Post-stroke dementia - a comprehensive review

Moxibustion Promoted Axonal Regeneration and Improved Learning and Memory of Post-stroke Cognitive Impairment by Regulating PI3K/AKt and TACC3

BACKGROUND

This study aimed to investigate whether moxibustion could affect PI3K/Akt pathway to regulate Transforming acidic coiled-coil containing protein 3 (TACC3) and promote axonal regeneration to improve learning and memory function in middle cerebral artery occlusion (MCAO) rats.

METHODS

Sixty SD rats were randomly divided into 4 groups: sham-operated control group (SC), model control group (MC), model+moxibustion group (MM), and model+inhibitor+moxibustion group (MIM). The rats in MC, MM, and MIM groups were made into MCAO models, and PI3K inhibitor LY294002 was injected into the rats in MIM group before modeling; while the rats in SC group were only treated with artery separation without monofilament inserting. After that, the rats in MM and MIM groups were intervented with moxibustion. We used the Zea-Longa scale, micro-Magnetic Resonance Imaging (micro-MRI), Morris water maze (MWM), TUNEL, western blot (WB), immunofluorescence and immunohistochemistry to evaluate the neurological deficits, cerebral infarct volume, learning and memory, apoptotic cell percentage in the hippocampal, the expression level of axonal regeneration and PI3K/AKt related proteins, the expression level of TACC3. The detection of 2h after surgery showed the result before moxibustion and 7 days after the intervention showed the results after moxibustion.

RESULTS

After 7d of intervention, the scores of Zea-Longa and the cerebral infarct volume, the escape latency, the percentage of apoptosis cells of MM group were lower than that of MC and MIM groups; the frequency of rats crossed the previous platform location, PI3K, p-Akt/t-Akt and TACC3, the level of GAP-43 in MM group was more than MC and MIM groups (P < 0.05). While no statistical difference existed between MIM group and MC group (P > 0.05).

CONCLUSION

Moxibustion can promote axonal regeneration and improve learning and memory of Post-stroke cognitive impairment via activating the PI3K/AKT signaling pathway and TACC3.

Post-stroke cognitive impairment: exploring molecular mechanisms and omics biomarkers for early identification and intervention

Post-stroke cognitive impairment (PSCI) is a major stroke consequence that has a severe impact on patients' quality of life and survival rate. For this reason, it is especially crucial to identify and intervene early in high-risk groups during the acute phase of stroke. Currently, there are no reliable and efficient techniques for the early diagnosis, appropriate evaluation, or prognostication of PSCI. Instead, plenty of biomarkers in stroke patients have progressively been linked to cognitive impairment in recent years. High-throughput omics techniques that generate large amounts of data and process it to a high quality have been used to screen and identify biomarkers of PSCI in order to investigate the molecular mechanisms of the disease. These techniques include metabolomics, which explores dynamic changes in the organism, gut microbiomics, which studies host-microbe interactions, genomics, which elucidates deeper disease mechanisms, transcriptomics and proteomics, which describe gene expression and regulation. We looked through electronic databases like PubMed, the Cochrane Library, Embase, Web of Science, and common databases for each omics to find biomarkers that might be connected to the pathophysiology of PSCI. As all, we found 34 studies: 14 in the field of metabolomics, 5 in the field of gut microbiomics, 5 in the field of genomics, 4 in the field of transcriptomics, and 7 in the field of proteomics. We discovered that neuroinflammation, oxidative stress, and atherosclerosis may be the primary causes of PSCI development, and that metabolomics may play a role in the molecular mechanisms of PSCI. In this study, we summarized the existing issues across omics technologies and discuss the latest discoveries of PSCI biomarkers in the context of omics, with the goal of investigating the molecular causes of post-stroke cognitive impairment. We also discuss the potential therapeutic utility of omics platforms for PSCI mechanisms, diagnosis, and intervention in order to promote the area's advancement towards precision PSCI treatment.

Melatonin Ameliorates Post-Stroke Cognitive Impairment in Mice by Inhibiting Excessive Mitophagy

Post-stroke cognitive impairment (PSCI) remains the most common consequence of ischemic stroke. In this study, we aimed to investigate the role and mechanisms of melatonin (MT) in improving cognitive dysfunction in stroke mice. We used CoCl2-induced hypoxia-injured SH-SY5Y cells as a cellular model of stroke and photothrombotic-induced ischemic stroke mice as an animal model. We found that the stroke-induced upregulation of mitophagy, apoptosis, and neuronal synaptic plasticity was impaired both in vivo and in vitro. The results of the novel object recognition test and Y-maze showed significant cognitive deficits in the stroke mice, and Nissl staining showed a loss of neurons in the stroke mice. In contrast, MT inhibited excessive mitophagy both in vivo and in vitro and decreased the levels of mitophagy proteins PINK1 and Parkin, and immunofluorescence staining showed reduced co-localization of Tom20 and LC3. A significant inhibition of mitophagy levels could be directly observed under transmission electron microscopy. Furthermore, behavioral experiments and Nissl staining showed that MT ameliorated cognitive deficits and reduced neuronal loss in mice following a stroke. Our results demonstrated that MT inhibits excessive mitophagy and improves PSCI. These findings highlight the potential of MT as a preventive drug for PSCI, offering promising therapeutic implications.

Acupuncture for cognitive impairment after stroke: A systematic review and meta-analysis

Objective

Acupuncture as an alternative therapy for post-stroke cognitive impairment (PSCI) has emerged as a research focus. The inclusion of additional external treatments in many previous studies prevents a clear, direct assessment of acupuncture's impact on PSCI. In order to prevent patients from developing hypersensitivity to other treatments and misinterpreting acupuncture's true therapeutic value, this study establish stricter intervention criteria and exclude therapies beyond acupuncture. The review aimed to offering a clearer evaluation of acupuncture's efficacy and safety in PSCI treatment.

Methods

This research involved a comprehensive search for randomized controlled trials (RCTs) across eight databases, adhering to the Cochrane Systematic Reviewer's Handbook 5.1.0 for risk-of-bias and quality assessments. A meta-analysis was conducted using RevMan 5.3 software.

Results

The inclusion of 18 publications, totaling 1361 patients, was achieved. The meta-analysis demonstrated a significantly higher overall efficacy of acupuncture for PSCI compared to controls (OR = 4.06, 95 % CI 2.86-5.76, Z = 7.82). Notable statistical differences were observed in the Montreal Cognitive Assessment scores (MD = 2.32, 95 % CI 1.68-2.97, Z = 7.10) and the Mini-Mental State Examination scores (MD = 2.02, 95 % CI 1.06-2.98, Z = 4.13) between the groups. Improvements in the Barthel Index scores were noted for the experimental group (MD = 5.70, 95 % CI 4.68-6.72, Z = 10.92).

Conclusion

Integrating acupuncture with Western medications offers significant benefits for treating PSCI over Western medications alone. However, the long-term efficacy of acupuncture in PSCI treatment and its potential in reducing recurrence rates remain undetermined. Further high-standard RCTs are essential to explore acupuncture's effectiveness in PSCI treatment more thoroughly.

Electroacupuncture Alleviates Post-stroke Cognitive Impairment Through Inhibiting miR-135a-5p/mTOR/NLRP3 Axis-mediated Autophagy

Post-stroke cognitive impairment is a significant challenge with limited treatment options. Electroacupuncture (EA) has shown promise in improving cognitive function after stroke. Our study explores the underlying mechanism of EA in alleviating cognitive impairment through the inhibition of autophagy. We utilized a rat model of stroke induced by middle cerebral artery occlusion (MCAO) to evaluate the efficacy of EA. Treatment with EA was observed to markedly improve cognitive function and reduce inflammation in MCAO rats, as evidenced by decreased neurological deficit scores, shorter latencies in the water maze test, and diminished infarct volumes. EA also attenuated tissue damage in the hippocampus and lowered the levels of pro-inflammatory cytokines and oxidative stress markers. Although autophagy was upregulated in MCAO rats, EA treatment suppressed this process, indicated by a reduction in autophagosome formation and alteration of autophagy-related protein expression. The protective effects of EA were reversed by the autophagy activator rapamycin. EA treatment elevated the levels of microRNA (miR)-135a-5p expression, and suppression of this elevation attenuated the remedial efficacy of EA in addressing cognitive impairment and inflammation. MiR-135a-5p targeted mammalian target of rapamycin (mTOR)/NOD-like receptor protein 3 (NLRP3) signaling to repress autophagy. EA treatment inhibits autophagy and alleviates cognitive impairment in post-stroke rats. It exerts its beneficial effects by upregulating miR-135a-5p and targeting the mTOR/NLRP3 axis.

Effect of transcranial direct current stimulation combined with transcutaneous auricular vagus nerve stimulation on poststroke cognitive impairment: a study protocol for a randomised controlled trial

INTRODUCTION

Poststroke cognitive impairment is a common complication in stroke survivors, seriously affecting their quality of life. Therefore, it is crucial to improve cognitive function of patients who had a stroke. Transcranial direct current stimulation (tDCS) and transcutaneous auricular vagus nerve stimulation (taVNS) are non-invasive, safe treatments with great potential to improve cognitive function in poststroke patients. However, further improvements are needed in the effectiveness of a single non-invasive brain stimulation technique for cognitive rehabilitation. This study protocol aims to investigate the effect and neural mechanism of the combination of tDCS and taVNS on cognitive function in patients who had a stroke.

METHODS AND ANALYSIS

In this single-centre, prospective, parallel, randomised controlled trial, a total of 66 patients with poststroke cognitive impairment will be recruited and randomly assigned (1:1:1) to the tDCS group, the taVNS group and the combination of tDCS and taVNS group. Each group will receive 30 min of treatment daily, five times weekly for 3 weeks. Primary clinical outcome is the Montreal Cognitive Assessment. Secondary clinical outcomes include the Mini-Mental State Examination, Stroop Colour Word Test, Trail Marking Test, Symbol Digit Modalities Test and Modified Barthel Index. All clinical outcomes, functional MRI and diffusion tensor imaging will be measured at preintervention and postintervention.

