Focal Ischemia Research Articles

Stroke triggers dynamic m6A reprogramming of cerebral circular RNAs

We previously showed that stroke alters circular RNA (circRNA) expression profiles. Many circRNAs undergo epitranscriptomic modifications, particularly methylation of adenosine to form N6-methyladenosine (m6A). This modification significantly influences the circRNA metabolism and functionality. Hence, we currently evaluated if transient focal ischemia in adult C57BL/6J mice alters the m6A methylation of circRNAs. Changes in m6A were profiled in the peri-infarct cortex following immunoprecipitation coupled with microarrays. Correlation and gene ontology analyses were performed to understand the association of m6A changes with circRNA regulation and functional implications after stroke. Many circRNAs showed differential regulation (up or down) after stroke, and this change was highest at 24h of reperfusion. Notably, most circRNAs differentially regulated after stroke also exhibited temporal changes in m6A modification patterns. The majority of circRNAs that showed post-stroke differential m6A modifications were derived from protein-coding genes. Hyper-than hypomethylation of circRNAs was most prevalent after stroke. Gene ontology analysis of the host genes suggested that m6A-modified circRNAs might regulate functions such as synapse-related processes, indicating that m6A epitranscriptomic modification in circRNAs could potentially influence post-stroke synaptic pathophysiology.

Troponin levels in transient ischemic attack and ischemic stroke: does “transient” in your brain mean “better” for your heart?

PurposeTransient ischemic attack (TIA) is defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, with clinical symptoms typically lasting less than one hour, and without evidence of acute infarction. In this type of ischemic event, there are no data about a possible cardiac injury tested with troponin. After a stroke, it is well established the cardiac involvement due to a neuro-inflammatory response (recently defined as Stroke Heart Syndrome). The aim of this study is to compare the troponin elevation after a stroke with the troponin elevation after a TIA. Materials and methodsThis is a retrospective, single center study on 565 patients (73 TIAs, 492 stroke). We collected demographic characteristics, cardiovascular risk factors, cardiac data such as troponin, NT-proBNP, left atrial dilatation, etiology of the ischemic event (TOAST classification). ResultsWe compare IS and TIA for each TOAST subtype. In all groups no substantial differences were found in demographic and past medical history (p > 0.05). However, the maximum troponin level reached were significantly lower in TIAs than IS (p < 0.05), except in lacunar etiology were troponin elevation was low also in IS group. We found a trend in favor to IS in the rise and fall troponin elevation over 30% in all the TOAST subgroups, but only in the cryptogenic etiology the difference was significant. About the others cardiac markers of injury, a significant higher rate of elevated NT-proBNP was found in the IS cohort. ConclusionsTroponin level after TIAs is significantly lower than after IS. Troponin elevation after an ischemic event may be more relevant in patients with higher NT-proBNP levels and older age. More studies are needed to better understand the pathophysiology of this phenomenon after an ischemic event.

Patología vascular mesentérica

Mesenteric vascular disease is wide-ranging and can produce different manifestations depending on various factors, including the presence of symptoms or not; the clinical form of presentation; the vessels involved, duration, and cause; and collateral blood flow. The clinical entities described herein include acute and chronic mesenteric artery ischemia; nonocclusive mesenteric ischemia; acute, subacute, and chronic mesenteric venous thrombosis; focal segmental ischemia of the small intestine; colonic ischemia; arterial aneurysms; and vasculitis.This disease produces a wide spectrum of clinical symptoms that share the same predisposing factors and many etiologies, although with different consequences. Abdominal pain is the most common clinical symptom in these diseases. In acute forms, high clinical suspicion is essential for making a rapid diagnosis and early treatment that prevents more severe lesions. The widespread use of computed tomography has led to greater diagnostic rates with an improved prognosis for these patients.Treatment varies from conservative to surgical, depending on the case. Early anticoagulation is a fundamental treatment in many cases and in recent years, vascular radiology techniques have been developed which produce good results.

Risk Factors and Clinical Significance of Ultra-Long-Term Microischemia After Intracranial Aneurysm Embolization.

