The determinants and longitudinal course of post-stroke mild cognitive impairment

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.

Cortical hemodynamic response during cognitive Stroop test in acute stroke patients assessed by fNIRS

BACKGROUND

Following acute ischemic stroke (AIS) many patients experience cognitive impairment which interferes neurorehabilitation. Understanding and monitoring pathophysiologic processes behind cognitive symptoms requires accessible methods during testing and training. Functional near-infrared spectroscopy (fNIRS) can assess activational hemodynamic responses in the prefrontal cortex (PFC) and feasibly be used as a biomarker to support stroke rehabilitation.

OBJECTIVE

Exploring the feasibility of fNIRS as a biomarker during the Stroop Color and Word Test (SCWT) assessing executive function in AIS patients.

METHODS

Observational study of 21 patients with mild to moderate AIS and 22 healthy age- and sex-matched controls (HC) examined with fNIRS of PFC during the SCWT. Hemodynamic responses were analyzed with general linear modeling.

RESULTS

The SCWT was performed worse by AIS patients than HC. Neither patients nor HC showed PFC activation, but an inverse activational pattern primarily in superolateral and superomedial PFC significantly lower in AIS. Hemodynamic responses were incoherent to test difficulty and performance. No other group differences or lateralization were found.

CONCLUSIONS

AIS patients had impaired executive function assessed by the SCWT, while both groups showed an inverse hemodynamic response significantly larger in HC. Investigations assessing the physiology behind inverse hemodynamic responses are warranted before deeming clinical implementation reasonable.

Effects of exercise therapy on patients with poststroke cognitive impairment: A systematic review and meta-analysis

Objective

To evaluate the effects of exercise therapy on patients with poststroke cognitive impairment and compare the differences in the effect of this method when compared with conventional measures, providing evidence for a more standardized and effective clinical application of exercise therapy.

Methods

A search was conducted using 7 electronic databases, including PubMed, CINAHL, Web of Science, CENTRAL, CNKI, Wanfang, SinoMed, and clinical trials registry platforms for randomized controlled trials concerning exercise therapy on patients with poststroke cognitive impairment. Two researchers independently screened the literature, evaluated the quality, and extracted information. Meta-analysis was carried out using Review Manager 5.4 software.

Results

There were 11 studies with 1,382 patients. Meta-analysis showed that exercise therapy could improve cognitive function [SMD = 0.67, 95% CI (0.31, 1.04), P = 0.0003], motor function [SMD = 1.81, 95% CI (0.41, 3.20), P = 0.01], and the activities of daily living [MD = 8.11, 95% CI (3.07, 13.16), P = 0.002] in patients with poststroke cognitive impairment.

Conclusion

Exercise therapy can not only improve cognitive function in patients with poststroke cognitive impairment but also improve motor function and the activities of daily living. Medical staff should prioritize the management of patients with poststroke cognitive impairment and carry out exercise therapy actively to improve the cognitive function of patients with stroke.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42023397553.

Designing stroke services for the delivery of cognitive rehabilitation: A qualitative study with stroke rehabilitation professionals

This qualitative study explored the potential to deliver cognitive rehabilitation for post-stroke cognitive impairment (PSCI), with a specific focus on barriers and facilitators to its delivery from the perspective of Irish stroke rehabilitation professionals. Sixteen semi-structured interviews were completed with healthcare professionals in both hospital and community settings. The sample comprised physiotherapists, occupational therapists, nurses, a stroke physician, a psychologist, a neuropsychologist, a speech and language therapist, a dietician, and a public health nurse. Interviews were audio-recorded and analysed in NVivo using inductive Thematic Analysis. Barriers and facilitators to the delivery of cognitive rehabilitation were identified and described under four key themes: (i) Cognitive screening; (ii) Cognitive rehabilitation: no one size fits all; (iii) Psychology: the lost dimension of stroke rehabilitation; and (iv) Joining the dots in the community. Staffing required to deliver cognitive rehabilitation for PSCI was highlighted as under-resourced in the Republic of Ireland. Inadequate resourcing of neuropsychology and stroke-related psychological services, in particular, has had negative implications for the delivery of cognitive rehabilitation. Stroke-specific cognitive rehabilitation expertise is virtually inaccessible in the community, highlighting an urgent need for investment in specialist rehabilitation teams to deliver cognitive rehabilitation in this setting.

Improvement of cognition across a decade after stroke correlates with the integrity of functional brain networks

BACKGROUND AND OBJECTIVE

We recently reported improvements of working memory across 10 years post stroke among middle-aged individuals. However, the mechanisms underlying working-memory recovery are largely unknown. This study investigated the associations between long-term improvement of working memory and resting-state functional connectivity in two frontoparietal networks: the frontoparietal network and the dorsal attention network.

METHODS

Working memory was repeatedly assessed by the Digit Span Backwards task in 21 persons, within 1 year after stroke onset and again 10 years post stroke onset. Brain functional connectivity was examined by resting state functional magnetic resonance imaging at the 10-year follow-up.

RESULTS

A significant improvement of working memory was found among 21 persons after stroke (median age = 64) at the 10-year follow-up compared to the within-one-year assessment. The magnitude of performance improvement on the Digit Span Backwards task was significantly positively correlated with stronger brain connectivity in the frontoparietal network (r = 0.51, p = 0.018) measured at the 10-year follow-up only. A similar association was observed in the dorsal attention network (r = 0.43, p = 0.052) but not in a visual network (r = -0.17, p = 0.46) that served as a control network. The association between functional connectivity within the above-mentioned networks and Digit Span Backwards scores at 10-year after stroke was in the same direction but did not reach significance.

CONCLUSIONS

The present work relate stronger long-term performance improvement on the Digit Span Backwards task with higher integrity of frontoparietal network connectivity.

Risk of Dementia Associated With Atrial Cardiopathy: The ARIC Study

Background The contribution of atrial cardiopathy to dementia risk is uncharacterized. We aimed to evaluate the association of atrial cardiopathy with incident dementia and potential mediation by atrial fibrillation (AF) and stroke. Methods and Results We conducted a prospective cohort analysis of participants in the ARIC (Atherosclerosis Risk in Communities) study attending visit 5 (2011-2013). We used Cox regression to determine the association between atrial cardiopathy and risk of dementia. Structural equation modeling methods were used to determine potential mediation by AF and/or stroke. Atrial cardiopathy was defined if ≥1 of the following at visit 5: P-wave terminal force >5000 mV·ms in ECG lead V1, NT-proBNP (N-terminal pro-brain natriuretic peptide) >250 pg/mL or left atrial volume index ≥34 mL/m2 by transthoracic echocardiography. We repeated our analysis necessitating ≥2 markers to define atrial cardiopathy. The prevalence of atrial cardiopathy was 34% in the 5078 participants (mean age 75 years, 59% female, 21% Black adults), with 763 participants developing dementia. Atrial cardiopathy was significantly associated with dementia (adjusted HR, 1.35 [95% CI, 1.16-1.58]), with strengthening of the effect estimate when necessitating ≥2 biomarkers (adjusted HR, 1.54 [95% CI, 1.25-1.89]). There was an increased risk of dementia among those with atrial cardiopathy when excluding those with AF (adjusted HR, 1.31 [95% CI, 1.12-1.55]) or stroke (adjusted HR, 1.28 [95% CI, 1.09-1.52]). The proportion of the effect mediated by AF was 4% (P=0.005), and 9% was mediated by stroke (P=0.048). Conclusions Atrial cardiopathy was significantly associated with an increased risk of dementia, with only a small percent mediation of the effect by AF or stroke.

Benefits of Treatment with Ginkgo Biloba Extract EGb 761 Alone or Combined with Acetylcholinesterase Inhibitors in Vascular Dementia

BACKGROUND

Vascular dementia (VaD) is the most severe manifestation of cognitive impairment caused by cerebrovascular disease. There are currently no specific drug treatments approved for VaD, with cholinesterase inhibitors (AChEI) being frequently used in VaD. However, the benefits they provide are small and short-lived. The standardized extract of Ginkgo biloba EGb 761 has demonstrated protective properties against neuronal and vascular damage and has been used as a pharmacological treatment for VaD.

OBJECTIVES

This study aims to study the efficacy of EGb 761 alone and in combination with AChEI in a real-life setting. We carried out a retrospective analysis of data over a 12-month period in a sample of people suffering from VaD.