ETHICS AND DISSEMINATION

The trial has been approved by the Ethics Committee of the First Affiliated Hospital of Yangtze University (approval no: KY202390). The results will be submitted for publication in peer-reviewed journals or at scientific conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2300076632.

Ion transporter cascade, reactive astrogliosis and cerebrovascular diseases

Cerebrovascular diseases and their sequalae, such as ischemic stroke, chronic cerebral hypoperfusion, and vascular dementia are significant contributors to adult disability and cognitive impairment in the modern world. Astrocytes are an integral part of the neurovascular unit in the CNS and play a pivotal role in CNS homeostasis, including ionic and pH balance, neurotransmission, cerebral blood flow, and metabolism. Astrocytes respond to cerebral insults, inflammation, and diseases through unique molecular, morphological, and functional changes, collectively known as reactive astrogliosis. The function of reactive astrocytes has been a subject of debate. Initially, astrocytes were thought to primarily play a supportive role in maintaining the structure and function of the nervous system. However, recent studies suggest that reactive astrocytes may have both beneficial and detrimental effects. For example, in chronic cerebral hypoperfusion, reactive astrocytes can cause oligodendrocyte death and demyelination. In this review, we will summarize the (1) roles of ion transporter cascade in reactive astrogliosis, (2) role of reactive astrocytes in vascular dementia and related dementias, and (3) potential therapeutic approaches for dementing disorders targeting reactive astrocytes. Understanding the relationship between ion transporter cascade, reactive astrogliosis, and cerebrovascular diseases may reveal mechanisms and targets for the development of therapies for brain diseases associated with reactive astrogliosis.

Biomarker profiling to determine clinical impact of microRNAs in cognitive disorders

Alzheimer's disease (AD) and post-stroke cognitive impairment (PSCI) are the leading causes of progressive dementia related to neurodegenerative and cerebrovascular injuries in elderly populations. Despite decades of research, patients with these conditions still lack minimally invasive, low-cost, and effective diagnostic and treatment methods. MicroRNAs (miRNAs) play a vital role in AD and PSCI pathology. As they are easily obtained from patients, miRNAs are promising candidates for the diagnosis and treatment of these two disorders. In this study, we performed complete sequencing analysis of miRNAs from 24 participants, split evenly into the PSCI, post-stroke non-cognitive impairment (PSNCI), AD, and normal control (NC) groups. To screen for differentially expressed miRNAs (DE-miRNAs) in patients, we predicted their target genes using bioinformatics analysis. Our analyses identified miRNAs that can distinguish between the investigated disorders; several of them were novel and never previously reported. Their target genes play key roles in multiple signaling pathways that have potential to be modified as a clinical treatment. In conclusion, our study demonstrates the potential of miRNAs and their key target genes in disease management. Further in-depth investigations with larger sample sizes will contribute to the development of precise treatments for AD and PSCI.

Remote ischemic conditioning after stroke: Research progress in clinical study

BACKGROUND AND PURPOSE

Stroke is a leading cause of global morbidity and mortality, indicating the necessity and urgency of effective prevention and treatment. Remote ischemic conditioning (RIC) is a convenient, simple, non-intrusive, and effective method that can be easily added to the treatment regime of stroke patients. Animal experiments and clinical trials have proved the neuroprotective effects of RIC on brain injury including (examples of neuroprotective effects). This neuroprotection is achieved by raising brain tolerance to ischemia, increasing local cerebral blood perfusion, promoting collateral circulations, neural regeneration, and reducing the incidence of hematomas in brain tissue. This current paper will summarize the studies within the last 2 years for the comprehensive understanding of the use of RIC in the treatment of stroke.

METHODS

This paper summarizes the clinical research progress of RIC on stroke (ischemic stroke and hemorrhagic stroke (HS)). This paper is a systematic review of research published on registered clinical trials using RIC in stroke from inception through November 2022. Four major databases (PUBMED, WEB OF SCIENCE, EMBASE, and ClinicalTrials.gov) were searched.

RESULTS

Forty-eight studies were identified meeting our criteria. Of these studies, 14 were in patients with acute ischemic stroke with onset times ranging from 6 h to 14 days, seven were in patients with intravenous thrombolysis or endovascular thrombectomy, 10 were in patients with intracranial atherosclerotic stenosis, six on patients with vascular cognitive impairment, three on patients with moyamoya disease, and eight on patients with HS. Of the 48 studies, 42 were completed and six are ongoing.

CONCLUSIONS

RIC is safe, feasible, and effective in the treatment of stroke. Large-scale research is still required to explore the optimal treatment options and mechanisms of RIC in the future to develop a breakthrough in stroke prevention and treatment.

Effects of Combined Use of Intermittent Theta Burst Stimulation and Cognitive Training on Poststroke Cognitive Impairment: A Single-Blind Randomized Controlled Trial

OBJECTIVE

Poststroke cognitive impairment substantially affects patients' quality of life. This study explored the therapeutic efficacy of intermittent theta burst stimulation combined with cognitive training for poststroke cognitive impairment.

DESIGN

The experimental group received intermittent theta burst stimulation and cognitive training, whereas the control group only received cognitive training, both for 6 wks. The outcome measures were the Loewenstein Occupational Therapy Cognitive Assessment, modified Barthel Index, transcranial Doppler ultrasonography, and functional near-infrared spectroscopy.

RESULTS

After therapy, between-group comparisons revealed a substantial difference in the Loewenstein Occupational Therapy Cognitive Assessment scores ( P = 0.024). Improvements in visuomotor organization and thinking operations were more noticeable in the experimental group than in the other groups ( P = 0.017 and P = 0.044, respectively). After treatment, the resistance index of the experimental group differed from that of the control group; channels 29, 37, and 41 were activated ( P < 0.05). The active locations were the left dorsolateral prefrontal cortex, prefrontal polar cortex, and left Broca's region.

CONCLUSIONS

Intermittent theta burst stimulation combined with cognitive training had a superior effect on improving cognitive function and everyday activities compared with cognitive training alone, notably in visuomotor organization and thinking operations. Intermittent theta burst stimulation may enhance cognitive performance by improving network connectivity.

Information needs of stroke survivors and their family members regarding post-stroke cognition: a scoping review protocol

OBJECTIVE

The aim of this review is to map current evidence describing the information needs of stroke survivors and family members regarding cognition.

INTRODUCTION

Managing cognitive changes is the most frequently reported unmet need among stroke survivors; hence, there is an urgent need to improve support for post-stroke cognitive impairment. While there is evidence that psychoeducation may help stroke survivors and their family members develop awareness about cognitive impairment and self-management strategies, it is unclear what information stroke survivors and their family members want to receive and how their needs change over time.

INCLUSION CRITERIA

This review will consider peer-reviewed articles describing information needs relating to the following cognitive domains: memory, language, attention, executive function, praxis, and number processing. Stroke survivors and/or their family members must comprise at least 50% of the study population and must be aged at least 18 years. Quantitative, qualitative, and mixed methods studies will be included.

METHODS

The review will be conducted in line with the JBI methodology for scoping reviews. A full literature search will be conducted in MEDLINE (PubMed), PsycINFO (Ovid), Embase, CINAHL (EBSCOhost), and Scopus using a search strategy developed in consultation with an expert university librarian. Articles will be screened by title, abstract, and full text; then, data will be extracted by 2 independent reviewers. The reference lists of included articles will be hand-searched for additional material. Data analysis and reporting will involve qualitative (textual narrative synthesis) and quantitative (descriptive statistics) methods.

Experimental Ischemic Stroke Induces Secondary Bihemispheric White Matter Degeneration and Long-Term Cognitive Impairment

Clinical studies have identified widespread white matter degeneration in ischemic stroke patients. However, contemporary research in stroke has predominately focused on the infarct and periinfarct penumbra regions. The involvement of white matter degeneration after ischemic stroke and its contribution to post-stroke cognitive impairment and dementia (PSCID) has remained less explored in experimental models. In this study, we examined the progression of locomotor and cognitive function up to 4 months after inducing ischemic stroke by middle cerebral artery occlusion in young adult rats. Despite evident ongoing locomotor recovery, long-term cognitive and affective impairments persisted after ischemic stroke, as indicated by Morris water maze, elevated plus maze, and open field performance. At 4 months after stroke, multimodal MRI was conducted to assess white matter degeneration. T2-weighted MRI (T2WI) unveiled bilateral cerebroventricular enlargement after ischemic stroke. Fluid Attenuated Inversion Recovery MRI (FLAIR) revealed white matter hyperintensities in the corpus callosum and fornix across bilateral hemispheres. A positive association between the volume of white matter hyperintensities and total cerebroventricular volume was noted in stroke rats. Further evidence of bilateral white matter degeneration was indicated by the reduction of fractional anisotropy and quantitative anisotropy at bilateral corpus callosum in diffusion-weighted MRI (DWI) analysis. Additionally, microglia and astrocyte activation were identified in the bilateral corpus callosum after stroke. Our study suggests that experimental ischemic stroke induced by MCAO in young rat replicate long-term cognitive impairment and bihemispheric white matter degeneration observed in ischemic stroke patients. This model provides an invaluable tool for unraveling the mechanisms underlying post-stroke secondary white matter degeneration and its contribution to PSCID.

Intermittent theta burst stimulation combined with cognitive training improves cognitive dysfunction and physical dysfunction in patients with post-stroke cognitive impairment

OBJECTIVE

Post-stroke cognitive impairment (PSCI) is a common complication of stroke. Intermittent theta burst stimulation (iTBS) can inducing motor learning. We observed the effects of combination of iTBS with cognitive training on physical/cognitive dysfunctions in PSCI patients.

