ABSTRACT
OBJECTIVE: We aimed to determine whether quantitative electroencephalography (QEEG) measures have predictive value for cerebral edema (CED) and clinical outcomes in acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion who underwent mechanical thrombectomy (MT). METHODS: A total of 105 patients with AIS in the anterior circulation were enrolled in this prospective study. The occurrence and severity of CED were assessed through computed tomography conducted 24 h after MT. Clinical outcomes were evaluated based on early neurological deterioration (END) and 3-month functional status, as measured by the modified Rankin scale (mRS). Electroencephalography (EEG) recordings were performed 24 h after MT, and QEEG indices were calculated from the standard 16 electrodes and 2 frontal channels (F3-C3, F4-C4). The delta/alpha ratio (DAR), the (delta + theta) / (alpha + beta) ratio (DTABR), and relative delta power were averaged over all electrodes (global) and the F3-C3 and F4-C4 channels (frontal). The predictive effect and value of QEEG indices for CED and clinical outcomes were assessed using ordinal and logistic regression models, as well as receiver operating characteristic (ROC) curves. RESULTS: Significantly, both global and frontal DAR were found to be associated with the severity of CED, END, and poor functional outcomes at 90 days, while global and frontal DTABR and relative delta power were not associated with outcomes. In ROC analysis, the best predictive effect was observed in frontal DAR, with an area under the curve of approximately 0.80. It exhibited approximately 75% sensitivity and 71% specificity for radiological and clinical outcomes when a threshold of 3.3 was used. CONCLUSIONS: QEEG techniques may be considered an efficient bedside monitoring method for assessing treatment efficacy, identifying patients at higher risk of severe CED and END, and predicting long-term functional outcomes. SIGNIFICANCE: QEEG can help identify patients at risk of severe neurological complications that can impact long-term functional recovery in AIS patients who underwent MT.
Subject(s)
Brain Edema , Electroencephalography , Thrombectomy , Humans , Male , Female , Aged , Brain Edema/physiopathology , Brain Edema/diagnostic imaging , Brain Edema/etiology , Middle Aged , Thrombectomy/methods , Electroencephalography/methods , Prospective Studies , Delta Rhythm/physiology , Treatment Outcome , Alpha Rhythm/physiology , Ischemic Stroke/physiopathology , Ischemic Stroke/surgery , Aged, 80 and over , Stroke/physiopathology , Stroke/surgery , Predictive Value of TestsABSTRACT
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.
Subject(s)
Brain Edema , Brain , Humans , Brain Edema/physiopathology , Brain Edema/metabolism , Brain Edema/etiology , Animals , Brain/metabolism , Brain/physiopathology , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/physiopathology , Brain Ischemia/physiopathology , Brain Ischemia/metabolismABSTRACT
Millions of people visit high-altitude regions annually and more than 80 million live permanently above 2,500 m. Acute high-altitude exposure can trigger high-altitude illnesses (HAIs), including acute mountain sickness (AMS), high-altitude cerebral oedema (HACE) and high-altitude pulmonary oedema (HAPE). Chronic mountain sickness (CMS) can affect high-altitude resident populations worldwide. The prevalence of acute HAIs varies according to acclimatization status, rate of ascent and individual susceptibility. AMS, characterized by headache, nausea, dizziness and fatigue, is usually benign and self-limiting, and has been linked to hypoxia-induced cerebral blood volume increases, inflammation and related trigeminovascular system activation. Disruption of the blood-brain barrier leads to HACE, characterized by altered mental status and ataxia, and increased pulmonary capillary pressure, and related stress failure induces HAPE, characterized by dyspnoea, cough and exercise intolerance. Both conditions are progressive and life-threatening, requiring immediate medical intervention. Treatment includes supplemental oxygen and descent with appropriate pharmacological therapy. Preventive measures include slow ascent, pre-acclimatization and, in some instances, medications. CMS is characterized by excessive erythrocytosis and related clinical symptoms. In severe CMS, temporary or permanent relocation to low altitude is recommended. Future research should focus on more objective diagnostic tools to enable prompt treatment, improved identification of individual susceptibilities and effective acclimatization and prevention options.
