Post-stroke dementia - a comprehensive review

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.

Prevalence and factors influencing cognitive impairment among the older adult stroke survivors: a cross-sectional study

Background

Cognitive impairment as a complication in post-stroke patients has high prevalence throughout the world. However, few studies have focused on the older adult stroke survivors and explored their prevalence and factors of post-stroke cognitive impairment (PSCI). The study aims to evaluate the cognitive status of stroke patients in Hunan Province, China and to determine the potential risk factors associated with PSCI in order to identify the older adult population in advance and promote healthy aging.

Methods

This cross-sectional study was carried out from August to December, 2021. A total of 520 stroke survivors from 6 tertiary hospitals were randomly selected. The information was collected using the general questionnaire, the Barthel Index Rating Scale and the Mini-mental State Examination (MMSE). Analysis was based on descriptive statistics, chi-square test and the significant variables were included in multivariate logistic regression. The reporting of this cross-sectional study followed the STROBE checklist.

Results

A total of 195 older adults (40.37%) were screened for cognitive impairment based on the results of the MMSE score. Patients in the PSCI group had a higher proportion of individuals aged 70 or older (35.90% vs. 24.65%, p<0.001). The potential risk factors for post-stroke cognitive impairment in older adults were being aged between 70 and 79 years old (OR = 3.973, 95% CI, 2.346-6.729, p<0.001), being aged 80 years or older (OR = 3.590, 95% CI, 1.373-9.387, p = 0.009), having a low level of education (OR = 9.183, 95% CI, 5.341-15.789, p<0.001), having hypertension (OR = 1.756, 95% CI, 1.121-2.753, p = 0.014), and having a dominant hemisphere lesion (OR = 1.880, 95% CI, 1.193-2.962, p<0.001).

Conclusion

The prevalence of PSCI was high among Chinese older adults, particularly those aged 80 years or older. The factors identified in our study could assist in the early identification of older adults at risk, develop personalized management plans, and promote healthy aging.

Astrocytes in stroke-induced neurodegeneration: a timeline

Stroke is a condition characterized by sudden deprivation of blood flow to a brain region and defined by different post-injury phases, which involve various molecular and cellular cascades. At an early stage during the acute phase, fast initial cell death occurs, followed by inflammation and scarring. This is followed by a sub-acute or recovery phase when endogenous plasticity mechanisms may promote spontaneous recovery, depending on various factors that are yet to be completely understood. At later time points, stroke leads to greater neurodegeneration compared to healthy controls in both clinical and preclinical studies, this is evident during the chronic phase when recovery slows down and neurodegenerative signatures appear. Astrocytes have been studied in the context of ischemic stroke due to their role in glutamate re-uptake, as components of the neurovascular unit, as building blocks of the glial scar, and synaptic plasticity regulators. All these roles render astrocytes interesting, yet understudied players in the context of stroke-induced neurodegeneration. With this review, we provide a summary of previous research, highlight astrocytes as potential therapeutic targets, and formulate questions about the role of astrocytes in the mechanisms during the acute, sub-acute, and chronic post-stroke phases that may lead to neurorestoration or neurodegeneration.

Efficacy and safety of acupuncture combined with rehabilitation training for poststroke cognitive impairment: A systematic review and meta-analysis

BACKGROUND

Accumulated evidence has proven that both acupuncture and rehabilitation therapy are beneficial for stroke sequelae. However, there is no systematic review to identify the efficacy and safety of acupuncture combined with rehabilitation training for poststroke cognitive impairment (PSCI). Therefore, the aim of this study was to assess the efficacy and safety of acupuncture combined with rehabilitation therapy for patients with PSCI.

METHODS

We searched nine databases, including PubMed, Embase, Scopus, Web of Science, EBSCO, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wan Fang, from their inception to September 2022. Randomized controlled trials (RCTs) examining the effect of acupuncture combined with rehabilitation on PSCI were included. The primary outcomes were the Mini-Mental State Examination (MMSE) score, Montreal Cognitive Assessment (MoCA) score, Modified Barthel Index (MBI) score, and Fugl-Meyer Assessment (FMA) score. The quality of the methodology was evaluated by Cochrane's risk of bias tool. Meta-analyses were performed by Revman 5.3 software.

RESULTS

A total of 18 RCTs involving 1654 patients were included. The overall methodological quality of the included studies was low. Pooled results demonstrated that acupuncture combined with rehabilitation could significantly improve the clinical efficacy of PSCI (OR=3.23, 95% CI: 2.13 to 4.89), MMSE score (MD= 2.85, 95% CI: 2.56 to 3.15), MoCA score (MD= 2.18, 95% CI: 1.38 to 2.97), MBI score (MD= 9.23, 95% CI: 5.62 to 12.84), and FMA score (MD=5.72, 95% CI: 3.48 to 7.96).

CONCLUSIONS

Acupuncture combined with rehabilitation may produce better outcomes than rehabilitation alone in the treatment of PSCI. However, the safety of combined interventions is still unclear. Therefore, research with more rigorous study designs and RCTs with larger sample sizes is still needed.

The efficacy and safety of post-stroke cognitive impairment therapies: an umbrella review

Background: Stroke survivors are at significantly increased risk of cognitive impairment, which affects patients' independence of activities of daily living (ADLs), social engagement, and neurological function deficit. Many studies have been done to evaluate the efficacy and safety of post-stroke cognitive impairment (PSCI) treatment, and due to the largely inconsistent clinical data, there is a need to summarize and analyze the published clinical research data in this area. Objective: An umbrella review was performed to evaluate the efficacy and safety of PSCI therapies. Methods: Three independent authors searched for meta-analyses and systematic reviews on PubMed, the Cochrane Library, and the Web of Science to address this issue. We examined ADL and Barthel index (BI), Montreal Cognitive Assessment (MoCA), neurological function deficit as efficacy endpoints, and the incidence of adverse events as safety profiles. Results: In all, 312 studies from 19 eligible publications were included in the umbrella review. The results showed that angiotensin-converting enzyme inhibitors (ACEI) and N-methyl-D-aspartate (NMDA) antagonists, cell therapies, acupuncture, and EGB76 can improve the MoCA and ADL, and the adverse effects were mild for the treatment of PSCI. Moreover, Vinpocetine, Oxiracetam, Citicoline, thrombolytic therapy, Actovegin, DL-3-n-Butylphthalide, and Nimodipine showed adverse events or low article quality in patients with PSCI. However, the research evidence is not exact and further research is needed. Conclusion: Our study demonstrated that ACEI inhibitors (Donepezil) and NMDA antagonists (Memantine), EGB761, and acupuncture are the ADL and BI, MoCA, and neurological function deficit medication/therapy, respectively, for patients with PSCI. Clinical Trial Registration: https://inplasy.com/inplasy-2022-11-0139/; Identifier: INPLASY2022110139.

Neuroinflammation in Acute Ischemic and Hemorrhagic Stroke

PURPOSE OF REVIEW

This review aims to provide an overview of neuroinflammation in ischemic and hemorrhagic stroke, including recent findings on the mechanisms and cellular players involved in the inflammatory response to brain injury.