This study aimed to explore influencing factors and clinical significance of ultra-long-term microischemia following intracranial aneurysm (IA) embolization and establish a theoretical foundation for reducing both the incidence of ultra-long-term microischemia and cognitive dysfunction in patients post embolization. A retrospective analysis was conducted on data from 147 patients who received endovascular treatment for IAs. Patients were categorized into microischemic and control (non-microischemic) groups on the based on the findings of high-resolution magnetic resonance vessel wall imaging (HR-VWI) examinations performed 3days postoperatively and 6months postoperatively. Risk factors for the occurrence of ultra-long-term microischemia were determined by univariate analysis and multivariate logistic regression analysis. Out of 147 patients included in the study, 51 (34.69%) developed microischemia while the remaining 96 (65.31%) did not experience this condition. Analysis revealed that factors such as sex, age, history of underlying diseases (hypertension, diabetes mellitus), aneurysmal site characteristics, the presence or absence of stenosis in the aneurysm-bearing artery, modified Fisher score at admission, Barthel's index at discharge, immunoinflammatory index at 3days postoperatively and at the 6-month follow-up, the presence or absence of aneurysmal wall enhancement, and the presence or absence of aneurysmal lumen showed no statistically significant differences between the two groups (all P > 0.05). By contrast, variables like in operative time, rupture status of the aneurysm before surgery according to World Federation of Neurologic Surgeons (WFNS) grade, aneurysm size, number of stents used, number of guidewires and catheters used, and Evans index between the two groups were found to have statistically significant disparities between those who developed microischemia and those who did not (P < 0.05). A subsequent multivariate analysis revealed that aneurysm size, Evans index, and the number of stents used were independent risk factors for the occurrence of ultra-long-term microischemia after surgical intervention of aneurysms (P < 0.05). The receiver operating characteristic (ROC) curves of the patients were constructed on the basis of risk factors determined through multivariate logistic regression analysis. Results indicated that aneurysm size (area under ROC curve (AUC) 0.619, sensitivity 94.7%, specificity 17.1%, P = 0.049), Evans index (AUC 0.670, sensitivity 96.4%, specificity 26.8%, P = 0.004), and number of stents (AUC 0.639, sensitivity 44.6%, specificity 90.2%, P < 0.001) effectively predicted the occurrence of microischemia. The incidence of cognitive dysfunction was higher in the microischemic group than in the control group (P < 0.05), and a greater number of microischemic foci was associated with a higher incidence of cognitive dysfunction. The proportion of microschemia foci in the thalamus and basal ganglia in patients with cognitive dysfunction (60.87%) was significantly higher than that in patients without cognitive dysfunction (34.55%) (P < 0.05). Aneurysm size, Evans index > 0.3, and the quantity of stents were independent risk factors for the occurrence of ultra-long-term microischemia after aneurysm embolization and provided good predictive performance. Cognitive dysfunction was closely associated with microischemia, with its severity increasing with an increase in the number of ischemic foci.

Rapid identification and prognosis evaluation by dual-phase computed tomography angiography for stroke patients with a large ischemic region in the anterior circulation treated with endovascular thrombectomy.

To investigate the value of dual-phase head-and-neck computed tomography angiography (CTA) in assessing advantages and risks associated with mechanical thrombectomy for stroke with a large ischemic region in the anterior circulation within 6 h of onset. We retrospectively analyzed the data of patients with acute occlusion of the internal carotid artery or middle cerebral artery-M1 segment. Baseline dual-phase CTA was performed for collateral grading using the 4-point visual collateral score (0, 0% filling; 1, >0% and ≤50% filling; 2, >50 and <100% filling; 3, 100% filling). The rates of modified Rankin score (MRS) ≤ 3 at 90 days, any intracranial hemorrhage (ICH) within 48 h, malignant cerebral edema within 24 h, and all-cause 90-day mortality were analyzed. Among the 69 study patients, 15, 26, 17, and 11 patients had collateral grades of 0, 1, 2, and 3, respectively. At 90 days, the MRS was ≤3 in 0, 8.33, 29.41, and 36.36% of patients with grades 0, 1, 2, and 3, respectively. ICH incidence was 73.33, 57.69, 29.41, and 18.18% for grades 0, 1, 2, and 3, respectively, while the incidence of malignant brain edema was 100, 76.92, 35.29, and 0%, respectively. All-cause 90-day mortality was 53.33% for grade 0 and 30.77% for grade 1; no deaths occurred at grades 2 and 3. Collateral grading based on dual-phase CTA enables simple and rapid preoperative evaluation prior to mechanical thrombectomy for acute anterior-circulation stroke with a large ischemic focus, particularly for patients presenting within the 6-h time window.

Striatal Blood Flow Changes by Middle Cerebral Artery Occlusion and Its Effect on Neurological Deficits in Mice.