METHODS

We retrospectively identified 77 patients with a diagnosis of VaD who had received treatment with any of the following drugs: Ginkgo biloba extract EGb 761 (240 mg daily), donepezil (10 mg daily), galantamine (16 or 24 mg daily), or rivastigmine patch (9.5 or 13.3 mg daily). Subjects were divided into three groups according to the treatment they had received: EGb 761 alone (n = 25), AChEI alone (n = 26), and EGb 761+AChEI (n = 26). Cognitive functioning was assessed by Mini-Mental State Examination (MMSE), Rey Auditory Verbal Learning Test (RAVLT), Symbol Digit Modalities Test (SDMT), Boston Naming Test (BNT), Trail Making Test forms A (TMTA) and B (TMTB), Letter (LFT) and Category Fluency Test (CFT); neuropsychiatric symptoms were assessed by the Neuropsychiatric Inventory (NPI); functional capacity was assessed by Interview for Deterioration in Daily Living (IDDD).

RESULTS

A statistically significant improvement was observed in the EGb 761 group versus the AChEI group at 12 months' follow-up in CFT (+1.74, p < 0.001), TMTA (-17.91, p = 0.031) and NPI (-5.89, p < 0.001). With regard to the combined treatment, a statistically significant improvement was shown in the EGb 761 plus AChEI treatment group versus AChEI group at the 12-month follow-up in MMSE (+2.0, p = 0.001), RAVLT (+2.23, p = 0.007), CFT (+1.15, p = 0.013), TMTA (-19.92, p = 0.012), TMTB (-46.50, p < 0.001) and NPI (-6.77, p < 0.001). In the same line, a statistically significant improvement was observed in the EGb 761 plus AChEI treatment group versus EGb 761 at 12-month follow-up regarding MMSE (+2.11, p = 0.001), RAVLT (+2.35, p = 0.004) and TMTB (-25.25, p = 0.015).

CONCLUSION

After 12 months of treatment EGb 761 alone or combined with AChEI showed cognitive and behavioral benefits in patients suffering from VaD. This study thus provides additional real-world evidence for the combined use of EGb 761 and anti-dementia drugs in VaD patients.

The impact of stroke, cognitive function and post-stroke cognitive impairment (PSCI) on healthcare utilisation in Ireland: a cross-sectional nationally representative study

Background

Cognitive impairment after stroke is associated with poorer health outcomes and increased need for long-term care. The aim of this study was to determine the impact of stroke, cognitive function and post-stroke cognitive impairment (PSCI) on healthcare utilisation in older adults in Ireland.

Methods

This cross-sectional study involved secondary data analysis of 8,175 community-dwelling adults (50 + years), from wave 1 of The Irish Longitudinal Study on Ageing (TILDA). Participants who had been diagnosed with stroke by a doctor were identified through self-report in wave 1. Cognitive function was measured using the Montreal Cognitive Assessment (MoCA). The main outcome of the study was healthcare utilisation, including General Practitioner (GP) visits, emergency department visits, outpatient clinic visits, number of nights admitted to hospital, and use of rehabilitation services. The data were analysed using multivariate adjusted negative binomial regression and logistic regression. Incidence-rate ratios (IRR), odds ratios (OR) and 95% confidence intervals (CI) are presented.

Results

The adjusted regression analyses were based on 5,859 participants who completed a cognitive assessment. After adjusting for demographic and clinical covariates, stroke was independently associated with an increase in GP visits [IRR (95% CI): 1.27 (1.07, 1.50)], and outpatient service utilisation [IRR: 1.49 (1.05, 2.12)]. Although participants with poor cognitive function also visited the GP more frequently than participants with normal cognitive function [IRR: 1.07 (1.04, 1.09)], utilisation of outpatient services was lower in this population [IRR: 0.92 (0.88, 0.97)]. PSCI was also associated with a significant decrease in outpatient service utilisation [IRR: 0.75 (0.57, 0.99)].

Conclusions

Stroke was associated with higher utilisation of GP and outpatient services. While poor cognitive function was also associated with more frequent GP visits, outpatient service utilisation was lower in participants with poor cognitive function, indicating that cognitive impairment may be a barrier to outpatient care. In Ireland, the lack of appropriate neurological or cognitive rehabilitation services appears to result in significant unaddressed need among individuals with cognitive impairment, regardless of stroke status.

Neuroinflammation as a Key Driver of Secondary Neurodegeneration Following Stroke?

Ischaemic stroke involves the rapid onset of focal neurological dysfunction, most commonly due to an arterial blockage in a specific region of the brain. Stroke is a leading cause of death and common cause of disability, with over 17 million people worldwide suffering from a stroke each year. It is now well-documented that neuroinflammation and immune mediators play a key role in acute and long-term neuronal tissue damage and healing, not only in the infarct core but also in distal regions. Importantly, in these distal regions, termed sites of secondary neurodegeneration (SND), spikes in neuroinflammation may be seen sometime after the initial stroke onset, but prior to the presence of the neuronal tissue damage within these regions. However, it is key to acknowledge that, despite the mounting information describing neuroinflammation following ischaemic stroke, the exact mechanisms whereby inflammatory cells and their mediators drive stroke-induced neuroinflammation are still not fully understood. As a result, current anti-inflammatory treatments have failed to show efficacy in clinical trials. In this review we discuss the complexities of post-stroke neuroinflammation, specifically how it affects neuronal tissue and post-stroke outcome acutely, chronically, and in sites of SND. We then discuss current and previously assessed anti-inflammatory therapies, with a particular focus on how failed anti-inflammatories may be repurposed to target SND-associated neuroinflammation.

StrokeCog Markov Model: Projected Prevalent and Incident Cases of Stroke and Poststroke Cognitive Impairment to 2035 in Ireland

BACKGROUND AND PURPOSE

Cognitive impairment no dementia (CIND) and dementia are common stroke outcomes, with significant health and societal implications for aging populations. These outcomes are not included in current epidemiological models. We aimed to develop an epidemiological model to project incidence and prevalence of stroke, poststroke CIND and dementia, and life expectancy, in Ireland to 2035, informing policy and service planning.

METHODS

We developed a probabilistic Markov model (the StrokeCog model) applied to the Irish population aged 40 to 89 years to 2035. Data sources included official population and hospital-episode statistics, longitudinal cohort studies, and published estimates. Key assumptions were varied in sensitivity analysis. Results were externally validated against independent sources. The model tracks poststroke progression into health states characterized by no cognitive impairment, CIND, dementia, disability, stroke recurrence, and death.

RESULTS

We projected 69 051 people with prevalent stroke in Ireland in 2035 (22.0 per 1000 population [95% CI, 20.8-23.1]), with 25 274 (8.0 per 1000 population [95% CI, 7.1-9.0]) of those projected to have poststroke CIND, and 12 442 having poststroke dementia (4.0 per 1000 population [95% CI, 3.2-4.8]). We projected 8725 annual incident strokes in 2035 (2.8 per 1000 population [95% CI, 2.7-2.9]), with 3832 of these having CIND (1.2 per 1000 population [95% CI, 1.1-1.3]), and 1715 with dementia (0.5 per 1000 population [95% CI, 0.5-0.6]). Life expectancy for stroke survivors at age 50 was 23.4 years (95% CI, 22.3-24.5) for women and 20.7 (95% CI, 19.5-21.9) for men.

CONCLUSIONS

This novel epidemiological model of stroke, poststroke CIND, and dementia draws on the best available evidence. Sensitivity analysis indicated that findings were robust to assumptions, and where there was uncertainty a conservative approach was taken. The StrokeCog model is a useful tool for service planning and cost-effectiveness analysis and is available for adaptation to other national contexts.

Novel Advances to Post-Stroke Aphasia Pharmacology and Rehabilitation

Aphasia is one of the most common clinical features of functional impairment after a stroke. Approximately 21–40% of stroke patients sustain permanent aphasia, which progressively worsens one’s quality of life and rehabilitation outcomes. Post-stroke aphasia treatment strategies include speech language therapies, cognitive neurorehabilitation, telerehabilitation, computer-based management, experimental pharmacotherapy, and physical medicine. This review focuses on current evidence of the effectiveness of impairment-based aphasia therapies and communication-based therapies (as well as the timing and optimal treatment intensities for these interventions). Moreover, we present specific interventions, such as constraint-induced aphasia therapy (CIAT) and melodic intonation therapy (MIT). Accumulated data suggest that using transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) is safe and can be used to modulate cortical excitability. Therefore, we review clinical studies that present TMS and tDCS as (possible) promising therapies in speech and language recovery, stimulating neuroplasticity. Several drugs have been used in aphasia pharmacotherapy, but evidence from clinical studies suggest that only nootropic agents, donepezil and memantine, may improve the prognosis of aphasia. This article is an overview on the current state of knowledge related to post-stroke aphasia pharmacology, rehabilitation, and future trends.

