Pathogenesis of brain edema and investigation into anti-edema drugs

Non-coding RNAs in acute ischemic stroke: from brain to periphery

Acute ischemic stroke is a clinical emergency and a condition with high morbidity, mortality, and disability. Accurate predictive, diagnostic, and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain undetermined. With innovations in high-throughput gene sequencing analysis, many aberrantly expressed non-coding RNAs (ncRNAs) in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental models. Differentially expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes, leading to neuroprotection or deterioration, thus ncRNAs can serve as therapeutic targets in acute ischemic stroke. Moreover, distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction, diagnosis, and prognosis. In particular, ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic stroke. In this review, we consolidate the latest progress of research into the roles of ncRNAs (microRNAs, long ncRNAs, and circular RNAs) in the pathological processes of acute ischemic stroke-induced brain damage, as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction, diagnosis, and prognosis. Findings from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.

The cornel Iridoid glycoside attenuated brain edema of the cerebral ischemia/reperfusion rats by modulating the polarized aquaporin 4

Brain edema after ischemic stroke could worsen cerebral injury in patients who received intravenous thrombolysis. Cornus officinalis Sieb. et Zucc., a long-established traditional Chinese medicine, is beneficial to the treatment of neurodegenerative diseases including ischemic stroke. In particular, its major component, cornel iridoid glycoside (CIG), was evidenced to exhibit neuroprotective effects against cerebral ischemic/reperfusion injury (CIR/I). Aimed to explore the effects of the CIG on brain edema of the CIR/I rats, the CIG was analyzed with the main constituents by using HPLC. The molecular docking analysis was performed between the CIG constituents and AQP4-M23. TGN-020, an AQP4 inhibitor, was used as a comparison. In the in vivo experiments, the rats were pre-treated with the CIG and were injured by performing middle cerebral artery occlusion/reperfusion (MCAO/R). After 24 h, the rats were examined for neurological function, pathological changes, brain edema, and polarized Aqp4 expressions in the brain. The HPLC analysis indicated that the CIG was composed of morroniside and loganin. The molecular docking analysis showed that both morroniside and loganin displayed lower binding energies to AQP4-M23 than TGN-020. The CIG pre-treated rats exhibited fewer neurological function deficits, minimized brain swelling, and reduced lesion volumes compared to the MCAO/R rats. In the peri-infarct and infarct regions, the CIG pre-treatment restored the polarized Aqp4 expression which was lost in the MCAO/R rats. The results suggested that the CIG could attenuate brain edema of the cerebral ischemia/reperfusion rats by modulating the polarized Aqp4 through the interaction of AQP4-M23 with morroniside and loganin.

Usefulness of magnetic resonance imaging in differentiation between status epilepticus and acute ischemic stroke

BACKGROUND

Status epilepticus, characterized by the temporal neurological deficits, often mimics acute ischemic stroke. We investigated the usefulness of magnetic resonance imaging for differentiation of status epilepticus from acute ischemic stroke.

METHODS

A retrospective case series of patients with status epilepticus who underwent brain magnetic resonance imaging. For comparative analysis, a series of patients with acute ischemic stroke caused by unilateral middle cerebral artery occlusion was used.

RESULTS

Ten patients (4 females and 6 males) with status epilepticus who underwent brain magnetic resonance imaging were included. The median age at diagnosis was 82 years (age range, 70-90 years). In all ten patients, hyperintensities in diffusion-weighted imaging with decreased apparent diffusion coefficient values, decreased venous intensity in susceptibility-weighted imaging, and hyperperfusion in arterial spin labeling perfusion were detected in the cortex of the affected side. Four patients showed an additional diffusion restriction in the thalamus. The apparent diffusion coefficient value of the lesional area was 13.1% less than the contralateral, which was less than one-third as acute ischemic stroke. Status epilepticus patients showed no change in medullary venous intensity of the affected area in susceptibility-weighted imaging, whereas acute ischemic stroke patients showed increased cortical and medullary venous intensity in affected hemisphere. Seven of eight patients with status epilepticus who underwent magnetic resonance angiography showed dilation of the cerebral arteries in the ipsilateral side.

CONCLUSIONS

The combined use of diffusion-weighted imaging, susceptibility-weighted imaging, and arterial spin labeling perfusion may help accurate and prompt diagnosis of status epilepticus.

Astrocytes in functional recovery following central nervous system injuries

Astrocytes are increasingly recognised as partaking in complex homeostatic mechanisms critical for regulating neuronal plasticity following central nervous system (CNS) insults. Ischaemic stroke and traumatic brain injury are associated with high rates of disability and mortality. Depending on the context and type of injury, reactive astrocytes respond with diverse morphological, proliferative and functional changes collectively known as astrogliosis, which results in both pathogenic and protective effects. There is a large body of research on the negative consequences of astrogliosis following brain injuries. There is also growing interest in how astrogliosis might in some contexts be protective and help to limit the spread of the injury. However, little is known about how astrocytes contribute to the chronic functional recovery phase following traumatic and ischaemic brain insults. In this review, we explore the protective functions of astrocytes in various aspects of secondary brain injury such as oedema, inflammation and blood-brain barrier dysfunction. We also discuss the current knowledge on astrocyte contribution to tissue regeneration, including angiogenesis, neurogenesis, synaptogenesis, dendrogenesis and axogenesis. Finally, we discuss diverse astrocyte-related factors that, if selectively targeted, could form the basis of astrocyte-targeted therapeutic strategies to better address currently untreatable CNS disorders.

Amyloid-related imaging abnormalities (ARIA): diagnosis, management, and care in the setting of amyloid-modifying therapy

Amyloid-related imaging abnormalities, were originally described by dementia care experts. The wider use of aducanumab and now lecanemab warrant broader understanding by the health care provider continuum. The optimal care approach for patients with Alzheimer's dementia, treated with amyloid-targeted therapy, includes proper clinical diagnosis, complication surveillance, specific imaging protocols, expert specialty consultation, integrated treatment strategies, and proper facility system planning. Improved awareness and understanding of amyloid-modifying therapy, both benefits and potential complications, among the health care provider continuum is paramount to the success of complex care programs. Specifically, recognition of treatment high risk, high benefit groups, and the interface of concurrent antiplatelet and anticoagulation. This integrated acute, specialty, and primary care approach should improve patient care quality and outcome.

A longitudinal MRI and TSPO PET-based investigation of brain region-specific neuroprotection by diazepam versus midazolam following organophosphate-induced seizures

Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures. Diazepam was long the benzodiazepine included in autoinjectors used to treat OP-induced seizures, but it is now being replaced in many guidelines by midazolam, which terminates seizures more quickly, particularly when administered intramuscularly. While a direct correlation between seizure duration and the extent of brain injury has been widely reported, there are limited data comparing the neuroprotective efficacy of diazepam versus midazolam following acute OP intoxication. To address this data gap, we used non-invasive imaging techniques to longitudinally quantify neuropathology in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) with and without post-exposure intervention with diazepam or midazolam. Magnetic resonance imaging (MRI) was used to monitor neuropathology and brain atrophy, while positron emission tomography (PET) with a radiotracer targeting translocator protein (TSPO) was utilized to assess neuroinflammation. Animals were scanned at 3, 7, 28, 65, 91, and 168 days post-DFP and imaging metrics were quantitated for the hippocampus, amygdala, piriform cortex, thalamus, cerebral cortex and lateral ventricles. In the DFP-intoxicated rat, neuroinflammation persisted for the duration of the study coincident with progressive atrophy and ongoing tissue remodeling. Benzodiazepines attenuated neuropathology in a region-dependent manner, but neither benzodiazepine was effective in attenuating long-term neuroinflammation as detected by TSPO PET. Diffusion MRI and TSPO PET metrics were highly correlated with seizure severity, and early MRI and PET metrics were positively correlated with long-term brain atrophy. Collectively, these results suggest that anti-seizure therapy alone is insufficient to prevent long-lasting neuroinflammation and tissue remodeling.

