The Cognition and Affect after Stroke - a Prospective Evaluation of Risks (CASPER) study: rationale and design

Exploring vascular contributions to cognitive impairment and dementia (ENIGMA): protocol for a prospective observational study

BACKGROUND

Post-stroke cognitive impairment (PSCI) is common. However, the underlying pathophysiology remains largely unknown. Understanding the role of microvascular changes and finding markers that can predict PSCI, could be a first step towards better screening and management of PSCI. Capillary dysfunction is a pathological feature of cerebral small vessel disease and may play a role in the mechanisms underlying PSCI. Extracellular vesicles (EVs) are secreted from cells and may act as disease biomarkers. We aim to investigate the role of capillary dysfunction in PSCI and the associations between EV characteristics and cognitive function one year after acute ischemic stroke (AIS) and transient ischemic attack (TIA).

METHODS

The ENIGMA study is a single-centre prospective clinical observational study conducted at Aarhus University Hospital, Denmark. Consecutive patients with AIS and TIA are included and followed for one year with follow-up visits at three and 12 months. An MRI is performed at 24 h and 12 months follow-up. EV characteristics will be characterised from blood samples drawn at 24 h and three months follow-up. Cognitive function is assessed three and 12 months after AIS and TIA using the Repeatable Battery for the Assessment of Neuropsychological Status.

DISCUSSION

Using novel imaging and molecular biological techniques the ENIGMA study will provide new knowledge about the vascular contributions to cognitive decline and dementia.

TRIAL REGISTRATION

The study is retrospectively registered as an ongoing observational study at ClinicalTrials.gov with the identifier NCT06257823.

Network analysis of neuropsychiatric, cognitive, and functional complications of stroke: implications for novel treatment targets

AIM

Recovery from stroke is adversely affected by neuropsychiatric complications, cognitive impairment, and functional disability. Better knowledge of their mutual relationships is required to inform effective interventions. Network theory enables the conceptualization of symptoms and impairments as dynamic and mutually interacting systems. We aimed to identify interactions of poststroke complications using network analysis in diverse stroke samples.

METHODS

Data from 2185 patients were sourced from member studies of STROKOG (Stroke and Cognition Consortium), an international collaboration of stroke studies. Networks were generated for each cohort, whereby nodes represented neuropsychiatric symptoms, cognitive deficits, and disabilities on activities of daily living. Edges characterized associations between them. Centrality measures were used to identify hub items.

RESULTS

Across cohorts, a single network of interrelated poststroke complications emerged. Networks exhibited dissociable depression, apathy, fatigue, cognitive impairment, and functional disability modules. Worry was the most central symptom across cohorts, irrespective of the depression scale used. Items relating to activities of daily living were also highly central nodes. Follow-up analysis in two studies revealed that individuals who worried had more densely connected networks than those free of worry (CASPER [Cognition and Affect after Stroke: Prospective Evaluation of Risks] study: S = 9.72, P = 0.038; SSS [Sydney Stroke Study]: S = 13.56, P = 0.069).

CONCLUSION

Neuropsychiatric symptoms are highly interconnected with cognitive deficits and functional disabilities resulting from stroke. Given their central position and high level of connectedness, worry and activities of daily living have the potential to drive multimorbidity and mutual reinforcement between domains of poststroke complications. Targeting these factors early after stroke may have benefits that extend to other complications, leading to better stroke outcomes.

White Matter Hyperintensity Volume and Poststroke Cognition: An Individual Patient Data Pooled Analysis of 9 Ischemic Stroke Cohort Studies

BACKGROUND

White matter hyperintensities (WMH) are associated with cognitive dysfunction after ischemic stroke. Yet, uncertainty remains about affected domains, the role of other preexisting brain injury, and infarct types in the relation between WMH burden and poststroke cognition. We aimed to disentangle these factors in a large sample of patients with ischemic stroke from different cohorts.

METHODS

We pooled and harmonized individual patient data (n=1568) from 9 cohorts, through the Meta VCI Map consortium (www.metavcimap.org). Included cohorts comprised patients with available magnetic resonance imaging and multidomain cognitive assessment <15 months poststroke. In this individual patient data meta-analysis, linear mixed models were used to determine the association between WMH volume and domain-specific cognitive functioning (Z scores; attention and executive functioning, processing speed, language and verbal memory) for the total sample and stratified by infarct type. Preexisting brain injury was accounted for in the multivariable models and all analyses were corrected for the study site as a random effect.

RESULTS

In the total sample (67 years [SD, 11.5], 40% female), we found a dose-dependent inverse relationship between WMH volume and poststroke cognitive functioning across all 4 cognitive domains (coefficients ranging from -0.09 [SE, 0.04, P=0.01] for verbal memory to -0.19 [SE, 0.03, P<0.001] for attention and executive functioning). This relation was independent of acute infarct volume and the presence of lacunes and old infarcts. In stratified analyses, the relation between WMH volume and domain-specific functioning was also largely independent of infarct type.

CONCLUSIONS

In patients with ischemic stroke, increasing WMH volume is independently associated with worse cognitive functioning across all major domains, regardless of old ischemic lesions and infarct type.

