RESUMEN
A modified enriched environment (mEE) with 12 h per night was recently proposed and exhibited cognitive improvement. The present study aimed to evaluate the effects of different courses of mEE on different deficits in ischemic mice. Mice were subjected to photothrombotic stroke at the left sensorimotor cortex and then randomly assigned to standard environment or mEE for 7 d (St-PE) or 28 d (Ct-PE) on the third day post-stroke. Neurological deficits and sensorimotor, emotional, and cognitive performances were assessed at the 10th, 17th, and 31st days post-stroke. Our results demonstrated that Ct-PE ameliorated neurological deficits, forelimb using asymmetry, and reduced slip rates of the affected limbs at all time points, while this effect of St-PE was observed only on the 10th day. Similarly, Ct-PE for 28 d promoted spatial learning and working memory, but St-PE did not. Differently, ischemic mice in both St-PE and Ct-PE groups exhibited increased exploration behavior in the open field, light-dark box and elevated plus maze, and less immobile behavior during the tail suspension at all the time points. Our findings indicated that Ct-PE improved sensorimotor and cognitive dysfunctions after cortical ischemia in a time-dependent manner, but St-PE appeared to have greater therapeutic potential on anxiety and depression.
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Isquemia Encefálica , Cognición , Emociones , Ambiente , Animales , Masculino , Cognición/fisiología , Ratones , Emociones/fisiología , Isquemia Encefálica/psicología , Isquemia Encefálica/fisiopatología , Ratones Endogámicos C57BL , Actividad Motora/fisiología , Aprendizaje por Laberinto/fisiologíaRESUMEN
OBJECTIVES: Vasospasm is a complication of aneurysmal subarachnoid hemorrhage (aSAH) that can change the trajectory of recovery and is associated with morbidity and mortality. Earlier detection of vasospasm could improve patient outcomes. Our objective is to evaluate the accuracy of smartphone-based quantitative pupillometry in the detection of radiographic vasospasm and delayed cerebral ischemia (DCI) after aSAH. MATERIALS AND METHODS: We prospectively collected pupillary light reflex (PLR) parameters from patients with aSAH admitted to a neurocritical care unit at a single hospital twice daily using quantitative smartphone pupillometry recordings. PLR parameters included: Maximum pupil diameter, minimum pupil diameter, percent change in pupil diameter, latency in beginning of pupil constriction to light, mean constriction velocity, maximum constriction velocity, and mean dilation velocity. Two-tailed t-tests for independent samples were performed to determine changes in average concurrent PLR parameter values between the following comparisons: (1) patients with and without radiographic vasospasm (defined by angiography with the need for endovascular intervention) and (2) patients with and without DCI. RESULTS: 49 subjects with aSAH underwent 323 total PLR recordings. For PLR recordings taken with (n=35) and without (n=241) radiographic vasospasm, significant differences were observed in MIN (35.0 ± 7.5 pixels with vasospasm versus 31.6 ± 6.2 pixels without; p=0.002). For PLR recordings taken with (n=43) and without (n=241) DCI, significant differences were observed in MAX (48.9 ± 14.3 pixels with DCI versus 42.5 ± 9.2 pixels without; p<0.001). CONCLUSIONS: Quantitative smartphone pupillometry has the potential to be used to detect radiographic vasospasm and DCI after aSAH.