Chemical Composition and Neuroprotective Properties of Indonesian Stingless Bee (Geniotrigona thoracica) Propolis Extract in an In-Vivo Model of Intracerebral Hemorrhage (ICH)

Stroke is the world's second-leading cause of death. Current treatments for cerebral edema following intracerebral hemorrhage (ICH) mainly involve hyperosmolar fluids, but this approach is often inadequate. Propolis, known for its various beneficial properties, especially antioxidant and anti-inflammatory properties, could potentially act as an adjunctive therapy and help alleviate stroke-associated injuries. The chemical composition of Geniotrigona thoracica propolis extract was analyzed by GC-MS after derivatization for its total phenolic and total flavonoid content. The total phenolic content and total flavonoid content of the propolis extract were 1037.31 ± 24.10 μg GAE/mL and 374.02 ± 3.36 μg QE/mL, respectively. By GC-MS analysis, its major constituents were found to be triterpenoids (22.4% of TIC). Minor compounds, such as phenolic lipids (6.7% of TIC, GC-MS) and diterpenic acids (2.3% of TIC, GC-MS), were also found. Ninety-six Sprague Dawley rats were divided into six groups; namely, the control group, the ICH group, and four ICH groups that received the following therapies: mannitol, propolis extract (daily oral propolis administration after the ICH induction), propolis-M (propolis and mannitol), and propolis-B+A (daily oral propolis administration 7 days prior to and 72 h after the ICH induction). Neurocognitive functions of the rats were analyzed using the rotarod challenge and Morris water maze. In addition, the expression of NF-κB, SUR1-TRPM4, MMP-9, and Aquaporin-4 was analyzed using immunohistochemical methods. A TUNEL assay was used to assess the percentage of apoptotic cells. Mannitol significantly improved cognitive-motor functions in the ICH group, evidenced by improved rotarod and Morris water maze completion times, and lowered SUR-1 and Aquaporin-4 levels. It also significantly decreased cerebral edema by day 3. Similarly, propolis treatments (propolis-A and propolis-B+A) showed comparable improvements in these tests and reduced edema. Moreover, combining propolis with mannitol (propolis-M) further enhanced these effects, particularly in reducing edema and the Virchow-Robin space. These findings highlight the potential of propolis from the Indonesian stingless bee, Geniotrigona thoracica, from the Central Tapanuli region as a neuroprotective, adjunctive therapy.

Examining Transcriptomic Alterations in Rat Models of Intracerebral Hemorrhage and Severe Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a life-threatening condition associated with significant morbidity and mortality. This study investigates transcriptomic alterations in rodent models of ICH and severe ICH to shed light on the genetic pathways involved in hemorrhagic brain injury. We performed principal component analysis, revealing distinct principal component segments of normal rats compared to ICH and severe ICH rats. We employed heatmaps and volcano plots to identify differentially expressed genes and utilized bar plots and KEGG pathway analysis to elucidate the molecular pathways involved. We identified a multitude of differentially expressed genes in both the ICH and severe ICH models. Our results revealed 5679 common genes among the normal, ICH, and severe ICH groups in the upregulated genes group, and 1196 common genes in the downregulated genes, respectively. A volcano plot comparing these groups further highlighted common genes, including PDPN, TIMP1, SERPINE1, TUBB6, and CD44. These findings underscore the complex interplay of genes involved in inflammation, oxidative stress, and neuronal damage. Furthermore, pathway enrichment analysis uncovered key signaling pathways, including the TNF signaling pathway, protein processing in the endoplasmic reticulum, MAPK signaling pathway, and Fc gamma R-mediated phagocytosis, implicated in the pathogenesis of ICH.

Neutrophil Targeting Platform Reduces Neutrophil Extracellular Traps for Improved Traumatic Brain Injury and Stroke Theranostics

Traumatic brain injuries (TBI) and stroke are major causes of morbidity and mortality in both developing and developed countries. The complex and heterogeneous pathophysiology of TBI and cerebral ischemia-reperfusion injury (CIRI), in addition to the blood-brain barrier (BBB) resistance, is a major barrier to the advancement of diagnostics and therapeutics. Clinical data showed that the severity of TBI and stroke is positively correlated with the number of neutrophils in peripheral blood and brain injury sites. Furthermore, neutrophil extracellular traps (NETs) released by neutrophils correlate with worse TBI and stroke outcomes by impairing revascularization and vascular remodeling. Therefore, targeting neutrophils to deliver NETs inhibitors to brain injury sites and reduce the formation of NETs can be an optimal strategy for TBI and stroke therapy. Herein, the study designs and synthesizes a reactive oxygen species (ROS)-responsive neutrophil-targeting delivery system loaded with peptidyl arginine deiminase 4 (PAD4) inhibitor, GSK484, to prevent the formation of NETs in brain injury sites, which significantly inhibited neuroinflammation and improved neurological deficits, and improved the survival rate of TBI and CIRI. This strategy may provide a groundwork for the development of targeted theranostics of TBI and stroke.

No-reflow after recanalization in ischemic stroke: From pathomechanisms to therapeutic strategies

Endovascular reperfusion therapy is the primary strategy for acute ischemic stroke. No-reflow is a common phenomenon, which is defined as the failure of microcirculatory reperfusion despite clot removal by thrombolysis or mechanical embolization. It has been reported that up to 25% of ischemic strokes suffer from no-reflow, which strongly contributes to an increased risk of poor clinical outcomes. No-reflow is associated with functional and structural alterations of cerebrovascular microcirculation, and the injury to the microcirculation seriously hinders the neural functional recovery following macrovascular reperfusion. Accumulated evidence indicates that pathology of no-reflow is linked to adhesion, aggregation, and rolling of blood components along the endothelium, capillary stagnation with neutrophils, astrocytes end-feet, and endothelial cell edema, pericyte contraction, and vasoconstriction. Prevention or treatment strategies aim to alleviate or reverse these pathological changes, including targeted therapies such as cilostazol, adhesion molecule blocking antibodies, peroxisome proliferator-activated receptors (PPARs) activator, adenosine, pericyte regulators, as well as adjunctive therapies, such as extracorporeal counterpulsation, ischemic preconditioning, and alternative or complementary therapies. Herein, we provide an overview of pathomechanisms, predictive factors, diagnosis, and intervention strategies for no-reflow, and attempt to convey a new perspective on the clinical management of no-reflow post-ischemic stroke.

Effects of d-allose on anti-brain edema effects and reduction of tumor necrosis factor-alpha and interleukin-6 in the water intoxication model

Rare sugars, which exist only in very small quantities in nature, have recently attracted attention for their various biological functions in medicine. Among them, d-allose is known to have cytoprotective effects by antioxidant effects. In this study, we investigated whether the antioxidant effects of d-allose reduce brain edema in a water intoxication model of cytotoxic brain edema. Methods: Mice were injected intraperitoneally with distilled water (10 % of body weight) to create a model of brain edema. d-allose was administered orally at 400 mg/kg 30 min before the model was created. Two hours later, the degree of brain edema was measured by the dry-weight method to determine whether d-allose reduced brain edema. As an index of antioxidant effects, we measured changes over time in inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6) induced by the water intoxication model, and whether d-allose reduced inflammatory cytokines 4 h after model creation. Results: Administration of d-allose significantly suppressed brain edema formation of the water-intoxication model. And it significantly reduced inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6). These results suggest that the antioxidant effect of d-allose exerts an anti-inflammatory effect and reduces brain edema.

Influence of cerebrospinal fluid drainage in the first days after aneurysm rupture on the severity of early brain injury following aneurysmal subarachnoid hemorrhage

PURPOSE

Progressive cerebral edema with refractory intracranial hypertension (ICP) requiring decompressive hemicraniectomy (DHC) is a severe manifestation of early brain injury (EBI) after aneurysmal subarachnoid hemorrhage (aSAH). The purpose of the study was to investigate whether a more pronounced cerebrospinal fluid (CSF) drainage has an influence on cerebral perfusion pressure (CPP) and the extent of EBI after aSAH.

METHODS

Patients with aSAH and indication for ICP-monitoring admitted to our center between 2012 and 2020 were retrospectively included. EBI was categorized based on intracranial blood burden, persistent loss of consciousness, and SEBES (Subarachnoid Hemorrhage Early Brain Edema Score) score on the third day after ictus. The draining CSF and vital signs such as ICP and CPP were documented daily.

RESULTS

90 out of 324 eligible aSAH patients (28%) were included. The mean age was 54.2 ± 11.9 years. DHC was performed in 24% (22/90) of patients. Mean CSF drainage within 72 h after ictus was 168.5 ± 78.5 ml. A higher CSF drainage within 72 h after ictus correlated with a less severe EBI and a less frequent need for DHC (r=-0.33, p = 0.001) and with a higher mean CPP on day 3 after ictus (r = 0.2351, p = 0.02).