METHODS

PSCI patients treated with basic treatment & cognitive training (Control group)/iTBS & cognitive training (iTBS group) were enrolled, with Mini-mental State Examination (MMSE)/Montreal Cognitive Assessment (MoCA)/Frontal Assessment Battery (FAB)/barthel index (BI)/Upper Limb Fugl-Meyer Assessment (U-FMA)/Action Research Arm Test (ARAT) scores compared. Gait spatiotemporal parameters/dynamic parameters were analyzed by 3D gait analysis. Correlations between MMSE/MoCA scores and gait parameters in PSCI patients after iTBS & cognitive training were analyzed by Spearman analysis.

RESULTS

Increased MMSE/MoCA/FAB/BI/U-FMA/ARAT scores, step speed, step frequency, stride length, step width, step length on the affected side, percentage of swing phase on the affected side, hip joint flexion angle on the affected side, knee joint flexion angle on the affected side, and ankle plantar flexion angle on the affected side and reduced gait period on the affected side and percentage of stance phase on the affected side were found in patients of both groups after treatment, with the effects in the iTBS group more profound.

CONCLUSION

iTBS & cognitive training obviously improved the cognitive function scores/upper limb function scores/gait parameters in PSCI patients versus cognitive training treatment. After combination therapy, the MMSE/MoCA scores of PSCI patients were significantly correlated with gait parameters. This provided more data support for iTBS & cognitive training application in the rehabilitation treatment of PSCI patients.

Neuroprotective effects of Aucubin against cerebral ischemia-reperfusion injury

AIMS

To study the role of Aucubin (AU) in cerebral ischemia-reperfusion injury and investigate the potential mechanisms.

METHODS

For the in vitro experiment, primary microglia were cultured and stimulated by Lipopolysaccharides (LPS) and treated with AU. Male C57/BL6J mice were used and middle cerebral artery occlusion (MCAO) model was performed to induce cerebral ischemia-reperfusion injury. For the short-term effects, mice administrated with AU (40 mg/kg) for 3 days after MCAO were evaluated for the infarct volume and neurological deficits. The neuroinflammatory factors and microglia activation were determined by Real-time PCR, western blot and immunofluorescence staining. For the long-term effects, MCAO mice were injected daily with AU (5 mg/kg or 10 mg/kg) for 28 days. Behavior tests were used to assess the neurological deficits of MCAO mice, and white matter integrity was determined by myelin basic protein (MBP) staining and black-gold staining.

RESULTS

AU suppressed LPS-induced activation of microglia and pro-inflammatory cytokines release, and downregulated the NF-κB and MAPK pathways in primary microglia. In addition, AU attenuated ischemic injury and inhibited the neuro-inflammatory response in MCAO mice. Moreover, AU induced prolonged improvements in sensorimotor function and memory function following MCAO, and preserved white matter integrity in the long-term experiments.

CONCLUSIONS

AU protected against ischemic injury, which might be correlated with the downregulation of NF-κB and MAPK signaling pathways. Furthermore, AU alleviated cognitive impairment after stroke and restored white matter integrity. Our data indicated that AU might be a potential compound for the treatment of stroke and post-stroke cognitive impairment.

The role of gut microbiota in cerebrovascular disease and related dementia

In recent years, increasing evidence suggests that commensal microbiota may play an important role not only in health but also in disease including cerebrovascular disease. Gut microbes impact physiology, at least in part, by metabolizing dietary factors and host-derived substrates and then generating active compounds including toxins. The purpose of this current review is to highlight the complex interplay between microbiota, their metabolites. and essential functions for human health, ranging from regulation of the metabolism and the immune system to modulation of brain development and function. We discuss the role of gut dysbiosis in cerebrovascular disease, specifically in acute and chronic stroke phases, and the possible implication of intestinal microbiota in post-stroke cognitive impairment and dementia, and we identify potential therapeutic opportunities of targeting microbiota in this context. LINKED ARTICLES: This article is part of a themed issue From Alzheimer's Disease to Vascular Dementia: Different Roads Leading to Cognitive Decline. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.6/issuetoc.

Astrocytic endothelin-1 overexpression impairs learning and memory ability in ischemic stroke via altered hippocampal neurogenesis and lipid metabolism

Vascular etiology is the second most prevalent cause of cognitive impairment globally. Endothelin-1, which is produced and secreted by endothelial cells and astrocytes, is implicated in the pathogenesis of stroke. However, the way in which changes in astrocytic endothelin-1 lead to poststroke cognitive deficits following transient middle cerebral artery occlusion is not well understood. Here, using mice in which astrocytic endothelin-1 was overexpressed, we found that the selective overexpression of endothelin-1 by astrocytic cells led to ischemic stroke-related dementia (1 hour of ischemia; 7 days, 28 days, or 3 months of reperfusion). We also revealed that astrocytic endothelin-1 overexpression contributed to the role of neural stem cell proliferation but impaired neurogenesis in the dentate gyrus of the hippocampus after middle cerebral artery occlusion. Comprehensive proteome profiles and western blot analysis confirmed that levels of glial fibrillary acidic protein and peroxiredoxin 6, which were differentially expressed in the brain, were significantly increased in mice with astrocytic endothelin-1 overexpression in comparison with wild-type mice 28 days after ischemic stroke. Moreover, the levels of the enriched differentially expressed proteins were closely related to lipid metabolism, as indicated by Kyoto Encyclopedia of Genes and Genomes pathway analysis. Liquid chromatography-mass spectrometry nontargeted metabolite profiling of brain tissues showed that astrocytic endothelin-1 overexpression altered lipid metabolism products such as glycerol phosphatidylcholine, sphingomyelin, and phosphatidic acid. Overall, this study demonstrates that astrocytic endothelin-1 overexpression can impair hippocampal neurogenesis and that it is correlated with lipid metabolism in poststroke cognitive dysfunction.

Dl-3-n-Butylphthalide Alleviates Secondary Brain Damage and Improves Working Memory After Stroke in Cynomolgus Monkeys

BACKGROUND

Remote secondary neurodegeneration is associated with poststroke cognitive impairment (PSCI). Dl-3-n-butylphthalide (NBP) improves PSCI clinically. However, whether it ameliorates PSCI by alleviating secondary neurodegeneration remains uncertain. Nonhuman primates provide more relevant models than rodents for human stroke and PSCI. This study investigated the effects of NBP on PSCI and secondary neurodegeneration in cynomolgus monkeys after permanent left middle cerebral artery occlusion (MCAO).

METHODS

Thirteen adult male cynomolgus monkeys were randomly assigned to sham (n=4), MCAO+placebo (n=5), and MCAO+NBP groups (n=4). The MCAO+placebo and MCAO+NBP groups received saline and NBP injections intravenously, respectively, starting at 6-hour postsurgery for 2 weeks, followed by soybean oil and NBP orally, respectively, for 10 weeks after MCAO. Infarct size was assessed at week 4 by magnetic resonance imaging. Working memory and executive function were evaluated dynamically using the delayed response task and object retrieval detour task, respectively. Neuron loss, glia proliferation, and neuroinflammation in the ipsilateral dorsal lateral prefrontal cortex, thalamus, and hippocampus were analyzed by immunostaining 12 weeks after MCAO.

RESULTS

Infarcts were located in the left middle cerebral artery region, apart from the ipsilateral dorsal lateral prefrontal cortex, thalamus, or hippocampus, with no significant difference between the MCAO+placebo and MCAO+NBP group. Higher success in delayed response task was achieved at weeks 4, 8, and 12 after NBP compared with placebo treatments (P<0.05), but not in the object retrieval detour task (all P>0.05). More neurons and less microglia, astrocytes, CD68-positive microglia, tumor necrosis factor-α, and inducible NO synthase were observed in the ipsilateral dorsal lateral prefrontal cortex and thalamus after 12 weeks of NBP treatment (P<0.05), but not in the hippocampus (P>0.05).

CONCLUSIONS

Our findings indicate that NBP improves working memory by alleviating remote secondary neurodegeneration and neuroinflammation in the ipsilateral dorsal lateral prefrontal cortex and thalamus after MCAO in cynomolgus monkeys.

Genome-Wide Association Studies of 3 Distinct Recovery Phenotypes in Mild Ischemic Stroke

BACKGROUND AND OBJECTIVES

Stroke genetic research has made substantial progress in the past decade. Its recovery application, however, remains behind, in part due to its reliance on the modified Rankin Scale (mRS) score as a measure of poststroke outcome. The mRS does not map well to biological processes because numerous psychosocial factors drive much of what the mRS captures. Second, the mRS contains multiple disparate biological events into a single measure further limiting its use for biological discovery. This led us to investigate the effect of distinct stroke recovery phenotypes on genetic variation associations with Genome-Wide Association Studies (GWASs) by repurposing the NIH Stroke Scale (NIHSS) and its subscores.

METHODS

In the Vitamin Intervention for Stroke Prevention cohort, we estimated changes in cognition, motor, and global impairments over 2 years using specific measures. We included genotyped participants with a total NIHSS score greater than zero at randomization and excluded those with recurrent stroke during the trial. A GWAS linear mixed-effects model predicted score changes, with participant as a random effect, and included initial score, age, sex, treatment group, and the first 5 ancestry principal components.

RESULTS

In total, 1,270 participants (64% male) were included with a median NIHSS score of 2 (interquartile range [IQR] 1-3) and median age 68 (IQR 59-75) years. At randomization, 20% had cognitive deficits (NIHSS Cog-4 score >0) and 70% had ≥1 motor deficits (impairment score >1). At 2 years, these percentages improved to 7.2% with cognitive deficits and 30% with motor deficits. GWAS identified novel suggestive gene-impairment associations (p < 5e-6) for cognition (CAMK2D, EVX2, LINC0143, PTPRM, SGMS1, and SMAD2), motor (ACBD6, KDM4B, MARK4, PTPRS, ROBO1, and ROBO2), and global (MSR1 and ROBO2) impairments.