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Valor Predictivo de las Pruebas , Reflejo Pupilar , Teléfono Inteligente , Hemorragia Subaracnoidea , Vasoespasmo Intracraneal , Humanos , Hemorragia Subaracnoidea/complicaciones , Hemorragia Subaracnoidea/fisiopatología , Hemorragia Subaracnoidea/diagnóstico , Vasoespasmo Intracraneal/etiología , Vasoespasmo Intracraneal/diagnóstico , Vasoespasmo Intracraneal/diagnóstico por imagen , Vasoespasmo Intracraneal/fisiopatología , Masculino , Persona de Mediana Edad , Femenino , Estudios Prospectivos , Anciano , Adulto , Reproducibilidad de los Resultados , Pupila/fisiología , Factores de Tiempo , Técnicas de Diagnóstico Oftalmológico/instrumentación , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/etiología , Isquemia Encefálica/complicacionesRESUMEN
INTRODUCTION: Revascularization surgery is recommended for all pediatric patients with moyamoya disease (MMD) with ischemic symptoms because the brains of such patients are still developing. By contrast, no clear guidelines for selective revascularization surgery in adult patients (30 years or more) with ischemic presentation have been established. Regarding the age of initial onset of ischemic MMD, patients in their 20s are at the bottom of the distribution and this age group may share features with both adult and pediatric patients. The present prospective study aimed to clarify the clinical features and treatment outcomes of patients in their 20s (younger patients) with ischemic MMD compared with patients aged 30-60 years (older patients). METHODS: While patients with misery perfusion in the symptomatic cerebral hemisphere on 15O-positron emission tomography underwent combined surgery including direct and indirect revascularizations in the first study period and indirect revascularization alone in the second study period, patients without misery perfusion in that hemisphere received pharmacotherapy alone through the two study periods. Cerebral angiography via arterial catheterization and neuropsychological testing were performed before and after surgery. RESULTS: During 12 years, 12 younger patients were included and comprised 6% of all adult patients (194 patients). The incidence of misery perfusion in the affected hemisphere was significantly higher in younger (12/12 [100%]) than in older patients (57/182 [31%]) (p < 0.0001). No difference in the incidence of cerebral hyperperfusion syndrome and postoperatively declined cognition was seen between younger (2/5 [40%] and 2/5 [40%], respectively) and older (11/36 [31%] and 15/36 [42%], respectively) cerebral hemispheres undergoing combined revascularization surgery. No difference in the incidence of postoperatively formed collateral flows feeding more than one-third of the middle cerebral artery cortical territory on angiograms and postoperatively improved cognition was seen between younger (9/10 [90%] and 6/10 [60%], respectively) and older (18/22 [83%] and 14/22 [64%], respectively) cerebral hemispheres undergoing indirect revascularization surgery alone. CONCLUSION: Patients in their 20s with ischemic MMD always exhibit misery perfusion in the affected hemisphere, unlike older patients, and sometimes develop cerebral hyperperfusion syndrome after combined revascularization surgery, leading to cognitive decline, similar to older patients. Moreover, indirect revascularization surgery alone forms sufficient collateral circulation and restores cognitive function in patients in their 20s, similar to older patients.
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Revascularización Cerebral , Circulación Cerebrovascular , Enfermedad de Moyamoya , Humanos , Enfermedad de Moyamoya/cirugía , Enfermedad de Moyamoya/diagnóstico por imagen , Enfermedad de Moyamoya/fisiopatología , Masculino , Femenino , Adulto , Persona de Mediana Edad , Resultado del Tratamiento , Estudios Prospectivos , Adulto Joven , Factores de Edad , Factores de Tiempo , Isquemia Encefálica/terapia , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/diagnóstico por imagen , Factores de Riesgo , Angiografía Cerebral , Tomografía de Emisión de Positrones , Cognición , Imagen de PerfusiónRESUMEN
PURPOSE: To investigate the relationship of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) parameters with dysfunction in acute focal cerebral ischemia (ACI) rabbits. METHODS: The model of ACI in the middle cerebral artery was made using 30 adult male New Zealand rabbits. The dysfunction severities of the ACI rabbits were assessed using Purdy's score. A paired-sample rank sum test was adopted to compare the abnormal signal zone (ASZ) volumes from T2 weighted imaging (T2WI), dynamic susceptibility contrast-enhanced (DSC) imaging, and DWI with a relative cerebral blood flow (rCBF) map; correlations were analyzed between the volume of each ASZ and Purdy's score by Spearman's rank correlation coefficient. The degree of necrotic and apoptotic cells was evaluated in the ASZ from DWI and DSC PWI-DWI mismatch (PDM) zone. Correlations were analyzed between the index of cellular damage and Purdy's score, the volume of ASZs by Spearman's rank correlation coefficient. RESULTS: The ASZ volumes from DSC-PWI and the rCBF maps were larger than those from DWI (p < 0.001 and p < 0.001, respectively); those from the rCBF map (Z = 0.959, p < 0.001) and DSC-PWI (Z = 0.970, p < 0.001) were positively correlated with DWI; a positive correlation was found between Purdy's score and the ASZ volumes from DSC-PWI (Z = 0.889, p < 0.001), DWI (Z = 0.921, p < 0.001), and rCBF (Z = 0.891, p < 0.001). A significant difference was observed between the ASZ from DWI and the PDM zone in terms of the degree of necrotic (p < 0.001) and apoptotic cells (p < 0.001). The degree of cellular damage in the ASZ of DWI and PDM zone had no relationship with Purdy's score and the volumes of ASZs. CONCLUSION: The ASZ volumes from DSC-PWI, rCBF, and particularly DWI reflected the level of dysfunction in rabbits with ACI.