CONCLUSION

A more pronounced CSF drainage in the first 3 days of aSAH was associated with higher CPP and a less severe course of EBI and required less frequently a DHC. These results support the hypothesis that an early and pronounced CSF drainage may facilitate blood clearance and positively influence the course of EBI.

The Basic Requirement of Tight Junction Proteins in Blood-Brain Barrier Function and Their Role in Pathologies

This review addresses the role of tight junction proteins at the blood-brain barrier (BBB). Their expression is described, and their role in physiological and pathological processes at the BBB is discussed. Based on this, new approaches are depicted for paracellular drug delivery and diagnostics in the treatment of cerebral diseases. Recent data provide convincing evidence that, in addition to its impairment in the course of diseases, the BBB could be involved in the aetiology of CNS disorders. Further progress will be expected based on new insights in tight junction protein structure and in their involvement in signalling pathways.

Acute hyponatremia post craniotomy resulting in a unilateral fixed and dilated pupil: A case study on diagnosis and management

Background

Postoperative hyponatremia is a known complication of intracranial surgery, which can present with depressed mental status. Hyponatremia resulting in focal neurologic deficits is less frequently described.

Case Description

We describe a patient who, after a bifrontal craniotomy for olfactory groove meningioma, developed acute hyponatremia overnight with a decline in mental status from Glasgow coma scale (GCS) score 15 to GCS 7 and a unilateral fixed dilated pupil. Head computed tomography showed expected postoperative changes without new acute or localizing findings, such as unilateral uncal herniation. The patient's mental status and pupil immediately improved with the administration of mannitol; however, there was a subsequent decline in mental status with a preserved pupil later that morning. Hypertonic saline reversed the neurologic change, and the patient was eventually discharged without a neurologic deficit. Focal neurologic deficits need not always arise following a craniotomy from a postoperative hematoma, stroke, or other finding with radiographic correlate.

Conclusion

Post-craniotomy hyponatremia should now be seen as a postoperative complication that can result in both a general neurologic decline in mental status, as well as with focal neurologic signs such as a fixed, dilated pupil, which can be reversed with hyperosmolar therapy and correction of the hyponatremia.

Longitudinal assessment of ventricular volume trajectories in early-stage schizophrenia: evidence of both enlargement and shrinkage

BACKGROUND

Lateral ventricular enlargement represents a canonical morphometric finding in chronic patients with schizophrenia; however, longitudinal studies elucidating complex dynamic trajectories of ventricular volume change during critical early disease stages are sparse.

METHODS

We measured lateral ventricular volumes in 113 first-episode schizophrenia patients (FES) at baseline visit (11.7 months after illness onset, SD = 12.3) and 128 age- and sex-matched healthy controls (HC) using 3T MRI. MRI was then repeated in both FES and HC one year later.

RESULTS

Compared to controls, ventricular enlargement was identified in 18.6% of patients with FES (14.1% annual ventricular volume (VV) increase; 95%CI: 5.4; 33.1). The ventricular expansion correlated with the severity of PANSS-negative symptoms at one-year follow-up (p = 0.0078). Nevertheless, 16.8% of FES showed an opposite pattern of statistically significant ventricular shrinkage during ≈ one-year follow-up (-9.5% annual VV decrease; 95%CI: -23.7; -2.4). There were no differences in sex, illness duration, age of onset, duration of untreated psychosis, body mass index, the incidence of Schneiderian symptoms, or cumulative antipsychotic dose among the patient groups exhibiting ventricular enlargement, shrinkage, or no change in VV.

CONCLUSION

Both enlargement and ventricular shrinkage are equally present in the early stages of schizophrenia. The newly discovered early reduction of VV in a subgroup of patients emphasizes the need for further research to understand its mechanisms.

Inhibition of EphA4 reduces vasogenic edema after experimental stroke in mice by protecting the blood-brain barrier integrity

Cerebral vasogenic edema, a severe complication of ischemic stroke, aggravates neurological deficits. However, therapeutics to reduce cerebral edema still represent a significant unmet medical need. Brain microvascular endothelial cells (BMECs), vital for maintaining the blood-brain barrier (BBB), represent the first defense barrier for vasogenic edema. Here, we analyzed the proteomic profiles of the cultured mouse BMECs during oxygen-glucose deprivation and reperfusion (OGD/R). Besides the extensively altered cytoskeletal proteins, ephrin type-A receptor 4 (EphA4) expressions and its activated phosphorylated form p-EphA4 were significantly increased. Blocking EphA4 using EphA4-Fc, a specific and well-tolerated inhibitor shown in our ongoing human phase I trial, effectively reduced OGD/R-induced BMECs contraction and tight junction damage. EphA4-Fc did not protect OGD/R-induced neuronal and astrocytic death. However, administration of EphA4-Fc, before or after the onset of transient middle cerebral artery occlusion (tMCAO), reduced brain edema by about 50%, leading to improved neurological function recovery. The BBB permeability test also confirmed that cerebral BBB integrity was well maintained in tMCAO brains treated with EphA4-Fc. Therefore, EphA4 was critical in signaling BMECs-mediated BBB breakdown and vasogenic edema during cerebral ischemia. EphA4-Fc is promising for the treatment of clinical post-stroke edema.

Edema progression in proximity to traumatic microbleeds: evolution of cytotoxic and vasogenic edema on serial MRI

Introduction

Although cerebral edema is common following traumatic brain injury (TBI), its formation and progression are poorly understood. This is especially true for the mild TBI population, who rarely undergo magnetic resonance imaging (MRI) studies, which can pick up subtle structural details not visualized on computed tomography, in the first few days after injury. This study aimed to visually classify and quantitatively measure edema progression in relation to traumatic microbleeds (TMBs) in a cohort of primarily mild TBI patients up to 30 days after injury. Researchers hypothesized that hypointense lesions on Apparent Diffusion Coefficient (ADC) detected acutely after injury would evolve into hyperintense Fluid Attenuated Inversion Recover (FLAIR) lesions.

Methods

This study analyzed the progression of cerebral edema after acute injury using multimodal MRI to classify TMBs as potential edema-related biomarkers. ADC and FLAIR MRI were utilized for edema classification at three different timepoints: ≤48 hours, ~1 week, and 30 days after injury. Hypointense lesions on ADC (ADC+) suggested the presence of cytotoxic edema while hyperintense lesions on FLAIR (FLAIR+) suggested vasogenic edema. Signal intensity Ratio (SIR) calculations were made using ADC and FLAIR to quantitatively confirm edema progression.

Results

Our results indicated the presence of ADC+ lesions ≤48 hours and ~1 week were associated with FLAIR+ lesions at ~1 week and 30 days, respectively, suggesting some progression of cytotoxic edema to vasogenic edema over time. Ten out of 15 FLAIR+ lesions at 30 days (67%) were ADC+ ≤48 hours. However, ADC+ lesions ≤48 hours were not associated with FLAIR+ lesions at 30 days; 10 out of 25 (40%) ADC+ lesions ≤48 hours were FLAIR+ at 30 days, which could indicate that some lesions resolved or were not visualized due to associated atrophy or tissue necrosis. Quantitative analysis confirmed the visual progression of some TMB lesions from ADC+ to FLAIR+. FLAIR SIRs at ~1 week were significantly higher when lesions were ADC+ ≤48 hours (1.22 [1.08-1.32] vs 1.03 [0.97-1.11], p=0.002).

Conclusion

Awareness of how cerebral edema can evolve in proximity to TMBs acutely after injury may facilitate identification and monitoring of patients with traumatic cerebrovascular injury and assist in development of novel therapeutic strategies.

Research on the classification of early-stage brain edema by combining intrinsic optical signal imaging and laser speckle contrast imaging

The early detection and pathological classification of brain edema are very important for symptomatic treatment. The dual-optical imaging system (DOIS) consists of intrinsic optical signal imaging (IOSI) and laser speckle contrast imaging (LSCI), which can acquire cerebral hemodynamic parameters of mice in real-time, including changes of oxygenated hemoglobin concentration ( Δ C HbO 2 ), deoxyhemoglobin concentration (ΔCHbR) and relative cerebral blood flow (rCBF) within the field of view. The slope sum of Δ C HbO 2 , ΔCHbR and rCBF was proposed to classify vasogenic edema (VE) and cytotoxic edema (CE). The slope sum values in the VE and CE group remain statistically different and the classification results provide higher accuracy of more than 93% for early brain edema detection. In conclusion, the differences of hemodynamic parameters between VE and CE in the early stage were revealed and the method helps in the classification of early brain edema.

