impairment (VCI) on the course of poststroke depression (PSD) and poststroke apathy (PSA).

METHODS

Included were 250 stroke patients who underwent neuropsychological and neuropsychiatric assessment 3 months after stroke (baseline) and at a 6- and 12-month follow-up after baseline. Linear mixed models tested the influence of VCI in at least one cognitive domain (any VCI) or multidomain VCI (VCI in multiple cognitive domains) at baseline and domain-specific VCI at baseline on levels of depression and apathy over time, with random effects for intercept and slope.

RESULTS

Almost half of the patients showed any VCI at baseline, and any VCI was associated with increasing apathy levels from baseline to the 12-month follow-up. Patients with multidomain VCI had higher apathy scores at the 6- and 12-month follow-up compared with patients with VCI in a single cognitive domain. Domain-specific analyses showed that impaired executive function and slowed information processing speed went together with increasing apathy levels from baseline to 6- and 12-month follow-up. None of the cognitive variables predicted the course of depressive symptoms.

CONCLUSION

Baseline VCI is associated with increasing apathy levels from baseline to the chronic stroke phase, whereas no association was found between baseline VCI and the course of depressive symptoms. Health professionals should be aware that apathy might be absent early after stroke but may evolve over time in patients with VCI.

Dehydroevodiamine·HCl enhances cognitive function in memory-impaired rat models

Progressive memory impairment such as that associated with depression, stroke, and Alzheimer's disease (AD) can interfere with daily life. In particular, AD, which is a progressive neurodegenerative disorder, prominently features a memory and learning impairment that is related to changes in acetylcholine and abnormal β-amyloid (Aβ) deposition in the brain. In the present study, we investigated the effects of dehydroevodiamine·HCl (DHED) on cognitive improvement and the related mechanism in memory-impaired rat models, namely, a scopolamine-induced amnesia model and a Aβ_1-42-infused model. The cognitive effects of DHED were measured using a water maze test and a passive avoidance test in the memory-impaired rat models. The results demonstrate that DHED (10 mg/kg, p.o.) and Donepezil (1 mg/kg, p.o.) ameliorated the spatial memory impairment in the scopolamine-induced amnestic rats. Moreover, DHED significantly improved learning and memory in the Aβ_1-42-infused rat model. Furthermore, the mechanism of these behavioral effects of DHED was investigated using a cell viability assay, reactive oxygen species (ROS) measurement, and intracellular calcium measurement in primary cortical neurons. DHED reduced neurotoxicity and the production of Aβ-induced ROS in primary cortical neurons. In addition, similar to the effect of MK801, DHED decreased intracellular calcium levels in primary cortical neurons. Our results suggest that DHED has strong protective effects against cognitive impairments through its antioxidant activity and inhibition of neurotoxicity and intracellular calcium. Thus, DHED may be an important therapeutic agent for memory-impaired symptoms.