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Imagen de Difusión por Resonancia Magnética , Modelos Animales de Enfermedad , Animales , Conejos , Masculino , Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/patología , Circulación Cerebrovascular/fisiología , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Imagen de Perfusión/métodosAsunto(s)
Demencia , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/fisiopatología , Demencia/fisiopatología , Demencia/etiología , Envejecimiento , Encéfalo/fisiopatología , Encéfalo/irrigación sanguínea , Gravitación , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/etiología , Factores de Edad , Circulación CerebrovascularRESUMEN
Circadian rhythm is a master process observed in nearly every type of cell throughout the body, and it macroscopically regulates daily physiology. Recent clinical trials have revealed the effects of circadian variation on the incidence, pathophysiological processes, and prognosis of acute ischemic stroke. Furthermore, core clock genes, the cell-autonomous pacemakers of the circadian rhythm, affect the neurovascular unit-composing cells in a nonparallel manner after the same pathophysiological processes of ischemia/reperfusion. In this review, we discuss the influence of circadian rhythms and clock genes on each type of neurovascular unit cell in the pathophysiological processes of acute ischemic stroke.
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Ritmo Circadiano , Humanos , Ritmo Circadiano/fisiología , Animales , Accidente Cerebrovascular Isquémico/fisiopatología , Encéfalo/fisiopatología , Isquemia Encefálica/fisiopatología , Proteínas CLOCK/genética , Proteínas CLOCK/metabolismo , Accidente Cerebrovascular/fisiopatologíaAsunto(s)
Argón , Fármacos Neuroprotectores , Humanos , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/administración & dosificación , Animales , Administración por Inhalación , Argón/farmacología , Investigación Biomédica Traslacional , Resultado del Tratamiento , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/fisiopatología , Encéfalo/irrigación sanguínea , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/prevención & control , Isquemia Encefálica/fisiopatologíaRESUMEN
Ischemic stroke is a type of brain dysfunction caused by pathological changes in the blood vessels of the brain which leads to brain tissue ischemia and hypoxia and ultimately results in cell necrosis. Without timely and effective treatment in the early time window, ischemic stroke can lead to long-term disability and even death. Therefore, rapid detection is crucial in patients with ischemic stroke. In this study, we developed a deep learning model based on fusion features extracted from electroencephalography (EEG) signals for the fast detection of ischemic stroke. Specifically, we recruited 20 ischemic stroke patients who underwent EEG examination during the acute phase of stroke and collected EEG signals from 19 adults with no history of stroke as a control group. Afterwards, we constructed correlation-weighted Phase Lag Index (cwPLI), a novel feature, to explore the synchronization information and functional connectivity between EEG channels. Moreover, the spatio-temporal information from functional connectivity and the nonlinear information from complexity were fused by combining the cwPLI matrix and Sample Entropy (SaEn) together to further improve the discriminative ability of the model. Finally, the novel MSE-VGG network was employed as a classifier to distinguish ischemic stroke from non-ischemic stroke data. Five-fold cross-validation experiments demonstrated that the proposed model possesses excellent performance, with accuracy, sensitivity, and specificity reaching 90.17%, 89.86%, and 90.44%, respectively. Experiments on time consumption verified that the proposed method is superior to other state-of-the-art examinations. This study contributes to the advancement of the rapid detection of ischemic stroke, shedding light on the untapped potential of EEG and demonstrating the efficacy of deep learning in ischemic stroke identification.
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Aprendizaje Profundo , Electroencefalografía , Accidente Cerebrovascular Isquémico , Humanos , Electroencefalografía/métodos , Accidente Cerebrovascular Isquémico/fisiopatología , Accidente Cerebrovascular Isquémico/diagnóstico , Masculino , Femenino , Anciano , Persona de Mediana Edad , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/diagnóstico , Procesamiento de Señales Asistido por Computador , Accidente Cerebrovascular/fisiopatología , Accidente Cerebrovascular/diagnósticoRESUMEN
OBJECTIVES: Delayed cerebral ischemia (DCI) is a major driver of morbidity after aneurysmal subarachnoid hemorrhage (aSAH). Quantitative pupillometry has been shown to be of prognostic value after acute neurological injury. However, the evidence for the use of pupillometric features for the detection of DCI has been conflicting. The aim of this study was to investigate the prognostic value of frequent pupillometric monitoring for DCI detection. DESIGN: Observational cohort study from a prospective aSAH registry. SETTING: Tertiary referral center. PATIENTS: Adult patients with confirmed aSAH admitted to the ICU between March 2019 and December 2023. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred fourteen patients were included, of which 31 (27.2%) suffered from DCI. All patients underwent frequent pupillometry (every 3 hr). We determined the absolute value of the neurological pupil index (NPi) and constriction velocity (CV), and their value normalized to the maximal recorded value between the admission and the pupillometry measure to account for personalized baselines. The association between pupillometry values and the occurrence of DCI within 6-24 hours was investigated. Normalized CV had the best discriminative performance to identify DCI within 8 hours, with an area under the receiver operating characteristic curve of 0.82 (95% CI, 0.69-0.91). NPi, as well as non-normalized metrics, were not significantly associated with DCI. CONCLUSIONS: Normalized CV has a clinically and statistically significant association with the occurrence of DCI after aSAH. Frequent quantitative pupillometry could improve the multimodal monitoring of patients after aSAH with the goal of improving the identification of patients likely to benefit from therapeutic interventions.