We attempted to record the regional cerebral blood flow (CBF) simultaneously at various regions of the cerebral cortex and the striatum during middle cerebral artery (MCA) occlusion and to evaluate neurological deficits and infarct formation. In male C57BL/6J mice, CBF was recorded in three regions including the ipsilateral cerebral cortex and the striatum with laser Doppler flowmeters, and the origin of MCA was occluded with a monofilament suture for 15-90 min. After 48 h, neurological deficits were evaluated, and infarct was examined by triphenyltetrazolium chloride (TTC) staining. CBF decrease in the striatum was approximately two-thirds of the MCA-dominant region of the cortex during MCA occlusion. The characteristic CBF fluctuation because of spontaneously occurred spreading depolarization observed throughout the cortex was not found in the striatum. Ischemic foci with slight lower staining to TTC were found in the ipsilateral striatum in MCA-occluded mice for longer than 30 min (n = 54). Twenty-nine among 64 MCA-occluded mice exhibited neurological deficits even in the absence of apparent infarct with minimum staining to TTC in the cortex, and the severity of neurological deficits was not correlated with the size of the cortical infarct. Neurological deficits might be associated with the ischemic striatum rather than with cortical infarction.

Ketamine-induced prevention of SD-associated late infarct progression in experimental ischemia

Spreading depolarizations (SDs) occur frequently in patients with malignant hemispheric stroke. In animal-based experiments, SDs have been shown to cause secondary neuronal damage and infarct expansion during the initial period of infarct progression. In contrast, the influence of SDs during the delayed period is not well characterized yet. Here, we analyzed the impact of SDs in the delayed phase after cerebral ischemia and the potential protective effect of ketamine. Focal ischemia was induced by distal occlusion of the left middle cerebral artery in C57BL6/J mice. 24 h after occlusion, SDs were measured using electrocorticography and laser-speckle imaging in three different study groups: control group without SD induction, SD induction with potassium chloride, and SD induction with potassium chloride and ketamine administration. Infarct progression was evaluated by sequential MRI scans. 24 h after occlusion, we observed spontaneous SDs with a rate of 0.33 SDs/hour which increased during potassium chloride application (3.37 SDs/hour). The analysis of the neurovascular coupling revealed prolonged hypoemic and hyperemic responses in this group. Stroke volume increased even 24 h after stroke onset in the SD-group. Ketamine treatment caused a lesser pronounced hypoemic response and prevented infarct growth in the delayed phase after experimental ischemia. Induction of SDs with potassium chloride was significantly associated with stroke progression even 24 h after stroke onset. Therefore, SD might be a significant contributor to delayed stroke progression. Ketamine might be a possible drug to prevent SD-induced delayed stroke progression.

The Role of GLP-1 Affects Fate of Astrocytes Following Ischemic Stroke in Mice

Stroke is one of the leading causes of physical and intellectual disability and mortality in adults of most of the developed countries. The most of studies in ischemic stroke focus on neuronal pathological mechanisms and neuronal death trying to rescue neurons via stopping the detrimental pathological processes or enhancing neuronal viability. Although astrocytes are the most abundant cells and in mammal central nervous system (CNS), they were ignored for period of time but are return to spotlight in recent years. Astrocyte play multiple roles in maintain normal function of central nervous system and respond to all kinds of CNS injury and disease. Responses of astrocytes to CNS damage lead to both detrimental and beneficial consequences. Previous studies have reported that astrocyte inflammatory responses to ischemic stroke may devastate the ischemic lesion, but other astrocytic responses lead to anti-excitotoxicity, secreting neurotrophic factors, neurogenesis, synaptogenesis, axonal remodeling, and angiogenesis promoting neuroprotective effects. Glucagon-like peptide-1 (GLP-1) have been intensively studied on beneficial effects of neurons, but not many studies work on effects of GLP-1 to astrocytes. Our early study has found that activation of GLP-1 receptors prevented ischemia-induced brain cell death and observed newly neuronal progenitor cells were from astrocyte-lineage in penumbral area of 3-day post-ischemic mouse brains by immunohistochemistry (IHC). RT-PCR, immunoblotting, and immunofluorescent results also clearly indicated the astrocytes expressed GLP-1 receptors. Furthermore, Western blotting results showed administration of GLP-1 analogue, exendin-4 (EX-4), suppressed expression of pro-inflammatory proteins in oxygen-glucose deprivation (OGD) treated mouse primary astrocytes. Interestingly, we also observed that infarct site obtained sever DNA damage and less GFAP positive astrocytes, on contrary, the penumbral area had more GFAP positive astrocytes and less DNA damage in IHC images of stroke brains. The results implied that A1 and A2 astrocytes play certain roles in ischemic brains and recovery. The goal of this study is to determine the mechanisms of GLP-1 involving in astrocytic fate decision and approach on minimizing detrimental effects and amplifying the beneficial effects, which possibly develop innovative therapies for ischemic stroke. The study is supported by 108-2320-B-182A-005-MY3 and 112-2320-B-182A-003- from Taiwan National Science and Technology Council. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