RECENT FINDINGS

Neuroinflammation is a crucial process following acute ischemic stroke (AIS) and hemorrhagic stroke (HS). In AIS, neuroinflammation is initiated within minutes of the ischemia onset and continues for several days. In HS, neuroinflammation is initiated by blood byproducts in the subarachnoid space and/or brain parenchyma. In both cases, neuroinflammation is characterized by the activation of resident immune cells, such as microglia and astrocytes, and infiltration of peripheral immune cells, leading to the release of pro-inflammatory cytokines, chemokines, and reactive oxygen species. These inflammatory mediators contribute to blood-brain barrier disruption, neuronal damage, and cerebral edema, promoting neuronal apoptosis and impairing neuroplasticity, ultimately exacerbating the neurologic deficit. However, neuroinflammation can also have beneficial effects by clearing cellular debris and promoting tissue repair. The role of neuroinflammation in AIS and ICH is complex and multifaceted, and further research is necessary to develop effective therapies that target this process. Intracerebral hemorrhage (ICH) will be the HS subtype addressed in this review. Neuroinflammation is a significant contributor to brain tissue damage following AIS and HS. Understanding the mechanisms and cellular players involved in neuroinflammation is essential for developing effective therapies to reduce secondary injury and improve stroke outcomes. Recent findings have provided new insights into the pathophysiology of neuroinflammation, highlighting the potential for targeting specific cytokines, chemokines, and glial cells as therapeutic strategies.

Comparing conventional treatment, single-target rTMS, or dual-target rTMS for the treatment of post-stroke cognitive impairment - clinical effects and neuroscientific insights: study protocol for a randomized controlled trial

BACKGROUND

Although increasing evidence suggests that repetitive transcranial magnetic stimulation may help improve cognitive impairment after stroke, its clinical efficacy is still limited. This limitation may be due to the fact that the left dorsolateral prefrontal cortex (DLPFC) is only one of several brain areas involved in post-stroke cognitive impairment (PSCI). The aim of the present study is to reveal whether dual-target stimulation is superior to single-target stimulation and usual care in the treatment of PSCI.

METHODS

A single-center, single-blind, randomized controlled trial will be conducted, and fifty-seven PSCI patients will be recruited and randomly assigned to one of three groups based on the stimulating site. The primary outcome is cognitive function, measured using the Montreal Cognitive Assessment Beijing Version (MoCA-BJ) and Mini-Mental Status Examination (MMSE). The secondary outcomes are the modified Barthel Index (MBI), Trail-Making Test (TMT), and digital span test (DST). Furthermore, changes in brain activity are assessed using transcranial Doppler sonography (TCD) examination and serum levels of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) closely related to nerve and vascular repair after brain injury. All outcomes will be measured at baseline and 4 weeks after treatment.

DISCUSSION

If dual-target rTMS in significant improvements in cognitive function, this method could be considered as a first-line clinical treatment for PSCI. This proposed study has the potential to identify a new, evidence-based intervention that can enhance cognition and independent living in patients with cognitive impairment after stroke.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200066184 . It was registered on 26 November 2022.

Correlating Eye-Tracking Fixation Metrics and Neuropsychological Assessment after Ischemic Stroke

Background and Objectives: Stroke survivors commonly experience cognitive deficits, which significantly impact their quality of life. Integrating modern technologies like eye tracking into cognitive assessments can provide objective and non-intrusive measurements. Materials and Methods: This study aimed to evaluate the cognitive and visual processing capabilities of stroke patients using eye-tracking metrics and psychological evaluations. A cohort of 84 ischemic stroke patients from the N-PEP-12 clinical study was selected for secondary analysis, based on the availability of eye-tracking data collected during a visual search task using an adapted Trail Making Test. Standardized cognitive assessments, including the Montreal Cognitive Assessment (MoCA) and digit span tasks, were also conducted. Results: Correlation analyses revealed some notable relationships between eye-tracking metrics and cognitive measures, such as a positive correlation between Symbol Search performance and the number of fixations. Anxiety levels were found to be positively correlated with first fixation duration, while longer first fixation durations were associated with poorer cognitive performance. However, most correlations were not statistically significant. Nonparametric ANOVA showed no significant differences in fixation metrics across the visits. Conclusions: These findings suggest a complex relationship between cognitive status, gaze fixation behavior, and psychological well-being in stroke patients. Further research with larger sample sizes and analysis of saccadic eye movements is needed to better understand these relationships and inform effective interventions for stroke rehabilitation.

The efficacy of acupuncture combined with other therapies in post stroke cognitive impairment: A network meta-analysis

BACKGROUND

The network meta-analysis was used to evaluate the efficacy of acupuncture combined with other therapies in the treatment of post stroke cognitive impairment (PSCI).

METHODS

The China National Knowledge Infrastructure, Wanfang DATA, Vip Chinese Periodic Service Platform, PUBMED, Cochrane Library, Web of Science, and Embase were searched for randomized controlled trials (RCTs) published before March 18, 2023. Two researchers independently reviewed articles and extracted data, and then qualified papers were included in the study. STATA 14.0 was used for network meta-analysis.

RESULTS

A total of 29 articles including 2241 patients were included in this study. The treatment of the intervention group includes acupuncture combined with traditional Chinese medicine prescriptions (TCMP), acupuncture combined with hyperbaric oxygen (HBO), acupuncture combined with repetitive transcranial magnetic stimulation (rTMS), acupuncture combined with cognitive rehabilitation (CR), acupuncture combined with donepezil. The intervention of the control group includes acupuncture, HBO, rTMS, CR, TCMP, and donepezil. In terms of improving the score of Minimum Mental State Examination (MMSE), acupuncture combined with TCMP was most likely to be the best treatment (P < .05). In terms of improving the score of Montreal Cognitive Assessment (MoCA), acupuncture combined with TCMP was most likely to be the best treatment (P < .05). In terms of improving the total effective rate of clinical treatment, acupuncture combined with rTMS was most likely to be the best treatment (P < .05).

CONCLUSION

Acupuncture combined with TCMP may be the best treatment method among all of the above treatments for PSCI.

Automated hippocampal segmentation algorithms evaluated in stroke patients

Deep learning segmentation algorithms can produce reproducible results in a matter of seconds. However, their application to more complex datasets is uncertain and may fail in the presence of severe structural abnormalities-such as those commonly seen in stroke patients. In this investigation, six recent, deep learning-based hippocampal segmentation algorithms were tested on 641 stroke patients of a multicentric, open-source dataset ATLAS 2.0. The comparisons of the volumes showed that the methods are not interchangeable with concordance correlation coefficients from 0.266 to 0.816. While the segmentation algorithms demonstrated an overall good performance (volumetric similarity [VS] 0.816 to 0.972, DICE score 0.786 to 0.921, and Hausdorff distance [HD] 2.69 to 6.34), no single out-performing algorithm was identified: FastSurfer performed best in VS, QuickNat in DICE and average HD, and Hippodeep in HD. Segmentation performance was significantly lower for ipsilesional segmentation, with a decrease in performance as a function of lesion size due to the pathology-based domain shift. Only QuickNat showed a more robust performance in volumetric similarity. Even though there are many pre-trained segmentation methods, it is important to be aware of the possible decrease in performance for the segmentation results on the lesion side due to the pathology-based domain shift. The segmentation algorithm should be selected based on the research question and the evaluation parameter needed. More research is needed to improve current hippocampal segmentation methods.

Association between intracranial vessel calcifications, structural brain damage, and cognitive impairment after minor strokes: a prospective study

Background

Vascular calcifications are a hallmark of atherosclerosis, and in the coronary arteries are routinely used as a prognostic marker. Calcifications of intracranial vessels (ICC) are frequently observed on non-contrast CT (NCCT) and their effect on post-stroke cognitive impairment (PSCI) remains unclear. Our aim was to explore the association of ICC with prospective long-term cognitive function and advanced MRI-measures in a large prospective cohort of cognitively intact mild stroke survivors.