DISCUSSION

Defining domain-specific stroke recovery phenotypes and using longitudinal clinical trial designs can help detect novel genes associated with chronic recovery. These data support the use of granular endpoints to identify genetic associations related to stroke recovery.

The contribution of β-amyloid, Tau and α-synuclein to blood-brain barrier damage in neurodegenerative disorders

Central nervous system (CNS) accumulation of fibrillary deposits made of Amyloid β (Aβ), hyperphosphorylated Tau or α-synuclein (α-syn), present either alone or in the form of mixed pathology, characterizes the most common neurodegenerative diseases (NDDs) as well as the aging brain. Compelling evidence supports that acute neurological disorders, such as traumatic brain injury (TBI) and stroke, are also accompanied by increased deposition of toxic Aβ, Tau and α-syn species. While the contribution of these pathological proteins to neurodegeneration has been experimentally ascertained, the cellular and molecular mechanisms driving Aβ, Tau and α-syn-related brain damage remain to be fully clarified. In the last few years, studies have shown that Aβ, Tau and α-syn may contribute to neurodegeneration also by inducing and/or promoting blood-brain barrier (BBB) disruption. These pathological proteins can affect BBB integrity either directly by affecting key BBB components such as pericytes and endothelial cells (ECs) or indirectly, by promoting brain macrophages activation and dysfunction. Here, we summarize and critically discuss key findings showing how Aβ, Tau and α-syn can contribute to BBB damage in most common NDDs, TBI and stroke. We also highlight the need for a deeper characterization of the role of these pathological proteins in the activation and dysfunction of brain macrophages, pericytes and ECs to improve diagnosis and treatment of acute and chronic neurological disorders.

Angiotensin II Type 2 Receptor Agonism Alleviates Progressive Post-stroke Cognitive Impairment in Aged Spontaneously Hypertensive Rats

Hypertension and aging are leading risk factors for stroke and vascular contributions to cognitive impairment and dementia (VCID). Most animal models fail to capture the complex interplay between these pathophysiological processes. In the current study, we examined the development of cognitive impairment in 18-month-old spontaneously hypertensive rats (SHR) before and following ischemic stroke. Sixty SHRs were housed for 18 months with cognitive assessments every 6 months and post-surgery. MRI scans were performed at baseline and throughout the study. On day 3 post-stroke, rats were randomized to receive either angiotensin II type 2 receptor (AT2R) agonist Compound 21 (C21) or plain water for 8 weeks. SHRs demonstrated a progressive cognitive decline and significant MRI abnormalities before stroke. Perioperative mortality within 72 h of stroke was low. Stroke resulted in significant acute brain swelling, chronic brain atrophy, and sustained sensorimotor and behavioral deficits. There was no evidence of anhedonia at week 8. C21 enhanced sensorimotor recovery and ischemic lesion resolution at week 8. SHRs represent a clinically relevant animal model to study aging and stroke-associated VCID. This study underscores the importance of translational disease modeling and provides evidence that modulation of the AT2R signaling via C21 may be a useful therapeutic option to improve sensorimotor and cognitive outcomes even in aged animals.

Protective mechanism of Paeonol on central nervous system

Cerebrovascular diseases involve neuronal damage, resulting in degenerative neuropathy and posing a serious threat to human health. The discovery of effective drug components from natural plants and the study of their mechanism are a research idea different from chemical synthetic medicines. Paeonol is the main active component of traditional Chinese medicine Paeonia lactiflora Pall. It widely exists in many medicinal plants and has pharmacological effects such as anti-atherosclerosis, antiplatelet aggregation, anti-oxidation, and anti-inflammatory, which keeps generally used in the treatment of cardiovascular and cerebrovascular diseases. Based on the therapeutic effects of Paeonol for cardiovascular and cerebrovascular diseases, this article reviewed the pharmacological effects of Paeonol in Alzheimer's disease, Parkinson's disease, stroke, epilepsy, diabetes encephalopathy, and other neurological diseases, providing a reference for the research of the mechanism of Paeonol in central nervous system diseases.

Absence in CX3CR1 receptor signaling promotes post-ischemic stroke cognitive function recovery through suppressed microglial pyroptosis in mice

BACKGROUND

Post-stroke cognitive impairment (PSCI) is a major source of morbidity and mortality after stroke, but the pathological mechanisms remain unclear. Previous studies have demonstrated that the CX3CR1 receptor plays a crucial role in maintaining an early protective microenvironment after stroke, but whether it persistently influences cognitive dysfunction in the chronic phase requires further investigation.

METHODS

Mouse was used to establish a middle cerebral artery occlusion (MCAO)/reperfusion model to study PSCI. Cognitive function was assessed by the Morris water maze (MWM) and the novel object recognition test. Neurogenesis was assessed by immunofluorescence staining with Nestin+ /Ki67+ and DCX+ /BrdU+ double-positive cells. The cerebral damage was monitored by [18 F]-DPA-714 positron emission tomography, Nissel, and TTC staining. The pyroptosis was histologically, biochemically, and electron microscopically examined.

RESULTS

Upon MCAO, at 28 to 35 days, CX3CR1 knockout (CX3CR1-/- ) mice had better cognitive behavioral performance both in MWM and novel object recognition test than their CX3CR1+/- counterparts. Upon MCAO, at 7 days, CX3CR1-/- mice increased the numbers of Nestin+ /Ki67+ and DCX+ /BrdU+ cells, and meanwhile it decreased the protein expression of GSDMD, NLRP3 inflammasome subunit, caspase-1, mature IL-1β/IL-18, and p-P65 in the hippocampus as compared with CX3CR1+/- mice. In addition, CX3CR1-/- mice could reverse infarct volume in the hippocampus region post-stroke.

CONCLUSION

Our study demonstrated that CX3CR1 gene deletion was beneficial to PSCI recovery. The mechanism might lie in inhibited pyroptosis and enhanced neurogenesis. CX3CR1 receptor may serve as a therapeutic target for improving the PSCI.

Psychosocial factors associated with 7-year change in cognition among middle-aged and older Hispanics/Latinos: The Hispanic Community Health Study/Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) and Sociocultural ancillary studies

INTRODUCTION

Few studies have examined the associations of psychosocial factors with cognitive change in Hispanics/Latinos.

METHODS

Data from the Hispanic Community Health Study/Study of Latinos-Investigation of Neurocognitive Aging (HCHS/SOL INCA) and Sociocultural studies were used (n = 2,155; ages ≥45 years). Psychosocial exposures included intrapersonal (ethnic identity, optimism, purpose in life), interpersonal (family cohesion, familism, social networks, social support), and social factors (ethnic discrimination, loneliness, subjective social status). Survey-linear regression models examined associations between psychosocial exposures and 7-year cognitive change (global cognition [GC], verbal learning, memory, word fluency [WF], and digit symbol substitution [DSS]).

RESULTS

Familism predicted decline in GC, verbal learning, and memory; family cohesion predicted DSS decline; and loneliness predicted memory decline. Ethnic identity was protective against decline in GC and memory, optimism and social support were protective against decline in memory, and purpose in life was protective against WF decline.

DISCUSSION

Psychosocial factors are differentially related to cognitive changes. Culturally relevant factors should be explored in Hispanic/Latino cognitive aging research.

HIGHLIGHTS

Psychosocial factors are differentially related to cognitive changes in Latinos. Role of culturally relevant factors on cognition should be further explored. Familism predicted decline in global cognition, verbal learning, and memory. Ethnic identity predicted increase in global cognition and memory.

High-density lipoprotein cholesterol is associated with lowered cognitive recovery among acute ischemic stroke patients with mild cognitive impairment

High-density lipoprotein (HDL) has been documented to be related to mild cognitive impairment (MCI) and dementia occurrence; however, the underlying basis behind this association remains unclear. We aimed to elucidate this basis by examining the association between HDL levels and cognitive improvements after 6 months, among acute ischemic stroke (AIS) patients with MCI. Five hundred fifty-eight AIS and MCI patients from the NICE study were enrolled, and divided into four groups, according to their baseline HDL quartiles; median HDL was 1.12 mmol/L (interquartile range 0.96-1.34 mmol/L). The primary outcome examined was the extent of cognitive improvement, defined as ΔMoCA (Montreal Cognitive Assessment) ≥ 2, while the secondary outcome was cognitive deterioration, defined as ΔADAS-cog (Alzheimer's Disease Assessment Scale-Cognitive Subscale) ≥ 4 or ΔMMSE (Mini-Mental State Examination) ≤ - 3, at 6-months post-AIS. We found that 314 (56.27%), 49 (8.78%), and 31 (5.56%) patients had ΔMoCA ≥ 2, ΔADAS-cog ≥ 4, and ΔMMSE ≤ - 3, respectively. Furthermore, cognitive improvement negatively correlated to HDL levels, with the lowest being present among patients in quartiles 4 (Q4; adjusted OR = 0.44, 95% CI 0.25-0.78, P = 0.0050) and Q3 (OR = 0.38, CI 0.23-0.65, P = 0.0004), compared to Q2 (OR = 0.57, CI 0.34-0.96, P = 0.0331). Q2 patients also had positive correlations with ΔADAS-cog ≥ 4 (OR = 5.18, CI 1.55-17.29, P = 0.0074). However, no association between HDL and ΔMMSE ≤ - 3 was observed, nor with LDL and any cognitive changes. Additionally, restricted cubic spline analysis found a nonlinear relationship between HDL and cognitive improvements. All these findings suggested that low plasma HDL was positively associated with improved cognitive functioning among AIS patients with MCI after 6 months.