MULTIDIMENSIONAL WEIGHTED ASSESSMENT IN THE ANALYSIS OF THE COURSE OF ISCHEMIC STROKE DUE TO CAROTID STENOSIS&#x0D; OF VARIABLE DEGREES OF EXPRESSION

Aim: to develop a multidimensional weighted assessment of the influence of risk factors for stroke on the course of ischemic stroke that developed against the background of carotid stenosis of varying severity.Material and methods. We studied 606 patients who were in the department for patients with stroke in the acute period of ischemic stroke, who were divided into three groups according to the severity of carotid stenosis according to NASCET. In all patients, risk factors for the development of stroke were identified, the size of the ischemic focus was determined using a CT scan of the brain, and the patient’s condition and its changes were assessed using the NIHSS, Rankin, and Rivermead scales.Results. Estimated indicators are represented by different measurement scales, so there is a need to bring them to the same basis. The methodology for constructing a weighted assessment involves the formation of weighting coefficients for each component of the new index. A multidimensional weighted assessment was modeled in order to identify the main factors influencing its variation. A selection of risk factors for stroke in the studied patients was carried out, regression models were built, their statistical analysis was performed and their quality was assessed. Conclusion. Regression models allow you to cover a wide range of factors and mathematically express their relationship with performance indicators. The developed logistic models show the degree of positive or negative influence of various risk factors on the course of ischemic stroke in the studied groups of patients.

Impact of inflammatory preconditioning on murine microglial proteome response induced by focal ischemic brain injury.

Preconditioning with lipopolysaccharide (LPS) induces neuroprotection against subsequent cerebral ischemic injury, mainly involving innate immune pathways. Microglia are resident immune cells of the central nervous system (CNS) that respond early to danger signals through memory-like differential reprogramming. However, the cell-specific molecular mechanisms underlying preconditioning are not fully understood. To elucidate the distinct molecular mechanisms of preconditioning on microglia, we compared these cell-specific proteomic profiles in response to LPS preconditioning and without preconditioning and subsequent transient focal brain ischemia and reperfusion, - using an established mouse model of transient focal brain ischemia and reperfusion. A proteomic workflow, based on isolated microglia obtained from mouse brains by cell sorting and coupled to mass spectrometry for identification and quantification, was applied. Our data confirm that LPS preconditioning induces marked neuroprotection, as indicated by a significant reduction in brain infarct volume. The established brain cell separation method was suitable for obtaining an enriched microglial cell fraction for valid proteomic analysis. The results show a significant impact of LPS preconditioning on microglial proteome patterns by type I interferons, presumably driven by the interferon cluster regulator proteins signal transducer and activator of transcription1/2 (STAT1/2).

Impact of the COVID-19 pandemic on acute ischemic stroke medical care: a prospective study