The role of the kynurenine pathway in cognitive functioning after stroke: A prospective clinical study

BACKGROUND

The kynurenine pathway is the main metabolic pathway of tryptophan degradation and has been associated with stroke and impaired cognitive functioning, but studies on its role in post-stroke cognitive impairment (PSCI) are scarce. We aimed to investigate associations between metabolites of the kynurenine pathway at baseline and post-stroke cognitive functioning over time.

METHODS

Baseline plasma kynurenines were quantified in 198 stroke patients aged 65.4 ± 10.8 years, 138 (69.7%) men, who were followed up over a period of three years after stroke. Baseline and longitudinal associations of kynurenines with PSCI and cognitive domain scores were investigated using linear mixed models, adjusted for several confounders.

RESULTS

No evidence of associations between kynurenines and odds of PSCI were found. However, considering individual cognitive domains, higher plasma levels of anthranilic acid (AA) were associated with better episodic memory at baseline (β per SD 0.16 [0.05, 0.28]). Additionally, a linear-quadratic association was found for the kynurenic acid/ quinolinic acid ratio (KA/QA), a neuroprotective index, with episodic memory (Wald χ2 = 8.27, p = .016). Higher levels of KA were associated with better processing speed in women only (pinteraction = .008; β per SD 0.15 [95% CI 0.02, 0.27]). These associations did not change over time.

CONCLUSIONS

Higher levels of KA, AA and KA/QA were associated with better scores on some cognitive domains at baseline. These associations did not change over time. Given the exploratory nature and heterogeneity of findings, these results should be interpreted with caution, and verified in other prospective studies.

Factors affecting the quality of life after ischemic stroke in young adults: a scoping review

PURPOSE

To synthesize the body of knowledge on the factors influencing the quality of life (QoL) after ischemic stroke (IS) in young adults.

METHODS

Guidelines regarding the scoping review methodology developed by the Joanna Briggs Institute, and the PRISMA-ScR checklist for a scoping review was used in this paper. A total of 1197 studies were identified through a bibliographic search in Web of Science, MEDLINE, PsycInfo, ScienceDirect, Scopus, and ProQuest Science Database. Articles published between the years 2000-2021 were included.

RESULTS

A total of nine papers were finally selected to respond to the research question. Three studies were prospective longitudinal studies compared QoL between young stroke and age-matched controls from the general population. Across all the analysed studies, 14 variables potentially associated with QoL were identified. QoL in young patients is mainly affected by clinical outcomes after IS (scored by the modified Rankin scale and the Barthel index-favourable initial functional status and higher independence in ADL leads to higher QoL) and psychological factors (post-stroke fatigue and depression-higher levels of fatigue and depression lead to lower QoL). The reviewed studies emphasized the importance of functional outcomes, post-stroke depression, fatigue and anxiety and early return to work.

CONCLUSION

Further longitudinal studies are needed to identify the trajectory of post-stroke psychosocial symptoms over time and other potential predictors of unfavourable long-term QoL, thus specific young stroke rehabilitation and stroke self-management support programmes should be developed (address physical, psychological factors which influence the psychosocial adaptation post-stroke and the perception of the QoL).

The course of post-stroke apathy in relation to cognitive functioning: a prospective longitudinal cohort study

Apathy is common after stroke and has been associated with cognitive impairment. However, causality between post-stroke apathy and cognitive impairment remains unclear. We assessed the course of apathy in relation to changes in cognitive functioning in stroke survivors. Using the Apathy Scale (AS) and cognitive tests on memory, processing speed and executive functioning at six- and 15 months post-stroke we tested for associations between (1) AS-scores and (change in) cognitive scores; (2) apathy course (persistent/incident/resolved) and cognitive change scores. Of 117 included participants, 29% had persistent apathy, 13% apathy resolving over time and 10% apathy emerging between 6-15 months post-stroke. Higher AS-scores were cross-sectionally and longitudinally associated with lower cognitive scores. Relations between apathy and cognitive change scores were ambiguous. These inconsistent relations between apathy and changes in cognition over time suggest that post-stroke apathy does not directly impact cognitive performance. Both these sequelae of stroke require separate attention.

Network impact score is an independent predictor of post-stroke cognitive impairment: A multicenter cohort study in 2341 patients with acute ischemic stroke

BACKGROUND

Post-stroke cognitive impairment (PSCI) is a common consequence of stroke. Accurate prediction of PSCI risk is challenging. The recently developed network impact score, which integrates information on infarct location and size with brain network topology, may improve PSCI risk prediction.

AIMS

To determine if the network impact score is an independent predictor of PSCI, and of cognitive recovery or decline.

METHODS

We pooled data from patients with acute ischemic stroke from 12 cohorts through the Meta VCI Map consortium. PSCI was defined as impairment in ≥ 1 cognitive domain on neuropsychological examination, or abnormal Montreal Cognitive Assessment. Cognitive recovery was defined as conversion from PSCI < 3 months post-stroke to no PSCI at follow-up, and cognitive decline as conversion from no PSCI to PSCI. The network impact score was related to serial measures of PSCI using Generalized Estimating Equations (GEE) models, and to PSCI stratified according to post-stroke interval (<3, 3-12, 12-24, >24 months) and cognitive recovery or decline using logistic regression. Models were adjusted for age, sex, education, prior stroke, infarct volume, and study site.