Methods

Data from the Tel-Aviv brain acute stroke cohort (TABASCO) study [ClinicalTrials.gov #NCT01926691] were analyzed. This prospective cohort study (n = 575) aimed to identify predictors of PSCI, in cognitively intact mild stroke survivors. A quantitative assessment of the intracranial calcium content - The ICC score (ICCS) was calculated semi-automatically on NCCT using a validated calcium quantification application. Participants underwent a 3 T-MRI and prospective comprehensive cognitive clinical and laboratory assessments at enrollment, 6, 12, and 24-months.

Results

Data were available for 531 participants (67.4 years, 59.5% males). The incidence of PSCI at two-years doubled in the high ICCS group (26% vs. 13.7%, p < 0.001). The high ICCS group had significantly greater small-vessel-disease (SVD) tissue changes and reduced microstructural-integrity assessed by Diffusion-Tensor-Imaging (DTI) maps (p < 0.05 for all). In multivariate analysis, a higher ICCS was independently associated with brain atrophy manifested by lower normalized white and gray matter, hippocampal and thalamic volumes (β = -0.178, β = -0.2, β = -0.137, β = -0.157; p < 0.05) and independently predicted PSCI (OR 1.83, 95%CI 1.01-3.35).

Conclusion

Our findings suggest that the ICCS, which is a simple and readily available imaging marker on NCCT, is associated with brain atrophy, microstructural damage, the extent of SVD, and may predict PSCI. This finding has implications for identifying individuals at risk for PSCI and implementing targeted interventions to mitigate this risk.

C-Reactive Protein Levels and Cognitive Decline following Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Cognitive decline (CD) is devastating with a high incidence in patients after stroke. Although some studies have explored underlying associations between C-reactive protein (CRP) levels and cognitive decline after stroke, consistent results have not been obtained. Therefore, this meta-analysis aimed to explore whether or not higher levels of C-reactive proteins were associated with an increased risk of cognitive decline after stroke. To this end, PubMed, Embase, the Cochrane Library, and Web of Science were searched for eligible studies, and pooled effect sizes from eligible studies were calculated using random effect models. Furthermore, subgroups were established and meta-regression analyses were performed to explain the causes of heterogeneity. Eventually, nine studies with 3893 participants were included. Our statistical results suggested that the concentrations of peripheral CRP may be significantly increased for CD patients after stroke, compared to those of non-CD patients. Subgroup analyses showed that CRP was higher in CD than that in non-CD patients when the mini-mental state examination was used. A higher level of CRP in the acute phase of ischemic stroke may suggest an increased risk of CD after stroke. However, these results should be cautiously interpreted because of the limited sample sizes and the diversity of potential confounders in the studies included in this meta-analysis.

White Matter Microstructural Alterations over the Year after Acute Ischemic Stroke in Patients with Baseline Impaired Cognitive Functions

Background

The disruption of white matter (WM) integrity is related to poststroke cognitive impairment (PSCI). The exploration of WM integrity alterations in the chronic stage of acute ischemic stroke (AIS) may help to improve the long-term outcomes of PSCI.

Methods

Sixty patients showing impaired cognitive functions within 3 days after AIS (baseline) and 25 healthy controls underwent diffusion kurtosis imaging scan and cognitive assessment at baseline and 1 year. Based on the tract-based spatial statistics (TBSS), kurtosis fractional anisotropy (KFA) and mean kurtosis (MK) were compared in WM tracts between the groups.

Results

One year after AIS, 25 patients were diagnosed with PSCI and 35 patients with non-cognitive impairment (NCI). Compared with baseline, cognitive performance improved in 54 patients and remained unchanged in 6 patients at 1 year. TBSS analysis showed that there were no significant differences in WM tract integrity between the AIS and control groups at baseline (P > 0.05). Compared with the control group, the KFA and MK in multiple WM tracts in the AIS group decreased significantly at 1 year (P < 0.05). Longitudinal analysis showed that the KFA and MK of multiple WM tracts recorded at 1 year were significantly lower than those recorded at baseline in the AIS, PSCI, and NCI groups (P < 0.05), and PSCI group had a faster degeneration than NCI group (P < 0.05).

Conclusion

The finding suggests that the patients with baseline impaired cognitive functions still have WM microstructural damages at 1 year poststroke, even if their cognitive function has improved or returned to normal. Cautions should be taken against the possible negative impact of these changes on long-term cognition.

Impact of Serum Cystatin C Level on Long-Term Cognitive Impairment After Acute Ischemic Stroke and Transient Ischemic Attack

Objective

Cognitive impairment after stroke/transient ischemic attack (TIA) has a high prevalence. Cystatin C (CysC) has been found as a novel biomarker of neurodegenerative diseases, such as dementia and Alzheimer's disease. We aimed to explore the possible correlations of serum CysC level with cognitive impairment in patients who had mild ischemic stroke and TIA after 1 year.

Methods

We measured serum CysC level in 1025 participants with a minor ischemic stroke/TIA from enrolled from the Impairment of Cognition and Sleep (ICONS) study of the China National Stroke Registry-3 (CNSR-3). They were divided into four groups according to quartiles of baseline CysC levels. Patients' cognitive functions were assessed by Montreal Cognitive Assessment (MoCA)-Beijing at day 14 and at 1 year. Multiple logistic regression models were performed to evaluate the relationship between CysC and post-stroke cognitive impairment (PSCI) at 1-year follow-up.

Results

Cognitive impairment was defined as MoCA-Beijing ≤22. Most patients were in 60s (61.52±10.97 years old) with a median (interquartile range) National Institute of Health Stroke Scale(NIHSS) score of 3.00 (4.00) and greater than primary school level of education, and 743 participants (72.49%) were male. Among the 1025 participants, 331 participants (32.29%) patients suffered PSCI at 1-year follow-up. A U-shaped association was observed between CysC and 1-year PSCI [quartile (Q)1 vs Q3: adjusted odds ratio (aOR) 2.69, 95% CI 1.67-4.34, p < 0.0001; Q2 vs Q3: aOR 1.63, 95% CI 1.03-2.57, p = 0.0354; Q4 vs Q3: aOR 1.83, 95% CI 1.16-2.87, p = 0.009]. Moreover, the U-shaped trends were also found between CysC level and the subscores of attention, recall, abstraction and language in MoCA.

Conclusion

CysC showed a U-shaped correlation with 1-year overall cognitive function. It is probable that measurement of the serum CysC level would aid in the early diagnosis of PSCI.

Scientific Evidence of Acupuncture for Post-Stroke Cognitive Impairment: An Overview of Systematic Reviews and Meta-Analyses

Background

Acupuncture may be effective to treat post-stroke cognitive impairment (PSCI). We aimed to evaluate the reliability of the systematic reviews/meta-analyses (SRs/MAs) evidence regarding acupuncture treatment of PSCI.

Methods

The methodological quality was appraised with Methodological Quality of Systematic Reviews 2 (AMSTAR-2). We evaluated reporting quality with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and evidence quality with Grade of Recommendation, Assessment, Development and Evaluation (GRADE) system.