Combined effect of trifluoperazine and sodium cromoglycate on reducing acute edema and limiting lasting functional impairments after spinal cord injury in rats

Edema formation is one of the very first events to occur after spinal cord injury (SCI) leading to an increase of the intrathecal pressure and consequently to serious spinal tissue and functional impairments. Current edema treatments are still symptomatic and/or non-specific. Since edema formation mechanisms are mainly described as vasogenic and cytotoxic, it becomes crucial to understand the interplay between these two subtypes. Acting on key targets to inhibit edema formation may reduce secondary damage and related functional impairments. In this study, we characterize the edema kinetic after T9-10 spinal contusion. We use trifluoperazine (TFP) to block the expression and the functional subcellular localization of aquaporin-4 supposed to be implicated in the cytotoxic edema formation. We also use sodium cromoglycate (SCG) to deactivate mast cell degranulation known to be implicated in the vasogenic edema formation. Our results show a significant reduction of edema after TFP treatment and after TFP-SCG combined treatment compared to control. This reduction is correlated with limited onset of initial sensorimotor impairments particularly after combined treatment. Our results highlight the importance of potential synergetic targets in early edema therapy after SCI as part of tissue sparing strategies.

(S)-roscovitine, a CDK inhibitor, decreases cerebral edema and modulates AQP4 and α1-syntrophin interaction on a pre-clinical model of acute ischemic stroke

Cerebral edema is one of the deadliest complications of ischemic stroke for which there is currently no pharmaceutical treatment. Aquaporin-4 (AQP4), a water-channel polarized at the astrocyte endfoot, is known to be highly implicated in cerebral edema. We previously showed in randomized studies that (S)-roscovitine, a cyclin-dependent kinase inhibitor, reduced cerebral edema 48 h after induction of focal transient ischemia, but its mechanisms of action were unclear. In our recent blind randomized study, we confirmed that (S)-roscovitine was able to reduce cerebral edema by 65% at 24 h post-stroke (t test, p = .006). Immunofluorescence analysis of AQP4 distribution in astrocytes revealed that (S)-roscovitine decreased the non-perivascular pool of AQP4 by 53% and drastically increased AQP4 clusters in astrocyte perivascular end-feet (671%, t test p = .005) compared to vehicle. Non-perivascular and clustered AQP4 compartments were negatively correlated (R = -0.78; p < .0001), suggesting a communicating vessels effect between the two compartments. α1-syntrophin, AQP4 anchoring protein, was colocalized with AQP4 in astrocyte endfeet, and this colocalization was maintained in ischemic area as observed on confocal microscopy. Moreover, (S)-roscovitine increased AQP4/α1-syntrophin interaction (40%, MW p = .0083) as quantified by proximity ligation assay. The quantified interaction was negatively correlated with brain edema in both treated and placebo groups (R = -.57; p = .0074). We showed for the first time, that a kinase inhibitor modulated AQP4/α1-syntrophin interaction, and was implicated in the reduction of cerebral edema. These findings suggest that (S)-roscovitine may hold promise as a potential treatment for cerebral edema in ischemic stroke and as modulator of AQP4 function in other neurological diseases.

Osmotic stress induces the formation of migrasome-like vesicles

Migrasomes are extracellular vesicles that form on the retraction fibers of migrating cells. In this study, we report the formation of migrasome-like vesicles enriched in tetraspanin 4 and containing cytoplasmic components in response to hypoosmotic stress. When migrating cells were subjected to hypoosmotic stress, vesicles with a size distribution of 0.5 to 2 μm formed on the retraction fibers, and vanished in a few minutes. The vesicles are rich in cholesterol, and their number was reduced when cells were pretreated with lipoprotein-deficient serum. The formation of migrasome-like vesicles upon hypoosmotic stress may provide biophysical cues regarding the cellular response to this external stimulus in cells and tissues.

Neuroprotection Afforded by an Enriched Mediterranean-like Diet Is Modified by Exercise in a Rat Male Model of Cerebral Ischemia

Ischemic stroke is an important cause of mortality and disability worldwide. Given that current treatments do not allow a remarkably better outcome in patients after stroke, it is mandatory to seek new approaches to preventing stroke and/or complementing the current treatments or ameliorating the ischemic insult. Multiple preclinical and clinical studies highlighted the potential beneficial roles of exercise and a Mediterranean diet following a stroke. Here, we investigated the effects of a pre-stroke Mediterranean-like diet supplemented with hydroxytyrosol and with/without physical exercise on male rats undergoing transient middle cerebral artery occlusion (tMCAO). We also assessed a potential synergistic effect with physical exercise. Our findings indicated that the diet reduced infarct and edema volumes, modulated acute immune response by altering cytokine and chemokine levels, decreased oxidative stress, and improved acute functional recovery post-ischemic injury. Interestingly, while physical exercise alone improved certain outcomes compared to control animals, it did not enhance, and in some aspects even impaired, the positive effects of the Mediterranean-like diet in the short term. Overall, these data provide the first preclinical evidence that a preemptive enriched Mediterranean diet modulates cytokines/chemokines levels downwards which eventually has an important role during the acute phase following ischemic damage, likely mediating neuroprotection.

Crossed Cerebellar Diaschisis in a Status Epilepticus Patient with Stroke-Mimicking Changes: A Case Report with Suboptimal Outcome

BACKGROUND Crossed cerebellar diaschisis is a rare phenomenon characterized by reduction of hemispheric cerebellar blood flow and metabolism that occurs contralateral to supratentorial injury. This finding is generally detected after ischemic stroke, but can also be observed during status epilepticus. CASE REPORT A 45-year-old woman with a history of focal epilepsy and alcohol abuse presented with an episode of seizure with initial stroke-mimicking changes and no epileptiform activity on electroencephalogram. Upon further examination, the radiological findings revealed a broad cytotoxic edema in the left hemisphere and a smaller lesion in the right cerebellum, showing a rare phenomenon of crossed cerebellar diaschisis. Later, diagnosis of status epilepticus was established. Although the initial trend of the patient's condition was negative, after weeks of therapy and intensive care, the patient slightly improved in her condition and there was a partially reversible lesion in the left cerebral hemisphere and right cerebellum. CONCLUSIONS It is crucial to detect seizures in patients with stroke-like changes on unenhanced computed tomography examination, and especially in cases in which there are no arterial occlusion on computed tomography angiography and asymmetric arterial vasodilatation are seen. Status epilepticus can mimic stroke, establishing this as a major diagnostic challenge. Although the radiological findings in the left cerebral hemisphere lesion and the right cerebellar hemisphere were similar, its characteristics on diffusion-weighted imaging and apparent diffusion coefficient value differed, raising an important question of the exact mechanics of how crossed cerebellar diaschisis occurs, as it seems to be a rare phenomenon.

Matrix Metalloproteinase-9 inhibitors as therapeutic drugs for traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality among young adults and the elderly. In the United States, TBI is responsible for around 30 percent of all injuries brought on by injuries in general. Vasogenic cerebral edema due to blood-brain barrier (BBB) dysfunction and the associated elevation of intracranial pressure (ICP) are some of the major causes of secondary injuries following traumatic brain injury. Matrix metalloproteinase-9 (MMP-9) is a therapeutic target for being an enzyme that degrades the proteins that make up a part of the microvascular basal lamina as well as inter-endothelial tight junctions of the blood-brain barrier. MMP-9-mediated BBB dysfunctions and the compromise of the BBB is a major pathway that leads the development of vasogenic cerebral edema, elevation of ICP, poor cerebral perfusion and brain herniation following traumatic brain injury. That makes MMP-9 an effective therapeutic target and endogenous or exogenous MMP-9 inhibitors as therapeutic drugs for preventing secondary brain damage after traumatic brain injury. Although our understanding of the mechanisms that underlie the primary and secondary stages of damage following a TBI has significantly improved in recent years, such information has not yet resulted in the successful development of novel pharmacological treatment options for traumatic brain injury. Recent pre-clinical and/or clinical studies have demonstrated that there are several compounds with specific or non-specific MMP-9 inhibitory properties either directly binding and inhibiting MMP-9 or by indirectly inhibiting MMP-9, with potential as therapeutic agents for traumatic brain injury. This article reviews the efficacy of several such medications and potential agents that include endogenous and exogeneous compounds that are at various levels of research and development. MMP-9-based therapeutic drug development has enormous potential in the pharmacological treatment of cerebral edema and/or neuronal injury resulting from traumatic brain injury.