RESULTS

We included 2341 patients with 4657 cognitive assessments. PSCI was present in 398/844 patients (47%) <3 months, 709/1640 (43%) at 3-12 months, 243/853 (28%) at 12-24 months, and 208/522 (40%) >24 months. Cognitive recovery occurred in 64/181 (35%) patients and cognitive decline in 26/287 (9%). The network impact score predicted PSCI in the univariable (OR 1.50, 95%CI 1.34-1.68) and multivariable (OR 1.27, 95%CI 1.10-1.46) GEE model, with similar ORs in the logistic regression models for specified post-stroke intervals. The network impact score was not associated with cognitive recovery or decline.

CONCLUSIONS

The network impact score is an independent predictor of PSCI. As such, the network impact score may contribute to a more precise and individualized cognitive prognostication in patients with ischemic stroke. Future studies should address if multimodal prediction models, combining the network impact score with demographics, clinical characteristics and other advanced brain imaging biomarkers, will provide accurate individualized prediction of PSCI. A tool for calculating the network impact score is freely available at https://metavcimap.org/features/software-tools/lsm-viewer/.

Long-Term Cognitive Decline After Stroke: An Individual Participant Data Meta-Analysis

BACKGROUND AND PURPOSE

Poststroke cognitive impairment is common, but the trajectory and magnitude of cognitive decline after stroke is unclear. We examined the course and determinants of cognitive change after stroke using individual participant data from the Stroke and Cognition Consortium.

METHODS

Nine longitudinal hospital-based cohorts from 7 countries were included. Neuropsychological test scores and normative data were used to calculate standardized scores for global cognition and 5 cognitive domains. One-step individual participant data meta-analysis was used to examine the rate of change in cognitive function and risk factors for cognitive decline after stroke. Stroke-free controls were included to examine rate differences. Based on the literature and our own data that showed short-term improvement in cognitive function after stroke, key analyses were restricted to the period beginning 1-year poststroke to focus on its long-term effects.

RESULTS

A total of 1488 patients (mean age, 66.3 years; SD, 11.1; 98% ischemic stroke) were followed for a median of 2.68 years (25th-75th percentile: 1.21-4.14 years). After an initial period of improvement through up to 1-year poststroke, decline was seen in global cognition and all domains except executive function after adjusting for age, sex, education, vascular risk factors, and stroke characteristics (-0.053 SD/year [95% CI, -0.073 to -0.033]; P<0.001 for global cognition). Recurrent stroke and older age were associated with faster decline. Decline was significantly faster in patients with stroke compared with controls (difference=-0.078 SD/year [95% CI, -0.11 to -0.045]; P<0.001 for global cognition in a subgroup analysis).

CONCLUSIONS

Patients with stroke experience cognitive decline that is faster than that of stroke-free controls from 1 to 3 years after onset. An increased rate of decline is associated with older age and recurrent stroke.

Synergistic Effects of Aldehyde Dehydrogenase 2 Polymorphisms and Alcohol Consumption on Cognitive Impairment after Ischemic Stroke in Han Chinese

Aldehyde dehydrogenase 2 (ALDH2) polymorphisms are related to both stroke risk and alcohol consumption. However, the influence of ALDH2 polymorphisms and alcohol consumption on cognitive impairment after ischemic stroke remains unknown, as do the possible mechanisms. We enrolled 180 Han Chinese ischemic stroke patients from four community health centers in Bengbu, China. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), and two different MoCA cutoff scores were used to define cognitive impairment in ischemic stroke patients. The ALDH2 genotypes were determined using polymerase chain reaction and direct sequencing. To assess the associations of ALDH2 polymorphisms and alcohol consumption with cognitive impairment after ischemic stroke, we performed binary logistic regression analysis with odds ratios. We revealed that individuals with the ALDH2 wild-type genotype were more likely to have high MoCA scores than those with the mutant and heterozygous types (p = 0.034). In addition, using two MoCA cutoff scores, the percentage of moderate to excessive alcohol consumption in the cognitive impairment group was higher than that in the nonimpairment group (p = 0.001). The levels of 4-hydroxy-2-nonenal (p = 0.001) and swallowing function (p = 0.001) were also higher in the cognitive impairment group than in the nonimpairment group. Moreover, after adjusting for other potential risk factors, ALDH2 polymorphisms and alcohol consumption had a significant synergistic effect on cognitive impairment (p = 0.022). Specifically, the ALDH2∗2 mutant allele and higher alcohol consumption were associated with cognitive impairment and swallowing ability after ischemic stroke. Targeting ALDH2 may be a useful biomarker for cognitive rehabilitation following ischemic stroke.

Strategic infarct locations for post-stroke cognitive impairment: a pooled analysis of individual patient data from 12 acute ischaemic stroke cohorts

BACKGROUND

Post-stroke cognitive impairment (PSCI) occurs in approximately half of people in the first year after stroke. Infarct location is a potential determinant of PSCI, but a comprehensive map of strategic infarct locations predictive of PSCI is unavailable. We aimed to identify infarct locations most strongly predictive of PSCI after acute ischaemic stroke and use this information to develop a prediction model.