Subject(s)
Altitude Sickness , Altitude , Humans , Altitude Sickness/physiopathology , Altitude Sickness/epidemiology , Altitude Sickness/complications , Acclimatization/physiology , Brain Edema/physiopathology , Brain Edema/etiology , Brain Edema/epidemiology , Pulmonary Edema/physiopathology , Pulmonary Edema/etiology , Pulmonary Edema/epidemiology , Hypertension, Pulmonary/physiopathology , Hypertension, Pulmonary/epidemiology , Hypertension, Pulmonary/etiology , Hypoxia/physiopathology , Hypoxia/complications , Hypoxia/etiologyABSTRACT
Ischemic stroke occurs due a blockage in the blood flow to the brain, leading to damage to the nervous system. The prevalent morbidities resulting from stroke include post-stroke infection, as sepsis. Additionally, oxidative stress is recognized for inducing functional deficits in peripheral organs during sepsis. Therefore, sex differences in stroke exist and we aimed to investigate the peripheral oxidative stress caused by sepsis after stroke in male and female rats. Wistar rats (male and female) were divided into sham+sham, middle cerebral artery occlusion (MCAO) + sham, sham+ cecal ligation and perforation (CLP) and MCAO+CLP groups to males and female rats. Animals were subjected to MCAO or sham and after 7 days, were subjected to sepsis by CLP or sham. After 24 h, serum, total brain, lung, liver, heart, and spleen were collected. Brain edema, myeloperoxidase (MPO) activity, nitrite/nitrate (N/N) concentration, oxidative damage to lipids and proteins, and catalase activity were evaluated. Brain edema was observed only in male rats in MCAO+CLP group compared to MCAO+sham. Regarding MPO activity, an increase was verified in male in different organs and serum in MCAO+CLP group. For N/N levels, the increase was more pronounced in females submitted to MCAO+CLP. In general, to oxidative stress, an increase was only observed in animals exposed to MCAO+CLP, or with a greater increase in this group compared to the others. The findings provided the first indication that animals exposed to MCAO exhibit a heightened vulnerability to the harmful impacts of sepsis, as evidenced by brain edema and peripheral oxidative stress, and this susceptibility is dependent of sex.
Subject(s)
Brain Edema , Disease Models, Animal , Infarction, Middle Cerebral Artery , Oxidative Stress , Peroxidase , Rats, Wistar , Sepsis , Animals , Female , Male , Infarction, Middle Cerebral Artery/metabolism , Infarction, Middle Cerebral Artery/pathology , Infarction, Middle Cerebral Artery/physiopathology , Infarction, Middle Cerebral Artery/blood , Sepsis/metabolism , Sepsis/physiopathology , Sepsis/complications , Sepsis/blood , Sex Factors , Peroxidase/metabolism , Brain Edema/metabolism , Brain Edema/pathology , Brain Edema/physiopathology , Nitrates/blood , Nitrates/metabolism , Nitrites/blood , Nitrites/metabolism , Rats , Brain/metabolism , Brain/pathology , Brain/blood supply , Catalase/metabolismABSTRACT
In ischaemic stroke, a large reduction in blood supply can lead to the breakdown of the blood-brain barrier and to cerebral oedema after reperfusion therapy. The resulting fluid accumulation in the brain may contribute to a significant rise in intracranial pressure (ICP) and tissue deformation. Changes in the level of ICP are essential for clinical decision-making and therapeutic strategies. However, the measurement of ICP is constrained by clinical techniques and obtaining the exact values of the ICP has proven challenging. In this study, we propose the first computational model for the simulation of cerebral oedema following acute ischaemic stroke for the investigation of ICP and midline shift (MLS) relationship. The model consists of three components for the simulation of healthy blood flow, occluded blood flow and oedema, respectively. The healthy and occluded blood flow components are utilized to obtain oedema core geometry and then imported into the oedema model for the simulation of oedema growth. The simulation results of the model are compared with clinical data from 97 traumatic brain injury patients for the validation of major model parameters. Midline shift has been widely used for the diagnosis, clinical decision-making, and prognosis of oedema patients. Therefore, we focus on quantifying the relationship between ICP and midline shift (MLS) and identify the factors that can affect the ICP-MLS relationship. Three major factors are investigated, including the brain geometry, blood-brain barrier damage severity and the types of oedema (including rare types of oedema). Meanwhile, the two major types (stress and tension/compression) of mechanical brain damage are also presented and the differences in the stress, tension, and compression between the intraparenchymal and periventricular regions are discussed. This work helps to predict ICP precisely and therefore provides improved clinical guidance for the treatment of brain oedema.