Intranasal administration of innovative triamcinolone acetonide encapsulated cubosomal in situ gel: formulation and characterization

AIM

The primary objective of the research was to develop a cubosomal in situ gel encapsulated with Triamcinolone acetonide (TCA) in order to enhance its penetration through the blood-brain barrier (BBB) when administered via the intranasal route, thus enabling efficient and rapid action.

METHOD

Cubosomes were formulated by top-down approach using glyceryl monooleate (GMO), using pluronics127 (PF127) and polyvinyl alcohol (PVA) in varying proportions based on the Box-Behnken design. High resolution transmission electron microscopy (HR-TEM) analysis confirmed the morphology of the cubosomes. The in situ gel was formulated and optimized. Experiments involving ex vivo permeation and histopathology analyses were undertaken to evaluate drug permeation and tissue effects.

RESULTS

The cubosomes exhibited a particle size (PS) of 197.9 nm, zeta potential (ZP) of -31.11 mV, and entrapment efficacy (EE) of 84.31%, with low deviation. Batch F4 (19% PF127) showed favorable results. In vitro and ex vivo permeation studies revealed drug release of 78.59% and 76.65%, respectively, after 8 h. Drug release followed the Hixson Crowell model of release kinetics. The histopathological examination revealed no signs of toxicity or adverse effects on the nasal mucosa of the sheep. The formulation exhibited short-term stability, maintaining its integrity and properties when stored at room temperature.

CONCLUSION

The utilization of an intranasal cubosomal in situ gel encapsulated with TCA was anticipated to lower intracranial pressure and improve patient adherence by offering effective relief for individuals suffering from Brain edema. This efficacy is attributed to its rapid onset of action and its safe and well-tolerated dosage form.

Dexamethasone and overall survival and progression free survival in patients with newly diagnosed glioblastoma: a meta-analysis

PURPOSE

Glioblastomas, the most common primary malignant brain tumors in adults, still hold poor prognosis. Corticosteroids, such as dexamethasone, are usually prescribed to reduce peritumoral edema and limit neurological symptoms, although potential detrimental effects of these drugs have been described. The present meta-analysis aimed to explore the association of dexamethasone with overall survival (OS) and progression free survival (PFS) in patients with newly diagnosed glioblastoma.

METHODS

PubMed, Cochrane Library, Embase, and ClinicalTrials.gov were searched for pertinent studies following the Preferred Reporting Items of Systematic Review and Meta-Analysis checklist. Pooled multivariable-adjusted hazard ratios (HR) for OS and PFS and their associated 95% confidence intervals (CIs) were calculated using the random-effects model and the heterogeneity among studies was assessed using I2. The quality of evidence was assessed using the GRADE criteria.

RESULTS

Seven studies were included, pooling data of 1,257 patients, with age varying from 11 to 81 years. Glioblastoma patients on pre- or peri-operative dexamethasone were associated with a significantly poorer overall survival (HR: 1.33, 95% CI: 1.15, 1.55; 7 studies; I2: 59.9%) and progression free survival (HR: 1.77, 95% CI: 1.05, 2.97; 3 studies; I2: 71.1%) compared to patients not on dexamethasone. The quality of evidence was moderate for overall survival and low for progression free survival.

CONCLUSION

Dexamethasone appeared to be associated with poor survival outcomes of glioblastoma patients.

Challenges and strategies faced in the electrochemical biosensing analysis of neurochemicals in vivo: A review

Our brain is an intricate neuromodulatory network, and various neurochemicals, including neurotransmitters, neuromodulators, gases, ions, and energy metabolites, play important roles in regulating normal brain function. Abnormal release or imbalance of these substances will lead to various diseases such as Parkinson's and Alzheimer's diseases, therefore, in situ and real-time analysis of neurochemical interactions in pathophysiological conditions is beneficial to facilitate our understanding of brain function. Implantable electrochemical biosensors are capable of monitoring neurochemical signals in real time in extracellular fluid of specific brain regions because they can provide excellent temporal and spatial resolution. However, in vivo electrochemical biosensing analysis mainly faces the following challenges: First, foreign body reactions induced by microelectrode implantation, non-specific adsorption of proteins and redox products, and aggregation of glial cells, which will cause irreversible degradation of performance such as stability and sensitivity of the microsensor and eventually lead to signal loss; Second, various neurochemicals coexist in the complex brain environment, and electroactive substances with similar formal potentials interfere with each other. Therefore, it is a great challenge to design recognition molecules and tailor functional surfaces to develop in vivo electrochemical biosensors with high selectivity. Here, we take the above challenges as a starting point and detail the basic design principles for improving in vivo stability, selectivity and sensitivity of microsensors through some specific functionalized surface strategies as case studies. At the same time, we summarize surface modification strategies for in vivo electrochemical biosensing analysis of some important neurochemicals for researchers' reference. In addition, we also focus on the electrochemical detection of low basal concentrations of neurochemicals in vivo via amperometric waveform techniques, as well as the stability and biocompatibility of reference electrodes during long-term sensing, and provide an outlook on the future direction of in vivo electrochemical neurosensing.

Prednisolone Targets Claudins in Mouse Brain Blood Vessels

Endothelial cells in brain capillaries are crucial for the function of the blood-brain barrier (BBB), and members of the tight junction protein family of claudins are regarded to be primarily responsible for barrier properties. Thus, the analysis of bioactive substances that can affect the BBB's permeability is of great importance and may be useful for the development of new therapeutic strategies for brain pathologies. In our study, we tested the hypothesis that the application of the glucocorticoid prednisolone affects the murine blood-brain barrier in vivo. Isolated brain tissue of control and prednisolone-injected mice was examined by employing immunoblotting and confocal laser scanning immunofluorescence microscopy, and the physiological and behavioral effects were analyzed. The control tissue samples revealed the expression of barrier-forming tight junction proteins claudin-1, -3, and -5 and of the paracellular cation and water-channel-forming protein claudin-2. Prednisolone administration for 7 days at doses of 70 mg/kg caused physiological and behavioral effects and downregulated claudin-1 and -3 and the channel-forming claudin-2 without altering their localization in cerebral blood vessels. Changes in the expression of these claudins might have effects on the ionic and acid-base balance in brain tissue, suggesting the relevance of our findings for therapeutic options in disorders such as cerebral edema and psychiatric failure.

Bevacizumab reduces peritumoral brain edema in lung cancer brain metastases after radiotherapy

BACKGROUND

The aim of this study was to investigate the efficacy of bevacizumab (Bev) in reducing peritumoral brain edema (PTBE) after stereotactic radiotherapy (SRT) for lung cancer brain metastases.

METHODS

A retrospective analysis was conducted on 44 patients with lung cancer brain metastases (70 lesions) who were admitted to our oncology and Gamma Knife center from January 2020 to May 2022. All patients received intracranial SRT and had PTBE. Based on treatment with Bev, patients were categorized as SRT + Bev and SRT groups. Follow-up head magnetic resonance imaging was performed to calculate PTBE and tumor volume changes. The edema index (EI) was used to assess the severity of PTBE. Additionally, the extent of tumor reduction and intracranial progression-free survival (PFS) were compared between the two groups.

RESULTS

The SRT + Bev group showed a statistically significant difference in EI values before and after radiotherapy (p = 0.0115), with lower values observed after treatment, but there was no difference in the SRT group (p = 0.4008). There was a difference in the distribution of EI grades in the SRT + Bev group (p = 0.0186), with an increased proportion of patients at grades 1-2 after radiotherapy, while there was no difference in the SRT group (p > 0.9999). Both groups demonstrated a significant reduction in tumor volume after radiotherapy (p < 0.05), but there was no difference in tumor volume changes between the two groups (p = 0.4089). There was no difference in intracranial PFS between the two groups (p = 0.1541).

CONCLUSION

Bevacizumab significantly reduces the severity of PTBE after radiotherapy for lung cancer. However, its impact on tumor volume reduction and intracranial PFS does not reach statistical significance.