METHODS

In this large-scale multicohort lesion-symptom mapping study, we pooled and harmonised individual patient data from 12 cohorts through the Meta-analyses on Strategic Lesion Locations for Vascular Cognitive Impairment using Lesion-Symptom Mapping (Meta VCI Map) consortium. The identified cohorts (as of Jan 1, 2019) comprised patients with acute symptomatic infarcts on CT or MRI (with available infarct segmentations) and a cognitive assessment up to 15 months after acute ischaemic stroke onset. PSCI was defined as performance lower than the fifth percentile of local normative data, on at least one cognitive domain on a multidomain neuropsychological assessment or on the Montreal Cognitive Assessment. Voxel-based lesion-symptom mapping (VLSM) was used to calculate voxel-wise odds ratios (ORs) for PSCI that were mapped onto a three-dimensional brain template to visualise PSCI risk per location. For the prediction model of PSCI risk, a location impact score on a 5-point scale was derived from the VLSM results on the basis of the mean voxel-wise coefficient (ln[OR]) within each patient's infarct. We did combined internal-external validation by leave-one-cohort-out cross-validation for all 12 cohorts using logistic regression. Predictive performance of a univariable model with only the location impact score was compared with a multivariable model with addition of other clinical PSCI predictors (age, sex, education, time interval between stroke onset and cognitive assessment, history of stroke, and total infarct volume). Testing of visual ratings was done by three clinicians, and accuracy, inter-rater reliability, and intra-rater reliability were assessed with Cohen's weighted kappa.

FINDINGS

In our sample of 2950 patients (mean age 66·8 years [SD 11·6]; 1157 [39·2%] women), 1286 (43·6%) had PSCI. We achieved high lesion coverage of the brain in our analyses (86·9%). Infarcts in the left frontotemporal lobes, left thalamus, and right parietal lobe were strongly associated with PSCI (after false discovery rate correction, q<0·01; voxel-wise ORs >20). On cross-validation, the location impact score showed good correspondence, based on visual assessment of goodness of fit, between predicted and observed risk of PSCI across cohorts after adjusting for cohort-specific PSCI occurrence. Cross-validations showed that the location impact score by itself had similar performance to the combined model with other PSCI predictors, while allowing for easy visual assessment. Therefore the univariable model with only the location impact score was selected as the final model. Correspondence between visual ratings and actual location impact score (Cohen's weighted kappa: range 0·88-0·92), inter-rater agreement (0·85-0·87), and intra-rater agreement (for a single rater, 0·95) were all high.

INTERPRETATION

To the best of our knowledge, this study provides the first comprehensive map of strategic infarct locations associated with risk of PSCI. A location impact score was derived from this map that robustly predicted PSCI across cohorts. Furthermore, we developed a quick and reliable visual rating scale that might in the future be applied by clinicians to identify individual patients at risk of PSCI.

FUNDING

The Netherlands Organisation for Health Research and Development.

Clinical correlates of social cognition after an ischemic stroke: preliminary findings

The co-occurrence of post-stroke behavioral disorders and cognitive impairment has been extensively investigated. However, studies usually do not include social cognition among the assessed cognitive domains.

Objective

To investigate the potential association between facial emotion recognition, a measure of social cognition, and behavioral and cognitive symptoms in the subacute phase of ischemic stroke.

Methods

Patients admitted to a Stroke Unit with ischemic stroke were followed up to 60 days. At this time point, they were evaluated with the following tools: Mini-Mental State Examination (MMSE); Frontal Assessment Battery (FAB); Visual Memory Test of the Brief Cognitive Battery (VMT); Phonemic Verbal Fluency (F-A-S Test); Digit Span; Facial Emotion Recognition Test (FERT) and Hospital Anxiety and Depression Scale (HADS). A control group composed of 21 healthy individuals also underwent the same evaluation.

Results

Eighteen patients with ischemic stroke were enrolled in this study. They had similar age, sex and schooling years compared to controls. Depression symptoms and episodic memory deficits were significantly more frequent in patients compared to controls. The recognition of sadness expression positively correlated with the levels of anxiety and depression, while and the recognition of fear expression negatively correlated with depression in the stroke group.

Conclusions

After an ischemic stroke, patients exhibit impairment in social cognition skills, specifically facial emotion recognition, in association with behavioral symptoms.

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.

Increased history of ischemic stroke and decreased neurocognitive performance in children with chronic kidney disease

BACKGROUND

This study aimed to determine stroke incidence and assess the association between stroke and neurocognitive functioning in children with chronic kidney disease (CKD).

METHODS

Data was derived from the Chronic Kidney Disease in Children (CKiD) cohort study. Stroke incidence was calculated after confirming self-reports of stroke occurrence by chart review. Each participant with stroke was matched with three stroke-free participants and performance on selected neurocognitive measures was compared. Wilcoxon rank-sum tests were used to compare neurocognitive test scores. Effect size (ES) was estimated using a modified version of Cohen's U₃ metric that measures the excess percentage of the stroke group worse than the median of the control group.