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Isquemia Encefálica , Hemorragia Subaracnoidea , Humanos , Hemorragia Subaracnoidea/complicaciones , Hemorragia Subaracnoidea/fisiopatología , Hemorragia Subaracnoidea/diagnóstico , Masculino , Femenino , Persona de Mediana Edad , Isquemia Encefálica/etiología , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/fisiopatología , Estudios Prospectivos , Anciano , Adulto , Estudios de Cohortes , Pupila/fisiología , Pronóstico , Reflejo Pupilar/fisiologíaRESUMEN
The ELECTRA-STROKE study investigated the potential of EEG for prehospital triage of patients with ischemic stroke due to large vessel occlusion (LVO), in which fast triage to stroke centers for endovascular treatment is crucial. The study was conducted in 4 phases, and this Journal Club article focuses on the fourth phase in the prehospital setting with suspected stroke patients. An EEG cap with dry electrodes was used to measure brain activity. The main focus was on the diagnostic accuracy of the theta/alpha ratio, which yielded an area under the receiver operator characteristic curve (AUC) of 0.80. Secondary endpoints, particularly the Brain Symmetry Index (a quantified EEG interhemispheric cortical power asymmetry index) in the delta frequency band, showed an AUC of 0.91. Despite the convenient study design and user-friendly EEG device, limitations include a single-arm design, a relatively small sample size, and exclusions due to data quality issues. The usefulness of EEG in the detection of neuronal changes based on brain ischemia was highlighted, but uncertainties remain regarding its use in certain patient groups. The improvements in the Brain Symmetry Index from phase 3 to 4 of the study indicate the potential for further refinement and investigation of combined methods to improve diagnostic accuracy. The study provides insight into the role of EEG in prehospital stroke detection, recognizing both the strengths and limitations. Overall, the study contributes to understanding the promise of EEG in optimizing LVO stroke triage and urges further refinement and exploration of complementary diagnostic approaches.
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Electroencefalografía , Servicios Médicos de Urgencia , Humanos , Electroencefalografía/métodos , Servicios Médicos de Urgencia/métodos , Accidente Cerebrovascular/fisiopatología , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular Isquémico/fisiopatología , Accidente Cerebrovascular Isquémico/diagnóstico , Masculino , Triaje/métodos , Femenino , Anciano , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/fisiopatologíaRESUMEN
Oedema occurs when higher than normal amounts of solutes and water accumulate in tissues. In brain parenchymal tissue, vasogenic oedema arises from changes in blood-brain barrier permeability, e.g. in peritumoral oedema. Cytotoxic oedema arises from excess accumulation of solutes within cells, e.g. ischaemic oedema following stroke. This type of oedema is initiated when blood flow in the affected core region falls sufficiently to deprive brain cells of the ATP needed to maintain ion gradients. As a consequence, there is: depolarization of neurons; neural uptake of Na+ and Cl- and loss of K+; neuronal swelling; astrocytic uptake of Na+, K+ and anions; swelling of astrocytes; and reduction in ISF volume by fluid uptake into neurons and astrocytes. There is increased parenchymal solute content due to metabolic osmolyte production and solute influx from CSF and blood. The greatly increased [K+]isf triggers spreading depolarizations into the surrounding penumbra increasing metabolic load leading to increased size of the ischaemic core. Water enters the parenchyma primarily from blood, some passing into astrocyte endfeet via AQP4. In the medium term, e.g. after three hours, NaCl permeability and swelling rate increase with partial opening of tight junctions between blood-brain barrier endothelial cells and opening of SUR1-TPRM4 channels. Swelling is then driven by a Donnan-like effect. Longer term, there is gross failure of the blood-brain barrier. Oedema resolution is slower than its formation. Fluids without colloid, e.g. infused mock CSF, can be reabsorbed across the blood-brain barrier by a Starling-like mechanism whereas infused serum with its colloids must be removed by even slower extravascular means. Large scale oedema can increase intracranial pressure (ICP) sufficiently to cause fatal brain herniation. The potentially lethal increase in ICP can be avoided by craniectomy or by aspiration of the osmotically active infarcted region. However, the only satisfactory treatment resulting in retention of function is restoration of blood flow, providing this can be achieved relatively quickly. One important objective of current research is to find treatments that increase the time during which reperfusion is successful. Questions still to be resolved are discussed.