From Three-Months to Five-Years: Sustaining Long-Term Benefits of Endovascular Therapy for Ischemic Stroke

Background and Purpose: During the months and years post-stroke, treatment benefits from endovascular therapy (EVT) may be magnified by disability-related differences in morbidity/mortality or may be eroded by recurrent strokes and non-stroke-related disability/mortality. Understanding the extent to which EVT benefits may be sustained at 5 years, and the factors influencing this outcome, may help us better promote the sustenance of EVT benefits until 5 years post-stroke and beyond.

Methods: In this review, undertaken 5 years after EVT became the standard of care, we searched PubMed and EMBASE to examine the current state of the literature on 5-year post-stroke outcomes, with particular attention to modifiable factors that influence outcomes between 3 months and 5 years post-EVT.

Results: Prospective cohorts and follow-up data from EVT trials indicate that 3-month EVT benefits will likely translate into lower 5-year disability, mortality, institutionalization, and care costs and higher quality of life. However, these group-level data by no means guarantee maintenance of 3-month benefits for individual patients. We identify factors and associated “action items” for stroke teams/systems at three specific levels (medical care, individual psychosocioeconomic, and larger societal/environmental levels) that influence the long-term EVT outcome of a patient. Medical action items include optimizing stroke rehabilitation, clinical follow-up, secondary stroke prevention, infection prevention/control, and post-stroke depression care. Psychosocioeconomic aspects include addressing access to primary care, specialist clinics, and rehabilitation; affordability of healthy lifestyle choices and preventative therapies; and optimization of family/social support and return-to-work options. High-level societal efforts include improving accessibility of public/private spaces and transportation, empowering/engaging persons with disability in society, and investing in treatments/technologies to mitigate consequences of post-stroke disability.

Conclusions: In the longtime horizon from 3 months to 5 years, several factors in the medical and societal spheres could negate EVT benefits. However, many factors can be leveraged to preserve or magnify treatment benefits, with opportunities to share responsibility with widening circles of care around the patient.

Association between Blood Pressure, Blood Pressure Variability, and Post-Stroke Cognitive Impairment

After stroke, dynamic changes take place from necrotic-apoptotic continuum, inflammatory response to poststroke neurogenesis, and remodeling of the network. These changes and baseline brain pathology such as small vessel disease (SVD) and amyloid burden may be associated with the occurrence of early or late poststroke cognitive impairment (PSCI) or dementia (PSD), which affect not only stroke victims but also their families and even society. We reviewed the current concepts and understanding of the pathophysiology for PSCI/PSD and identified useful tools for the diagnosis and the prediction of PSCI in serological, CSF, and image characteristics. Then, we untangled their relationships with blood pressure (BP) and blood pressure variability (BPV), important but often overlooked risk factors for PSCI/PSD. Finally, we provided evidence for the modifying effects of BP and BPV on PSCI as well as pharmacological and non-pharmacological interventions and life style modification for PSCI/PSD prevention and treatment.

Decreased neuronal synaptosome associated protein 29 contributes to poststroke cognitive impairment by disrupting presynaptic maintenance

Background: Poststroke cognitive impairments are common in stroke survivors, and pose a high risk of incident dementia. However, the cause of these cognitive impairments is obscure and required an investigation.

Methods: Oxygen-glucose deprivation (OGD) model and middle cerebral artery occlusion (MCAO) model were used to imitate in vitro or in vivo acute cerebral ischemia, respectively. The differentially expressed synaptosome associated protein 29 (SNAP29)-interacting proteins upon ischemia and reperfusion were analyzed with bioinformatics analysis and the results indicated that the changes of SNAP29 after acute ischemia were mainly involved in the synaptic functions. The outcomes of SNAP29 reduction were assessed with SNAP29 knockdown, which mimicked the distribution of SNAP29 along neuronal processes after acute ischemia. Using the whole-cell patch clamp recording method and transmission electron microscope, the pre-synaptic function and readily releasable pool (RRP) were observed after SNAP29 knock down. Using photogenetic manipulations and behavioral tests, the neuronal projection and cognitive functions of mice with SNAP29 knock down in hippocampus CA1 region were evaluated.

Results: It was found that SNAP29 protein levels decreased in both in vitro and in vivo ischemic models. Further, the SNAP29 reduction wasn't associated with impaired autophagy flux and neuronal survival. When SNAP29 was knocked down in primary cortical neurons, the frequency of AMPARs-mediated mEPSCs, but not the amplitude, significantly decreased. Meanwhile, the mice with SNAP29 knockdown at CA1 region of hippocampus developed an impairment in hippocampus-mPFC (middle prefrontal cortex) circuit and behavioral dysfunctions. Moreover, the size of RRP at presynaptic sites was diminished.

Conclusion: Since SNAP29 protein levels didn't significantly influence the neuronal survival and its decrease was sufficient to disturb the neural circuit via a presynaptic manner, the SNAP29-associated strategies may be an efficient target against poststroke synaptic dysfunction and cognitive deficits.

Inclusion of stroke patients in expanded cardiac rehabilitation services: a cross-national qualitative study with cardiac and stroke rehabilitation professionals

PURPOSE

This qualitative study explored healthcare professionals' views in relation to the potential expansion of cardiac rehabilitation services to include stroke patients, thereby becoming a cardiovascular rehabilitation model.

DESIGN AND METHODS

23 semi-structured interviews were completed with hospital and community-based stroke and cardiac rehabilitation professionals in Switzerland (n = 7) and Ireland (n = 19). The sample comprised physiotherapists, occupational therapists, speech and language therapists, stroke physicians, cardiologists, psychologists, dieticians and nurses. Interviews were audio-recorded and the transcripts were analysed in NVivo using inductive Thematic Analysis.

RESULTS

Barriers and facilitators to cardiovascular rehabilitation were captured under four broad themes; (i) Cardiac rehabilitation as "low-hanging fruit," (ii) Cognitive impairment ("the elephant in the room"), (iii) Adapted cardiac rehabilitation for mild stroke, and (iv) Resistance to change.

CONCLUSIONS

Hybrid cardiac rehabilitation programmes could be tailored to deliver stroke-specific education, exercises and multidisciplinary expertise. Post-stroke cognitive impairment was identified as a key barrier to participation in cardiac rehabilitation. A cognitive rehabilitation intervention could potentially be delivered as part of cardiac rehabilitation, to address the cognitive needs of stroke and cardiac patients.Implications for rehabilitationThe cardiac rehabilitation model has the potential to be expanded to include mild stroke patients given the commonality of secondary prevention needs.Up to half of stroke survivors are affected by post-stroke cognitive impairment, consequently mild stroke patients may not be such an "easy fit" for cardiac rehabilitation.A cardiovascular programme which includes common rehabilitation modules, in addition to stroke- and cardiac-specific content is recommended.A cognitive rehabilitation module could potentially be added as part of the cardiac rehabilitation programme to address the cognitive needs of stroke and cardiac patients.

Cerebrovascular and Neurodegenerative Pathologies in Long-Term Stable Mild Cognitive Impairment

BACKGROUND

Mild cognitive impairment (MCI) is considered by some to be a prodromal phase of a progressive disease (i.e., neurodegeneration) resulting in dementia; however, a substantial portion of individuals (ranging from 5-30%) remain cognitively stable over the long term (sMCI). The etiology of sMCI is unclear but may be linked to cerebrovascular disease (CVD), as evidence from longitudinal studies suggest a significant proportion of individuals with vasculopathy remain stable over time.

OBJECTIVE

To quantify the presence of neurodegenerative and vascular pathologies in individuals with long-term (>5-year) sMCI, in a preliminary test of the hypothesis that CVD may be a contributor to non-degenerative cognitive impairment. We expect frequent vasculopathy at autopsy in sMCI relative to neurodegenerative disease, and relative to individuals who convert to dementia.

METHODS

In this retrospective study, using data from the National Alzheimer's Coordinating Center, individuals with sMCI (n = 28) were compared to those with MCI who declined over a 5 to 9-year period (dMCI; n = 139) on measures of neurodegenerative pathology (i.e., Aβ plaques, neurofibrillary tangles, TDP-43, and cerebral amyloid angiopathy) and CVD (infarcts, lacunes, microinfarcts, hemorrhages, and microbleeds).

RESULTS

Alzheimer's disease pathology (Aβ plaques, neurofibrillary tangles, and cerebral amyloid angiopathy) was significantly higher in the dMCI group than the sMCI group. Microinfarcts were the only vasculopathy associated with group membership; these were more frequent in sMCI.

CONCLUSION

The most frequent neuropathology in this sample of long-term sMCI was microinfarcts, tentatively suggesting that silent small vessel disease may characterize non-worsening cognitive impairment.