RESULTS

Of 891 subjects, five (0.56%) had a confirmed stroke prior to study entry. Median time at risk was 15.7 years [interquartile range, 12.5-18.4]. Estimated incidence rate of history of stroke was 36.8 per 100,000 children per year (95% confidence interval 15.3, 88.5). Controls and subjects with stroke were similar in age, CKD duration, race, and maternal education. ES for many of the neurocognitive comparisons was moderate to large. Subjects in the CKID cohort with a history of stroke had lower scores on spatial span reverse, spatial span forward, and design fluency, and worse parent ratings on BRIEF Metacognition Index compared to a matched sample of children with CKD without stroke.

CONCLUSIONS

Children with CKD have an increased incidence of prior ischemic stroke compared to the general pediatric population. A stroke history was associated with poorer performance on neurocognitive measures. Graphical abstract.

Assessing the Predictive Validity of Simple Dementia Risk Models in Harmonized Stroke Cohorts

Supplemental Digital Content is available in the text.

Stroke is associated with an increased risk of dementia. To assist in the early identification of individuals at high risk of future dementia, numerous prediction models have been developed for use in the general population. However, it is not known whether such models also provide accurate predictions among stroke patients. Therefore, the aim of this study was to determine whether existing dementia risk prediction models that were developed for use in the general population can also be applied to individuals with a history of stroke to predict poststroke dementia with equivalent predictive validity.

Apathy and depression during the recovery stage after stroke

Background/Aims

Both apathy and depression occur during the recovery period following stroke; however, the relationship between post-stroke apathy and depression is still unclear. The present study investigated the clinical course of apathy and its association with depression, cognitive function and daily function during the recovery period after stroke.

Methods

A total of 42 patients (29 male and 13 female, aged 69.1 ± 12.4 years) who had experienced stroke participated in this study. Each participant was assessed using the Apathy Scale, Self-rating Depression Scale, Mini-Mental State Examination, Clinical Assessment of Attention and Trail-Making-Test parts A and B. Quality of life was evaluated using the Stroke Specific Quality of Life Scale. Physical function and functional status were assessed using the Brunnstrom Stages of Stroke Recovery and Functional Independence Measure respectively.

Results

The incidence of apathy did not change from the time of admission to discharge. Apathy Scale score did not correlate with Self-rating Depression Scale score at admission, but it did correlate at the time of discharge. Patients with apathy after stroke suffered from greater cognitive disturbance and attention and executive dysfunctions than those without apathy. Total Functional Independence Measure score did not correlate with Apathy Scale or Self-rating Depression Scale score, but there was an association between Self-rating Depression Scale score and the Functional Independence Measure motor and Brunnstrom scores at discharge.

Conclusions

Apathy and depression had different relationships with cognitive and physical function during the recovery stage after stroke. The prevalence of apathy and depression changed, with the interrelationship between apathy and depression altering during the recovery period. Symptoms of apathy and depression should be distinguished from each other and appropriately evaluated to provide effective intervention to support physical and mental recovery after stroke.

The Meta VCI Map consortium for meta-analyses on strategic lesion locations for vascular cognitive impairment using lesion-symptom mapping: Design and multicenter pilot study

INTRODUCTION

The Meta VCI Map consortium performs meta-analyses on strategic lesion locations for vascular cognitive impairment using lesion-symptom mapping. Integration of data from different cohorts will increase sample sizes, to improve brain lesion coverage and support comprehensive lesion-symptom mapping studies.

METHODS

Cohorts with available imaging on white matter hyperintensities or infarcts and cognitive testing were invited. We performed a pilot study to test the feasibility of multicenter data processing and analysis and determine the benefits to lesion coverage.

RESULTS

Forty-seven groups have joined Meta VCI Map (stroke n = 7800 patients; memory clinic n = 4900; population-based n = 14,400). The pilot study (six ischemic stroke cohorts, n = 878) demonstrated feasibility of multicenter data integration (computed tomography/magnetic resonance imaging) and achieved marked improvement of lesion coverage.

DISCUSSION

Meta VCI Map will provide new insights into the relevance of vascular lesion location for cognitive dysfunction. After the successful pilot study, further projects are being prepared. Other investigators are welcome to join.

Imaging markers associated with the development of post-stroke depression and apathy: Results of the Cognition and Affect after Stroke - a Prospective Evaluation of Risks study

Introduction

It has been suggested that the development of post-stroke apathy (PSA) and depression (PSD) may be more strongly associated with generalised brain pathology, rather than the stroke lesion itself. The present study aimed to investigate associations between imaging markers of lesion-related and generalised brain pathology and the development of PSA and PSD during a one-year follow-up.

Patients and methods

In a prospective cohort study, 188 stroke patients received 3-Tesla MRI at baseline (three months post-stroke) for evaluation of lesion-related, vascular, and degenerative brain pathology. Presence of lacunes, microbleeds, white matter hyperintensities, and enlarged perivascular spaces was summed to provide a measure of total cerebral small vessel disease (cSVD) burden (range 0-4). The Mini International Neuropsychiatric Interview and Apathy Evaluation Scale were administered at baseline and repeated at 6- and 12-month follow-up to define presence of PSD and PSA, respectively.