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Edema Encefálico , Encéfalo , Humanos , Edema Encefálico/fisiopatología , Edema Encefálico/metabolismo , Edema Encefálico/etiología , Animales , Encéfalo/metabolismo , Encéfalo/fisiopatología , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/fisiopatología , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/metabolismoRESUMEN
BACKGROUND: Preconditioning by intermittent fasting is linked to improved cognition and motor function, and enhanced recovery after stroke. Although the duration of fasting was shown to elicit different levels of neuroprotection after ischemic stroke, the impact of time of fasting with respect to the circadian cycles remains unexplored. METHODS: Cohorts of mice were subjected to a daily 16-hour fast, either during the dark phase (active-phase intermittent fasting) or the light phase (inactive-phase intermittent fasting) or were fed ad libitum. Following a 6-week dietary regimen, mice were subjected to transient focal cerebral ischemia and underwent behavioral functional assessment. Brain samples were collected for RNA sequencing and histopathologic analyses. RESULTS: Active-phase intermittent fasting cohort exhibited better poststroke motor and cognitive recovery as well as reduced infarction, in contrast to inactive-phase intermittent fasting cohort, when compared with ad libitum cohort. In addition, protection of dendritic spine density/morphology and increased expression of postsynaptic density protein-95 were observed in the active-phase intermittent fasting. CONCLUSIONS: These findings indicate that the time of daily fasting is an important factor in inducing ischemic tolerance by intermittent fasting.
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Ritmo Circadiano , Espinas Dendríticas , Ayuno , Animales , Ayuno/fisiología , Ratones , Ritmo Circadiano/fisiología , Espinas Dendríticas/patología , Masculino , Isquemia Encefálica/patología , Isquemia Encefálica/fisiopatología , Ratones Endogámicos C57BL , Recuperación de la Función/fisiología , Ayuno IntermitenteRESUMEN
Background: Hematopoietic stem cells (HSC) are recruited to ischemic areas in the brain and contribute to improved functional outcome in animals. However, little is known regarding the mechanisms of improvement following HSC administration post cerebral ischemia. To better understand how HSC effect post-stroke improvement, we examined the effect of HSC in ameliorating motor impairment and cortical dysfunction following cerebral ischemia. Methods: Baseline motor performance of male adult rats was established on validated motor tests. Animals were assigned to one of three experimental cohorts: control, stroke, strokeâ+âHSC. One, three and five weeks following a unilateral stroke all animals were tested on motor skills after which intracortical microstimulation was used to derive maps of forelimb movement representations within the motor cortex ipsilateral to the ischemic injury. Results: Strokeâ+âHSC animals significantly outperformed stroke animals on single pellet reaching at weeks 3 and 5 (28±3% and 33±3% versus 11±4% and 17±3%, respectively, pâ<â0.05 at both time points). Control animals scored 44±1% and 47±1%, respectively. Sunflower seed opening task was significantly improved in the strokeâ+âHSC cohort versus the stroke cohort at week five-post stroke (79±4 and 48±5, respectively, pâ<â0.05). Furthermore, Strokeâ+âHSC animals had significantly larger forelimb motor maps than animals in the stroke cohort. Overall infarct size did not significantly differ between the two stroked cohorts. Conclusion: These data suggest that post stroke treatment of HSC enhances the functional integrity of residual cortical tissue, which in turn supports improved behavioral outcome, despite no observed reduction in infarct size.