Therapeutic effects of a novel electrode for transcranial direct current stimulation in ischemic stroke mice

Rationale: Non-invasive transcranial direct current stimulation (tDCS), a promising stimulation tool to modulate a wide range of brain disorders, has major limitations, such as poor cortical stimulation intensity and focality. We designed a novel electrode for tDCS by conjugating a needle to a conventional ring-based high-definition (HD) electrode to enhance cortical stimulation efficacy. Method: HD-tDCS (43 µA/mm2, charge density 51.6 kC/m2, 20 min) was administered to male C57BL/6J mice subjected to early-stage ischemic stroke. Behavioral tests were employed to determine the therapeutic effects, and the underlying mechanisms of HD-tDCS were determined by performing RNA sequencing and other biomedical analyses. Results: The new HD-tDCS application, showing a higher electric potential and spatial focality based on computational modeling, demonstrated better therapeutic effects than conventional HD-tDCS in alleviating motor and cognitive deficits, with a decrease in infarct volume and inflammatory response. We assessed different electrode configurations in the new HD electrode; the configurations variously showed potent therapeutic effects, ameliorating neuronal death in the peri-infarct region via N-methyl-D-aspartate-dependent sterol regulatory element-binding protein 1 signaling and related inflammatory factors, further alleviating motor and cognitive deficits in stroke. Conclusion: This new HD-tDCS application showed better therapeutic effects than those with conventional HD-tDCS in early-stage stroke via the amelioration of neuronal death in the penumbra. It may be applied in the early stages of stroke to alleviate neurological impairment.

NeuroAIreh@b: an artificial intelligence-based methodology for personalized and adaptive neurorehabilitation

Cognitive impairments are a prevalent consequence of acquired brain injury, dementia, and age-related cognitive decline, hampering individuals' daily functioning and independence, with significant societal and economic implications. While neurorehabilitation represents a promising avenue for addressing these deficits, traditional rehabilitation approaches face notable limitations. First, they lack adaptability, offering one-size-fits-all solutions that may not effectively meet each patient's unique needs. Furthermore, the resource-intensive nature of these interventions, often confined to clinical settings, poses barriers to widespread, cost-effective, and sustained implementation, resulting in suboptimal outcomes in terms of intervention adaptability, intensity, and duration. In response to these challenges, this paper introduces NeuroAIreh@b, an innovative cognitive profiling and training methodology that uses an AI-driven framework to optimize neurorehabilitation prescription. NeuroAIreh@b effectively bridges the gap between neuropsychological assessment and computational modeling, thereby affording highly personalized and adaptive neurorehabilitation sessions. This approach also leverages virtual reality-based simulations of daily living activities to enhance ecological validity and efficacy. The feasibility of NeuroAIreh@b has already been demonstrated through a clinical study with stroke patients employing a tablet-based intervention. The NeuroAIreh@b methodology holds the potential for efficacy studies in large randomized controlled trials in the future.

Evaluation of the functional outcome and mobility of patients after stroke depending on their cognitive state

The study aimed to analyze the functional outcome and mobility in stroke patients depending on their cognitive state. 180 patients after first stroke were divided into four groups: 48 patients without symptoms of cognitive impairment (G1); 38 with mild cognitive impairment without dementia (G2); 47 with mild dementia (G3); 47 with moderate dementia (G4). The Mini Mental State Examination (MMSE), Barthel Index (BI), Sitting Assessment Scale (SAS), Berg Balance Scale, Trunk Control Test and Test Up & Go were used. The tests were carried out at the time of admission to the ward (T1) and at the time of discharge (T2). A statistically significant improvement was demonstrated in all parameters in almost all groups. No significant difference was observed only in groups G1 and G4 in SAS head. Statistically significant differences in BI results in T2 between groups G1 and G4 were noted. The lowest change in BI was observed in the G4. Regression analysis showed that MMSE and BI at T1 and MMSE score at T2 explained the functional status at T2. Cognitive dysfunction at the time of admission to the ward and discharge may determining the patient's functional status at the time of discharge from the ward.

Molecular mechanism of cognitive impairment associated with Parkinson's disease: A stroke perspective

Parkinson's disease (PD) is a common neurological illness that causes several motor and non-motor symptoms, most characteristically limb tremors and bradykinesia. PD is a slowly worsening disease that arises due to progressive neurodegeneration of specific areas of the brain, especially the substantia nigra of the midbrain. Even though PD has continuously been linked to a higher mortality risk in numerous epidemiologic studies, there have been significant discoveries regarding the connection between PD and stroke. The incidence of strokes such as cerebral infarction and hemorrhage is substantially associated with the development of PD. Moreover, cognitive impairments, primarily dementia, have been associated with stroke and PD. However, the underlying molecular mechanism of this phenomenon is still obscure. This concise review focuses on the relationship between stroke and PD, emphasizing the molecular mechanism of cognition deficit and memory loss evident in PD and stroke. Furthermore, we are also highlighting some potential drug molecules that can target both PD and stroke.

Single-Cell Transcriptome Reveals Cell Type-Specific Molecular Pathology in a 2VO Cerebral Ischemic Mouse Model

Post-ischemia memory impairment is a major sequela in cerebral ischemia patients. However, cell type-specific molecular pathology in the hippocampus after ischemia is poorly understood. In this study, we adopted a mouse two-vessel occlusion ischemia model (2VO model) to mimic cerebral ischemia-induced memory impairment and investigated the single-cell transcriptome in the hippocampi in 2VO mice. A total of 27,069 cells were corresponding 14 cell types with neuronal, glial, and vascular lineages. We next analyzed cell-specific gene alterations in 2VO mice and the function of these cell-specific genes. Differential expression analysis identified cell type-specific genes with altered expression in neurons, astrocytes, microglia, and oligodendrocytes in 2VO mice. Notably, four subtypes of oligodendrocyte precursor cells with distinct differentiation pathways were suggested. Taken together, this is the first single-cell transcriptome analysis of gene expression in a 2VO model. Furthermore, we suggested new types of oligodendrocyte precursor cells with angiogenesis and neuroprotective potential, which might offer opportunities to identify new avenues of research and novel targets for ischemia treatment.

Non-invasive brain stimulation for functional recovery in animal models of stroke: A systematic review

Motor and cognitive dysfunction occur frequently after stroke, severely affecting a patient´s quality of life. Recently, non-invasive brain stimulation (NIBS) has emerged as a promising treatment option for improving stroke recovery. In this context, animal models are needed to improve the therapeutic use of NIBS after stroke. A systematic review was conducted based on the PRISMA statement. Data from 26 studies comprising rodent models of ischemic stroke treated with different NIBS techniques were included. The SYRCLE tool was used to assess study bias. The results suggest that both repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) improved overall neurological, motor, and cognitive functions and reduced infarct size both in the short- and long-term. For tDCS, it was observed that either ipsilesional inhibition or contralesional stimulation consistently led to functional recovery. Additionally, the application of early tDCS appeared to be more effective than late stimulation, and tDCS may be slightly superior to rTMS. The optimal stimulation protocol and the ideal time window for intervention remain unresolved. Future directions are discussed for improving study quality and increasing their translational potential.

Current perspectives on prevention of vascular cognitive impairment and promotion of vascular brain health

INTRODUCTION

The true global burden of vascular cognitive impairment (VCI) is unknown. Reducing risk factors for stroke and cardiovascular disease would inevitably curtail VCI.

AREAS COVERED

The authors review current diagnosis, epidemiology, and risk factors for VCI. VCI increases in older age and by inheritance of known genetic traits. They emphasize modifiable risk factors identified by the 2020 Lancet Dementia Commission. The most profound risks for VCI also include lower education, cardiometabolic factors, and compromised cognitive reserve. Finally, they discuss pharmacological and non-pharmacological interventions.

EXPERT OPINION

By virtue of the high frequencies of stroke and cardiovascular disease the global prevalence of VCI is expectedly higher than prevalent neurodegenerative disorders causing dementia. Since ~ 90% of the global burden of stroke can be attributed to modifiable risk factors, a formidable opportunity arises to reduce the burden of not only stroke but VCI outcomes including progression from mild to the major in form of vascular dementia. Strict control of vascular risk factors and secondary prevention of cerebrovascular disease via pharmacological interventions will impact on burden of VCI. Non-pharmacological measures by adopting healthy diets and encouraging physical and cognitive activities and urging multidomain approaches are important for prevention of VCI and preservation of vascular brain health.

Incident Dementia After Spontaneous Intracerebral Hemorrhage

 Post-stroke cognitive impairment and dementia (PSCID) is a complication that affects long-term functional outcomes after stroke. Studies on dementia after long-term follow-up in stroke have focused predominantly on ischemic stroke, which may be different from the development of dementia after spontaneous intracerebral hemorrhage (ICH). In this review, we summarize the existing data and hypotheses on the development of dementia after spontaneous ICH, review the management of post-ICH dementia, and suggest areas for future research. Dementia after spontaneous ICH has a cumulative incidence of up to 32.0-37.4% at 5 years post-ICH. Although the pathophysiology of post-ICH dementia has not been fully understood, two main theoretical frameworks can be considered: 1) the triggering role of ICH (both primary and secondary brain injury) in precipitating cognitive decline and dementia; and 2) the contributory role of pre-existing brain pathology (including small vessel disease and neurodegenerative pathology), reduced cognitive reserve, and genetic factors predisposing to cognitive dysfunction. These pathophysiological pathways may have synergistic effects that converge on dysfunction of the neurovascular unit and disruptions in functional connectivity leading to dementia post-ICH. Management of post-ICH dementia may include screening and monitoring, cognitive therapy, and pharmacotherapy. Non-invasive brain stimulation is an emerging therapeutic modality under investigation for safety and efficacy. Our review highlights that there remains a paucity of data and standardized reporting on incident dementia after spontaneous ICH. Further research is imperative for determining the incidence, risk factors, and pathophysiology of post-ICH dementia, in order to identify new therapies for the treatment of this debilitating condition.