Sirtuins as Potential Targets for Neuroprotection: Mechanisms of Early Brain Injury Induced by Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a prevalent cerebrovascular disease with significant global mortality and morbidity rates. Despite advancements in pharmacological and surgical approaches, the quality of life for SAH survivors has not shown substantial improvement. Traditionally, vasospasm has been considered a primary contributor to death and disability following SAH, but anti-vasospastic therapies have not demonstrated significant benefits for SAH patients' prognosis. Emerging studies suggest that early brain injury (EBI) may play a crucial role in influencing SAH prognosis. Sirtuins (SIRTs), a group of NAD + -dependent deacylases comprising seven mammalian family members (SIRT1 to SIRT7), have been found to be involved in neural tissue development, plasticity, and aging. They also exhibit vital functions in various central nervous system (CNS) processes, including cognition, pain perception, mood, behavior, sleep, and circadian rhythms. Extensive research has uncovered the multifaceted roles of SIRTs in CNS disorders, offering insights into potential markers for pathological processes and promising therapeutic targets (such as SIRT1 activators and SIRT2 inhibitors). In this article, we provide an overview of recent research progress on the application of SIRTs in subarachnoid hemorrhage and explore their underlying mechanisms of action.

Epidemiology and Outcomes of Cerebral Edema in Hospitalized Children

BACKGROUND

Cerebral edema can be a consequence of multiple disease processes. Untreated cerebral edema can be fatal, and even with aggressive management, it can be devastating. The objective of this study was to describe the prevalence, underlying causes, and outcomes of cerebral edema in hospitalized children.

METHODS

A retrospective cross-sectional study using the 2016 Kids' Inpatient Database was performed. Children aged one month to 20 years were included. Sample weighting was employed to produce national estimates. Univariate analyses were used to compare those who died and survived. Multivariable logistic regression was performed to assess the influence of demographic variables and etiologic factors on mortality.

RESULTS

Cerebral edema was documented in 4903 children of 2,210,263 (2.2 of 1000) discharges. Among children with cerebral edema, males were 57%, white children were 47.9%, and adolescents were 48.9%. The three most common etiologies associated with cerebral edema in this cohort were stroke (21.7%), anoxic injury (21.4%), and central nervous system (CNS) malignancy (16%). The overall hospital mortality rate was 29.4%. The adjusted mortality rate was significantly higher when cerebral edema was associated with anoxic injury (84%). The mortality was lower when cerebral edema was associated with CNS malignancy (9.5%) or diabetic ketoacidosis (DKA) (4.3%).

CONCLUSIONS

Cerebral edema is uncommon in hospitalized children but has a high mortality. Stroke and anoxic brain injury are the two most common etiologies for cerebral edema in hospitalized children in the United States. Among all etiologies for cerebral edema in children, anoxic brain injury has the highest mortality, whereas DKA has the lowest mortality.

Fecal microbial transplantation limits neural injury severity and functional deficits in a pediatric piglet traumatic brain injury model

Pediatric traumatic brain injury (TBI) is a leading cause of death and disability in children. Due to bidirectional communication between the brain and gut microbial population, introduction of key gut bacteria may mitigate critical TBI-induced secondary injury cascades, thus lessening neural damage and improving functional outcomes. The objective of this study was to determine the efficacy of a daily fecal microbial transplant (FMT) to alleviate neural injury severity, prevent gut dysbiosis, and improve functional recovery post TBI in a translational pediatric piglet model. Male piglets at 4-weeks of age were randomly assigned to Sham + saline, TBI + saline, or TBI + FMT treatment groups. A moderate/severe TBI was induced by controlled cortical impact and Sham pigs underwent craniectomy surgery only. FMT or saline were administered by oral gavage daily for 7 days. MRI was performed 1 day (1D) and 7 days (7D) post TBI. Fecal and cecal samples were collected for 16S rRNA gene sequencing. Ipsilateral brain and ileum tissue samples were collected for histological assessment. Gait and behavior testing were conducted at multiple timepoints. MRI showed that FMT treated animals demonstrated decreased lesion volume and hemorrhage volume at 7D post TBI as compared to 1D post TBI. Histological analysis revealed improved neuron and oligodendrocyte survival and restored ileum tissue morphology at 7D post TBI in FMT treated animals. Microbiome analysis indicated decreased dysbiosis in FMT treated animals with an increase in multiple probiotic Lactobacilli species, associated with anti-inflammatory therapeutic effects, in the cecum of the FMT treated animals, while non-treated TBI animals showed an increase in pathogenic bacteria, associated with inflammation and disease such in feces. FMT mediated enhanced cellular and tissue recovery resulted in improved motor function including stride and step length and voluntary motor activity in FMT treated animals. Here we report for the first time in a highly translatable pediatric piglet TBI model, the potential of FMT treatment to significantly limit cellular and tissue damage leading to improved functional outcomes following a TBI.

Effect of Bevacizumab Treatment in Cerebral Radiation Necrosis : Investigation of Response Predictors in a Single-Center Experience

OBJECTIVE

Bevacizumab is a feasible option for treating cerebral radiation necrosis (RN). We investigated the clinical outcome of RN after treatment with bevacizumab and factors related to the initial response and the sustained effect.

METHODS

Clinical data of 45 patients treated for symptomatic RN between September 2019 and February 2021 were retrospectively collected. Bevacizumab (7.5 mg/kg) was administered at 3-week intervals with a maximum four-cycle schedule. Changes in the lesions magnetic resonance image (MRI) scans were examined for the response evaluation. The subgroup analysis was performed based on the initial response and the long-term maintenance of the effect.

RESULTS

Of the 45 patients, 36 patients (80.0%) showed an initial response, and eight patients (17.8%) showed delayed worsening of the corresponding lesion. The non-responders showed a significantly higher incidence of diffusion restriction on MRI than the responders (100.0% vs. 25.0%, p<0.001). The delayed worsening group showed a significantly higher proportion of glioma pathology than the maintenance group (87.5% vs. 28.6%, p=0.005). Cumulative survival rates with sustained effect were significantly higher in the groups with non-glioma pathology (p=0.019) and the absence of diffusion restriction (p<0.001). Pathology of glioma and diffusion restriction in MRI were the independent risk factors for non-response or delayed worsening after initial response.

CONCLUSION

The initial response of RN to bevacizumab was favorable, with improvement in four-fifths of the patients. However, a certain proportion of patients showed non-responsiveness or delayed exacerbations. Bevacizumab may be more effective in treating RN in patients with non-glioma pathology and without diffusion restriction in the MRI.

Roles and therapeutic potential of different extracellular vesicle subtypes on traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of injury-related disability and death around the world, but the clinical stratification, diagnosis, and treatment of complex TBI are limited. Due to their unique properties, extracellular vesicles (EVs) are emerging candidates for being biomarkers of traumatic brain injury as well as serving as potential therapeutic targets. However, the effects of different extracellular vesicle subtypes on the pathophysiology of traumatic brain injury are very different, or potentially even opposite. Before extracellular vesicles can be used as targets for TBI therapy, it is necessary to classify different extracellular vesicle subtypes according to their functions to clarify different strategies for EV-based TBI therapy. The purpose of this review is to discuss contradictory effects of different EV subtypes on TBI, and to propose treatment ideas based on different EV subtypes to maximize their benefits for the recovery of TBI patients. Video Abstract.

Cellular and Molecular Pathophysiology of Traumatic Brain Injury: What Have We Learned So Far?

Traumatic brain injury (TBI) is one of the leading causes of long-lasting morbidity and mortality worldwide, being a devastating condition related to the impairment of the nervous system after an external traumatic event resulting in transitory or permanent functional disability, with a significant burden to the healthcare system. Harmful events underlying TBI can be classified into two sequential stages, primary and secondary, which are both associated with breakdown of the tissue homeostasis due to impairment of the blood-brain barrier, osmotic imbalance, inflammatory processes, oxidative stress, excitotoxicity, and apoptotic cell death, ultimately resulting in a loss of tissue functionality. The present study provides an updated review concerning the roles of brain edema, inflammation, excitotoxicity, and oxidative stress on brain changes resulting from a TBI. The proper characterization of the phenomena resulting from TBI can contribute to the improvement of care, rehabilitation and quality of life of the affected people.

A Single-Center Experience of Correlation of Pulse Pressure to Mortality of Stroke Hemorrhage Patients in Indonesia

Introduction

The relationship between pulse pressure and mortality in acute stroke hemorrhage patients is a subject of debate. To investigate this relationship in the Indonesian context, a study was conducted due to the increasing prevalence of stroke in the country.