INTRODUCTION: Acute ischemic stroke (AIS) is not uncommon in patients with novel coronavirus infection. During the COVID-19 pandemic, an increase of the frequency of adverse clinical and functional outcomes of AIS was noted.OBJECTIVE: The recent study was to evaluate the impact of the COVID-19 pandemic on the clinical and diagnostic characteristics of patients with AIS, as well as on the results of various types of treatment.MATERIALS AND METHODS: The prospective study included 460 patients with AIS after systemic or selective thrombolysis, thromboextraction and combination of thromboextraction with thrombolysis and stenting, hospitalized in 2019–2022: 55 patients in 2019, and in 2020–2022 — 405 patients. All patients were clinically evaluated using NIHSS and Rankin scales. Instrumental data included: assessment of computed tomography (CT) lesion size, extracranial and transcranial Duplex ultrasound (DUS) and computed angiography. Patients who received invasive treatment (thromboextraction, including in combination with thrombolysis or stenting) underwent cerebral angiography (CA). The characteristics of cerebral hemodynamics before and after the use of various types of treatment, clinical and functional outcomes were subject for comparison.Statistics: The statistical software Statistica 12.0, SPSS Statistics 17.0 were used. Normality of distribution was assessed using the Shapiro–Wilks test. Comparison of groups based on quantitative parameters was carried out using the Mann–Whitney U test. When testing statistical hypotheses, the acceptable level of error of the first type was considered to be a value not exceeding 0.05. To assess the correlation between parameters, the Spearman method was used.RESULTS: During the pandemic of COVID-19, patients with AIS were younger, had lower percentage of comorbidities and a higher NIHSS score. A significantly lower rate of favorable clinical and functional outcomes was obtained during the pandemic compared to the period before the pandemic, including after the use of invasive treatment methods: only 47% of patients had clinical improvement during the pandemic, while in 2019 the proportion of favorable outcomes was 64% (p=0.003). There was an increase in the share of pulmonary embolism and pneumonia in the structure of mortality from AIS during the pandemic (25% in the period before the pandemic vs 38% during the pandemic). Duplex ultrasound of cerebral arteries demonstrated high comparability with angiography data (correlation coefficient with invasive methods 0.84).DISCUSSION: According to the literature data, strokes are not uncommon in patients with COVID-19, especially in those with severe disease and risk factors. The authors consider thrombosis and/or thromboembolism of cerebral arteries to be possible ways of cerebral ischemia. According to Russian scientists, from the beginning of the pandemic, a significant increase in the incidence of ischemic stroke of varying severity was noted. The statistical pattern we identified confirms the data from literature sources that when infected with the SARS-CoV-2 virus, the brain and cerebral arteries are target organs. It is significant for clinical practice that we have evaluated the clinical and instrumental characteristics of these lesions in relatively homogeneous gender, age and clinical groups.CONCLUSION: The incidence of favorable clinical and functional outcomes during the pandemic was significantly lower compared to the pre-pandemic period. Complete and partial restoration of blood flow, as well as a decrease in the ischemic focus, were significantly more common before the pandemic. The effectiveness of invasive methods of cerebral revascularization during the pandemic were also lower. Duplex ultrasound serves as a reliable method not only for primary diagnosis, but also for dynamic monitoring. Initial changes in hemodynamics in patients with AIS before and during the pandemic did not differ significantly and were represented by hypoperfusion with a decrease in peripheral resistance. In 2020–2022 after treatment, hypoperfusion was observed significantly more often, which can be considered as one of the reasons for the less favorable clinical and functional outcomes obtained during the pandemic.

Advanced Diagnostic Tools in Hypothermia-Related Fatalities-A Pathological Perspective.

Although classical gross features are known in hypothermia victims, they lack specific diagnosis features. The aim of our study was to reveal specific brain and lung pathological features in a group of hypothermia-related fatalities. The study group comprised 107 cases from our files associated with hypothermia. Routine hematoxylin-eosin (H&E) staining and postmortem immunohistochemistry were performed. The microscopic cerebral exam revealed diffuse perineuronal and perivascular edema, gliosis, mononuclear cell infiltration, acute brain injuries, focal neuronal ischemia, lacunar infarction, and variable hemorrhages. Variable alveolar edema, pulmonary emphysema, intra-alveolar and/or pleural hemorrhage, and bronchopneumonia, as well as other pre-existing lesions, were identified in lung tissue samples. Glial cells displayed S100β expression, while neurons showed moderate Hsp70 immunopositivity. Alveolar basal membranes exhibited diffuse ICAM-1 positive expression, while ICAM-1 and AQP-1 positivity was observed in the alveolar septum vascular endothelium. Statistical analysis revealed a significant correlation between S100β and Hps70 immunoexpression and cerebral pathological features, between ICAM-1 immunoexpression and alveolar edema and pulmonary emphysema, and between AQP-1 immunoexpression and pulmonary emphysema. Our results add supplementary data to brain and lung pathological findings in hypothermia-related fatalities, with potential therapeutic value in hypothermia patients.

Transient global amnesia and hippocampal diffusion restriction: an overlooked radiological finding.

Transient global amnesia (TGA) is characterized by isolated sudden anterograde amnesia. Diffusion restriction can be observed in the hippocampus on DWI-MRI at varying rates in TGA patients. This study analyzes the prevalence and characteristics of the hippocampal diffusion restriction (HDR), its relationship with vascular risk factors, and the prevalence of lesions overlooked in routine reports. 91 patients diagnosed with TGA at a tertiary hospital between 2011 and 2022 were evaluated retrospectively. The mean age was 64.8 ± 7.3years, and 63.7% of patients were female. 75.8% of the patients had at least one vascular risk factor. Focal diffusion restriction was detected in 17 patients (18.5%) on DWI-MRI, with only one being extra-hippocampal. 81.2% of HDR was detected when DWI-MRI scan was performed between 12 and 96h after the onset of symptoms. HDR was detected most when the imaging was performed in 24 to 48h (p = 0.03). There was no correlation between the duration of symptoms and the detection rates of HDR (p = 0.55). In 9 patients (53% of 17) diffusion restriction was not specified in routine radiology reports. Although focal ischemia, venous flow abnormalities, migraine and epileptic phenomena have been suggested in its etiology, TGA is a clinical condition of which pathophysiology has not been determined clearly. Signal changes observed in DWI-MRI has led to discussions that cerebrovascular etiology may play a role, yet more comprehensive studies are required to prevent and manage TGA. HDRs can be overlooked in routine reports. Therefore, the DWI-MRI images of patients with TGA should be examined vigilantly.