Results

Population-averaged logistic regression models showed that global brain atrophy and severe cSVD burden (score 3-4) were significantly associated with the odds of having PSA (OR_GEE 5.33, 95% CI 1.99-14.25 and 3.04, 95% CI 1.20-7.69, respectively), independent of stroke lesion volume and co-morbid PSD. Medium cSVD burden (score 2) was significantly associated with the odds of having PSD (OR_GEE 2.92, 95% CI 1.09-7.78), independent of stroke lesion volume, co-morbid PSA, and pre-stroke depression. No associations were found with lesion-related markers.

Conclusions

The results suggest that generalised degenerative and vascular brain pathology, rather than lesion-related pathology, is an important predictor for the development of PSA, and less strongly for PSD.

Cerebral microbleeds and stroke risk after ischaemic stroke or transient ischaemic attack: a pooled analysis of individual patient data from cohort studies

BACKGROUND

Cerebral microbleeds are a neuroimaging biomarker of stroke risk. A crucial clinical question is whether cerebral microbleeds indicate patients with recent ischaemic stroke or transient ischaemic attack in whom the rate of future intracranial haemorrhage is likely to exceed that of recurrent ischaemic stroke when treated with antithrombotic drugs. We therefore aimed to establish whether a large burden of cerebral microbleeds or particular anatomical patterns of cerebral microbleeds can identify ischaemic stroke or transient ischaemic attack patients at higher absolute risk of intracranial haemorrhage than ischaemic stroke.

METHODS

We did a pooled analysis of individual patient data from cohort studies in adults with recent ischaemic stroke or transient ischaemic attack. Cohorts were eligible for inclusion if they prospectively recruited adult participants with ischaemic stroke or transient ischaemic attack; included at least 50 participants; collected data on stroke events over at least 3 months follow-up; used an appropriate MRI sequence that is sensitive to magnetic susceptibility; and documented the number and anatomical distribution of cerebral microbleeds reliably using consensus criteria and validated scales. Our prespecified primary outcomes were a composite of any symptomatic intracranial haemorrhage or ischaemic stroke, symptomatic intracranial haemorrhage, and symptomatic ischaemic stroke. We registered this study with the PROSPERO international prospective register of systematic reviews, number CRD42016036602.

FINDINGS

Between Jan 1, 1996, and Dec 1, 2018, we identified 344 studies. After exclusions for ineligibility or declined requests for inclusion, 20 322 patients from 38 cohorts (over 35 225 patient-years of follow-up; median 1·34 years [IQR 0·19-2·44]) were included in our analyses. The adjusted hazard ratio [aHR] comparing patients with cerebral microbleeds to those without was 1·35 (95% CI 1·20-1·50) for the composite outcome of intracranial haemorrhage and ischaemic stroke; 2·45 (1·82-3·29) for intracranial haemorrhage and 1·23 (1·08-1·40) for ischaemic stroke. The aHR increased with increasing cerebral microbleed burden for intracranial haemorrhage but this effect was less marked for ischaemic stroke (for five or more cerebral microbleeds, aHR 4·55 [95% CI 3·08-6·72] for intracranial haemorrhage vs 1·47 [1·19-1·80] for ischaemic stroke; for ten or more cerebral microbleeds, aHR 5·52 [3·36-9·05] vs 1·43 [1·07-1·91]; and for ≥20 cerebral microbleeds, aHR 8·61 [4·69-15·81] vs 1·86 [1·23-1·82]). However, irrespective of cerebral microbleed anatomical distribution or burden, the rate of ischaemic stroke exceeded that of intracranial haemorrhage (for ten or more cerebral microbleeds, 64 ischaemic strokes [95% CI 48-84] per 1000 patient-years vs 27 intracranial haemorrhages [17-41] per 1000 patient-years; and for ≥20 cerebral microbleeds, 73 ischaemic strokes [46-108] per 1000 patient-years vs 39 intracranial haemorrhages [21-67] per 1000 patient-years).

INTERPRETATION

In patients with recent ischaemic stroke or transient ischaemic attack, cerebral microbleeds are associated with a greater relative hazard (aHR) for subsequent intracranial haemorrhage than for ischaemic stroke, but the absolute risk of ischaemic stroke is higher than that of intracranial haemorrhage, regardless of cerebral microbleed presence, antomical distribution, or burden.

FUNDING

British Heart Foundation and UK Stroke Association.

CXCL8 gene silencing promotes neuroglial cells activation while inhibiting neuroinflammation through the PI3K/Akt/NF-κB-signaling pathway in mice with ischemic stroke

OBJECTIVE

Ischemic stroke is known as a neurodegenerative disorder, which induces long-period tissue damage. Chemokine (C-X-C motif) ligand 8 (CXCL8) is involved in acute inflammation and tumor progression through the phosphoinositide-3-kinase/protein kinase B/nuclear factor-κB (PI3K/Akt/NF-κB)-signaling pathway. In this study, we aimed to explore the mechanism of CXCL8 in ischemic stroke in relation to the PI3K/Akt/NF-κB-signaling pathway.