Results

The inclusion criteria were met by fifteen reviews. All studies assessed by AMSTAR-2 had critically poor methodological quality due to the limitations on the lack of the provision of the list of excluded trails, screening of duplicate study, and protocol registration. For reporting quality, response rate of "yes" was less than 50% in Q5 (protocol and registration topic), Q8 (Search) and Q23 (Additional analysis). Evidence quality of outcome measures was low or worse with GRADE because when the data was qualitatively synthesized, low quality and small sample size trials provided the data.

Conclusion

Acupuncture may be beneficial for PSCI. Because of limitations and inconsistent conclusions, further research is needed to provide higher evidence for acupuncture on PSCI.

Extrasynaptic NMDA receptors in acute and chronic excitotoxicity: implications for preventive treatments of ischemic stroke and late-onset Alzheimer's disease

Stroke and late-onset Alzheimer's disease (AD) are risk factors for each other; the comorbidity of these brain disorders in aging individuals represents a significant challenge in basic research and clinical practice. The similarities and differences between stroke and AD in terms of pathogenesis and pathophysiology, however, have rarely been comparably reviewed. Here, we discuss the research background and recent progresses that are important and informative for the comorbidity of stroke and late-onset AD and related dementia (ADRD). Glutamatergic NMDA receptor (NMDAR) activity and NMDAR-mediated Ca²⁺ influx are essential for neuronal function and cell survival. An ischemic insult, however, can cause rapid increases in glutamate concentration and excessive activation of NMDARs, leading to swift Ca²⁺ overload in neuronal cells and acute excitotoxicity within hours and days. On the other hand, mild upregulation of NMDAR activity, commonly seen in AD animal models and patients, is not immediately cytotoxic. Sustained NMDAR hyperactivity and Ca²⁺ dysregulation lasting from months to years, nevertheless, can be pathogenic for slowly evolving events, i.e. degenerative excitotoxicity, in the development of AD/ADRD. Specifically, Ca²⁺ influx mediated by extrasynaptic NMDARs (eNMDARs) and a downstream pathway mediated by transient receptor potential cation channel subfamily M member (TRPM) are primarily responsible for excitotoxicity. On the other hand, the NMDAR subunit GluN3A plays a "gatekeeper" role in NMDAR activity and a neuroprotective role against both acute and chronic excitotoxicity. Thus, ischemic stroke and AD share an NMDAR- and Ca²⁺-mediated pathogenic mechanism that provides a common receptor target for preventive and possibly disease-modifying therapies. Memantine (MEM) preferentially blocks eNMDARs and was approved by the Federal Drug Administration (FDA) for symptomatic treatment of moderate-to-severe AD with variable efficacy. According to the pathogenic role of eNMDARs, it is conceivable that MEM and other eNMDAR antagonists should be administered much earlier, preferably during the presymptomatic phases of AD/ADRD. This anti-AD treatment could simultaneously serve as a preconditioning strategy against stroke that attacks ≥ 50% of AD patients. Future research on the regulation of NMDARs, enduring control of eNMDARs, Ca²⁺ homeostasis, and downstream events will provide a promising opportunity to understand and treat the comorbidity of AD/ADRD and stroke.

Educational Attainment and Dementia: Mediation by Mid-Life Vascular Risk Factors

INTRODUCTION

Lower education is associated with higher burden of vascular risk factors in mid-life and higher risk of dementia in late life. We aim to understand the causal mechanism through which vascular risk factors potentially mediate the relationship between education and dementia.

METHODS

In a cohort of 13,368 Black and White older adults in the Atherosclerosis Risk in Communities Study, we assessed the relationship between education (grade school, high school without graduation, high school graduate or equivalent, college, graduate/professional school) and dementia among all participants and among those with incident stroke. Cox models were adjusted for age, race-center (a variable stratified by race and field center), sex, apolipoprotein E (APOE) ε4 genotype, and family history of cardiovascular disease. Causal mediation models assessed mediation by mid-life systolic blood pressure, fasting blood glucose, body mass index, and smoking.

RESULTS

More education was associated with 8 to 44% lower risk of dementia compared to grade school-level education in a dose-response pattern, while the relationship between education and post-stroke dementia was not statistically significant. Up to 25% of the association between education and dementia was mediated through mid-life vascular risk factors, with a smaller percentage mediated for lower levels of education.

INTERPRETATION

A substantial proportion of the relationship between education and dementia was mediated through mid-life vascular risk factors. However, risk factor modification is unlikely to fully address the large educational disparities in dementia risk. Prevention efforts must also address disparities in socioeconomic resources leading to divergent early-life education and other structural determinants of mid-life vascular risk factors. ANN NEUROL 2023;94:13-26.

Comparative efficacy of different noninvasive brain stimulation therapies for recovery of global cognitive function, attention, memory, and executive function after stroke: a network meta-analysis of randomized controlled trials

Background

Which noninvasive brain stimulation (NIBS) treatment - transcranial direct current stimulation (tDCS) or transcranial magnetic stimulation (TMS) - is more beneficial for stroke patients' cognitive rehabilitation is still up for debate.

Objectives

Our goal is to provide an overview of the research on the effectiveness and safety of various NIBS protocols.

Design

Systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs).

Methods

This NMA compared any active NIBS versus sham stimulation in adult stroke survivors to enhance cognitive function, with a focus on global cognitive function (GCF), attention, memory, and executive function (EF) using the databases MEDLINE, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov. The NMA statistical approach was built on a frequency framework. The effect size was estimated by the standardized mean difference (SMD) and a 95% confidence interval (CI). We compiled a relative ranking of the competing interventions based on their surface under the cumulative ranking curve (SUCRA).

Results

NMA showed that high-frequency repeated TMS (HF-rTMS) improved GCF compared with sham stimulation (SMD = 1.95; 95% CI: 0.47-3.43), while dual-tDCS improved memory performance versus sham stimulation significantly (SMD = 6.38; 95% CI: 3.51-9.25). However, various NIBS stimulation protocols revealed no significant impact on enhancing attention, executive function, or activities of daily living. There was no significant difference between the active stimulation protocols for TMS and tDCS and sham stimulation in terms of safety. Subgroup analysis demonstrated an effect favoring activation site of the left dorsolateral prefrontal cortex (DLPFC) (SUCRA = 89.1) for enhancing GCF and bilateral DLPFC (SUCRA = 99.9) stimulation for enhancing memory performance.

Conclusion

The HF-rTMS over the left DLPFC appears to be the most promising NIBS therapeutic option for improving global cognitive performance after stroke, according to a comparison of numerous NIBS protocols. Furthermore, for patients with post-stroke memory impairment, dual-tDCS over bilateral DLPFC may be more advantageous than other NIBS protocols. Both tDCS and TMS are reasonably safe.

Registration

PROSPERO ID: CRD42022304865.

Can acupuncture reverse oxidative stress and neuroinflammatory damage in animal models of vascular dementia?: A preclinical systematic review and meta-analysis

BACKGROUND

Vascular dementia is a cognitive dysfunction syndrome caused by cerebral vascular factors such as ischemic stroke and hemorrhagic stroke. The effect of acupuncture on vascular dementia models is ambiguous, and there is controversy about whether acupuncture has a placebo effect. Oxidative stress and inflammation are the most essential mechanisms in preclinical studies of vascular dementia. However, there is no meta-analysis on the mechanism of vascular dementia in animal models. It is necessary to explore the efficacy of acupuncture through Meta-analysis of preclinical studies.