Out of the core: the impact of focal ischemia in regions beyond the penumbra.

The changes in the necrotic core and the penumbra following induction of focal ischemia have been the focus of attention for some time. However, evidence shows, that ischemic injury is not confined to the primarily affected structures and may influence the remote areas as well. Yet many studies fail to probe into the structures beyond the penumbra, and possibly do not even find any significant results due to their short-term design, as secondary damage occurs later. This slower reaction can be perceived as a therapeutic opportunity, in contrast to the ischemic core defined as irreversibly damaged tissue, where the window for salvation is comparatively short. The pathologies in remote structures occur relatively frequently and are clearly linked to the post-stroke neurological outcome. In order to develop efficient therapies, a deeper understanding of what exactly happens in the exo-focal regions is necessary. The mechanisms of glia contribution to the ischemic damage in core/penumbra are relatively well described and include impaired ion homeostasis, excessive cell swelling, glutamate excitotoxic mechanism, release of pro-inflammatory cytokines and phagocytosis or damage propagation via astrocytic syncytia. However, little is known about glia involvement in post-ischemic processes in remote areas. In this literature review, we discuss the definitions of the terms "ischemic core", "penumbra" and "remote areas." Furthermore, we present evidence showing the array of structural and functional changes in the more remote regions from the primary site of focal ischemia, with a special focus on glia and the extracellular matrix. The collected information is compared with the processes commonly occurring in the ischemic core or in the penumbra. Moreover, the possible causes of this phenomenon and the approaches for investigation are described, and finally, we evaluate the efficacy of therapies, which have been studied for their anti-ischemic effect in remote areas in recent years.

Features of Mental Disorders in Right- and Left-Hemisphere Localization of Stroke on the Background of Motor Rehabilitation: Comparative Study

INTRODUCTION. In post-stroke patients have a high incidence of cognitive and emotional pathology, it is very important to take into account the particular features of mental state in order to achieve significant results of rehabilitation. The data on brain asymmetry indicate a certain lateralization of some mental functions (speech, emotional and cognitive functions).&#x0D; AIM. To study cognitive, emotional disorders and quality of life in patients with ischemic stroke depending on the localization of the lesion in the right or left cerebral hemisphere and their dynamics on the background of motor rehabilitation.&#x0D; MATERIALS AND METHODS. 39 patients with localization of an ischemic focus in the middle cerebral artery territory (group 1 (n = 19) — right hemisphere, and group 2 (n = 20) — left hemisphere) in the recovery period after an ischemic stroke, underwent an inpatient course of motor rehabilitation. Conditions of the patients were assessed at the beginning and at the end of hospitalization using the 6-point muscular strength scale, the modified Ashfort scale, a TUG test, the FIM and Berg balance scales, MMSE, MoCA, the Schulte Table methods, he Beck Depression Inventory, the State-Trait Anxiety Inventory (Spielberger-Khanin) and the Quality of Life at stroke.&#x0D; RESULTS. Attention disorders were found in patients of groups 1 and 2 in 84.6 and 75 %, respectively. Emotional disorders were diagnosed in almost half of post-stroke patients, anxiety disorders prevailed over depressive ones. In group 2 patients scoring ≤ 23 points on the MMSE were found 5 times more frequently. In group 1 depression was 4 times more frequent. However, the obtained intergroup differences were not statistically significant. At the end of the rehabilitation, both groups demonstrated a significant decrease in the level of trait anxiety, and in group 1 an increase in the attentional stability.&#x0D; DISCUSSION. The observed prevalence of more severe cognitive impairments in the LMCA group and emotional impairments in the RMCA group are consistent with the data on brain asymmetry.&#x0D; CONCLUSION. Motor rehabilitation has a positive effect on the emotional state of patients after a stroke, and insignificantly on their cognitive functions, which, along with a high incidence of cognitive impairments, necessitates consideration of the transition from motor to cognitive-motor rehabilitation in order to improve the effectiveness of the treatment.