METHODS

Microarray-based gene expression profiling of peripheral blood mononuclear cells was used to identify ischemic stroke-related differentially expressed genes and explore role of CXCL8 in ischemic stroke. Next, the ischemic mice model was successfully established, with transfection efficiency detected. After that, deflection index, recovery of nervous system, infarct sizes, ischemia-induced apoptosis, and neuroinflammatory response in ischemic stroke were measured. At last, the content of inflammatory factors as well as the expression of CXCL8, caspase-3, caspase-9, Bad, interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), Akt, PI3K, and NF-κB were determined.

RESULTS

Comprehensive gene expression profiling analysis identified that CXCL8 might affect the development of ischemic stroke through regulating the PI3K/Akt/NF-κB-signaling pathway. CXCL8 silencing significantly reduced deflection index and infarct size, improved neurological function, and suppressed neuroglial cell loss and apoptosis index. In addition, glial fibrillary acidic portein (GFAP) and ionized calcium-binding adapter molecule 1 (IBA-1) expressions were decreased following CXCL8 suppression, suggesting CXCL8 affected neuroglial activation. Importantly, we also found that CXCL8 silencing activated neuroglial cell and suppressed inflammatory cytokine production in ischemic stroke mice.

CONCLUSION

Taken together, these findings highlight that functional suppression of CXCL8 promotes neuroglial activation and inhibits neuroinflammation by regulating the PI3K/Akt/NF-κB-signaling pathway in mice with ischemic stroke, which might provide new insight for ischemic stroke treatment.

Personality traits and course of symptoms of depression and apathy after stroke: Results of the CASPER study

OBJECTIVE

Post-stroke depression (PSD) and post-stroke apathy (PSA) are both associated with adverse outcome after stroke. This study aimed to examine whether personality traits predict the course of PSD and PSA.

METHODS

In this prospective cohort study, 240 stroke patients completed the NEO Five Factor Inventory, Montgomery-Åsberg Depression Rating Scale, and Apathy Evaluation Scale at 3 months post-stroke. Neuropsychiatric assessment was repeated at 6- and 12-month follow-up after initial testing.

RESULTS

Linear mixed models showed that high neuroticism scores were associated with higher depression levels at baseline, and this association remained stable at follow-up. High extraversion scores and high conscientiousness scores were associated with lower apathy levels at baseline. For neuroticism, a significant interaction with time was found, with higher neuroticism scores at baseline being associated with an increase in apathy scores from 6-month to 12-month follow-up. Prospective analyses showed that high extraversion predicted low apathy levels at 6-month and 12-month follow-up independent of its relations with baseline depression and apathy. High neuroticism predicted high apathy levels at 12-month follow-up, whereas high agreeableness and high openness predicted high apathy levels and low apathy levels, respectively, at 6-month follow-up. None of the personality traits predicted depression scores at follow-up.

CONCLUSION

Personality traits are associated with the development and sustainability of PSD and PSA. The traits associated with PSD and PSA were different, providing support for the independence of these constructs. The findings highlight the importance to take personality traits into account as a potential vulnerability factor for PSD and PSA.

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.

Effects of virtual reality-based training with BTs-Nirvana on functional recovery in stroke patients: preliminary considerations

AIM OF THE STUDY

Cognitive impairment occurs frequently in post-stroke patients. This study aimed to determine the effects of a virtual reality training (VRT) with BTs-Nirvana (BTsN) on the recovery of cognitive functions in stroke patients, using the Interactive-Semi-Immersive Program (I-SIP).

MATERIALS AND METHODS

We enrolled 12 subjects (randomly divided into two groups: experimental group (EG); and control group (CG)), who attended the Laboratory of Robotic and Cognitive Rehabilitation of IRCCS Neurolesi of Messina from January to June 2016. The EG underwent a VRT with BTsN, whereas CG received a standard cognitive treatment. Both the groups underwent the same conventional physiotherapy program. Each treatment session lasted 45 minutes and was repeated three times a week for 8 weeks. All the patients were evaluated by a specific clinical-psychometric battery before (T0), immediately (T1), and one month (T2) after the end of the training.

RESULTS

At T1, the EG presented a greater improvement in the trunk control test (p = 0.03), the Montreal Cognitive Assessment (p = 0.01), the selective attention assessment scores (p = 0.01), the verbal memory (p = 0.03), and the visuospatial and constructive abilities (p = 0.01), as compared to CG. Moreover, such amelioration persisted at T2 only in the EG.

CONCLUSIONS

According to these preliminary data, VRT with I-SIP can be considered a useful complementary treatment to potentiate functional recovery, with regard to attention, visual-spatial deficits, and motor function in patients affected by stroke.

Temporal Associations between Fatigue, Depression, and Apathy after Stroke: Results of the Cognition and Affect after Stroke, a Prospective Evaluation of Risks Study

BACKGROUND

Poststroke fatigue (PSF) is a form of pathological fatigue that can develop after stroke and has a negative impact on functional outcome. PSF is associated with poststroke depression (PSD), which in turn shows similarities with poststroke apathy (PSA). This study aimed at disentangling the temporal associations between PSF and PSD and between PSF and PSA.

METHODS

A total of 250 stroke patients were included, of which 243 completed the Fatigue Severity Scale, Montgomery-Åsberg Depression Rating Scale, and Apathy Evaluation Scale at 3 months poststroke, with follow-up measurements at 6 and 12 months after initial testing. Linear mixed models and linear regressions were performed to evaluate the temporal associations between PSF and PSD, and between PSF and PSA.