Post-Stroke Working Memory Dysfunction: A Meta-Analysis and Systematic Review

This review investigates the severity and nature of post-stroke working memory deficits with reference to the multi-component model of working memory. We conducted a systematic search in PubMed up to March 2019 with search terms for stroke and memory. Studies on adult stroke patients, that included a control group, and assessed working memory function, were selected. Effect sizes (Hedges' g) were extracted from 50 studies (in total 3,084 stroke patients) based on the sample size, mean and standard deviation of patients and controls. Performance of stroke patients was compared to healthy controls on low-load (i.e. capacity) and high-load (executively demanding) working memory tasks, grouped by modality (verbal, non-verbal). A separate analysis compared patients in the sub-acute and the chronic stage. Longitudinal studies and effects of lesion location were systematically reviewed. Stroke patients demonstrated significant deficits in working memory with a moderate effect size for both low-load (Hedges' g = -.58 [-.82 to -.43]) and high-load (Hedges' g = -.59 [-.73 to -.45]) tasks. The effect sizes were comparable for verbal and non-verbal material. Systematically reviewing the literature showed that working memory deficits remain prominent in the chronic stage of stroke. Lesions in a widespread fronto-parietal network are associated with working memory deficits. Stroke patients show decrements of moderate magnitude in all subsystems of working memory. This review clearly demonstrates the global nature of the impairment in working memory post-stroke.

Bridging therapy is associated with improved cognitive function after large vessel occlusion stroke - an analysis of the German Stroke Registry

BACKGROUND

The targeted use of endovascular therapy (EVT), with or without intravenous thrombolysis (IVT) in acute large cerebral vessel occlusion stroke (LVOS) has been proven to be superior compared to IVT alone. Despite favorable functional outcome, many patients complain about cognitive decline after EVT. If IVT in addition to EVT has positive effects on cognitive function is unclear.

METHODS

We analyzed data from the German Stroke Registry (GSR, an open, multicenter and prospective observational study) and compared cognitive function 90 days after index ischemic stroke using MoCA in patients with independent (mRS ≤ 2 pts) and excellent (mRS = 0 pts) functional outcome receiving combined EVT and IVT (EVT + IVT) vs. EVT alone (EVT-IVT).

RESULTS

Of the 2636 GSR patients, we included 166 patients with mRS ≤ 2 at 90 days in our analysis. Of these, 103 patients (62%) received EVT + IVT, 63 patients (38%) were treated with EVT alone. There was no difference in reperfusion status between groups (mTICI ≥ 2b in both groups at 95%, p = 0.65). Median MoCA score in the EVT + IVT group was 20 pts. (18-25 IQR) vs. 18 pts. (16-21 IQR) in the EVT-IVT group (p = 0.014). There were more patients with cognitive impairment (defined as MoCA < 26 pts) in the EVT-IVT group (54 patients (86%)) compared to the EVT + IVT group (78 patients (76%)). EVT + IVT was associated with a higher MoCA score at 90 days (mRS ≤ 2: p = 0.033, B = 2.39; mRS = 0: p = 0.021, B = 4.38).

CONCLUSIONS

In Patients with good functional outcome after LVOS, rates of cognitive impairment are lower with combined EVT and IVT compared to EVT alone.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03356392.

Post-stroke Cognitive Impairment-Impact of Follow-Up Time and Stroke Subtype on Severity and Cognitive Profile: The Nor-COAST Study

Background: Post-stroke cognitive impairment (PSCI) is common, but evidence of cognitive symptom profiles, course over time, and pathogenesis is scarce. We investigated the significance of time and etiologic stroke subtype for the probability of PSCI, severity, and cognitive profile.

Methods: Stroke survivors (n = 617) underwent cognitive assessments of attention, executive function, memory, language, perceptual-motor function, and the Montreal Cognitive Assessment (MoCA) after 3 and/or 18 months. PSCI was classified according to DSM-5 criteria. Stroke severity was assessed with the National Institutes of Health Stroke Scale (NIHSS). Stroke subtype was categorized as intracerebral hemorrhage (ICH), large artery disease (LAD), cardioembolic stroke (CE), small vessel disease (SVD), or un-/other determined strokes (UD). Mixed-effects logistic or linear regression was applied with PSCI, MoCA, and z-scores of the cognitive domains as dependent variables. Independent variables were time as well as stroke subtype, time, and interaction between these. The analyses were adjusted for age, education, and sex. The effects of time and stroke subtype were analyzed by likelihood ratio tests (LR).

Results: Mean age was 72 years (SD 12), 42% were females, and mean NIHSS score at admittance was 3.8 (SD 4.8). Probability (95% CI) for PSCI after 3 and 18 months was 0.59 (0.51–0.66) and 0.51 (0.52–0.60), respectively and remained constant over time. Global measures and most cognitive domains were assessed as impaired for the entire stroke population and for most stroke subtypes. Executive function and language improved for the entire stroke population (LR) = 9.05, p = 0.003, and LR = 10.38, p = 0.001, respectively). After dividing the sample according to stroke subtypes, language improved for ICH patients (LR = 18.02, p = 0.003). No significant differences were found in the severity of impairment between stroke subtypes except for attention, which was impaired for LAD and CE in contrast to no impairment for SVD (LR = 56.58, p < 0.001).

Conclusions: In this study including mainly minor strokes, PSCI is common for all subtypes, both early and long-term after stroke, while executive function and language improve over time. The findings might contribute to personalizing follow-up and offer new insights into underlying mechanisms. Further research is needed on underlying mechanisms, PSCI prevention and treatment, and relevance for rehabilitation.

Association of blood lipids, atherosclerosis and statin use with dementia and cognitive impairment after stroke: A systematic review and meta-analysis

BACKGROUND

Trial and observational evidence is conflicting in terms of the association of blood lipids, atherosclerosis and statin use with dementia and cognitive impairment in the general population. It is uncertain whether the associations occur in stroke patients, who are at known higher risk of cognitive decline. This systematic review was to synthesize the evidence for these associations among stroke patients.

METHODS

MEDLINE, EMBASE, the Cochrane Library and trial registries were searched. We included randomized controlled trials (RCTs) or observational cohort studies conducted among patients with stroke and reported on the association of blood lipids, atherosclerosis or statin use with dementia or cognitive impairment. Meta-analysis was conducted separately for crude and maximally adjusted odds ratios (ORs) and hazard ratios (HRs).

RESULTS

Of 18,026 records retrieved, 56 studies (one RCT and 55 cohort studies) comprising 38,423 stroke patients were included. For coronary heart disease, the pooled OR of dementia and cognitive impairment was 1.32 (95%CI 1.10-1.58, n = 15 studies, I² = 0%) and 1.23 (95%CI 0.99-1.54, n = 14, I² = 26.9%), respectively. Peripheral artery disease was associated with dementia (OR 3.59, 95%CI 1.47-8.76, n = 2, I² = 0%) and cognitive impairment (OR 2.70, 95%CI 1.09-6.69, n = 1). For carotid stenosis, the pooled OR of dementia and cognitive impairment was 2.67 (95%CI 0.83-8.62, n = 3, I² = 77.9%) and 3.34 (95%CI 0.79-14.1, n = 4, I² = 96.6%), respectively. For post-stroke statin use, the pooled OR of dementia and cognitive impairment was 0.89 (95%CI 0.65-1.21, n = 1) and 0.56 (95%CI 0.46-0.69, n = 3, I² = 0%), respectively. No association was observed for hypercholesterolemia. These results were mostly consistent with adjusted ORs or HRs, which were reported from limited evidence.

CONCLUSION

Atherosclerosis was associated with an increased risk of post-stroke dementia. Post-stroke statin use was associated with decreased risk of cognitive impairment. To confirm whether or not statins confer advantages in the post-stroke population in terms of preventing cognitive decline over and above their known effectiveness in reducing risk of further vascular events, further stroke trials including cognitive assessment and observational analyses adjusted for key confounders, focusing on key subgroups or statin use patterns are required.

A systematic review and meta-analysis of the effects of cardiac rehabilitation interventions on cognitive impairment following stroke

PURPOSE

The cardiac rehabilitation model has potential as an approach to providing rehabilitation following stroke. This review aims to identify evidence for the participation of stroke patients in cardiac/cardiovascular rehabilitation programs internationally, whether or not such programs offer a cognitive intervention as part of treatment, and the impact of rehabilitation on post-stroke cognitive function.

METHOD

Five electronic databases were searched from inception to 1 May 2019, namely: MEDLINE, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature, the Cochrane Central Register of Controlled Trials, and the Web of Science. Eligible studies included both randomized and non-randomized studies of cardiac rehabilitation-type interventions which measured cognitive function in patients with transient ischemic attack (TIA) or stroke.