Abstract TP292: Chronic Kidney Disease Exacerbates Post-Stroke Cell Death and Inflammatory Mechanisms

Chronic kidney disease (CKD) is an important independent risk factor for stroke. To understand the mechanisms of CKD that exacerbates stroke pathogenesis, we developed a rodent CKD model by feeding adult C57BL/6 mice with adenine. There was a gradual progression of CKD from mild to severe stages between days 7 and 28 identified by a combination of hematological (creatinine, blood urea nitrogen, and total protein) and imaging (MRI, μCT, dual-energy X-ray absorptiometry, and ultrasound) markers. The CKD cohort showed significant vascular fibrosis, collagen deposition, microvascular rarefaction, and tubulointerstitial abnormalities in the kidneys compared to the control. Induction of transient focal ischemia (by MCA occlusion) on day 28 of adenine treatment led to bigger infarcts (estimated by MRI on day 1 of reperfusion) and worsened motor function (assessed by rotarod test and beam walk test on days 1, 3, 7 and 14 of reperfusion) compared with non-CKD control cohort. The CKD group also showed twice higher mortality by day 14 of reperfusion after transient MCAO compared to control. Proteomic profiling showed that pro cell death and inflammatory mechanisms were directly induced in the brain by CKD pathogenesis. Overall, these studies conclude that CKD-induced cell death and inflammatory mechanisms in the brain contribute to severe and disabling stroke.

Abstract TP293: Juvenile Mice Are Susceptible to Infarct-Induced Neurodegeneration That Causes Cognitive Decline

Introduction: Over half of pediatric stroke survivors have permanent neurologic and cognitive deficits. Executive function and processing speed are two domains that are consistently affected on neuropsychiatric testing of pediatric stroke survivors. In adult mice, stroke triggers an immune-mediated, infarct-induced neurodegeneration that causes similar cognitive deficits. However, it is unknown whether similar pathophysiology causes children’s cognitive deficits after stroke. Hypothesis: We hypothesize that infarct-induced neurodegeneration occurs in a mouse model of pediatric arterial ischemic stroke. Methods: Male and female C57BL/6J mice were randomized to stroke or sham surgery at p28 to model stroke in late childhood and compared to adult 6-month-old mice. We used permanent distal MCAO followed by 60 minutes of hypoxia, an established model for focal ischemia that generates a purely cortical stroke. Mice underwent behavioral testing at 1- and 7-weeks post stroke with a standard Barnes Maze protocol used in adult mice, and with a protocol adapted for juveniles by increasing difficulty of the task. We performed immunostaining to quantify acute and chronic neuroinflammation, stroke size, myelination, and atrophy 3 days and 8 weeks after surgery. Results: At 7 weeks post-stroke, stroke mice performed significantly worse on Barnes Maze testing than sham mice (n = 7 stroke, 7 sham, p = 0.0265 2-way ANOVA with repeated measures) on the more difficult but not the standard protocol. Like adult mice, pediatric mice exhibited chronic B- and T- lymphocyte neuroinflammation in the stroke scar at 8 weeks after stroke and activated (CD68+) microglia in the scar and connected regions. Both groups had decreased subcortical myelin staining compared to age-equivalent sham mice. However, this decrease was more dramatic in pediatric mice at 65 ± 14% vs. 27% ± 9% in adults, p &lt; 0.05). Conclusions: In a model of pediatric ischemic stroke, juvenile mice develop chronic neuroinflammation in the stroke and in white matter tracts that are connected to the stroke in conjunction with a delayed cognitive deficit. Our results suggest that infarct-induced neurodegeneration occurs after stroke in juvenile mice and may cause more severe dysmyelination than in adults.

Alleviating sleep disturbances and modulating neuronal activity after ischemia: Evidence for the benefits of zolpidem in stroke recovery.

Sleep disorders are prevalent among stroke survivors and impede stroke recovery, yet they are still insufficiently considered in the management of stroke patients, and the mechanisms by which they occur remain unclear. There is evidence that boosting phasic GABA signaling with zolpidem during the repair phase improves stroke recovery by enhancing neural plasticity; however, as a non-benzodiazepine hypnotic, the effects of zolpidem on post-stroke sleep disorders remain unclear. Transient ischemic stroke in male rats was induced with a 30-minute middle cerebral artery occlusion. Zolpidem or vehicle was intraperitoneally delivered once daily from 2 to 7 days after the stroke, and the electroencephalogram and electromyogram were recorded simultaneously. At 24 h after ischemia, c-Fos immunostaining was used to assess the effect of transient ischemic stroke and acute zolpidem treatment on neuronal activity. In addition to the effects on reducing brain damage and mitigating behavioral deficits, repeated zolpidem treatment during the subacute phase of stroke quickly ameliorated circadian rhythm disruption, alleviated sleep fragmentation, and increased sleep depth in ischemic rats. Immunohistochemical staining showed that in contrast to robust activation in para-infarct and some remote areas by 24 h after the onset of focal ischemia, the activity of the ipsilateral suprachiasmatic nucleus, the biological rhythm center, was strongly suppressed. A single dose of zolpidem significantly upregulated c-Fos expression in the ipsilateral suprachiasmatic nucleus to levels comparable to the contralateral side. Stroke leads to suprachiasmatic nucleus dysfunction. Zolpidem restores suprachiasmatic nucleus activity and effectively alleviates post-stroke sleep disturbances, indicating its potential to promote stroke recovery.