Stroke and Vascular Cognitive Impairment: The Role of Intestinal Microbiota Metabolite TMAO

The gut microbiome interacts with the brain bidirectionally through the microbiome-gutbrain axis, which plays a key role in regulating various nervous system pathophysiological processes. Trimethylamine N-oxide (TMAO) is produced by choline metabolism through intestinal microorganisms, which can cross the blood-brain barrier to act on the central nervous system. Previous studies have shown that elevated plasma TMAO concentrations increase the risk of major adverse cardiovascular events, but there are few studies on TMAO in cerebrovascular disease and vascular cognitive impairment. This review summarized a decade of research on the impact of TMAO on stroke and related cognitive impairment, with particular attention to the effects on vascular cognitive disorders. We demonstrated that TMAO has a marked impact on the occurrence, development, and prognosis of stroke by regulating cholesterol metabolism, foam cell formation, platelet hyperresponsiveness and thrombosis, and promoting inflammation and oxidative stress. TMAO can also influence the cognitive impairment caused by Alzheimer's disease and Parkinson's disease via inducing abnormal aggregation of key proteins, affecting inflammation and thrombosis. However, although clinical studies have confirmed the association between the microbiome-gut-brain axis and vascular cognitive impairment (cerebral small vessel disease and post-stroke cognitive impairment), the molecular mechanism of TMAO has not been clarified, and TMAO precursors seem to play the opposite role in the process of poststroke cognitive impairment. In addition, several studies have also reported the possible neuroprotective effects of TMAO. Existing therapies for these diseases targeted to regulate intestinal flora and its metabolites have shown good efficacy. TMAO is probably a new target for early prediction and treatment of stroke and vascular cognitive impairment.

Predictors of Cognitive Functions After Stroke Assessed Using the Wechsler Adult Intelligence Scale: A Retrospective Study

Background

The mechanism(s) of cognitive impairment remains complex, making it difficult to confirm the factors influencing poststroke cognitive impairment (PSCI).

Objective

This study quantitatively investigated the degree of influence and interactions of clinical indicators of PSCI.

Methods

Information from 270 patients with PSCI and their Wechsler Adult Intelligence Scale (WAIS-RC) scores, totaling 18 indicators, were retrospectively collected. Correlations between the indicators and WAIS scores were calculated. Multiple linear regression model(MLR), genetic algorithm modified Back-Propagation neural network(GA-BP), logistic regression model (LR), XGBoost model (XGB), and structural equation model were used to analyze the degree of influence of factors on the WAIS and their mediating effects.

Results

Seven indicators were significantly correlated with the WAIS scores: education, lesion side, aphasia, frontal lobe, temporal lobe, diffuse lesions, and disease course. The MLR showed significant effect of education, lesion side, aphasia, diffuse lesions, and frontal lobe on the WAIS. The GA-BP included five factors: education, aphasia, frontal lobe, temporal lobe, and diffuse lesions. LR predicted that the lesion side contributed more to mild cognitive impairment, while education, lesion side, aphasia, and course of the disease contributed more to severe cognitive impairment. XGB showed that education, side of the lesion, aphasia, and diffuse lesions contributed the most to PSCI. Aphasia plays a significant mediating role in patients with severe PSCI.

Conclusions

Education, lesion side, aphasia, frontal lobe, and diffuse lesions significantly affected PSCI. Aphasia is a mediating variable between clinical information and the WAIS in patients with severe PSCI.

Mobile health applications for improving physical function, physical activity, and quality of life in stroke survivors: a systematic review

PURPOSE

To evaluate the effectiveness of mobile health applications (mHealth apps) containing a physical training component on physical function and physical activity in stroke rehabilitation.

MATERIALS AND METHODS

A systematic literature search was conducted in three databases for studies published from inception to 12 July 2022. Clinical trials including mHealth apps with a physical training component were included using outcomes of physical function and physical activity. Quality of life was extracted as a secondary outcome.

RESULTS

Five RCTs, two non-RCTs, and four uncontrolled clinical trials were included with a total of 264 stroke survivors. Eleven apps were identified with a physical training component using features of gamification (six apps), exercise prescription (three apps), and physical activity (two apps). Six out of seven studies reported statistically significant improvements in physical function in favor of the experimental group, with the most robust findings for upper extremity function. For physical activity, statistically significant improvements were seen in the experimental groups. Only one study showed significant improvement in quality of life. Overall study quality was fair.

CONCLUSIONS

mHealth apps containing a physical training component are promising for physical function and physical activity in stroke rehabilitation. Further research is warranted to confirm these conclusions.Implications for rehabilitationDesign content of mobile apps with a physical training component were focused on gamification, exercise prescription, and physical activityUsing mobile app-delivered therapy seem promising for improving upper extremity function in stroke rehabilitationUsing mobile apps also supported an increase of physical activity in people with strokeStudies using mobile apps should report more specifically the dosage of physical training and adherenceUsing mobile apps seems promising as an additional tool for clinical work, however, more studies are required to understand their effectiveness in stroke rehabilitation.

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.

Pragmatic solutions to reduce the global burden of stroke: a World Stroke Organization-Lancet Neurology Commission

Stroke is the second leading cause of death worldwide. The burden of disability after a stroke is also large, and is increasing at a faster pace in low-income and middle-income countries than in high-income countries. Alarmingly, the incidence of stroke is increasing in young and middle-aged people (ie, age <55 years) globally. Should these trends continue, Sustainable Development Goal 3.4 (reducing the burden of stroke as part of the general target to reduce the burden of non-communicable diseases by a third by 2030) will not be met.

In this Commission, we forecast the burden of stroke from 2020 to 2050. We project that stroke mortality will increase by 50%—from 6·6 million (95% uncertainty interval [UI] 6·0 million–7·1 million) in 2020, to 9·7 million (8·0 million–11·6 million) in 2050—with disability-adjusted life-years (DALYs) growing over the same period from 144·8 million (133·9 million–156·9 million) in 2020, to 189·3 million (161·8 million–224·9 million) in 2050. These projections prompted us to do a situational analysis across the four pillars of the stroke quadrangle: surveillance, prevention, acute care, and rehabilitation. We have also identified the barriers to, and facilitators for, the achievement of these four pillars. Disability-adjusted life-years (DALYs) The sum of the years of life lost as a result of premature mortality from a disease and the years lived with a disability associated with prevalent cases of the disease in a population. One DALY represents the loss of the equivalent of one year of full health

On the basis of our assessment, we have identified and prioritised several recommendations. For each of the four pillars (surveillance, prevention, acute care, and rehabilitation), we propose pragmatic solutions for the implementation of evidence-based interventions to reduce the global burden of stroke. The estimated direct (ie, treatment and rehabilitation) and indirect (considering productivity loss) costs of stroke globally are in excess of US$891 billion annually. The pragmatic solutions we put forwards for urgent implementation should help to mitigate these losses, reduce the global burden of stroke, and contribute to achievement of Sustainable Development Goal 3.4, the WHO Intersectoral Global Action Plan on epilepsy and other neurological disorders (2022–2031), and the WHO Global Action Plan for prevention and control of non-communicable diseases.

Reduction of the global burden of stroke, particularly in low-income and middle-income countries, by implementing primary and secondary stroke prevention strategies and evidence-based acute care and rehabilitation services is urgently required. Measures to facilitate this goal include: the establishment of a framework to monitor and assess the burden of stroke (and its risk factors) and stroke services at a national level; the implementation of integrated population-level and individual-level prevention strategies for people at any increased risk of cerebrovascular disease, with emphasis on early detection and control of hypertension; planning and delivery of acute stroke care services, including the establishment of stroke units with access to reperfusion therapies for ischaemic stroke and workforce training and capacity building (and monitoring of quality indicators for these services nationally, regionally, and globally); the promotion of interdisciplinary stroke care services, training for caregivers, and capacity building for community health workers and other health-care providers working in stroke rehabilitation; and the creation of a stroke advocacy and implementation ecosystem that includes all relevant communities, organisations, and stakeholders.

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Factors Associated With Transition From Community to Permanent Residential Aged Care Following Stroke: A Linked Registry Data Study

BACKGROUND

Understanding factors that influence the transition to permanent residential aged care following a stroke or transient ischemic attack may inform strategies to support people to live at home longer. We aimed to identify the demographic, clinical, and system factors that may influence the transition from living in the community to permanent residential care in the 6 to 18 months following stroke/transient ischemic attack.

METHODS

Linked data cohort analysis of adults from Queensland and Victoria aged ≥65 years and registered in the Australian Stroke Clinical Registry (2012-2016) with a clinical diagnosis of stroke/transient ischemic attack and living in the community in the first 6 months post-hospital discharge. Participant data were linked with primary care, pharmaceutical, aged care, death, and hospital data. Multivariable survival analysis was performed to determine demographic, clinical, and system factors associated with the transition to permanent residential care in the 6 to 18 months following stroke, with death modeled as a competing risk.

RESULTS

Of 11 176 included registrants (median age, 77.2 years; 44% female), 520 (5%) transitioned to permanent residential care between 6 and 18 months. Factors most associated with transition included the history of urinary tract infections (subhazard ratio [SHR], 1.41 [95% CI, 1.16-1.71]), dementia (SHR, 1.66 [95% CI, 1.14-2.42]), increasing age (65-74 versus 85+ years; SHR, 1.75 [95% CI, 1.31-2.34]), living in regional Australia (SHR, 31 [95% CI, 1.08-1.60]), and aged care service approvals: respite (SHR, 4.54 [95% CI, 3.51-5.85]) and high-level home support (SHR, 1.80 [95% CI, 1.30-2.48]). Protective factors included being dispensed antihypertensive medications (SHR, 0.68 [95% CI, 0.53-0.87]), seeing a cardiologist (SHR, 0.72 [95% CI, 0.57-0.91]) following stroke, and less severe stroke (SHR, 0.71 [95% CI, 0.58-0.88]).