Subject(s)
Brain Edema , Computer Simulation , Intracranial Pressure , Ischemic Stroke , Brain Edema/physiopathology , Humans , Ischemic Stroke/physiopathology , Ischemic Stroke/complications , Intracranial Pressure/physiology , Computational Biology , Cerebral Ventricles/physiopathology , Cerebral Ventricles/diagnostic imaging , Blood-Brain Barrier/physiopathology , MaleABSTRACT
Glioblastoma multiforme (GBM) is characterized by a remarkable cellular and molecular heterogeneity that make the behavior of this tumor highly variable and resistant to therapy. In addition, the most serious clinical complication of GBM and other brain tumors is the development of vasogenic edema which dramatically increase the intracranial pressure. In the present study we evaluate the expression, supramolecular organization and spatial distribution of AQP4 and AQP4ex, the new readthrough isoform of AQP4, in relationship with the degree of vasogenic brain edema and tumor progression. To this purpose, tissue samples from regions of tumor core, peritumoral and non-infiltrated tissues of each GBM patient (n = 31) were analyzed. Immunofluorescence experiments revealed that the expression of AQP4ex was almost absent in tumoral regions while the canonical AQP4 isoforms appear mostly delocalized. In peritumoral tissues, AQP4 expression was found altered in those perivascular astrocyte processes where AQP4ex appeared reduced and partially delocalized. Protein expression levels measured by immunoblot showed that global AQP4 was reduced mainly in the tumor core. Notably, the relative amount of AQP4ex was more severely reduced starting from the peritumoral region. BN-PAGE experiments showed that the supramolecular organization of AQP4 is only partially affected in GBM. Edema assessment by magnetic resonance imaging revealed that the level of AQP4ex downregulation correlated with edema severity. Finally, the degree of BBB alteration, measured with sodium fluorescein content in GBM biopsies, correlated with the edema index and AQP4ex downregulation. Altogether these data suggest that the AQP4ex isoform is critical in the triggering event of progressive downregulation and mislocalization of AQP4 in GBM, which may affect the integrity of the BBB and contributes to accumulation of edema in the peritumoral tissue. Thus, AQP4ex could be considered as a potential early biomarker of GBM progression.
Subject(s)
Aquaporin 4/metabolism , Brain Edema/physiopathology , Brain Neoplasms/pathology , Glioblastoma/pathology , Protein Biosynthesis , Aged , Aquaporin 4/genetics , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Child , Female , Glioblastoma/genetics , Glioblastoma/metabolism , Humans , Male , Middle Aged , Protein IsoformsABSTRACT
Intracerebral hemorrhage (ICH) is a severe, life-threatening subtype of stoke that constitutes a crucial health and socioeconomic problem worldwide. However, the current clinical treatment can only reduce the mortality of patients to a certain extent, but cannot ameliorate neurological dysfunction and has a high recurrence rate. Increasing evidence has demonstrated that mitochondrial dysfunction occurs in the early stages of brain injury and participates in all stages of secondary brain injury (SBI) after ICH. As the energy source of cells, various pathobiological processes that lead to SBI closely interact with the mitochondria, such as oxidative stress, calcium overload, and neuronal injury. In this review, we discussed the structure and function of mitochondria and the abnormal morphological changes after ICH. In addition, we discussed recent research on the involvement of mitochondrial dynamics in the pathological process of SBI after ICH and introduced the pathological variations and related molecular mechanisms of mitochondrial dysfunction in the occurrence of brain injury. Finally, we summarized the latest progress in mitochondrion-targeted agents for ICH, which provides a direction for the development of emerging therapeutic strategies targeting the mitochondria after ICH.