METHODS

Three major databases, PubMed, Embase and Web of Science (including medline), were searched in English until December 2022.The quality of the including literature was assessed using SYRCLE's risk of bias tool. Review Manager 5.3 was used to statistically summarize the included studies and the statistical effect values were expressed by SMD. The outcomes included: behavioral tests (escape latency, number of crossings), pathological sections (Nissl and TUNEL staining), oxidative stress markers (ROS, MDA, SOD, GSH-PX) and neuroinflammatory factors (TNF-α, IL-1β, IL-6).

RESULTS

A total of 31 articles were included in this meta-analysis. The results showed that the escape latency, the contents of ROS, MDA, IL-1β, and IL-6 were decreased, and the contents of SOD and Nissl-positive neurons were increased in the acupuncture group as compared with the non-group (P < .05). Compared with the impaired group, the acupuncture group also had the above advantages (P < .05). In addition, the acupuncture group also increased the number of crossings and GSH-PX content, and decreased the expression of TUNEL-positive neurons and TNF-α (P < .05).

CONCLUSIONS

From behavioral tests to slices and pathological markers in animal models of vascular dementia, it can be proved that acupuncture is effective in targeting oxidative stress and neuroinflammatory damage, and acupuncture is not a placebo effect. Nevertheless, attention needs to be paid to the gap between animal experiments and clinical applications.

Research trends and hotspots of post-stroke cognitive impairment: a bibliometric analysis

Background: Post-stroke cognitive impairment (PSCI) is a major complication of stroke that affects more than one-third of stroke survivors, threatening their quality of life and increasing the risk of disability and death. Although various studies have described the etiology, epidemiology, and risk factors of PSCI, there are a limited number of comprehensive and accurate reports on research trends and hotspots in this field. Therefore, this review aimed to evaluate research trends, hotspots, and frontiers in PSCI using bibliometric analysis. Methods: We screened the literature spanning 20 years in the Web of Science Core Collection: Science Citation Index Expanded (SCI-Expanded) database from 1 January 2003 to 31 December 2022. We included all eligible literature reports based on our comprehensive search strategy, inclusion criteria, and exclusion criteria. The analysis of annual publications, countries/regions, institutions, journals, co-cited references, and keywords was conducted using CiteSpace and VOSviewer, and the hotspots and major findings of PSCI were summarized. Results: A total of 1,024 publications were included in this review. We found that the number of publications on PSCI increased annually. These publications were published in 75 countries or regions by over 400 institutions. Although Chinese institutions had the highest number of publications, their international influence was limited. The United States showed a strong influence in the field. The journal "Stroke" published the most publications (57) with a high impact factor and was considered the most co-cited journal. The most frequently cited references focused on the prevalence, incidence, neuropsychological assessment scales, criteria, and guidelines of PSCI. The strongest citation burst keywords for PSCI were "neurotrophic factor" and "synaptic plasticity", which were regarded as research focuses and research hotspots, respectively. Conclusion: This review provided a comprehensive summary of the literature of PSCI, identified the authoritative and frequently cited literature and journals, clarified the trends in PSCI research, and highlighted the hotspots in this field. Currently, studies on the mechanisms and treatment of PSCI are limited, and we hope that this review has effectively highlighted the research trajectory of PSCI and will lay the foundation for more innovative research in the future.

Therapeutic effects of repetitive transcranial magnetic stimulation on cognitive impairment in stroke patients: a systematic review and meta-analysis

Background

In recent years, repetitive transcranial magnetic stimulation (rTMS) has emerged as a noninvasive and painless treatment for post-stroke cognitive impairment (PSCI). However, few studies have analyzed the intervention parameters of cognitive function and the effectiveness and safety of rTMS for treating patients with PSCI. Thus, this meta-analysis aimed to analyze the interventional parameters of rTMS and evaluate the safety and effectiveness of rTMS for treating patients with PSCI.

Methods

According to the PRISMA guidelines, we searched the Web of Science, PubMed, EBSCO, Cochrane Library, PEDro, and Embase to retrieve randomized controlled trials (RCTs) of rTMS for the treatment of patients with PSCI. Studies were screened according to the inclusion and exclusion criteria, and two reviewers independently performed literature screening, data extraction, and quality assessment. RevMan 5.40 software was used for data analysis.

Results

12 RCTs involving 497 patients with PSCI met the inclusion criteria. In our analysis, rTMS had a positive therapeutic effect on cognitive rehabilitation in patients with PSCI (P < 0.05). Both high-frequency rTMS and low-frequency rTMS were effective in improving the cognitive function of patients with PSCI by stimulating the dorsolateral prefrontal cortex (DLPFC), but their efficacy was not statistically different (P > 0.05).

Conclusions

rTMS treatment on the DLPFC can improve cognitive function in patients with PSCI. There is no significant difference in the treatment effect of high-frequency rTMS and low-frequency rTMS in patients with PSCI between high-frequency and low-frequency rTMS.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=323720, identifier CRD 42022323720.

The analysis of brain functional connectivity of post-stroke cognitive impairment patients: an fNIRS study

Background

Post-stroke cognitive impairment (PSCI) is a considerable risk factor for developing dementia and reoccurrence of stroke. Understanding the neural mechanisms of cognitive impairment after stroke can facilitate early identification and intervention.

Objectives

Using functional near-infrared spectroscopy (fNRIS), the present study aimed to examine whether resting-state functional connectivity (FC) of brain networks differs in patients with PSCI, patients with Non-PSCI (NPSCI), and healthy controls (HCs), and whether these features could be used for clinical diagnosis of PSCI.

Methods

The present study recruited 16 HCs and 32 post-stroke patients. Based on the diagnostic criteria of PSCI, post-stroke patients were divided to the PSCI or NPSCI group. All participants underwent a 6-min resting-state fNRIS test to measure the hemodynamic responses from regions of interests (ROIs) that were primarily distributed in the prefrontal, somatosensory, and motor cortices.

Results

The results showed that, when compared to the HC group, the PSCI group exhibited significantly decreased interhemispheric FC and intra-right hemispheric FC. ROI analyses showed significantly decreased FC among the regions of somatosensory cortex, dorsolateral prefrontal cortex, and medial prefrontal cortex for the PSCI group than for the HC group. However, no significant difference was found in the FC between the PSCI and the NPSCI groups.

Conclusion

Our findings provide evidence for compromised interhemispheric and intra-right hemispheric functional connectivity in patients with PSCI, suggesting that fNIRS is a promising approach to investigate the effects of stroke on functional connectivity of brain networks.

Characteristics of cognition impairment in patients after stroke based on the Wechsler Adult Intelligence Scale-Revised in China

We aimed to explore the cognitive characteristics of patients with post-stroke cognition impairment (PSCI) on the basis of the Wechsler Adult Intelligence Scale-Revised in China (WAIS-RC) and the individual contribution of the subtests to WAIS score. We included 227 patients with PSCI who were assessed using the WAIS-RC. We described the characteristics and score distribution of the scale and subtests individually and compared them with those of the normal group to measure the damage degree of these patients. We performed item response theory analysis to explore the best criterion score for all dimensions that allowed ideal discrimination and difficulty for reflecting cognitive level. Finally, we analyzed the contribution of each dimension to the overall cognitive function. Patients with PSCI showed worse cognition levels than healthy individuals in terms of overall intelligence quotient (73.26-100, -1.78 SD), with a difference of 4.54-7.96 points in each dimension (-0.68 to -1.82 SD), and a range of 5-7 points is the appropriate range for reflecting cognitive ability in patients with PSCI. The average cognitive level of patients with PSCI was significantly inferior to normal people (-1.78 SD, 96.25%). Vocabulary contributes most to WAIS score.