RESULTS

PSF was present in 119 patients (49%), of whom 62 patients also had PSD (26%), and 21 patients (9%) also had PSA. At baseline, PSF patients showed higher depression levels, which remained stable at follow-up. PSD patients had higher fatigue levels compared with no-PSD patients at baseline, which remained stable at follow-up. No association between apathy and fatigue was found at baseline and no interaction with time was found. Change in fatigue from baseline to 12-month follow-up was associated with change in depression and with change in apathy.

CONCLUSIONS

Bidirectional associations were found between PSF and PSD. In treatment and rehabilitation programs, early focus on the presence of PSD and PSF is important, since these conditions tend to persist. As there are currently more treatment options for PSD, attention for PSD is important and might also have a beneficial effect on PSF.

Is two better than one? Muscle vibration plus robotic rehabilitation to improve upper limb spasticity and function: A pilot randomized controlled trial

Even though robotic rehabilitation is very useful to improve motor function, there is no conclusive evidence on its role in reducing post-stroke spasticity. Focal muscle vibration (MV) is instead very useful to reduce segmental spasticity, with a consequent positive effect on motor function. Therefore, it could be possible to strengthen the effects of robotic rehabilitation by coupling MV. To this end, we designed a pilot randomized controlled trial (Clinical Trial NCT03110718) that included twenty patients suffering from unilateral post-stroke upper limb spasticity. Patients underwent 40 daily sessions of Armeo-Power training (1 hour/session, 5 sessions/week, for 8 weeks) with or without spastic antagonist MV. They were randomized into two groups of 10 individuals, which received (group-A) or not (group-B) MV. The intensity of MV, represented by the peak acceleration (a-peak), was calculated by the formula (2πf)2A, where f is the frequency of MV and A is the amplitude. Modified Ashworth Scale (MAS), short intracortical inhibition (SICI), and H_max/M_max ratio (HMR) were the primary outcomes measured before and after (immediately and 4 weeks later) the end of the treatment. In all patients of group-A, we observed a greater reduction of MAS (p = 0.007, d = 0.6) and HMR (p<0.001, d = 0.7), and a more evident increase of SICI (p<0.001, d = 0.7) up to 4 weeks after the end of the treatment, as compared to group-B. Likewise, group-A showed a greater function outcome of upper limb (Functional Independence Measure p = 0.1, d = 0.7; Fugl-Meyer Assessment of the Upper Extremity p = 0.007, d = 0.4) up to 4 weeks after the end of the treatment. A significant correlation was found between the degree of MAS reduction and SICI increase in the agonist spastic muscles (p = 0.004). Our data show that this combined rehabilitative approach could be a promising option in improving upper limb spasticity and motor function. We could hypothesize that the greater rehabilitative outcome improvement may depend on a reshape of corticospinal plasticity induced by a sort of associative plasticity between Armeo-Power and MV.

Does body shadow improve the efficacy of virtual reality-based training with BTS NIRVANA?: A pilot study

BACKGROUND

Aim of the present study was to evaluate whether the presence of body shadows during virtual reality (VR) training with BTS NIRVANA (BTs-N) may lead to a better functional recovery.

METHODS

We enrolled 20 poststroke rehabilitation inpatients, who underwent a neurocognitive-rehabilitative training consisting of 24 sessions (3 times a week for 8 weeks) of BTs-N. All the patients were randomized into 2 groups: semi-immersive virtual training with (S-IVTS group) or without (S-IVT group) body shadows. Each participant was evaluated before (T0) and immediately (T1) after the end of the training (Trial Registration Number: NCT03095560).

RESULTS

The S-IVTS group showed a greater improvement in visuo-constructive skills and sustained attention, as compared with the S-IVT group. The other measures showed nonsignificant within-group and between-group differences.

CONCLUSION

Our results showed that body shadow may represent a high-priority class of stimuli that act by "pushing" attention toward the body itself. Further studies are needed to clarify the role of body shadow in promoting the internal representation construction and thus self-recognition.

STROKOG (stroke and cognition consortium): An international consortium to examine the epidemiology, diagnosis, and treatment of neurocognitive disorders in relation to cerebrovascular disease

INTRODUCTION

The Stroke and Cognition consortium (STROKOG) aims to facilitate a better understanding of the determinants of vascular contributions to cognitive disorders and help improve the diagnosis and treatment of vascular cognitive disorders (VCD).

METHODS

Longitudinal studies with ≥75 participants who had suffered or were at risk of stroke or TIA and which evaluated cognitive function were invited to join STROKOG. The consortium will facilitate projects investigating rates and patterns of cognitive decline, risk factors for VCD, and biomarkers of vascular dementia.

RESULTS

Currently, STROKOG includes 25 (21 published) studies, with 12,092 participants from five continents. The duration of follow-up ranges from 3 months to 21 years.

DISCUSSION

Although data harmonization will be a key challenge, STROKOG is in a unique position to reuse and combine international cohort data and fully explore patient level characteristics and outcomes. STROKOG could potentially transform our understanding of VCD and have a worldwide impact on promoting better vascular cognitive outcomes.