Methods

The study sample consisted of 111 patients with acute stroke hemorrhage admitted to the hospital between January 1, 2016, and December 31, 2019. Patients with sepsis, cancer, or other hematology disorders were excluded, as were those who were lost to follow-up. Statistical analysis was performed using SPSS 22, and correlations were evaluated between various patient characteristics and laboratory values.

Results

It was revealed that patients with a wider pulse pressure were more likely to die (adjusted odds ratio = 3,070) than those with a normal or constricted pulse pressure.

Conclusion

Pulse pressure had an impact on the mortality of patients with acute hemorrhagic stroke.

The Role of Substance P Within Traumatic Brain Injury and Implications for Therapy

This review examines the role of the neuropeptide substance P within the neuroinflammation that follows traumatic brain injury. It examines it in reference to its preferential receptor, the neurokinin-1 receptor, and explores the evidence for antagonism of this receptor in traumatic brain injury with therapeutic intent. Expression of substance P increases following traumatic brain injury. Subsequent binding to the neurokinin-1 receptor results in neurogenic inflammation, a cause of deleterious secondary effects that include an increased intracranial pressure and poor clinical outcome. In several animal models of TBI, neurokinin-1 receptor antagonism has been shown to reduce brain edema and the resultant rise in intracranial pressure. A brief overview of the history of substance P is presented, alongside an exploration into the chemistry of the neuropeptide with a relevance to its functions within the central nervous system. This review summarizes the scientific and clinical rationale for substance P antagonism as a promising therapy for human TBI.

Heart-Rate-to-Blood-Pressure Ratios Correlate with Malignant Brain Edema and One-Month Death in Large Hemispheric Infarction: A Cohort Study

INTRODUCTION

Large hemispheric infarction (LHI) can lead to fatal complications such as malignant brain edema (MBE). We aimed to investigate the correlation between heart-rate-to-blood-pressure ratios and MBE or one-month death after LHI.

METHODS

We prospectively included LHI patients from a registered cohort. Hourly heart-rate-to-blood-pressure ratios were recorded as a variation of the traditional shock index (SI), SIs and SId (systolic and diastolic pressures, respectively), and calculated for mean and variability (standard deviation) in 24 h and two 12 h epochs (1-12 h and 13-24 h) after onset of symptoms. MBE was defined as neurological deterioration symptoms with imaging evidence of brain swelling. We employed a generalized estimating equation to compare the trend in longitudinal collected SIs and SId between patients with and without MBE. We used multivariate logistic regression to investigate the correlation between SIs, SId and outcomes.

RESULTS

Of the included 162 LHI patients, 28.4% (46/162) developed MBE and 25.3% (40/158) died within one month. SIs and SId increased over baseline in all patients, with a similar ascending profile during the first 12 h epoch and a more intensive increase in the MBE group during the second 12 h epoch (p < 0.05). During the overall 24 h, patients with greater SId variability had a significantly increased MBE risk after adjustment (OR 3.72, 95%CI 1.38-10.04). Additionally, during the second 12 h epoch (13-24 h after symptom onset), patients developing MBE had a significantly higher SId level (OR 1.18, 95%CI 1.00-1.39) and greater SId variability (OR 3.16, 95%CI 1.35-7.40). Higher SId and greater SId variability within 24 h independently correlated with one-month death (all p < 0.05). Within the second 12 h epoch, higher SIs, higher SId and greater SId variability independently correlated with one-month death (all p < 0.05). No significant correlation was observed in the first 12 h epoch.

CONCLUSIONS

Higher and more fluctuated heart-rate-to-blood-pressure ratios independently correlated with MBE development and one-month death in LHI patients, especially during the second 12 h (13-24 h) epoch after onset.

Dexamethasone for delayed edema after intracerebral hemorrhage： To be or not to be?

The pathogenesis of delayed cerebral edema after intracerebral hemorrhage is still unclear. In this case report, we speculate that the formation of subdural effusion or hemorrhage is associated with delayed cerebral edema. By referring to the treatment plan of chronic subdural hematoma, adding dexamethasone to routine medication, certain therapeutic effect has been achieved. Dexamethasone may maintain the stability of blood-brain barrier by directly increasing the expression of ZO-1, and reduce the neuroinflammatory response caused by NF-κB pathway by upregulating KLF2 expression, ultimately reducing nerve injury through multiple pathways.

Wernicke Encephalopathy: An Updated Narrative Review

Wernicke's encephalopathy (WE) and Korsakoff Syndrome (KS) are distinct neurological disorders that may have overlapping clinical features. Due to the overlap, they are collectively known as Wernicke-Korsakoff syndrome. WE is related to diencephalic and mesencephalic dysfunction due to thiamine. WE typically manifests as confusion, ophthalmoplegia, nystagmus, and gait ataxia (Wernicke's triad), although they may not consistently occur together. Although WE mostly occurs in alcoholics, other etiologies, such as post-bariatric surgery, must be considered. Early diagnosis and therapy by intravenous thiamine are essential to prevent WE complications and to reduce morbidity and mortality. Therefore, physicians' and patients' awareness of WE is essential for early diagnosis and therapy. Accordingly, this narrative review aimed to provide an update on WE by reviewing articles published between April 2015 to April 2022 about the etiology, pathophysiology, diagnosis, and WE management updates. EMBASE, PubMed, Google Scholar, Google, and Scopus search engines were used to conduct the literature search.

Pneumatic Compression Combined with Standard Treatment after Total Hip Arthroplasty and Its Effects on Edema of the Operated Limb and on Physical Outcomes: A Pilot Clinical Randomized Controlled Study

Total hip arthroplasty (THA) is one of the most successful orthopedic procedures and is highly effective at improving function and quality of life. However, patients commonly experience edema immediately after hospitalization and also after discharge, which can lead to health consequences and a lower quality of life. For these reasons, the aim of this study (NCT05312060) was to evaluate the effectiveness of a specific intermittent leg pneumatic compression on lower limb edema and physical outcomes in patients after total hip arthroplasty, compared to standard conservative treatment. A total of 47 patients were enrolled and randomly allocated into two groups: the pneumatic compression group (PG = 24) and the control group (CG = 23). The CG performed the standard venous thromboembolism therapy, which included pharmacological prophylaxis, compressive stockings, and electrostimulation, while the PG combined pneumatic compression with standard VTE therapy. We evaluated thigh and calf circumferences, knee and ankle ranges of motion, pain, and walking autonomy. Our results showed a greater reduction in thigh and calf circumferences for PG (p < 0.001), while other outcomes were similar for the two groups (p > 0.05). The combination of standard therapy with pneumatic leg compression was more effective at reducing lower limb edema and thigh and calf circumferences than standard treatment. Our results suggest that pressotherapy treatment is a valuable and efficient option for managing lower limb edema after THA.

Edema after CNS Trauma: A Focus on Spinal Cord Injury

Edema after spinal cord injury (SCI) is one of the first observations after the primary injury and lasts for few days after trauma. It has serious consequences on the affected tissue and can aggravate the initial devastating condition. To date, the mechanisms of the water content increase after SCI are not fully understood. Edema formation results in a combination of interdependent factors related to mechanical damage after the initial trauma progressing, along with the subacute and acute phases of the secondary lesion. These factors include mechanical disruption and subsequent inflammatory permeabilization of the blood spinal cord barrier, increase in the capillary permeability, deregulation in the hydrostatic pressure, electrolyte-imbalanced membranes and water uptake in the cells. Previous research has attempted to characterize edema formation by focusing mainly on brain swelling. The purpose of this review is to summarize the current understanding of the differences in edema formation in the spinal cord and brain, and to highlight the importance of elucidating the specific mechanisms of edema formation after SCI. Additionally, it outlines findings on the spatiotemporal evolution of edema after spinal cord lesion and provides a general overview of prospective treatment strategies by focusing on insights to prevent edema formation after SCI.