RESULTS

Of 14,153 records reviewed, nine studies which delivered cardiac rehabilitation-type interventions to stroke patients were finally included. Only three of these studies delivered cognitive rehabilitation as part of the intervention. Cardiac rehabilitation had no statistically significant effect on cognitive function in five randomized controlled trials (standardized mean difference= 0.28, 95% CI= -0.16 to 0.73) or in three one group pre-post studies (standardized mean difference= 0.15, 95% CI= -0.03 to 0.33).

CONCLUSIONS

This review highlights that there are very few studies of delivery of cardiac rehabilitation to stroke patients and that the inclusion of cognitive interventions is even less common, despite the high prevalence of post-stroke cognitive impairment.IMPLICATIONS FOR REHABILITATIONThe cardiac rehabilitation model has the potential to be expanded to include patients post-stroke given the commonality of secondary prevention needs, thereby becoming a cardiovascular rehabilitation model.Up to half of patients experience cognitive impairment after stroke; suggesting that a post-stroke cardiovascular rehabilitation model should incorporate specific cognitive strategies for patients.This systematic review identified three cardiovascular rehabilitation programmes which delivered cognitive rehabilitation as part of treatment; however, evidence for efficacy is weak.

Addressing cognitive impairment following stroke: systematic review and meta-analysis of non-randomised controlled studies of psychological interventions

OBJECTIVE

Cognitive impairment is a pervasive outcome of stroke, reported in over half of patients 6 months post-stroke and is associated with increased disability and a poorer quality of life. Despite the prevalence of post-stroke cognitive impairment, the efficacy of existing psychological interventions for the rehabilitation of cognitive impairment following stroke has yet to be established. The aim of this study is to identify psychological interventions from non-randomised studies that intended to improve post-stroke cognitive function and establish their efficacy.

DESIGN

Systematic review and meta-analysis of non-randomised studies of psychological interventions addressing post-stroke cognitive impairment.

DATA SOURCES

Electronic searches were performed in the Pubmed, EMBASE and PsycINFO databases, the search dating from inception to February 2017.

ELIGIBILITY CRITERIA

All non-randomised controlled studies and quasi-randomised controlled trials examining psychological interventions to improve cognitive function following stroke were included, such as feasibility studies, pilot studies, experimental studies, and quasi-experimental studies. The primary outcome was cognitive function. The prespecified secondary outcomes were functional abilities in daily life and quality of life.

METHODS

The current meta-analyses combined the findings of seven controlled studies, examining the efficacy of psychological interventions compared with treatment-as-usual controls or active controls, and 13 one-group pre-post studies.

RESULTS

Results indicated an overall small effect on cognition across the controlled studies (Hedges' g=0.38, 95% CI=0.06 to 0.7) and a moderate effect on cognition across the one-group pre-post studies (Hedges' g=0.51, 95% CI=0.3 to 0.73). Specific cognitive domains, such as memory and attention also demonstrated a benefit of psychological interventions.

CONCLUSIONS

This review provides support for the potential of psychological interventions to improve overall cognitive function post-stroke. Limitations of the study, in terms of risk of bias and quality of included studies, and future research directions are explored.

PROSPERO REGISTRATION NUMBER

CRD42017069714.

The Norwegian Cognitive impairment after stroke study (Nor-COAST): study protocol of a multicentre, prospective cohort study

BACKGROUND

Early and late onset post-stroke cognitive impairment (PCI) contributes substantially to disability following stroke, and is a high priority within stroke research. The aetiology for PCI is complex and related to the stroke itself, brain resilience, comorbid brain diseases, prestroke vulnerability and complications during the hospital stay. The aim of the Norwegian Cognitive Impairment After Stroke study (Nor-COAST) is to quantify and measure levels of cognitive impairments in a general Norwegian stroke population and to identify biological and clinical markers associated with prognosis for cognitive disorders following incident stroke. The study will be organised within five work packages: 1) Incidence and trajectories 2) Pathological mechanisms 3) Development of a risk score 4) Impact of physical activity and 5) Adherence to secondary prevention.

METHODS

Nor-COAST is an ongoing multicentre (five participating hospitals), prospective, cohort study with consecutive inclusion during the acute phase and with follow-up at three and 18 months, and at three years. Inclusion criteria are stroke defined according to the WHO criteria. During the recruitment period from 18.05.2015 to 31.03.2017, 816 participants have been included. Cognitive impairment will be classified according to the DSM-5 criteria using a consensus group. Cognitive function is assessed by a standardised neuropsychological test battery, the Montreal Cognitive Assessment, Trail making A and B, ten-word immediate and delayed recall test, the Controlled Oral Word Association, Global Deterioration Scale and proxy based information by and the Ascertain Dementia 8 item informant questionnaire. Biomarkers include magnetic resonance imaging, routine blood samples and bio-banking. Clinical assessments include characteristics of the stroke, comorbidity, delirium, frailty and tests for cognitive and physical function, sensor based activity monitoring and adherence to secondary prophylaxis.

DISCUSSION

Nor-COAST is the first Norwegian multicentre study to quantify burden of PCI that will provide reliable estimates in a general stroke population. A multidisciplinary approach aiming to identify biomarkers and clinical markers of overall prognosis will add new knowledge about risk profiles, including pre-stroke vulnerability and modifiable factors such as physical activity and secondary prophylaxis of relevance for clinical practice and later intervention studies.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02650531 . Retrospectively registered January 8, 2016. First participant included May 18, 2015.

Biological and imaging predictors of cognitive impairment after stroke: a systematic review

BACKGROUND

Cognitive impairment is frequent after stroke, and several studies have suggested that biological and imaging characteristics present before stroke are associated with the development of post-stroke cognitive impairment.

OBJECTIVE

The aim of our study was to systematically review biological and imaging predictors of cognitive impairment after stroke.

METHOD

Studies were identified from bibliographic databases and reference lists, and were included if conducted in patients with acute stroke, with at least 30 patients, and a follow-up of at least 3 months. We included articles on potential biomarkers of cognitive impairment that pre-existed to stroke.

RESULTS

We identified 22,169 articles, including 20,349 with abstract. After analysis, 66 studies conducted in 42 cohorts met selection criteria. They included 30-9522 patients [median 170; interquartile range (IQR) 104-251] with a median follow-up of 12 months (IQR 3-36). All studies met quality criteria for description of the study population and standardization of biomarkers. Twenty-nine studies met all quality criteria. There was no convincing evidence that any biological marker may predict cognitive impairment. The most consistent predictors of cognitive impairment after stroke were global atrophy and medial temporal lobe atrophy.

CONCLUSION

Pre-existing cerebral atrophy is the most consistent predictor of cognitive impairment that can be identified in patients with an acute stroke.

A Systematic Review of the Definitions of Vascular Cognitive Impairment, No Dementia in Cohort Studies

BACKGROUND/AIMS

No set operational criteria for vascular cognitive impairment, no dementia (VCI-ND) have yet been established. The aim of this study is to undertake a systematic review to compare definitions of VCI-ND that have been used in cohort studies.

METHODS

Medline, PsycINFO and Embase were searched from inception to October 13, 2015. Initially, 3,142 records were screened, and 30 were included in this review.

RESULTS

No single set of criteria for defining VCI-ND was identified. VCI-ND was broadly defined as an absence of dementia, cognitive impairment in at least one cognitive domain with signs of vascular involvement, and intact activities of daily living.

CONCLUSION

Defining criteria will enable individuals with VCI-ND to be efficiently compared across cohort studies to more accurately determine the prevalence and risk of dementia.

Managing cognitive impairment following stroke: protocol for a systematic review of non-randomised controlled studies of psychological interventions

INTRODUCTION

Stroke is one of the primary causes of death and disability worldwide, leaving a considerable proportion of survivors with persistent cognitive and functional deficits. Despite the prevalence of poststroke cognitive impairment, there is no established treatment aimed at improving cognitive function following a stroke. Therefore, the aims of this systematic review are to identify psychological interventions intended to improve poststroke cognitive function and establish their efficacy.

METHODS AND ANALYSIS

A systematic review of non-randomised controlled studies that investigated the efficacy of psychological interventions aimed at improving cognitive function in stroke survivors will be conducted. Electronic searches will be performed in the PubMed, Embase and PsycINFO databases, the search dating from the beginning of the index to February 2017. Reference lists of all identified relevant articles will be reviewed to identify additional studies not previously identified by the electronic search. Potential grey literature will be reviewed using Google Scholar. Titles and abstracts will be assessed for eligibility by one reviewer, with a random sample of 50% independently double-screened by second reviewers. Any discrepancies will be resolved through discussion, with referral to a third reviewer where necessary. Risk of bias will be assessed with the Risk of Bias in Non-randomized Studies of Interventions tool. Meta-analyses will be performed if studies are sufficiently homogeneous. This review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The quality of the evidence regarding cognitive function will be assessed according to the Grading of Recommendations Assessment, Development and Evaluation.