Subject(s)
Brain Injuries/physiopathology , Cerebral Hemorrhage/physiopathology , Mitochondria/metabolism , Mitochondria/pathology , Animals , Antioxidants/metabolism , Apoptosis , Brain Edema/physiopathology , Brain Injuries/metabolism , Cerebral Hemorrhage/drug therapy , Cerebral Hemorrhage/metabolism , Disease Models, Animal , Humans , Inflammation/metabolism , Mice , Mitochondrial Dynamics , Neurons/metabolism , Oxidative Stress , Rats , Reactive Oxygen Species/metabolismABSTRACT
Intracerebral hemorrhage (ICH) has one of the worst prognoses among patients with stroke. Surgical measures have been adopted to relieve the mass effect of the hematoma, and developing targeted therapy against secondary brain injury (SBI) after ICH is equally essential. Numerous preclinical and clinical studies have demonstrated that perihematomal edema (PHE) is a quantifiable marker of SBI after ICH and is associated with a poor prognosis. Thus, PHE has been considered a promising therapeutic target for ICH. However, the findings derived from existing studies on PHE are disparate and unclear. Therefore, it is necessary to classify, compare, and summarize the existing studies on PHE. In this review, we describe the growth characteristics and relevant underlying mechanism of PHE, analyze the contributions of different risk factors to PHE, present the potential impact of PHE on patient outcomes, and discuss the currently available therapeutic strategies.
Subject(s)
Brain Edema/physiopathology , Brain/pathology , Cerebral Hemorrhage/physiopathology , Hematoma/physiopathology , Brain/diagnostic imaging , Brain Edema/etiology , Brain Edema/prevention & control , Cerebral Hemorrhage/complications , Cerebral Hemorrhage/therapy , Glyburide/therapeutic use , Hematoma/etiology , Hematoma/prevention & control , Humans , Hypoglycemic Agents/therapeutic use , Magnetic Resonance Imaging , Neurogenic Inflammation , Risk FactorsABSTRACT
The pathology of cerebrovascular disorders takes an important role in traumatic brain injury (TBI) by increasing intracranial pressure. Fibroblast growth factor 20 (FGF20) is a brain-derived neurotrophic factor, that has been shown to play an important role in the survival of dopaminergic neurons and the treatment of Parkinson's disease (PD). However, little is known about the role of FGF20 in the treatment of TBI and its underlying mechanism. The purpose of this study was to evaluate the protective effect of recombinant human FGF20 (rhFGF20) on protecting cerebral blood vessels after TBI. In this study, we indicated that rhFGF20 could reduce brain edema, Evans blue penetration and upregulated the expression of blood-brain barrier (BBB)-related tight junction (TJ) proteins, exerting a protective effect on the BBB in vivo after TBI. In the TBI repair phase, rhFGF20 promoted angiogenesis, neurological and cognitive function recovery. In tumor necrosis factor-α (TNF-α)-induced human brain microvascular endothelial cells (hCMEC/D3), an in vitro BBB disruption model, rhFGF20 reversed the impairment in cell migration and tube formation induced by TNF-α. Moreover, in both the TBI mouse model and the in vitro model, rhFGF20 increased the expression of ß-catenin and GSK3ß, which are the two key regulators in the Wnt/ß-catenin signaling pathway. In addition, the Wnt/ß-catenin inhibitor IWR-1-endo significantly reversed the effects of rhFGF20. These results indicate that rhFGF20 may prevent vascular repair and angiogenesis through the Wnt/ß-catenin pathway.
Subject(s)
Angiogenesis Inducing Agents/pharmacology , Blood-Brain Barrier/drug effects , Brain Injuries, Traumatic/drug therapy , Endothelial Cells/drug effects , Fibroblast Growth Factors/pharmacology , Intracranial Pressure , Neovascularization, Physiologic/drug effects , Wnt Signaling Pathway/drug effects , Animals , Behavior, Animal/drug effects , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/pathology , Blood-Brain Barrier/physiopathology , Brain Edema/drug therapy , Brain Edema/metabolism , Brain Edema/pathology , Brain Edema/physiopathology , Brain Injuries, Traumatic/metabolism , Brain Injuries, Traumatic/pathology , Brain Injuries, Traumatic/physiopathology , Capillary Permeability/drug effects , Cell Movement/drug effects , Cells, Cultured , Disease Models, Animal , Endothelial Cells/metabolism , Endothelial Cells/pathology , Humans , Male , Memory/drug effects , Mice, Inbred C57BL , Morris Water Maze Test/drug effects , Motor Activity/drug effects , Recombinant Proteins/pharmacology , Rotarod Performance Test , Tight Junction Proteins/metabolism , Tight Junctions/drug effects , Tight Junctions/metabolism , Tight Junctions/pathologyABSTRACT