Polygalasaponin F ameliorates middle cerebral artery occlusion-induced focal ischemia / reperfusion injury in rats through inhibiting TXNIP/NLRP3 signaling pathway

BackgroundPolygalasaponin F (PGSF), an oleanane triterpenoid saponin extracted from Polygala japonica, has been demonstrated with neuroprotective effect. However, the therapeutic effects and mechanisms of PGSF on focal ischemia remain unknown; MethodsIn this study, male Sprague Dawley (SD) rats aged 6–8 weeks were initially selected to establish a rat model of middle cerebral artery occlusion (MCAO) to evaluate the therapeutic effect of PGSF intervention and to investigate the impact of PGSF on the thioredoxin-interacting protein/NOD-, LRR-, and pyrin domain-containing protein 3 (TXNIP/NLRP3) inflammatory pathway. Secondly, brain neuron cells were isolated, and the cells received oxygen-glucose deprivation/reoxygenation (OGD/R) culture to establish the cell injury model in vitro. The mechanism of PGSF on the TXNIP/NLRP3 pathway was further validated; ResultsOur results showed that PGSF treatment reduced neurological scores, brain tissue water content and infarct volume and ameliorated the pathological changes in cerebral cortex in MCAO-induced focal ischemia rats. The TNF-α, IL-1β and IL-6 levels decreased in MCAO-induced focal ischemia rats after PGSF treatment. Moreover, PGSF down-regulated the protein expressions of TXNIP, NLRP3, ASC, cleaved caspase-1, IL-1β, and IL-18 in MCAO-induced focal ischemia rats. Meanwhile, PGSF treatment inhibited apoptosis, and reduced the levels of ROS, inflammatory cytokine and TXNIP/NLRP3 pathway-related proteins (TXNIP, NLRP3, ASC, cleaved caspase-1, IL-1β, and IL-18) in OGD/R-induced neuronal injury cells. Finally, PGSF treatment also disrupted the interaction between NLRP3 and TXNIP in vitro; ConclusionsOur study demonstrated the therapeutic effects of PGSF on MCAO-induced focal ischemia rats. Moreover, the neuroprotective mechanism of PGSF on focal ischemia was associated with the inhibition of TXNIP/NLRP3 signaling pathway.

Mass spectrometry-based proteomic profiling of extracellular vesicle proteins in diabetic and non-diabetic ischemic stroke patients: a case-control study.

Acute ischemic stroke is the most common cause of neurologic dysfunction caused by focal brain ischemia and tissue injury. Diabetes is a major risk factor of stroke, exacerbating disease management and prognosis. Therefore, discovering new diagnostic markers and therapeutic targets is critical for stroke prevention and treatment. Extracellular vesicles (EVs), with their distinctive properties, have emerged as promising candidates for biomarker discovery and therapeutic application. This case-control study utilized mass spectrometry-based proteomics to compare EVs from non-diabetic stroke (nDS = 14), diabetic stroke (DS = 13), and healthy control (HC = 12) subjects. Among 1288 identified proteins, 387 were statistically compared. Statistical comparisons using a general linear model (log2 foldchange ≥0.58 and FDR-p≤0.05) were performed for nDS vs HC, DS vs HC, and DS vs nDS. DS vs HC and DS vs nDS comparisons produced 123 and 149 differentially expressed proteins, respectively. Fibrinogen gamma chain (FIBG), Fibrinogen beta chain (FIBB), Tetratricopeptide repeat protein 16 (TTC16), Proline rich 14-like (PR14L), Inhibitor of nuclear factor kappa-B kinase subunit epsilon (IKKE), Biorientation of chromosomes in cell division protein 1-like 1 (BD1L1), and protein PR14L exhibited significant differences in the DS group. The pathway analysis revealed that the complement system pathways were activated, and blood coagulation and neuroprotection were inhibited in the DS group (z-score ≥2; p ≤ 0.05). These findings underscore the potential of EVs proteomics in identifying biomarkers for stroke management and prevention, warranting further clinical investigation.