Efficacy and association of hyperbaric oxygen therapy combined with butylphthalide and oxiracetam with serum levels of inflammatory markers in vascular cognitive impairment after acute ischemic stroke

Objectives

This study evaluated the efficacy of hyperbaric oxygen therapy (HBOT) combined with butylphthalide (NBP) and oxiracetam (OXR) for vascular cognitive impairment after acute ischemic stroke and investigated the association between such combination therapy and the serum levels of inflammatory markers.

Methods

This was a prospective study which included eighty patients with post-AIS cognitive impairment (PAISCI) treated in Dongguan City People's Hospital from January 2020 to January 2022. They were randomized into study group and control group. The control group was provided with conventional therapy consisting of NBP for intravenous transfusion and oral OXR, while the study group received combination therapy of HBOT, NBP, and OXR. A comparison was drawn between the two groups regarding clinical outcomes, levels of recovery of cognitive and neurological function and intelligence, changes in inflammatory markers, and incidence of adverse drug reactions (ADRs).

Results

The response rate of the study group was significantly higher than that of the control group (p=0.04). The cognitive function scores of the study group were significantly better than those of the control group at the end of treatment (p<0.05). The post-treatment levels of inflammatory markers were significantly reduced in the study group when compared with the control group (p<0.05). At two weeks after treatment, the ADR rate of study group was significantly lower than the control group (p=0.03).

Conclusions

The combination therapy of HBOT, NBP, and OXR demonstrates robust efficacy in patients with PAISCI. It is deemed to be a safe and effective treatment regimen.

Exploratory Transcriptomic Profiling Reveals the Role of Gut Microbiota in Vascular Dementia

Stroke is the second most common cause of cognitive impairment and dementia. Vascular dementia (VaD), a cognitive impairment following a stroke, is common and significantly impacts the quality of life. We recently demonstrated via gut microbe transplant studies that the gut microbe-dependent trimethylamine-N-oxide (TMAO) pathway impacts stroke severity, both infarct size and long-term cognitive outcomes. However, the molecular mechanisms that underly the role of the microbiome in VaD have not been explored in depth. To address this issue, we performed a comprehensive RNA-sequencing analysis to identify differentially expressed (DE) genes in the ischemic cerebral cortex of mouse brains at pre-stroke and post-stroke day 1 and day 3. A total of 4016, 3752 and 7861 DE genes were identified at pre-stroke and post-stroke day 1 and day 3, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated pathways of neurodegeneration in multiple diseases, chemokine signaling, calcium signaling, and IL-17 signaling as the key enriched pathways. Inflammatory response genes interleukin-1 beta (Il-1β), chemokines (C-X-C motif chemokine ligand 10 (Cxcl10), chemokine ligand 2 (Ccl2)), and immune system genes (S100 calcium binding protein 8 (S100a8), lipocalin-2 (Lcn2)) were among the most significantly upregulated genes. Hypocretin neuropeptide precursor (Hcrt), a neuropeptide, and transcription factors such as neuronal PAS domain protein 4 (Npas4), GATA binding protein 3 (Gata3), and paired box 7 (Pax7) were among the most significantly downregulated genes. In conclusion, our results indicate that higher plasma TMAO levels induce differential mRNA expression profiles in the ischemic brain tissue in our pre-clinical stroke model, and the predicted pathways provide the molecular basis for regulating the TMAO-enhanced neuroinflammatory response in the brain.

Vascular dementia subtypes, pathophysiology, genetics, neuroimaging, biomarkers, and treatment updates along with its association with Alzheimer's dementia and diabetes mellitus

Dementia is a chronic progressive cognitive decline illness that results in functional impairment. Vascular dementia (VaD), second only to Alzheimer's disease (AD), is one of the most prevalent forms of dementia in the elderly (aged over 65 years), with a varied presentation and unpredictable disease development caused by cerebrovascular or cardiovascular illness. To get a better understanding of the changes occurring in the brain and to drive therapy efforts, new biomarkers for early and precise diagnosis of AD and VaD are required. In this review, Firstly, we describe the subtypes of vascular dementia, their clinical features, pathogenesis, genetics implemented, and their associated neuroimaging and biomarkers, while describing extensively the recent biomarkers discovered in the literature. Secondly, we describe some of the well-documented and other less-defined risk factors and their association and pathophysiology in relation to vascular dementia. Finally, we follow recent updates in the management of vascular dementia along with its association and differentiation from Alzheimer's disease. The aim of this review is to gather the scattered updates and the most recent changes in blood, CSF, and neuroimaging biomarkers related to the multiple subtypes of vascular dementia along with its association with Alzheimer's dementia and diabetes mellitus.

Role of lipocalin 2 in stroke

Stroke is the second leading cause of death worldwide; however, the treatment choices available to neurologists are limited in clinical practice. Lipocalin 2 (LCN2) is a secreted protein, belonging to the lipocalin superfamily, with multiple biological functions in mediating innate immune response, inflammatory response, iron-homeostasis, cell migration and differentiation, energy metabolism, and other processes in the body. LCN2 is expressed at low levels in the brain under normal physiological conditions, but its expression is significantly up-regulated in multiple acute stimulations and chronic pathologies. An up-regulation of LCN2 has been found in the blood/cerebrospinal fluid of patients with ischemic/hemorrhagic stroke, and could serve as a potential biomarker for the prediction of the severity of acute stroke. LCN2 activates reactive astrocytes and microglia, promotes neutrophil infiltration, amplifies post-stroke inflammation, promotes blood-brain barrier disruption, white matter injury, and neuronal death. Moreover, LCN2 is involved in brain injury induced by thrombin and erythrocyte lysates, as well as microvascular thrombosis after hemorrhage. In this paper, we review the role of LCN2 in the pathological processes of ischemic stroke; intracerebral hemorrhage; subarachnoid hemorrhage; and stroke-related brain diseases, such as vascular dementia and post-stroke depression, and their underlying mechanisms. We hope that this review will help elucidate the value of LCN2 as a therapeutic target in stroke.

Intermittent theta burst stimulation vs. high-frequency repetitive transcranial magnetic stimulation for post-stroke cognitive impairment: Protocol of a pilot randomized controlled double-blind trial

Introduction

Intermittent theta burst stimulation (iTBS), a novel mode of transcranial magnetic stimulation (TMS), has curative effects on patients with post-stroke cognitive impairment (PSCI). However, whether iTBS will be more applicable in clinical use than conventional high-frequency repetitive transcranial magnetic stimulation (rTMS) is unknown. Our study aims to compare the difference in effect between iTBS and rTMS in treating PSCI based on a randomized controlled trial, as well as to determine its safety and tolerability, and to further explore the underlying neural mechanism.

Methods

The study protocol is designed as a single-center, double-blind, randomized controlled trial. Forty patients with PSCI will be randomly assigned to two different TMS groups, one with iTBS and the other with 5 Hz rTMS. Neuropsychological evaluation, activities of daily living, and resting electroencephalography will be conducted before treatment, immediately post-treatment, and 1 month after iTBS/rTMS stimulation. The primary outcome is the change in the Montreal Cognitive Assessment Beijing Version (MoCA-BJ) score from baseline to the end of the intervention (D11). The secondary outcomes comprise changes in resting electroencephalogram (EEG) indexes from baseline to the end of the intervention (D11) as well as the Auditory Verbal Learning Test, the symbol digit modality test, the Digital Span Test findings, and the MoCA-BJ scores from baseline to endpoint (W6).