The Apicomplexa protozoan Toxoplasma gondii is a mandatory intracellular parasite and the causative agent of toxoplasmosis. This illness is of medical importance due to its high prevalence worldwide and may cause neurological alterations in immunocompromised persons. In chronically infected immunocompetent individuals, this parasite forms tissue cysts mainly in the brain. In addition, T. gondii infection has been related to mental illnesses such as schizophrenia, bipolar disorder, depression, obsessive-compulsive disorder, as well as mood, personality, and other behavioral changes. In the present study, we evaluated the kinetics of behavioral alterations in a model of chronic infection, assessing anxiety, depression and exploratory behavior, and their relationship with neuroinflammation and parasite cysts in brain tissue areas, blood-brain-barrier (BBB) integrity, and cytokine status in the brain and serum. Adult female C57BL/6 mice were infected by gavage with 5 cysts of the ME-49 type II T. gondii strain, and analyzed as independent groups at 30, 60 and 90 days postinfection (dpi). Anxiety, depressive-like behavior, and hyperactivity were detected in the early (30 dpi) and long-term (60 and 90 dpi) chronic T. gondii infection, in a direct association with the presence of parasite cysts and neuroinflammation, independently of the brain tissue areas, and linked to BBB disruption. These behavioral alterations paralleled the upregulation of expression of tumor necrosis factor (TNF) and CC-chemokines (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1ß and CCL5/RANTES) in the brain tissue. In addition, increased levels of interferon-gamma (IFNγ), TNF and CCL2/MCP-1 were detected in the peripheral blood, at 30 and 60 dpi. Our data suggest that the persistence of parasite cysts induces sustained neuroinflammation, and BBB disruption, thus allowing leakage of cytokines of circulating plasma into the brain tissue. Therefore, all these factors may contribute to behavioral changes (anxiety, depressive-like behavior, and hyperactivity) in chronic T. gondii infection.
Subject(s)
Behavior, Animal , Blood-Brain Barrier/pathology , Blood-Brain Barrier/parasitology , Inflammation/parasitology , Toxoplasma/physiology , Toxoplasmosis, Cerebral/parasitology , Animals , Anxiety/complications , Anxiety/physiopathology , Brain Edema/complications , Brain Edema/physiopathology , Chronic Disease , Cytokines/metabolism , Depression/complications , Depression/physiopathology , Female , Inflammation/physiopathology , Locomotion , Mice, Inbred C57BL , Muscle Strength , Parasites/physiology , Time Factors , Toxoplasmosis, Cerebral/physiopathology , Up-RegulationABSTRACT
BACKGROUND: Intracerebral hemorrhage (ICH) is aggravated by immune cells that participate in the inflammatory response from the blood-brain barrier (BBB). O-Glycosylation has been reported to regulate the inflammatory response in the central nervous system but its cerebral protective effects remain unknown. Therefore, this study was carried out to investigate the protective effects of O-GlcNAcylation in a murine model of ICH and the possible mechanisms involved. METHODS: The effects of O-GlcNAcylation on hematoma and edema formation were tested using pathological and dry/wet weight methods, whereas its effects on neural function were determined using neurologic tests. The effect of O-GlcNAcylation on BBB integrity was determined by Evans blue dye extrusion. Flow cytometry was used to quantify the immune cells in the central nervous system. Immunofluorescence was used to detect the protective effect of O-GlcNAcylation in ICH. RESULTS: The hematoma volume was significantly lower in the prevention and treatment groups than in the control group after ICH induction, indicating that O-GlcNAcylation had reduced the formation of cerebral hematoma in ICH. In the prevention and treatment groups, the modified neurological severity score, corner turn test and rotating rod test results were improved and the BBB integrity was better than that in the control group. O-GlcNAcylation also regulated the microglia, neutrophils and other central nervous system immune cells after ICH, effectively reducing the inflammatory response. CONCLUSIONS: O-GlcNAcylation played an important role in suppressing the inflammatory response, enhancing the BBB integrity and reducing edema after ICH.