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Isquemia Encefálica , Modelos Animales de Enfermedad , Corteza Motora , Animales , Masculino , Corteza Motora/fisiopatología , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/patología , Isquemia Encefálica/terapia , Ratas , Mapeo Encefálico , Células Progenitoras Endoteliales/fisiología , Trasplante de Células Madre Hematopoyéticas/métodos , Recuperación de la Función/fisiología , Miembro Anterior/fisiopatología , Ratas Sprague-DawleyRESUMEN
Background and objectives: while acute ischemic stroke is the leading cause of epilepsy in the elderly population, data about its risk factors have been conflicting. Therefore, the aim of our study is to determine the association of early and late epileptic seizures after acute ischemic stroke with cerebral cortical involvement and electroencephalographic changes. Materials and methods: a prospective cohort study in the Hospital of the Lithuanian University of Health Sciences Kaunas Clinics Department of Neurology was conducted and enrolled 376 acute ischemic stroke patients. Data about the demographical, clinical, radiological, and encephalographic changes was gathered. Patients were followed for 1 year after stroke and assessed for late ES. Results: the incidence of ES was 4.5%, the incidence of early ES was 2.7% and the incidence of late ES was 2.4%. The occurrence of early ES increased the probability of developing late ES. There was no association between acute cerebral cortical damage and the occurrence of ES, including both early and late ES. However, interictal epileptiform discharges were associated with the occurrence of ES, including both early and late ES.
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Corteza Cerebral , Electroencefalografía , Epilepsia , Accidente Cerebrovascular Isquémico , Humanos , Masculino , Femenino , Estudios Prospectivos , Electroencefalografía/métodos , Anciano , Persona de Mediana Edad , Corteza Cerebral/fisiopatología , Epilepsia/fisiopatología , Epilepsia/complicaciones , Accidente Cerebrovascular Isquémico/complicaciones , Accidente Cerebrovascular Isquémico/fisiopatología , Lituania/epidemiología , Incidencia , Convulsiones/fisiopatología , Convulsiones/etiología , Convulsiones/epidemiología , Factores de Riesgo , Estudios de Cohortes , Anciano de 80 o más Años , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/complicaciones , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/fisiopatologíaRESUMEN
PURPOSE: Our aim was to use intracortical recording to enable the tracking of ischemic infarct development over the first few critical hours of ischemia with a high time resolution in pigs. We employed electrophysiological measurements to obtain quick feedback on neural function, which might be useful for screening, e.g., for the optimal dosage and timing of agents prior to further pre-clinical evaluation. METHODS: Micro-electrode arrays containing 16 (animal 1) or 32 electrodes (animal 2-7) were implanted in the primary somatosensory cortex of seven female pigs, and continuous electrical stimulation was applied at 0.2 Hz to a cuff electrode implanted on the ulnar nerve. Ischemic stroke was induced after 30 min of baseline recording by injection of endothelin-1 onto the cortex adjacent to the micro-electrode array. Evoked responses were extracted over a moving window of 180 s and averaged across channels as a measure of cortical excitability. RESULTS: Across the animals, the cortical excitability was significantly reduced in all seven 30 min segments following endothelin-1 injection, as compared to the 30 min preceding this intervention. This difference was not explained by changes in the anesthesia, ventilation, end-tidal CO2, mean blood pressure, heart rate, blood oxygenation, or core temperature, which all remained stable throughout the experiment. CONCLUSIONS: The animal model may assist in maturing neuroprotective approaches by testing them in an accessible model of resemblance to human neural and cardiovascular physiology and body size. This would constitute an intermediate step for translating positive results from rodent studies into human application, by more efficiently enabling effective optimization prior to chronic pre-clinical studies in large animals.
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Modelos Animales de Enfermedad , Accidente Cerebrovascular Isquémico , Animales , Porcinos , Femenino , Accidente Cerebrovascular Isquémico/fisiopatología , Endotelina-1/metabolismo , Endotelina-1/farmacología , Estimulación Eléctrica , Corteza Somatosensorial/fisiopatología , Corteza Somatosensorial/fisiología , Isquemia Encefálica/fisiopatología , Monitoreo Fisiológico/métodosRESUMEN
Adequate reperfusion after ischemic stroke is a major determinant of functional outcome yet remains unpredictable and insufficient for most survivors. In this issue of Neuron, Binder et al.1 identify leptomeningeal collaterals (LMCs) in mice and human patients as a key factor in regulating reperfusion and hemorrhagic transformation following stroke.