CircBCL11B acts as a ceRNA to facilitate 1,2-dichloroethane-induced astrocyte swelling via miR-29b-3p/AQP4 axis in SVG p12 cells

1,2-Dichloroethane (1,2-DCE) is a pervasive environmental pollutant found in ambient and residential air, as well as ground and drinking water. Brain edema is the primary pathological consequence of 1,2-DCE overexposure. We found that microRNA (miRNA)-29b dysregulation after 1,2-DCE exposure can aggravate brain edema by suppressing aquaporin 4 (AQP4). Moreover, circular RNAs (circRNAs) can regulate the expression of downstream target genes through miRNA, and affect protein function. However, circRNAs' role in 1,2-DCE-induced brain edema via miR-29b-3p/AQP4 axis remains unclear. To address the mechanism's bottleneck, we explored the circRNA-miRNA-mRNA network underlying 1,2-DCE-driven astrocyte swelling in SVG p12 cells by circRNA sequencing, electron microscopy and isotope ³H labeling combined with the 3-O-methylglucose uptake method. The results showed that 25 and 50mM 1,2-DCE motivated astrocyte swelling, characterized by increased water content, enlarged cell vacuoles, and mitochondrial swelling. This was accompanied by miR-29b-3p downregulation and AQP4 upregulation. We verified that AQP4 were negatively regulated by miR-29b-3p in 1,2-DCE-induced astrocyte swelling. Also, circRNA sequencing highlighted that circBCL11B was upregulated by 1,2-DCE. This was manifested as circBCL11B overexpression playing an endogenous competitive role via upregulating AQP4 by binding to miR-29b-3p, thus leading to astrocyte swelling. Conversely, circBCL11B knockdown reversed the 1,2-DCE-motivated AQP4 upregulation and alleviated the cell swelling. Finally, we demonstrated that the circBCL11B was targeted to miR-29b-3p by fluorescence in situ hybridization and dual-luciferase reporter assay. In conclusion, our findings indicate that circBCL11B acts as a competing endogenous RNA to facilitate 1,2-DCE-caused astrocyte swelling via miR-29b-3p/AQP4 axis. These observations provide new insight into the epigenetic mechanisms underlying 1,2-DCE-induced brain edema.

Peritumoral edema in meningiomas: pathophysiology, predictors, and principles for treatment

Meningiomas is a tumor of the meninges and is among the most common intracranial neoplasms in adults, accounting for over a third of all primary brain tumors in the United States. Meningiomas can be associated with peritumoral brain edema (PTBE) which if not managed appropriately can lead to poor clinical outcomes. In this review, we summarize the relevant pathophysiology, predictors, and principles for treatment of PTBE. The results of various case-reports and case-series have found that meningioma-associated PTBE have patterns in age, tumor size, and hormone receptor positivity. Our study describes how increased age, increased tumor size, tumor location in the middle fossa, and positive expression of hormone receptors, VEGF, and MMP-9 can all be predictors for worse clinical outcomes. We also characterize treatment options for PTBE such as glucocorticoids and VEGF inhibitors along with the ongoing clinical trials attempting to alleviate PTBE in meningioma cases. The trends summarized in this review can be used to better predict the behavior of meningioma-associated PTBE and establish prognosis models to identify at risk patients.

The modulatory effects of gut microbes and metabolites on blood–brain barrier integrity and brain function in sepsis-associated encephalopathy

Background

Intestinal microbiota homeostasis and the gut-brain axis are key players associated with host health and alterations in metabolic, inflammatory, and neurodegenerative disorders. Sepsis-associated encephalopathy (SAE), which is closely associated with bacterial translocation, is a common secondary organ dysfunction and an urgent, unsolved problem affecting patient quality of life. Our study examined the neuroprotective effects of the gut microbiome and short-chain fatty acid (SCFA) metabolites on SAE.

Methods

Male C57BL/6 mice were administered SCFAs in drinking water, then subjected to cecal ligation and puncture (CLP) surgery to induce SAE. 16S rRNA sequencing was used to investigate gut microbiome changes. The open field test (OFT) and Y-maze were performed to evaluate brain function. The permeability of the blood–brain barrier (BBB) was assessed by Evans blue (EB) staining. Hematoxylin and eosin (HE) staining was used to examine intestinal tissue morphology. The expression levels of tight junction (TJ) proteins and inflammatory cytokines was assessed by western blots and immunohistochemistry. In vitro, bEND.3 cells were incubated with SCFAs and then with lipopolysaccharide (LPS). Immunofluorescence was used to examine the expression of TJ proteins.

Results

The composition of the gut microbiota was altered in SAE mice; this change may be related to SCFA metabolism. SCFA treatment significantly alleviated behavioral dysfunction and neuroinflammation in SAE mice. SCFAs upregulated occludin and ZO-1 expression in the intestine and brain in SAE mice and LPS-treated cerebromicrovascular cells.

Conclusions

These findings suggested that disturbances in the gut microbiota and SCFA metabolites play key roles in SAE. SCFA supplementation could exert neuroprotective effects against SAE by preserving BBB integrity.

Bumetanide Rescues Aquaporin-4 Depolarization via Suppressing β-Dystroglycan Cleavage and Provides Neuroprotection in Rat Retinal Ischemia-Reperfusion Injury

Aquaporin-4 (AQP4) regulates retinal water homeostasis and participates in retinal oedema pathophysiology. β-dystroglycan (β-DG) is responsible for AQP4 polarization and can be cleaved by matrix metalloproteinase-9 (MMP9). Retinal oedema induced by ischemia-reperfusion (I/R) injury is an early complication. Bumetanide (BU) has potential efficacy against cytotoxic oedema. Our study investigated the effects of β-DG cleavage on AQP4 and the roles of BU in a rat retinal I/R injury model. The model was induced by applying 110 mm Hg intraocular pressure to the anterior eye chamber. BU and U0126 (a selective ERK inhibitor) were intraperitoneally administered 15 and 30 min, respectively, before I/R induction. Rhodamine isothiocyanate extravasation detection, quantitative real-time PCR, transmission electron microscopy, hematoxylin-eosin staining, immunofluorescence staining, western blotting, and TUNEL staining were performed. AQP4 lost its polarization in the retinal perivascular domain as a result of β-DG cleavage. BU rescued AQP4 depolarization, suppressed AQP4 protein expression, attenuated retinal cytotoxic oedema, and downregulated β-DG and AQP4 mRNA expression. BU suppressed glial responses and mitochondria-mediated apoptotic protein expression, including that of Caspase-3 and Cyto C, raised the Bcl-2/Bax ratio, and lowered the number of apoptotic cells in the retina. Both BU and U0126 downregulated p-ERK and MMP9 expression. Thus, BU treatment suppressed β-DG cleavage, recovered AQP4 polarization partially via inhibiting ERK/MMP9 signaling pathway, and possess potential neuroprotective efficacy in the rat retinal ischemia-reperfusion injury model.

Posterior reversible encephalopathy syndrome and autoimmunity

Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome characterized by acute or subacute onset of neurological symptoms (e.g., headache, seizure, confusion, vomiting, and diminished eyesight) and impaired endothelial barrier function of the cerebral circulation that leads to bilateral subcortical vasogenic edema, while exhibiting a "reversible" feature in most cases. Clinically, various predisposing or precipitating conditions have been identified, such as hypertension, autoimmune diseases, renal dysfunction/failure, preeclampsia/eclampsia, post-transplantation conditions, and certain therapeutic agents. Among several putative mechanisms, the immune activation hypothesis prevails, as up to 50% of patients with PRES harbor abnormalities related to autoimmunity, such as concurrent systemic lupus erythematosus. In this Review, we summarize the clinical and laboratory evidence that places PRES in the context of autoimmunity.

Memantine as a neuroprotective agent in ischemic stroke: Preclinical and clinical analysis

The primary mechanism for neuron death after an ischemic stroke is excitotoxic injury. Excessive depolarization leads to NMDA-mediated calcium entry to the neuron and, subsequently, cellular death. Therefore, the inhibition of the NMDA channel has been proposed as a neuroprotective measure in ischemic stroke. The high morbimortality associated with stroke warrants new therapies that can improve the functional prognosis of patients. Memantine is a non-competitive NMDA receptor antagonist which has gained attention as a potential drug for ischemic stroke. Here we analyze the available preclinical and clinical evidence concerning the use of memantine following an ischemic stroke. Preclinical evidence shows inhibition of the excitotoxic cascade, as well as improved outcomes in terms of motor and sensory function with the use of memantine. The available clinical trials of high-dose memantine in patients poststroke have found that it can improve patients' NIHSS and Barthel index and help patients with poststroke aphasia and intracranial hemorrhage. These results suggest that memantine has a clinically relevant neuroprotective effect; however, small sample sizes and other study shortcomings limit the impact of these findings. Even so, current studies show promising results that should serve as a basis to promote future research to conclusively determine if memantine does improve the outcomes of patients' post-ischemic stroke. We anticipate that future trials will fill current gaps in knowledge, and these latter results will broaden the therapeutic arsenal for clinicians looking to improve the prognosis of patients poststroke.