Subject(s)
Blood-Brain Barrier/drug effects , Brain Edema/metabolism , Cerebral Hemorrhage/metabolism , Hematoma/metabolism , Neuroinflammatory Diseases/metabolism , Neuroprotective Agents/pharmacology , Pyrans/pharmacology , Thiazoles/pharmacology , beta-N-Acetylhexosaminidases/antagonists & inhibitors , Animals , B-Lymphocytes/drug effects , Behavior, Animal , Blood-Brain Barrier/metabolism , Brain Edema/physiopathology , CD4-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/drug effects , Cerebral Hemorrhage/physiopathology , Cytokines/drug effects , Cytokines/metabolism , Disease Models, Animal , Hematoma/physiopathology , Killer Cells, Natural/drug effects , Mice , Microglia/drug effects , Neuroinflammatory Diseases/physiopathology , Neutrophils/drug effects , Protein Processing, Post-Translational/drug effects , Rotarod Performance TestABSTRACT
BACKGROUND: Previous models of intracranial pressure (ICP) dynamics have not included flow of cerebral interstitial fluid (ISF) and changes in resistance to its flow when brain swelling occurs. We sought to develop a mathematical model that incorporates resistance to the bulk flow of cerebral ISF to better simulate the physiological changes that occur in pathologies in which brain swelling predominates and to assess the model's ability to depict changes in cerebral physiology associated with cerebral edema. METHODS: We developed a lumped parameter model which includes a representation of cerebral ISF flow within brain tissue and its interactions with CSF flow and cerebral blood flow (CBF). The model is based on an electrical analog circuit with four intracranial compartments: the (1) subarachnoid space, (2) brain, (3) ventricles, (4) cerebral vasculature and the extracranial spinal thecal sac. We determined changes in pressure and volume within cerebral compartments at steady-state and simulated physiological perturbations including rapid injection of fluid into the intracranial space, hyperventilation, and hypoventilation. We simulated changes in resistance to flow or absorption of CSF and cerebral ISF to model hydrocephalus, cerebral edema, and to simulate disruption of the blood-brain barrier (BBB). RESULTS: The model accurately replicates well-accepted features of intracranial physiology including the exponential-like pressure-volume curve with rapid fluid injection, increased ICP pulse pressure with rising ICP, hydrocephalus resulting from increased resistance to CSF outflow, and changes associated with hyperventilation and hypoventilation. Importantly, modeling cerebral edema with increased resistance to cerebral ISF flow mimics key features of brain swelling including elevated ICP, increased brain volume, markedly reduced ventricular volume, and a contracted subarachnoid space. Similarly, a decreased resistance to flow of fluid across the BBB leads to an exponential-like rise in ICP and ventricular collapse. CONCLUSIONS: The model accurately depicts the complex interactions that occur between pressure, volume, and resistances to flow in the different intracranial compartments under specific pathophysiological conditions. In modelling resistance to bulk flow of cerebral ISF, it may serve as a platform for improved modelling of cerebral edema and blood-brain barrier disruption that occur following brain injury.
Subject(s)
Blood-Brain Barrier/physiology , Brain Edema/physiopathology , Brain/physiology , Cerebrospinal Fluid/physiology , Cerebrovascular Circulation/physiology , Models, Theoretical , Blood-Brain Barrier/anatomy & histology , Brain/anatomy & histology , Brain/blood supply , Cerebral Ventricles/anatomy & histology , Cerebral Ventricles/blood supply , Cerebral Ventricles/physiology , Humans , Intracranial Pressure/physiologyABSTRACT
Cardiac arrest (CA) remains a major public health issue. Inflammatory responses with overproduction of interleukin-1ß regulated by NLRP3 inflammasome activation play a crucial role in cerebral ischemia/reperfusion injury. We investigated the effects of the selective NLRP3-inflammasome inhibitor MCC950 on post-resuscitation cerebral function and neurologic outcome in a rat model of cardiac arrest. Thirty-six male rats were randomized into the MCC950 group, the control group, or the sham group (N = 12 of each group). Each group was divided into a 6 h non-survival subgroup (N = 6) and a 24 h survival subgroup (N = 6). Ventricular fibrillation (VF) was electrically induced and untreated for 6 min, followed by 8 min of precordial compressions and mechanical ventilation. Resuscitation was attempted with a 4J defibrillation. Either MCC950 (10 mg/kg) or vehicle was injected intraperitoneally immediately after the return of spontaneous circulation (ROSC). Rats in the sham group underwent the same surgical procedures without VF and CPR. Brain edema, cerebral microcirculation, plasma interleukin Iß (IL-1ß), and neuron-specific enolase (NSE) concentration were measured at 6 h post-ROSC of non-survival subgroups, while 24 h survival rate, neurological deficits were measured at 24 h post-ROSC of survival subgroups. Post-resuscitation brain edema was significantly reduced in animals treated with MCC950 (p < 0.05). Cerebral perfused vessel density (PVD) and microcirculatory flow index (MFI) values were significantly higher in the MCC950 group compared with the control group (p < 0.05). The plasma concentrations of IL-1ß and NSE were significantly decreased in animals treated with MCC950 compared with the control group (p < 0.05). 