ETHICS AND DISSEMINATION

This systematic review will collect secondary data only and as such ethical approval is not required. Findings will be disseminated through presentations and peer-reviewed publication. This review will provide information on the effectiveness of psychological interventions for poststroke cognitive impairment, identifying which psychological interventions are effective for improving poststroke cognitive function.

PROSPERO REGISTRATION NUMBER

CRD42017069714.

Dementia and Death After Stroke in Older Adults During a 10-year Follow-up: Results from a Competing Risk Model

OBJECTIVES

To investigate the association between stroke and incident dementia in the presence of a competing risk of death.

METHODS

This study used the National Health Insurance Service-Senior (NHIS-Senior) claim database from 2002 to 2013 (n = 22,792). Stroke (I69.0-I69.9) and dementia (F01-F03, G30, G31.1) patients were defined by the International Classification of Disease 10th revision. The association of stroke with dementia or death was assessed with Cox proportional hazards model and competing-risk model.

RESULTS

During the 10-year follow-up period, there were 1,307 dementia events (5.7%) and 9,272 deaths (40.7%). In the Cox model, the adjusted hazard ratio (HR) for dementia was 2.37 times higher in those who experienced strokes, compared with the non-stroke group (95% CI: 2.23, 2.51). In the presence of death as competing event, stroke was associated with an elevated dementia incidence (HR = 2.06, 95% CI: 1.92, 2.20).

CONCLUSION

Stroke was significantly associated with an increased risk of incident dementia, with the magnitude of the association being attenuated in the competing risk model.

Microbleeds in fronto-subcortical circuits are predictive of dementia conversion in patients with vascular cognitive impairment but no dementia

Cerebral small vessel disease (CSVD) is a common etiology of vascular cognitive impairment with no dementia (V-CIND). Studies have revealed that cerebral microbleeds (CMBs), a feature of CSVD, contribute to cognitive impairment. However, the association between CMBs and dementia conversion in individuals with V-CIND is still unclear. Here, we analyzed the predictive role of CMBs in the conversion from V-CIND to dementia in CSVD patients. We recruited and prospectively assessed 85 patients with CSVD and V-CIND. V-CIND was evaluated using a series of comprehensive neuropsychological scales, including the Chinese version of the Montreal Cognitive Assessment and the Clinical Dementia Rating. MRI assessments were used to quantify lacunar infarcts, white matter hyperintensities, CMBs, and medial temporal lobe atrophy. Eighty-two of the 85 patients completed the assessment for dementia conversion at a 1-year follow-up assessment. Multivariate logistic regression analyses were conducted to examine independent clinical and MRI variables associated with dementia conversion. Twenty-four patients (29.3%) had converted to dementia at the 1-year follow-up, and these individuals had significantly more CMBs in the fronto-subcortical circuits. Multivariate logistic regression analyses revealed that the patients with CMBs in the fronto-subcortical circuits (odds ratio = 4.4; 95% confidence interval: 1.602–12.081, P = 0.004) and 5 or more CMBs overall (odds ratio = 17.6, 95% confidence interval: 3.23–95.84, P = 0.001) had a significantly increased risk of dementia at the 1-year follow-up. These findings indicate that CMBs in the fronto-subcortical circuits may be predictive of dementia conversion in CSVD patients with V-CIND, and thus extend the clinical significance of CMBs. This trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1800017077). Protocol version: 1.0.

Potential Therapeutics for Vascular Cognitive Impairment and Dementia

BACKGROUND

As the human lifespan increases, the number of people affected by agerelated dementia is growing at an epidemic pace. Vascular pathology dramatically affects cognitive profiles, resulting in dementia and cognitive impairment. While vascular dementia itself constitutes a medical challenge, hypo-perfusion/vascular risk factors enhance amyloid toxicity and other memory- damaging factors and hasten Alzheimer's disease (AD) and other memory disorders' progression, as well as negatively affect treatment outcome.

METHODS

Research and online content related to vascular cognitive impairment and dementia is reviewed, specifically focusing on the potential treatment of the disorder.

RESULTS

Few therapeutic options are currently available to improve the prognosis of patients with vascular dementia and cognitive impairment, mixed AD dementia with vascular pathology, or other memory disorders. Emerging evidence, however, indicates that, like AD and other memory disorders, synaptic impairment underlies much of the memory impairment in the cognitive decline of vascular cognitive impairment and vascular dementia.

CONCLUSION

Effective rescues of the memory functions might be achieved through synaptic and memory therapeutics, targeting distinct molecular signaling pathways that support the formation of new synapses and maintaining their connections. Potential therapeutic agents include: 1) memory therapeutic agents that rescue synaptic and memory functions after the brain insults; 2) antipathologic therapeutics and an effective management of vascular risk factors; and 3) preventative therapeutic agents that achieve memory therapy through functional enhancement. These therapeutic agents are also likely to benefit patients with AD and/or other types of memory disorders.

Cognitive Deficits in Chronic Stroke Patients: Neuropsychological Assessment, Depression, and Self-Reports

BACKGROUND

Following stroke, clinicians are challenged to detect and untangle symptoms of cognitive dysfunction and mood disorders. Additionally, they need to evaluate the informative value of self-reports to identify patients in need of further attendance.

AIMS

To examine the association between neuropsychological measures, symptoms of depression, and self-reported cognitive function.

METHODS

One-hundred and five chronic stroke patients underwent assessment covering 6 cognitive domains and answered the Hospital Anxiety and Depression Scale and the Memory and Thinking Scale from the Stroke Impact Scale 1 year after stroke. Age and gender difference in cognitive impairment were examined; linear regression was used to predict depression scores. Sensitivity and specificity analyses were used to validate self-reported functioning against performance on cognitive tests.

RESULTS

Cognitive impairment was observed in 60% of the patients in at least 1 cognitive domain. Cognitive performance was associated with symptoms of depression as well as with self-reported cognitive function. The final analyses revealed low sensitivity and specificity for the Memory and Thinking subscale from the Stroke Impact Scale.

CONCLUSION

Cognitive impairment occurs frequently even in patients in a chronic phase after stroke and predicts symptoms of depression. Using the Stroke Impact Scale, clinicians should be aware of low sensitivity of self-reported cognitive function.

Determinants of post-stroke cognitive impairment: analysis from VISTA

BACKGROUND

Post-stroke cognitive impairment (PSCI) occurs commonly and is linked with development of dementia. We investigated the relationship between demographic, clinical and stroke symptoms at stroke onset and the presence of PSCI at 1 and 3 years after stroke.

METHODS

We accessed anonymized data from the Virtual International Stroke Trial Archive (VISTA), including demographic and clinical variables. Post-stroke cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score of ≤26. We assessed univariate relationships between baseline stroke symptoms and PSCI at 1 and 3 years following stroke, retaining the significant and relevant clinical factors as covariates in a final adjusted logistic regression model.

RESULTS

We analysed data on 5435 patients with recent (median 33 days) stroke or transient ischaemic attack (TIA). Mean (±SD) age was 62.6 (±12.6) years; 3476 (65%) patients were male. Follow-up data were available for 2270 and 1294 patients at 1 and 3 years, respectively. At 1 year, 781 (34%) patients had MMSE≤26; at 3 years, 391 (30%) had MMSE≤26. After adjusting for age, stroke severity, hypertension, diabetes and type of qualifying event, initial stroke impairment (leg paralysis) was associated with increased rate of PSCI at 1 year (OR=1.62; 95% CI=1.20-2.20) and at 3 years (OR=1.95; 95% CI=1.23-3.09). Associations were consistent on subgroup analysis restricted to ischaemic stroke and transient ischaemic attack (N=4992).

CONCLUSIONS

Besides well-known determinants of PSCI such as age, stroke severity and the presence of vascular risk factors, also leg paralysis is associated with subsequent of PSCI up to 3 years after stroke.