CONCLUSIONS

Our findings provide an improved understanding of factors that influence the transition from community to permanent residential care following stroke and can inform future strategies designed to delay this transition.

Preliminary MRS study of critical values of relevant brain metabolites in elderly Chinese patients with post-stroke cognitive impairment

Objective

Proton magnetic resonance spectroscopy (1H-MRS) was applied in this study to detect metabolite changes in the brain of post-stroke cognitive impairment (PSCI) and normal volunteers. The levels of N-acetylaspartate (NAA) and creatinine (Cr) and in the frontal lobe, hippocampus and cingulate gyrus were measured to distinguish patients with post-stroke cognitive impairment (PSCI) and normal control group (NC). The relationship between them and cognitive function was explored and a critical value of the metabolite ratio was predicted. This study may serve as a reference for the diagnosis of cognitive dysfunction after stroke.

Methods

A total of 46 patients with PSCI (PSCI group, all patients are unilateral cerebral infarction or intracerebral haemorrhage) were screened by the Mini-Mental Status Examination (MMSE), and 35 healthy volunteers were selected as normal control group (NC group). The general information of gender, age, and education level was matched between the two groups. Two groups of subjects were examined using MRS and evaluated for cognitive function using the MMSE test and the Montreal Cognitive Assessment Scale (MoCA). The correlation between MRS and neurobehavioral scale (MMSE test and MoCA scale) was analysed, and the possible demarcation points of the brain metabolism of PSCI were evaluated.

Result

The MMSE and MoCA scores of patients with PSCI were lower significantly when compared with those of the NC group (P < 0.05). The NAA/Cr values of the bilateral hippocampus, bilateral frontal lobe and bilateral anterior and posterior cingulate gyrus in the PSCI group were lower than those in the NC group (P < 0.05). The NAA/Cr cut-off value for the right frontal lobe was 1.533, and the NAA/Cr sensitivity, specificity and Youden index for the right frontal lobe were 0.943, 0.935, and 0.878.

Conclusion

NAA/Cr values in the MRS bilateral frontal, bilateral hippocampus and bilateral anterior and posterior cingulate gyrus were reduced in the cognitively impaired post-stroke patients compared to the normal control group. MRS was also found to be correlated with the score of neurobehavioral scale (MMSE test and MoCA scale) and the combination of the two could evaluate cognitive dysfunction more comprehensively and objectively. NAA/Cr value of the right frontal lobe < 1.533 indicated that PSCI may occur. In accordance with this cut-off point, PSCI could be detected as early as possible and timely intervention could be carried out.

P25/CDK5-mediated Tau Hyperphosphorylation in Both Ipsilateral and Contralateral Cerebra Contributes to Cognitive Deficits in Post-stroke Mice

OBJECTIVE

Post-stroke cognitive impairment (PSCI) develops in approximately one-third of stroke survivors and is associated with ingravescence. Nonetheless, the biochemical mechanisms underlying PSCI remain unclear. The study aimed to establish an ischemic mouse model by means of transient unilateral middle cerebral artery occlusions (MCAOs) and to explore the biochemical mechanisms of p25/cyclin-dependent kinase 5 (CDK5)-mediated tau hyperphosphorylation on the PSCI behavior.

METHODS

Cognitive behavior was investigated, followed by the detection of tau hyperphosphorylation, mobilization, activation of kinases and/or inhibition of phosphatases in the lateral and contralateral cerebrum of mice following ischemia in MACO mice. Finally, we treated HEK293/tau cells with oxygen-glucose deprivation (OGD) and a CDK5 inhibitor (Roscovitine) or a GSK3β inhibitor (LiCl) to the roles of CDK5 and GSK3β in mediating ischemia-reperfusion-induced tau phosphorylation.

RESULTS

Ischemia induced cognitive impairments within 2 months, as well as causing tau hyperphosphorylation and its localization to neuronal somata in both ipsilateral and contralateral cerebra. Furthermore, p25 that promotes CDK5 hyperactivation had significantly higher expression in the mice with MCAO than in the shamoperation (control) group, while the expression levels of protein phosphatase 2 (PP2A) and the phosphorylation level at Tyr307 were comparable between the two groups. In addition, the CDK5 inhibitor rescued tau from hyperphosphorylation induced by OGD.

CONCLUSION

These findings demonstrate that upregulation of CDK5 mediates tau hyperphosphorylation and localization in both ipsilateral and contralateral cerebra, contributing to the pathogenesis of PSCI.

Post-Stroke Neuropsychiatric Complications: Types, Pathogenesis, and Therapeutic Intervention

Almost all stroke survivors suffer physical disabilities and neuropsychiatric disturbances, which can be briefly divided into post-stroke neurological diseases and post-stroke psychiatric disorders. The former type mainly includes post-stroke pain, post-stroke epilepsy, and post-stroke dementia while the latter one includes post-stroke depression, post-stroke anxiety, post-stroke apathy and post-stroke fatigue. Multiple risk factors are related to these post-stroke neuropsychiatric complications, such as age, gender, lifestyle, stroke type, medication, lesion location, and comorbidities. Recent studies have revealed several critical mechanisms underlying these complications, namely inflammatory response, dysregulation of the hypothalamic pituitary adrenal axis, cholinergic dysfunction, reduced level of 5-hydroxytryptamine, glutamate-mediated excitotoxicity and mitochondrial dysfunction. Moreover, clinical efforts have successfully given birth to many practical pharmaceutic strategies, such as anti-inflammatory medications, acetylcholinesterase inhibitors, and selective serotonin reuptake inhibitors, as well as diverse rehabilitative modalities to help patients physically and mentally. However, the efficacy of these interventions is still under debate. Further investigations into these post-stroke neuropsychiatric complications, from both basic and clinical perspectives, are urgent for the development of effective treatment strategies.

Transcranial Direct Current Stimulation for Global Cognitive Functioning and Ability in Daily Life Activities in Poststroke Cognitive Impairment: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study is to determine the efficacy of transcranial direct current stimulation on global cognition and ability in daily life activities of patients with poststroke cognitive impairment.

DESIGN

Nine electronic databases were searched from their respective inceptions through January 2022. We included the randomized controlled trials that used transcranial direct current stimulation for poststroke cognitive impairment and included at least one global cognitive function or ability in daily life activities outcome indicators. Two reviewers appraised the risks of bias through the Cochrane Collaboration's tool and performed the meta-analysis. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines.

RESULTS

Twenty-two studies (1198 participants) were included. Most studies had no significant bias in the quality of the methodology. Meta-analyses found that compared with the control group, transcranial direct current stimulation increased Montreal cognitive assessment, Mini-mental state examination, Loewenstein occupational therapy cognitive assessment, total effective rate of cognition, modified Barthel Index, and decreased P300 latency (all P < 0.05). These results showed transcranial direct current stimulation can improve cognitive function and ability in daily life activities in poststroke cognitive impairment.

CONCLUSIONS

The transcranial direct current stimulation may have a significant rehabilitation effect on global cognitive functioning and ability in daily life activities of patients with poststroke cognitive impairment.

Predicting post-stroke cognitive impairment using machine learning: A prospective cohort study

BACKGROUND

Post-stroke cognitive impairment (PSCI) is a serious complication of stroke that warrants prompt detection and management. Consequently, the development of a diagnostic prediction model holds clinical significance.

OBJECTIVE

Machine learning algorithms were employed to identify crucial variables and forecast PSCI occurrence within 3-6 months following acute ischemic stroke (AIS).

METHODS

A prospective study was conducted on a developed cohort (331 patients) utilizing data from the Affiliated Zhongda Hospital of Southeast University between January 2022 and August 2022, as well as an external validation cohort (66 patients) from December 2022 to January 2023. The optimal model was determined by integrating nine machine learning classification models, and personalized risk assessment was facilitated by a Shapley Additive exPlanations (SHAP) interpretation.

RESULTS

Age, education, baseline National Institutes of Health Scale (NIHSS), Cerebral white matter degeneration (CWMD), Homocysteine (Hcy), and C-reactive protein (CRP) were identified as predictors of PSCI occurrence. Gaussian Naïve Bayes (GNB) model was determined to be the optimal model, surpassing other classifier models in the validation set (area under the curve [AUC]: 0.925, 95 % confidence interval [CI]: 0.861 - 0.988) and achieving the lowest Brier score. The GNB model performed well in the test sets (AUC: 0.919, accuracy: 0.864, sensitivity: 0.818, and specificity: 0.932).

CONCLUSIONS

The present study involved the development of a GNB model and its elucidation through employment of the SHAP method. These findings provide compelling evidence for preventing PSCI, which could serve as a guide for high-risk patients to undertake appropriate preventive measures.

Possible involvement of inflammasomes on the post-stroke cognitive impairment in a mouse model of embolic cerebral infarct

Post-stroke cognitive impairment (PSCI) of the complications after stroke has been shown to be involved in brain proinflammatory cytokines such as interleukin (IL)-1β (IL-lβ) and IL-18. In the present study, we examined using acetic acid-induced embolic cerebral infarct (ECI) mice whether post-stroke inflammasome activation is involved in the development of PSCI. In behavioral tests, long-term learning and memory assessed using the passive avoidance test were impaired after ECI. On the other hand, the impairment of short-term learning and memory assessed using the Y-maze test was not observed. Furthermore, the phosphorylated α-amino-3hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit glutamate receptor 1 (GluR1) at Ser 831 and Ser 845 protein was found to be significantly decreased in the dorsal hippocampus of ECI mice. In addition, the expression levels of ionized calcium-binding adapter protein 1 (Iba1), glial fibrillary acidic protein (GFAP), apoptosis-associated speck-like protein containing a caspase recruitment domain / target of methylation-induced silencing 1 (ASC/TMS1), Caspase-1, IL-1β, IL-18 and tumor necrosis factor-α (TNF-α) were significantly increased in the dorsal hippocampus of ECI mice. These results indicate that development of PSCI after embolic cerebral infarction is due to a decrease in AMPA receptor subunit GluR1 at Ser831 and Ser845 through the inflammasome activation pathway in the dorsal hippocampus.