Discussion

In this study, the effects of iTBS and rTMS will be evaluated using cognitive function scales in patients with PSCI as well as data from resting EEG, which allows for an in-depth exploration of underlying neural oscillations. In the future, these results may contribute to the application of iTBS for cognitive rehabilitation of patients with PSCI.

Supervised, Self-Administered Tablet-Based Cognitive Assessment in Neurodegenerative Disorders and Stroke

INTRODUCTION

As the population ages, the prevalence of cognitive impairment is expanding. Given the recent pandemic, there is a need for remote testing modalities to assess cognitive deficits in individuals with neurological disorders. Self-administered, remote, tablet-based cognitive assessments would be clinically valuable if they can detect and classify cognitive deficits as effectively as traditional in-person neuropsychological testing.

METHODS

We tested whether the Miro application, a tablet-based neurocognitive platform, measured the same cognitive domains as traditional pencil-and-paper neuropsychological tests. Seventy-nine patients were recruited and then randomized to either undergo pencil-and-paper or tablet testing first. Twenty-nine age-matched healthy controls completed the tablet-based assessments. We identified Pearson correlations between Miro tablet-based modules and corresponding neuropsychological tests in patients and compared scores of patients with neurological disorders with those of healthy controls using t tests.

RESULTS

Statistically significant Pearson correlations between the neuropsychological tests and their tablet equivalents were found for all domains with moderate (r > 0.3) or strong (r > 0.7) correlations in 16 of 17 tests (p < 0.05). All tablet-based subtests differentiated healthy controls from neurologically impaired patients by t tests except for the spatial span forward and finger tapping modules. Participants reported enjoyment of the tablet-based testing, denied that it provoked anxiety, and noted no preference between modalities.

CONCLUSIONS

This tablet-based application was found to be widely acceptable to participants. This study supports the validity of these tablet-based assessments in the differentiation of healthy controls from patients with neurocognitive deficits in a variety of cognitive domains and across multiple neurological disease etiologies.

Importance of Retesting for the Final Diagnosis of Post-Stroke Cognitive Impairment

Background and Objectives: Post-stroke cognitive impairment (PSCI) has been defined as all problems in cognitive function that occur following a stroke. Studies published thus far on the prevalence of PSCI and post-stroke dementia (PSD) have shown conflicting estimates. The aim of this study was screening for cognitive impairment (CogI) in patients with an ischaemic stroke and finding the relationship between CogI (and its changes) and cardiovascular risk factors and imaging procedures-CT/MRI. Materials and Methods: We prospectively included patients with an ischaemic stroke admitted in the period from October 2019 to May 2022. In this period, 1328 patients were admitted, 305 of whom met the established inclusion criteria and underwent an examination of cognitive functions using the Montreal Cognitive Assessment (MoCA). Of these, 50 patients appeared for the control examination after 6 months. Results: In the retested group, CogI at discharge was diagnosed in 37 patients (74%). In follow-up testing after 6 months, CogI was present in 30 patients (60%). Only arterial hypertension (OR: 15; 95% CI; Pearson r: 0.001), lower education level (less than 13 years) (OR: 9.7; 95% CI 2.0-48.5; Pearson r: 0.002), and higher age were significantly associated with CogI after stroke. Conclusions: We established the prevalence of CogI and its course after 6 months in a well-defined group of patients after a mild ischaemic stroke (mean NIHSS: 2 and mean mRS: 1 at the discharge). Our results show that the prevalence of CogI after an ischaemic stroke at discharge is relatively high (74%), and it tends to be a spontaneous reduction. Cognitive functions were changed in 35% of patients. The definition of PSCI was completed in only 24% of individuals. Only an examination several months after a stroke can give us more accurate information about the true prevalence of persistent CogI after a stroke.

Multimodality neuroimaging in vascular mild cognitive impairment: A narrative review of current evidence

The vascular mild cognitive impairment (VaMCI) is generally accepted as the premonition stage of vascular dementia (VaD). However, most studies are focused mainly on VaD as a diagnosis in patients, thus neglecting the VaMCI stage. VaMCI stage, though, is easily diagnosed by vascular injuries and represents a high-risk period for the future decline of patients’ cognitive functions. The existing studies in China and abroad have found that magnetic resonance imaging technology can provide imaging markers related to the occurrence and development of VaMCI, which is an important tool for detecting the changes in microstructure and function of VaMCI patients. Nevertheless, most of the existing studies evaluate the information of a single modal image. Due to the different imaging principles, the data provided by a single modal image are limited. In contrast, multi-modal magnetic resonance imaging research can provide multiple comprehensive data such as tissue anatomy and function. Here, a narrative review of published articles on multimodality neuroimaging in VaMCI diagnosis was conducted，and the utilization of certain neuroimaging bio-markers in clinical applications was narrated. These markers include evaluation of vascular dysfunction before tissue damages and quantification of the extent of network connectivity disruption. We further provide recommendations for early detection, progress, prompt treatment response of VaMCI, as well as optimization of the personalized treatment plan.

Post-stroke cognitive impairment and synaptic plasticity: A review about the mechanisms and Chinese herbal drugs strategies

Post-stroke cognitive impairment, is a major complication of stroke, characterized by cognitive dysfunction, which directly affects the quality of life. Post-stroke cognitive impairment highlights the causal relationship between stroke and cognitive impairment. The pathological damage of stroke, including the increased release of excitatory amino acids, oxidative stress, inflammatory responses, apoptosis, changed neurotrophic factor levels and gene expression, influence synaptic plasticity. Synaptic plasticity refers to the activity-dependent changes in the strength of synaptic connections and efficiency of synaptic transmission at pre-existing synapses and can be divided into structural synaptic plasticity and functional synaptic plasticity. Changes in synaptic plasticity have been proven to play important roles in the occurrence and treatment of post-stroke cognitive impairment. Evidence has indicated that Chinese herbal drugs have effect of treating post-stroke cognitive impairment. In this review, we overview the influence of pathological damage of stroke on synaptic plasticity, analyze the changes of synaptic plasticity in post-stroke cognitive impairment, and summarize the commonly used Chinese herbal drugs whose active ingredient or extracts can regulate synaptic plasticity. This review will summarize the relationship between post-stroke cognitive impairment and synaptic plasticity, provide new ideas for future exploration of the mechanism of post-stroke cognitive impairment, compile evidence of applying Chinese herbal drugs to treat post-stroke cognitive impairment and lay a foundation for the development of novel formulas for treating post-stroke cognitive impairment.

The nonverbal BriefScreen: A cognitive screening method for patients with limited language and motor abilities

Dementia and significant cognitive decline are frequent sequelae of stroke, but are difficult to evaluate when aphasia and/or motor impairment are present. The linguistic and motor requirements of commonly employed screening tests render them problematic for use post-stroke. The present study examines the validity of the Nonverbal BriefScreen, a brief screening method with limited verbal and motor requirements, in groups of patients with known cognitive impairment using the MMSE as a gold standard. Participants were 137 healthy middle aged and older community dwellers, 21 patients with MCI/early dementia and 35 patients with different types of dementia. The sensitivity and specificity of the Nonverbal BriefScreen were calculated for various cutoff scores, with the MMSE as comparison. The Nonverbal BriefScreen was effective in discriminating between healthy controls and patients with dementia, as well as between healthy controls and all patients, with areas under the ROC curve similar to that of the MMSE. ROC analyses with a smaller sample of 35 age-matched healthy controls showed adequate discriminant ability to detect cognitive impairment. The Nonverbal BriefScreen was shown to be a valid method for screening for cognitive impairment that could be employed as a screening method for patients with limited language.