Electroacupuncture Regulates Hippocampal Synaptic Plasticity via miR-134-Mediated LIMK1 Function in Rats with Ischemic Stroke

MircoRNAs (miRs) have been implicated in learning and memory, by regulating LIM domain kinase (LIMK1) to induce synaptic-dendritic plasticity. The study aimed to investigate whether miRNAs/LIMK1 signaling was involved in electroacupuncture- (EA-) mediated synaptic-dendritic plasticity in a rat model of middle cerebral artery occlusion induced cognitive deficit (MICD). Compared to untreatment or non-acupoint-EA treatment, EA at DU20 and DU24 acupoints could shorten escape latency and increase the frequency of crossing platform in Morris water maze test. T2-weighted imaging showed that the MICD rat brain lesions were located in cortex, hippocampus, corpus striatum, and thalamus regions and injured volumes were reduced after EA. Furthermore, we found that the density of dendritic spine and the number of synapses in the hippocampal CA1 pyramidal cells were obviously reduced at Day 14 after MICD. However, synaptic-dendritic loss could be rescued after EA. Moreover, the synaptic-dendritic plasticity was associated with increases of the total LIMK1 and phospho-LIMK1 levels in hippocampal CA1 region, wherein EA decreased the expression of miR-134, negatively regulating LIMK1 to enhance synaptic-dendritic plasticity. Therefore, miR-134-mediated LIMK1 was involved in EA-induced hippocampal synaptic plasticity, which served as a contributor to improving learning and memory during the recovery stage of ischemic stroke.

Vascular Contributions to Cognitive Impairment and Treatments with Traditional Chinese Medicine

The prevalence of cognitive impairment and dementia caused by cerebrovascular disease is likely to increase with the global aging population. Vascular contributions to cognitive impairment and dementia (VCID) is a wide spectrum term used to include a diverse heterogeneous group of cognitive syndromes with vascular factors regardless of the cause of pathogenesis. VCID ranges from mild cognitive impairment to full-blown dementia with vascular dementia (VaD) as the most severe stage. It is further complexed by the coexistence of other forms of dementia such as Alzheimer's disease (AD). Recent researches in the functions of the neurovascular unit (NVU) suggest that dysfunction of the NVU might be the cause of primary vascular events in the brain that leads to further neurodegeneration. In this review, we have briefly summarized various forms of VCID. There is currently no standard therapy for VCID or dementia. Given the fact that Traditional Chinese Medicine (TCM) has gained popularity worldwide, we also reviewed recent scientific and clinical findings on various antidementia TCM for the treatment of VCID, including Salvia miltiorrhiza, Huperzia serrata, Ligusticum chuanxiong, Ginkgo biloba, Panax ginseng, and also TCM formula Sailuotong capsule (SLT) and Fufangdanshen tablets (FFDS).

Is the time ripe for new diagnostic criteria of cognitive impairment due to cerebrovascular disease? Consensus report of the International Congress on Vascular Dementia working group

BACKGROUND

Long before Alzheimer's disease was established as the leading cause of dementia in old age, cerebrovascular lesions were known to cause cognitive deterioration and associated disability. Since the middle of the last century, different diagnostic concepts for vascular dementia and related syndromes were put forward, yet no widely accepted diagnostic consensus exists to date.

DISCUSSION

Several international efforts, reviewed herein, are ongoing to define cognitive impairment due to cerebrovascular disease in its different stages and subtypes. The role of biomarkers is also being discussed, including cerebrospinal fluid proteins, structural and functional brain imaging, and genetic markers. The influence of risk factors, such as diet, exercise and different comorbidities, is emphasised by population-based research, and lifestyle changes are considered for the treatment and prevention of dementia.

CONCLUSION

To improve the diagnosis and management of vascular cognitive impairment, further progress has to be made in understanding the relevant pathomechanisms, including shared mechanisms with Alzheimer's disease; bringing together fragmented research initiatives in coordinated international programs; testing if known risk factors are modifiable in prospective interventional studies; and defining the pre-dementia and pre-clinical stages in line with the concept of mild cognitive impairment due to Alzheimer's disease.

A Review of Risk Factors for Cognitive Impairment in Stroke Survivors

In this review, we aimed to identify the risk factors that may influence cognitive impairment among stroke survivors, namely, demographic, clinical, psychological, and physical determinants. A search from Medline, Scopus, and ISI Web of Science databases was conducted for papers published from year 2004 to 2015 related to risk factors of cognitive impairment among adult stroke survivors. A total of 1931 articles were retrieved, but only 27 articles met the criteria and were reviewed. In more than half of the articles it was found that demographical variables that include age, education level, and history of stroke were significant risk factors of cognitive impairment among stroke survivors. The review also indicated that diabetes mellitus, hypertension, types of stroke and affected region of brain, and stroke characteristics (e.g., size and location of infarctions) were clinical determinants that affected cognitive status. In addition, the presence of emotional disturbances mainly depressive symptoms showed significant effects on cognition. Independent relationships between cognition and functional impairment were also identified as determinants in a few studies. This review provided information on the possible risk factors of cognitive impairment in stroke survivors. This information may be beneficial in the prevention and management strategy of cognitive impairments among stroke survivors.

Application and Revision of Montreal Cognitive Assessment in China's Military Retirees with Mild Cognitive Impairment

Objective

In an effort to accommodate MOCA to better fit for the Chinese context, this study was designed to employ the MOCA criteria to screen mild cognitive impairment (MCI) and analyze associated risk factors in military retirees.

Methods

Three hundred and four retired military cadres were recruited using a random cluster sampling technique with information collected including personal, prevalence, MOCA scale, and related neuropsychiatry scale. Thirty retirees were randomly chosen to be further analyzed one month later using the revised MOCA scale.

Results

①Our data indicated an incidence rate of 64.8% for mild cognitive impairment in retired military cadres. The incidence rate for MCI was significantly higher in those aged 80 or above compared with those 80 years of age or younger (P<0.05). The incidence rate of MCI was significantly higher in those with fewer than 6 years of education compared with those with over 7 years of education (P<0.05). The MCI incidence was higher for those with little exercise than those taking regular exercise (P<0.01). Moreover, the MCI incidence was higher in stroke patients than those who never had a stroke episode (P<0.05). ②There was a significant correlation between MOCA and MMSE scale scores (r = 0.81). MOCA scale scores were negatively correlated with ADL and CES-D scores (although not PSQI scores). ③ MOCA recension Cronbach’s alpha value was 0.862. The related coefficient of MOCA and MOCA recension was 0.878(P<0.01). When the Score of cut-off -point of the MOCA recension was 28, the area in ROC curve analyses was 0.859, as well as the largest area.

Conclusion

Retired cadres exhibited a greater incidence of MCI (than general population), which was closely associated with age, level of education and physical exercise and cerebral apoplexy. Revised MOCA scale displays a better validity and reaction degree of reliability and is more suitable for screening and diagnosis of MCI in the elderly in China.

Cognitive performance after ischaemic stroke

Cognitive impairment after stroke affects the patient recovery process. Therefore, the identification of factors associated with cognitive outcomes is important since it allows risk profiles of stroke survivors to be determined.

Objective

To assess cognitive outcome of stroke outpatients and investigate associations among clinical and demographic variables, vascular risk factors, depression symptoms and functional ability; and to describe the neuropsychological profile of these patients.

Methods

A cross-sectional design study was conducted. Subjects who suffered a first-ever ischaemic stroke 6 to 10 months prior to data collection underwent neuropsychological assessment and screening for depressive symptoms and functional ability. The outcome "cognitive performance" was analyzed considering two groups: "cognitive impairment" and "no cognitive impairment".

Results

There was a statistically significant association between cognitive impairment and female gender, age, stroke severity and functional ability. Regarding neuropsychological profile, the cognitive impairment group exhibited more generalized deficits in attention, visuospatial organization, verbal functions and verbal memory domains compared to the community control group.

Conclusion

The occurrence of cognitive impairment among patients was high, especially in women, older participants, individuals with more severe stroke, and greater impairment in functional ability. Multiple cognitive domains are affected and this may hamper recovery and negatively impact independence and quality of life after stroke.

A meta-analysis of acupuncture use in the treatment of cognitive impairment after stroke

OBJECTIVE

This meta-analysis was conducted to evaluate the efficacy of acupuncture on cognitive impairment (function) after a stroke.

DESIGN

Randomized controlled trials (RCTs) comparing acupuncture with no acupuncture in addition to medicine or rehabilitation were identified from databases (PubMed, Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure, VIP Chinese Periodical Database, Wangfang Chinese Periodical Database, Chinese Bio-medicine Database, Cochrane Library, and Chinese medical literature databases) and two relevant journals (Chinese Acupuncture and Moxibustion and the Journal of Shanghai Acupuncture and Moxibustion). Meta-analyses were conducted for the eligible RCTs.