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Circulación Colateral , Reperfusión , Accidente Cerebrovascular , Humanos , Animales , Accidente Cerebrovascular/fisiopatología , Circulación Colateral/fisiología , Ratones , Accidente Cerebrovascular Isquémico/fisiopatología , Circulación Cerebrovascular/fisiología , Meninges/irrigación sanguínea , Isquemia Encefálica/fisiopatologíaRESUMEN
BACKGROUND: Electroacupuncture (EA) has been shown to facilitate brain plasticity-related functional recovery following ischemic stroke. The functional magnetic resonance imaging technique can be used to determine the range and mode of brain activation. After stroke, EA has been shown to alter brain connectivity, whereas EA's effect on brain network topology properties remains unclear. An evaluation of EA's effects on global and nodal topological properties in rats with ischemia reperfusion was conducted in this study. METHODS AND RESULTS: There were three groups of adult male Sprague-Dawley rats: sham-operated group (sham group), middle cerebral artery occlusion/reperfusion (MCAO/R) group, and MCAO/R plus EA (MCAO/R + EA) group. The differences in global and nodal topological properties, including shortest path length, global efficiency, local efficiency, small-worldness index, betweenness centrality (BC), and degree centrality (DC) were estimated. Graphical network analyses revealed that, as compared with the sham group, the MCAO/R group demonstrated a decrease in BC value in the right ventral hippocampus and increased BC in the right substantia nigra, accompanied by increased DC in the left nucleus accumbens shell (AcbSh). The BC was increased in the right hippocampus ventral and decreased in the right substantia nigra after EA intervention, and MCAO/R + EA resulted in a decreased DC in left AcbSh compared to MCAO/R. CONCLUSION: The results of this study provide a potential basis for EA to promote cognitive and motor function recovery after ischemic stroke.
Asunto(s)
Electroacupuntura , Infarto de la Arteria Cerebral Media , Imagen por Resonancia Magnética , Ratas Sprague-Dawley , Daño por Reperfusión , Animales , Electroacupuntura/métodos , Masculino , Ratas , Daño por Reperfusión/fisiopatología , Daño por Reperfusión/terapia , Daño por Reperfusión/diagnóstico por imagen , Infarto de la Arteria Cerebral Media/terapia , Infarto de la Arteria Cerebral Media/fisiopatología , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Encéfalo/fisiopatología , Encéfalo/diagnóstico por imagen , Isquemia Encefálica/terapia , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/diagnóstico por imagen , Modelos Animales de Enfermedad , Red Nerviosa/fisiopatología , Red Nerviosa/diagnóstico por imagen , Accidente Cerebrovascular Isquémico/terapia , Accidente Cerebrovascular Isquémico/fisiopatología , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Hipocampo/diagnóstico por imagen , Hipocampo/fisiopatologíaRESUMEN
OBJECTIVE: To explore the imaging and transcranial Doppler cerebral blood flow characteristics of cerebrovascular fenestration malformation and its relationship with the occurrence of ischemic cerebrovascular disease. METHODS: A retrospective analysis was conducted on the imaging data of 194 patients with cerebrovascular fenestration malformation who visited the Heyuan People's Hospital from July 2021 to July 2023. The location and morphology of the fenestration malformation blood vessels as well as the presence of other cerebrovascular diseases were analyzed. Transcranial Doppler cerebral blood flow detection data of patients with cerebral infarction and those with basilar artery fenestration malformation were also analyzed. RESULTS: A total of 194 patients with cerebral vascular fenestration malformation were found. Among the artery fenestration malformation, basilar artery fenestration was the most common, accounting for 46.08% (94/194). 61 patients (31.44%) had other vascular malformations, 97 patients (50%) had cerebral infarction, of which 30 were cerebral infarction in the fenestrated artery supply area. 28 patients with cerebral infarction in the fenestrated artery supply area received standardized antiplatelet, lipid-lowering and plaque-stabilizing medication treatment. During the follow-up period, these patients did not experience any symptoms of cerebral infarction or transient ischemic attack again. There were no differences in peak systolic flow velocity and end diastolic flow velocity, pulsatility index and resistance index between the ischemic stroke group and the no ischemic stroke group in patients with basal artery fenestration malformation (P > 0.05). CONCLUSION: Cerebrovascular fenestration malformation is most common in the basilar artery. Cerebrovascular fenestration malformation may also be associated with other cerebrovascular malformations. Standardized antiplatelet and statin lipid-lowering and plaque-stabilizing drugs are suitable for patients with cerebral infarction complicated with fenestration malformation. The relationship between cerebral blood flow changes in basilar artery fenestration malformation and the occurrence of ischemic stroke may not be significant.