A systematic review of auricular therapy for poststroke cognitive impairment and dementia: A protocol for systematic review and meta-analysis

BACKGROUND

Post-stroke cognitive impairment and dementia (PSCID) is the main source of morbidity and mortality after stroke worldwide. It is one consequence of ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage. Cognitive impairment and dementia after the clinical stroke may contribute to the clinical expression of PSCID, which are prevalent clinical symptoms, especially in the elderly. Current problems in the field of PSCID are related to a lack of harmonization of the classification and definition, deficiency of well-defined diagnosis, deficiency of standardized and objective treatment plans, etc. Auricular therapy can effectively improve the symptoms of patients with PSCID. However, there has been no systematic review of auricular therapy for PSCID. This study aimed to evaluate the efficacy and safety of auricular therapy in patients with PSCID.

METHODS

Before December 2022, a systematic literature search was conducted using the following databases: PubMed, Embase, SinoMed (previously called the Chinese Biomedical Database), Web of Science, Chinese National Knowledge Infrastructure, and Wanfang Database. Review Manager software (version 5.3) will be used for statistical analysis; otherwise, descriptive analysis or subgroup analysis will be conducted. The quality of evidence for outcomes will be assessed with the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

This meta-analysis further confirmed the beneficial effects of auricular therapy in patients with PSCID.

CONCLUSION

This study investigated the efficacy and safety of auricular therapy in patients with PSCID, providing clinicians and patients with additional options for this disease.

Post-Stroke Environmental Enrichment Improves Neurogenesis and Cognitive Function and Reduces the Generation of Aberrant Neurons in the Mouse Hippocampus

Ischemic lesions stimulate adult neurogenesis in the dentate gyrus, however, this is not associated with better cognitive function. Furthermore, increased neurogenesis is associated with the formation of aberrant neurons. In a previous study, we showed that a running task after a stroke not only increases neurogenesis but also the number of aberrant neurons without improving general performance. Here, we determined whether stimulation in an enriched environment after a lesion could increase neurogenesis and cognitive function without enhancing the number of aberrant neurons. After an ischemic stroke induced by MCAO, animals were transferred to an enriched environment containing a running wheel, tunnels and nest materials. A GFP-retroviral vector was delivered on day 3 post-stroke and a modified water maze test was performed 6 weeks after the lesion. We found that the enriched environment significantly increased the number of new neurons compared with the unstimulated stroke group but not the number of aberrant cells after a lesion. Increased neurogenesis after environmental enrichment was associated with improved cognitive function. Our study showed that early placement in an enriched environment after a stroke lesion markedly increased neurogenesis and flexible learning but not the formation of aberrant neurons, indicating that rehabilitative training, as a combination of running wheel training and enriched environment housing, improved functional and structural outcomes after a stroke.

Role of Citicoline in Patients With Mild Cognitive Impairment

The term mild cognitive impairment (MCI) defines an intermediate state between normal aging and dementia. Vascular cognitive impairment refers to a decline in cognitive function that is caused by or associated with vascular disease and comprises all the spectrum of cognitive impairments, from MCI of vascular origin to vascular dementia. One of the available treatments for cognitive impairment is cytidine diphosphate-choline (CDP-Choline), or citicoline. The objective of the present manuscript is to provide complete evidence about the efficacy of citicoline for MCI, especially of vascular origin, but also due to other neurodegenerative disorders. Citicoline is a pharmaceutical product constituted by the combination of 2 natural molecules (cytidine and choline) and is marketed as a food supplement. It has been proposed to provide neuroprotective effects through diverse mechanisms of action. Taking into account the available literature, citicoline has shown a consistent improvement in cognitive function in patients with MCI, especially of vascular origin. Moreover, it provides beneficial effects on vascular, Alzheimer, and mixed dementias, stroke sequelae, intracerebral hemorrhages, traumatic brain injuries, and neurodegenerative diseases. Long-term treatment with citicoline has also been demonstrated to be well-tolerated and has not been associated with severe adverse events. Citicoline is a safe, well-tolerated, and promising agent with evidenced neuroprotective properties.

Determining ischemic stroke subtype: an improved algorithm and its use in a comprehensive stroke unit

Objective ‒ to implement a inified algorithm for determining an ischemic cerebral stroke (ICS) etiological subtype and evaluate the results of its use in patients who were admitted to a comprehensive stroke unit (CSU).Materials and methods. The study enrolled 689 patients with ICS (43.4 % women, 56.6 % men; median age 68.1 years (59.7–75.5)) who in 2010 to 2018 were admitted to a hospital unit where the structure and processes correspond to the principles of CSU. The participants’ age, gender, National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale scores were analyzed. All patients underwent an initial workup that included neuroimaging, vascular imaging, a cardiologist’s exam and a set of laboratory tests, and an advanced evaluation, at his physician discretion. All ICS was assigned to one of the four etiological subtypes: cardioembolic, atherosclerotic, lacunar or other. Results. According to the proposed algorithm, 294 (42.7 %) cases were assigned to cardioembolic subtype, 282 (40.9 %) to atherosclerotic subtype, 52 (7.5 %) to lacunar subtype and 61 (8.9 %) to ischemic cerebral stroke unknown etiology. Differences in the shown frequency of the main etiological ICS subtypes compared to the results of epidemiological studies are due to the greater severity of ICS in our sample: baseline median NIHSS total score was 10 (6–17), and median modified Rankin scale score was 4 (3–5), and, on the other hand, to in-depth assessment using modern diagnostic technologies and a longer length of stay that allowed for the tests to be completed.Conclusions. Thorough evaluation and the use of a unified algorithm based on causal etiological classifications allow to successfully determine an ICS subtype in the CSU patients with low proportion of ICS of unknown etiology, which is the key to effective secondary prevention.

Leukoaraiosis as a Predictor of Depression and Cognitive Impairment among Stroke Survivors: A Systematic Review

Stroke survivors are at increased risk of developing depression and cognitive decline. Thus, it is crucial for both clinicians and stroke survivors to be provided with timely and accurate prognostication of post-stroke depression (PSD) and post-stroke dementia (PSDem). Several biomarkers regarding stroke patients' propensity to develop PSD and PSDem have been implemented so far, leukoaraiosis (LA) being among them. The purpose of the present study was to review all available work published within the last decade dealing with pre-existing LA as a predictor of depression (PSD) and cognitive dysfunction (cognitive impairment or PSDem) in stroke patients. A literature search of two databases (MEDLINE and Scopus) was conducted to identify all relevant studies published between 1 January 2012 and 25 June 2022 that dealt with the clinical utility of preexisting LA as a prognostic indicator of PSD and PSDem/cognitive impairment. Only full-text articles published in the English language were included. Thirty-four articles were traced and are included in the present review. LA burden, serving as a surrogate marker of "brain frailty" among stroke patients, appears to be able to offer significant information about the possibility of developing PSD or cognitive dysfunction. Determining the extent of pre-existing white matter abnormalities can properly guide decision making in acute stroke settings, as a greater degree of such lesioning is usually coupled with neuropsychiatric aftermaths, such as PSD and PSDem.