RESULTS

Twenty-one trials with a total of 1421 patients met inclusion criteria. Pooled random-effects estimates of the change in the Mini-Mental State Examination were calculated for the comparison of acupuncture with no acupuncture in addition to medicine or rehabilitation. Following 4 weeks and 8 weeks of intervention with acupuncture, the merged mean difference was 3.14 (95% confidence interval [CI], 2.06-4.21; p<.00001) and 2.03 (95% CI, 0.26-3.80; p=0.02), respectively. For the comparison of 3-4 weeks of acupuncture with no acupuncture in addition to medicine or rehabilitation groups, the merged MD in Neurobehavioral Cognitive State Examination total scores was 5.63 (95% CI, 3.95-7.31; p<.00001). For the comparison of 8-12 weeks of acupuncture with no acupuncture in addition to medicine or rehabilitation groups, the P300 latency merged MD was -12.80 (95% CI, -21.08 to -4.51; p<.00001), while the P300 amplitude merged MD was 1.38 (95% CI, 0.93-1.82; p<.00001). Overall, the study quality was rated as moderate on the basis of the Cochrane Handbook for Systematic Reviews of Interventions (part 2: 8.5).

CONCLUSIONS

This meta-analysis suggests that acupuncture had positive effects on cognitive function after stroke and supports the need for additional research on the potential benefits of this therapeutic approach.

A Randomised, Double-Blind, Placebo-Controlled Trial of Actovegin in Patients with Post-Stroke Cognitive Impairment: ARTEMIDA Study Design

Background

No drug treatment to date has shown convincing clinical evidence of restoring cognitive function or preventing further decline after stroke. The ongoing ARTEMIDA study will evaluate the efficacy and safety of Actovegin for the symptomatic treatment of post-stroke cognitive impairment (PSCI) and will explore whether Actovegin has any disease-modifying effect by assessing whether any changes are sustained after treatment.

Design

ARTEMIDA is a 12-month, multicentre trial in patients (planned a total of 500, now recruited) with cognitive impairment following ischaemic stroke. The study consists of a baseline screening (≤7 days after stroke), after which eligible patients are randomised to Actovegin (2,000 mg/day for up to 20 intravenous infusions followed by 1,200 mg/day orally) or placebo for a 6-month double-blind treatment period. Patients will be followed up for a further 6 months, during which time they will be treated in accordance with standard clinical practice. The primary study endpoint is change from baseline in the Alzheimer's Disease Assessment Scale, cognitive subscale, extended version. Secondary outcomes include: Montreal Cognitive Assessment; dementia diagnosis (ICD-10); National Institutes of Health Stroke Scale; Barthel Index; EQ-5D; Beck Depression Inventory, version II, and safety.

Conclusion

There is a clear need for effective treatments for PSCI. ARTEMIDA should provide important insights into the use of a novel drug therapy for PSCI.

Identifying patients with poststroke mild cognitive impairment by pattern recognition of working memory load-related ERP

The early detection of subjects with probable cognitive deficits is crucial for effective appliance of treatment strategies. This paper explored a methodology used to discriminate between evoked related potential signals of stroke patients and their matched control subjects in a visual working memory paradigm. The proposed algorithm, which combined independent component analysis and orthogonal empirical mode decomposition, was applied to extract independent sources. Four types of target stimulus features including P300 peak latency, P300 peak amplitude, root mean square, and theta frequency band power were chosen. Evolutionary multiple kernel support vector machine (EMK-SVM) based on genetic programming was investigated to classify stroke patients and healthy controls. Based on 5-fold cross-validation runs, EMK-SVM provided better classification performance compared with other state-of-the-art algorithms. Comparing stroke patients with healthy controls using the proposed algorithm, we achieved the maximum classification accuracies of 91.76% and 82.23% for 0-back and 1-back tasks, respectively. Overall, the experimental results showed that the proposed method was effective. The approach in this study may eventually lead to a reliable tool for identifying suitable brain impairment candidates and assessing cognitive function.

Strategies to improve recovery in acute ischemic stroke patients: Iberoamerican Stroke Group Consensus

Stroke is not only a leading cause of death worldwide but also a main cause of disability. In developing countries, its burden is increasing as a consequence of a higher life expectancy. Whereas stroke mortality has decreased in developed countries, in Latin America, stroke mortality rates continue to rise as well as its socioeconomic dramatic consequences. Therefore, it is necessary to implement stroke care and surveillance programs to better describe the epidemiology of stroke in these countries in order to improve therapeutic strategies. Advances in the understanding of the pathogenic processes of brain ischemia have resulted in development of effective therapies during the acute phase. These include reperfusion therapies (both intravenous thrombolysis and interventional endovascular approaches) and treatment in stroke units that, through application of management protocols directed to maintain homeostasis and avoid complications, helps to exert effective brain protection that decreases further cerebral damage. Some drugs may enhance protection, and besides, there is increasing knowledge about brain plasticity and repair mechanisms that take place for longer periods beyond the acute phase. These mechanisms are responsible for recovery in certain patients and are the focus of basic and clinical research at present. This paper discusses recovery strategies that have demonstrated clinical effect, or that are promising and need further study. This rapidly evolving field needs to be carefully and critically evaluated so that investment in patient care is grounded on well-proven strategies.

Predictive value of MoCA in the acute phase of stroke on the diagnosis of mid-term cognitive impairment

Post-stroke cognitive impairment (PSCI) includes all forms of cognitive decline that develop after stroke, even if not severe enough to fit the criteria of dementia. Our aims were to investigate the predictive value of a brief bedside examination (Montreal Cognitive Assessment, MoCA) in the acute phase of stroke on the diagnosis of mid-term PSCI, taking into account other clinical, cognitive, functional, and neuroimaging predictors. Consecutive patients admitted to a stroke unit were evaluated with MoCA between 5 and 9 days after stroke. At baseline, clinical, functional, and neuroimaging data were collected. Patients were reassessed between 6 and 9 months after stroke by means of an extensive neuropsychological and functional evaluation. Out of 137 enrolled stroke patients, 80 (58.4%) were followed up (mean age 68.2 ± 14.6 years, males 66%, mean NIHSS score 3.6 ± 4.8). PSCI was diagnosed in 47 patients (59%; 35 mild cognitive impairment, 12 dementia). Controlling for age, education, functional and cognitive pre-morbid status, stroke severity, and pre-existing lacunar infarcts, MoCA baseline score [OR (95% CI) = 1.4(1.1-1.8)] for each point] and leukoaraiosis severity [OR (95% CI) = 0.4(0.2-0.9)] for each point of the van Swieten scale] were independently associated with PSCI. Using a ROC analysis, a cut-off of 21 predicted the diagnosis of PSCI with 91.4 % sensitivity, 75.8 % specificity, 80 % positive predictive value, and 89.3 % negative predictive value. In a sample of mild stroke patients, MoCA seems to be a good predictor of mid-term PSCI, making it a possible candidate for a brief cognitive screening in the acute stroke setting.

Clinical, methodological and theoretical issues in the assessment of cognition after anaesthesia and surgery: a review

As people live longer, the burden of cognitive impairment to elderly patients, their families and society becomes increasingly common and important. The loss of independence, a reduction in the quality of life and increased mortality are possible correlates to the mental disintegration. Cognitive dysfunction following major surgery on the elderly is a significant problem which adds to other cognitive impairments caused by neurodegeneration, cerebrovascular impairments and other causes. There are challenges in reviewing the literature because of many methodological concerns. There is no standard definition; the diagnosis is made only by the results of neuropsychological tests which are not standardised for this purpose; test results are analysed by different statistical methods (some of them inappropriate); controls are often absent or poorly matched; and pre-existing mild cognitive impairment, which affects 10 to 20% of people older than 65 years and is similar to the subtle cognitive impairment following surgery, is not sought for and recognised. Reviews of the subject have varied from descriptions such as 'a well recognised and significant problem' to 'a hypothetical phenomenon for which there is no International Statistical Classification of Disease (ICD-9) code, and no Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) code'. This article examines both sides of the spectrum in a detailed review which explains the necessary psychological 'jargon', discusses the methods used and points to areas of future research.

Relationship between cortical microinfarcts and cognitive impairment in Alzheimer's disease

Cerebrovascular disease and AD pathology co-exist in most dementia cases, and microinfarcts (MIs), particularly if cortical and multiple, play an additive and independent role in AD cognitive impairment. The main cause of cortical MIs is chronic cerebral hypoperfusion but occlusive vascular diseases, embolism and blood-brain barrier disruptions, isolated or combined, may also play a role. The precise mechanisms by which MIs cause cognitive impairment are not well known, but one plausible explanation is that they are widespread and accompanied by diffuse hypoperfusion, hypoxia, oxidative stress and inflammation, particularly in the watershed areas of the tertiary association cortex, and hence could damage cognition networks and explain many of AD's cognitive and behavioral disturbances. Therefore, it is crucial to control vascular risk factors and avoid uncontrolled use of the antihypertensives, neuroleptics and other sedative drugs frequently prescribed to AD patients.