Asunto(s)
Circulación Cerebrovascular , Humanos , Femenino , Masculino , Persona de Mediana Edad , Circulación Cerebrovascular/fisiología , Adulto , Estudios Retrospectivos , Anciano , Ultrasonografía Doppler Transcraneal/métodos , Velocidad del Flujo Sanguíneo , Adolescente , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/etiología , Isquemia Encefálica/diagnóstico por imagen , Trastornos Cerebrovasculares/fisiopatología , Trastornos Cerebrovasculares/etiología , Trastornos Cerebrovasculares/diagnóstico por imagen , Adulto Joven , Infarto Cerebral/fisiopatología , Infarto Cerebral/etiología , Infarto Cerebral/diagnóstico por imagenRESUMEN
Poststroke cognitive impairment (PSCI) is a common complication of stroke, but effective treatments are currently lacking. Repetitive transcranial magnetic stimulation (rTMS) is gradually being applied to treat PSCI, but there is limited evidence of its efficacy. To determine rTMS effects on PSCI, we constructed a transient middle cerebral artery occlusion (tMCAO) rat model. Rats were then grouped by random digital table method: the sham group (nâ¯=â¯10), tMCAO group (nâ¯=â¯10) and rTMS group (nâ¯=â¯10). The shuttle box and Morris water maze (MWM) tests were conducted to detect the cognitive functions of the rats. In addition, synaptic density and synaptic ultrastructural parameters, including the active zone length, synaptic cleft width, and postsynaptic density (PSD) thickness, were quantified and analyzed using an electron microscope. What's more, synaptic associated proteins, including PSD95, SYN, and BDNF were detected by western blot. According to the shuttle box and MWM tests, rTMS improved tMCAO rats' cognitive functions, including spatial learning and memory and decision-making abilities. Electron microscopy revealed that rTMS significantly increased the synaptic density, synaptic active zone length and PSD thickness and decreased the synaptic cleft width. The western blot results showed that the expression of PSD95, SYN, and BDNF was markedly increased after rTMS stimulation. Based on these results, we propose that 20â¯Hz rTMS can significantly alleviate cognitive impairment after stroke. The underlying mechanism might be modulating the synaptic plasticity and up-regulating the expression PSD95, SYN, and BDNF in the hippocampus.
Asunto(s)
Isquemia Encefálica , Disfunción Cognitiva , Modelos Animales de Enfermedad , Hipocampo , Plasticidad Neuronal , Ratas Sprague-Dawley , Estimulación Magnética Transcraneal , Animales , Plasticidad Neuronal/fisiología , Disfunción Cognitiva/terapia , Disfunción Cognitiva/etiología , Disfunción Cognitiva/fisiopatología , Masculino , Ratas , Hipocampo/metabolismo , Isquemia Encefálica/terapia , Isquemia Encefálica/fisiopatología , Infarto de la Arteria Cerebral Media/terapia , Infarto de la Arteria Cerebral Media/fisiopatología , Infarto de la Arteria Cerebral Media/complicaciones , Homólogo 4 de la Proteína Discs Large/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Aprendizaje por Laberinto/fisiologíaRESUMEN
BACKGROUND: As a leading cause of mortality and long-term disability, acute ischemic stroke can produce far-reaching pathophysiological consequences. Accumulating evidence has demonstrated abnormalities in the lower motor system following stroke, while the existence of Transsynaptic degeneration of contralateral spinal cord ventral horn (VH) neurons is still debated. METHODS: Using a rat model of acute ischemic stroke, we analyzed spinal cord VH neuron counts contralaterally and ipsilaterally after stroke with immunofluorescence staining. Furthermore, we estimated the overall lower motor unit abnormalities after stroke by simultaneously measuring the modified neurological severity score (mNSS), compound muscle action potential (CMAP) amplitude, repetitive nerve stimulation (RNS), spinal cord VH neuron counts, and the corresponding muscle fiber morphology. The activation status of microglia and extracellular signal-regulated kinase 1/2 (ERK 1/2) in the spinal cord VH was also assessed. RESULTS: At 7 days after stroke, the contralateral CMAP amplitudes declined to a nadir indicating lower motor function damage, and significant muscle disuse atrophy was observed on the same side; meanwhile, the VH neurons remained intact. At 14 days after focal stroke, lower motor function recovered with alleviated muscle disuse atrophy, while transsynaptic degeneration occurred on the contralateral side with elevated activation of ERK 1/2, along with the occurrence of neurogenic muscle atrophy. No apparent decrement of CMAP amplitude was observed with RNS during the whole experimental process. CONCLUSIONS: This study offered an overview of changes in the lower motor system in experimental ischemic rats. We demonstrated that transsynaptic degeneration of contralateral VH neurons occurred when lower motor function significantly recovered, which indicated the minor role of transsynaptic degeneration in lower motor dysfunction during the acute and subacute phases of focal ischemic stroke.