Effects of Ischemic Stroke on Interstitial Fluid Clearance in Mouse Brain: a Bead Study

The clearance of brain interstitial fluid (ISF) is important in maintaining brain homeostasis. ISF clearance impairment leads to toxic material accumulation in the brain, and ischemic stroke could impair ISF clearance. The present study investigates ISF clearance under normal and ischemic conditions. The carboxylate-modified FluoSpheres beads (0.04 μm in diameter) were injected into the striatum. Sham or transient middle cerebral artery occlusion surgeries were performed on the mice. The brain sections were immunostained with cell markers, and bead distribution at various time points was examined with a confocal microscope. Primary mouse neuronal cultures were incubated with the beads to explore in vitro endocytosis.  Two physiological routes for ISF clearance were identified. The main one was to the lateral ventricle (LV) through the cleft between the striatum and the corpus callosum (CC)/external capsule (EC), where some beads were captured by the ependymal macrophages and choroid plexus. An alternative and minor route was to the subarachnoid space through the CC/EC and the cortex, where some of the beads were endocytosed by neurons. After ischemic stroke, a significant decrease in the main route and an increase in the minor route were observed. Additionally, microglia/macrophages engulfed the beads in the infarction. In conclusion, we report that the physiological clearance of ISF and beads mainly passes through the cleft between the CC/EC and striatum into the LV, or alternatively through the cortex into the subarachnoid space. Stroke delays the main route but enhances the minor route, and microglia/macrophages engulf the beads in the infarction. Ischemic stroke impairs the clearance of brain interstitial fluid/beads. Under physiological conditions, the main route ( ① ) of interstitial fluid clearance is to the lateral ventricle, and the minor one ( ② ) is to the subarachnoid space. Ischemic stroke weakens the main route ( ① ), enhances the minor one ( ② ), and leads to microglial/macrophage phagocytosis within the infarction ( ③ ).

Association of Neuroimaging Markers on Clinical CT Scans With Domain-Specific Cognitive Impairment in the Early and Later Poststroke Stages

BACKGROUND AND OBJECTIVES

Poststroke cognitive impairment (PSCI) is associated with neuroimaging markers, including cortical atrophy and white matter lesions (WMLs), on clinically acquired CT neuroimaging. The objective was to investigate the association between cortical atrophy/WMLs and PSCI in specific cognitive domains in the acute/subacute and chronic stages after stroke, to provide clarity on the relationship between these neuroimaging markers and the temporal evolution of PSCI.

METHODS

We visually assessed cortical atrophy using the Global Cortical Atrophy (GCA) scale and WMLs using the Fazekas scale. Oxford Cognitive Screen or Birmingham Cognitive Screen assessed PSCI at 2 time points (acute/subacute and chronic) in 6 domains (language, memory, number processing, executive function, attention, and praxis). We binarized domain-specific performance as impaired/unimpaired using normative cutoffs. Multivariable linear and logistic regression analyses evaluated associations between GCA/Fazekas scores with acute/subacute and chronic global and domain-specific PSCI, and ANCOVAs examined whether these scores were significantly different in patients with recovered vs persistent PSCI. Age, sex, education, NIHSS, lesion volume, and recurrent stroke were covariates in these analyses.

RESULTS

Among 411 stroke patients (Mdn/IQR age = 76.16/66.84-83.47; 193 female; 346 ischemic stroke; 107 recurrent stroke), GCA and Fazekas scores were not associated with global cognitive impairment in the acute/subacute stage after stroke, but GCA score was associated with chronic global PSCI (B = 0.01, p < 0.001, 95% CI 0.00-0.01). In domain-specific analyses, GCA score was associated with chronic impairment in the memory (B = 0.06, p < 0.001, 95% CI 0.03-0.10) and attention (B = 0.05, p = 0.003, 95% CI 0.02-0.09) domains, and in patients with persistent PSCI, these domains showed significantly higher GCA scores than patients who had recovered (memory: F(1, 157) = 6.63, p = 0.01, η 2 G = 0.04; attention: F(1, 268) = 10.66, p = 0.001, η 2 G = 0.04).

DISCUSSION

This study highlights the potential effect of cortical atrophy on the cognitive recovery process after stroke and demonstrates the prognostic utility of CT neuroimaging for poststroke cognitive outcomes. Clinical neuroimaging could help identify patients at long-term risk of PSCI during acute hospitalization.

Post-stroke dysphagia and ambient air pollution are associated with dementia

Introduction

This cohort study aimed to explore the potential association between ambient air pollution and dementia incidence in adults who have experienced a stroke. Additionally, the study aimed to determine dysphagia as a predictive factor for the subsequent development of dementia in patients with stroke.

Materials and methods

This retrospective nested case-control study used data from the Kaohsiung Medical University Hospital Database in Taiwan. Data collected include average ambient air pollution concentrations within 3 months and 1 year after the index dysphagia date. The primary outcome includes incident dementia in patients with or without dysphagia. Logistic regression analysis was performed to examine the association between significant air pollution exposure and the risk of dementia while controlling for baseline demographic characteristics (age and sex), and comorbidities.

Results

The univariable regression models revealed a higher likelihood of dementia diagnosis in patients with dysphagia (odds ratio = 1.493, 95% confidence interval = 1.000-2.228). The raw odds ratios indicated a potential link between air pollution exposure and elevated dementia risks in the overall study population and patients with stroke without dysphagia, except for O3. Particulate matter (PM)2.5 and nitrogen oxides (NOx) exhibited significant effects on the risk of dementia in the stepwise logistic regression models.

Conclusion

The presence of dysphagia following a stroke may pose a risk of developing dementia. Additionally, PM2.5 and NOx exposure appears to elevate the risk of dementia in patients with stroke.

Which cutoff value of the Montreal Cognitive Assessment should be used for post-stroke cognitive impairment? A systematic review and meta-analysis on diagnostic test accuracy

BACKGROUND

Post-stroke cognitive impairment (PSCI) is one of the serious complications of stroke. The Montreal Cognitive Assessment (MoCA), as a brief cognitive impairment screening tool, is widely used in stroke survivors. However, some studies have suggested that the use of the universal cutoff value of 26 may be inappropriate for detecting cognitive impairments in stroke settings.

AIM

We conducted this study to identify the optimal cutoff value of the MoCA in screening for PSCI.

METHODS

PubMed, CINAHL, Embase, the Cochrane Library, and Web of Science were searched for eligible studies until March 23, 2023. All studies were screened by two independent researchers. The quality of each article was evaluated by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate mixed-effects model was used to pool sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the summary receiver operating characteristic curve.

RESULTS

Twenty-four studies with a total of 4231 patients were included in this review. Despite the lack of evidence of publication bias, a high degree of heterogeneity was observed. A meta-analysis revealed that a cutoff value of 21/22 yielded the best diagnostic accuracy. The optimal cutoff varied in different regions, stroke types, and stroke phases as well.

CONCLUSION

The optimal cutoff of MoCA was 21/22 for stroke populations rather than the initially recommended cutoff of 26. A revised (lower) cutoff should be considered for stroke survivors.

Ipsilesional Hippocampal GABA Is Elevated and Correlates With Cognitive Impairment and Maladaptive Neurogenesis After Cortical Stroke in Mice

BACKGROUND

Cognitive dysfunction is a frequent stroke sequela, but its pathogenesis and treatment remain unresolved. Involvement of aberrant hippocampal neurogenesis and maladaptive circuitry remodeling has been proposed, but their mechanisms are unknown. Our aim was to evaluate potential underlying molecular/cellular events implicated.

METHODS

Stroke was induced by permanent occlusion of the middle cerebral artery occlusion in 2-month-old C57BL/6 male mice. Hippocampal metabolites/neurotransmitters were analyzed longitudinally by in vivo magnetic resonance spectroscopy. Cognitive function was evaluated with the contextual fear conditioning test. Microglia, astrocytes, neuroblasts, interneurons, γ-aminobutyric acid (GABA), and c-fos were analyzed by immunofluorescence.

RESULTS

Approximately 50% of mice exhibited progressive post-middle cerebral artery occlusion cognitive impairment. Notably, immature hippocampal neurons in the impaired group displayed more severe aberrant phenotypes than those from the nonimpaired group. Using magnetic resonance spectroscopy, significant bilateral changes in hippocampal metabolites, such as myo-inositol or N-acetylaspartic acid, were found that correlated, respectively, with numbers of glia and immature neuroblasts in the ischemic group. Importantly, some metabolites were specifically altered in the ipsilateral hippocampus suggesting its involvement in aberrant hippocampal neurogenesis and remodeling processes. Specifically, middle cerebral artery occlusion animals with higher hippocampal GABA levels displayed worse cognitive outcome. Implication of GABA in this setting was supported by the amelioration of ischemia-induced memory deficits and aberrant hippocampal neurogenesis after blocking pharmacologically GABAergic neurotransmission, an intervention which was ineffective when neurogenesis was inhibited. These data suggest that GABA exerts its detrimental effect, at least partly, by affecting morphology and integration of newborn neurons into the hippocampal circuits.

CONCLUSIONS

Hippocampal GABAergic neurotransmission could be considered a novel diagnostic and therapeutic target for poststroke cognitive impairment.