24 h-survival rate and neurological deficits score (NDS) was also significantly improved in the MCC950 group compared with the control group (p < 0.05). NLRP3 inflammasome blockade with MCC950 at ROSC reduces the circulatory level of IL-1ß, preserves cerebral microcirculation, mitigates cerebral edema, improves the 24 h-survival rate, and neurological deficits.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Brain Edema/prevention & control , Brain/drug effects , Cardiopulmonary Resuscitation/adverse effects , Furans/pharmacology , Indenes/pharmacology , Inflammasomes/antagonists & inhibitors , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , Sulfonamides/pharmacology , Animals , Brain/metabolism , Brain/pathology , Brain/physiopathology , Brain Edema/metabolism , Brain Edema/pathology , Brain Edema/physiopathology , Cerebrovascular Circulation/drug effects , Disease Models, Animal , Inflammasomes/metabolism , Interleukin-1beta/metabolism , Male , Microcirculation/drug effects , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Rats, Sprague-Dawley , Signal TransductionABSTRACT
BACKGROUND: The NLRP3 inflammasome is a critical mediator of several vascular diseases through positive regulation of proinflammatory pathways. In this study, we defined the role of NLRP3 in both the acute and delayed phases following subarachnoid hemorrhage (SAH). SAH is associated with devastating early brain injury (EBI) in the acute phase, and those that survive remain at risk for developing delayed cerebral ischemia (DCI) due to cerebral vasospasm. Current therapies are not effective in preventing the morbidity and mortality associated with EBI and DCI. NLRP3 activation is known to drive IL-1ß production and stimulate microglia reactivity, both hallmarks of SAH pathology; thus, we hypothesized that inhibition of NLRP3 could alleviate SAH-induced vascular dysfunction and functional deficits. METHODS: We studied NLRP3 in an anterior circulation autologous blood injection model of SAH in mice. Mice were randomized to either sham surgery + vehicle, SAH + vehicle, or SAH + MCC950 (a selective NLRP3 inhibitor). The acute phase was studied at 1 day post-SAH and delayed phase at 5 days post-SAH. RESULTS: NLRP3 inhibition improved outcomes at both 1 and 5 days post-SAH. In the acute (1 day post-SAH) phase, NLRP3 inhibition attenuated cerebral edema, tight junction disruption, microthrombosis, and microglial reactive morphology shift. Further, we observed a decrease in apoptosis of neurons in mice treated with MCC950. NLRP3 inhibition also prevented middle cerebral artery vasospasm in the delayed (5 days post-SAH) phase and blunted SAH-induced sensorimotor deficits. CONCLUSIONS: We demonstrate a novel association between NLRP3-mediated neuroinflammation and cerebrovascular dysfunction in both the early and delayed phases after SAH. MCC950 and other NLRP3 inhibitors could be promising tools in the development of therapeutics for EBI and DCI.
Subject(s)
Brain Injuries/etiology , Brain Injuries/physiopathology , Furans/pharmacology , Indenes/pharmacology , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , Subarachnoid Hemorrhage/pathology , Subarachnoid Hemorrhage/physiopathology , Sulfonamides/pharmacology , Vasospasm, Intracranial , Animals , Apoptosis/drug effects , Brain Edema/physiopathology , Brain Injuries/complications , Brain Ischemia/etiology , Brain Ischemia/physiopathology , Disease Models, Animal , Female , Interleukin-1beta/metabolism , Mice , Microglia/drug effects , Microglia/metabolism , Neuroinflammatory Diseases/physiopathology , Signal Transduction/drug effects , Vasospasm, Intracranial/etiology , Vasospasm, Intracranial/pathology , Vasospasm, Intracranial/physiopathologyABSTRACT
The spatial heterogeneity in the temporal occurrence of pseudo-normalization of MR apparent diffusion coefficient values for ischemic lesions may be related to morphological and functional vascular remodeling. As the area of accelerated pseudo-normalization tends to expand faster and more extensively into the chronic stage, detailed vascular characterization of such areas is necessary. During the subacute stage of transient middle cerebral artery occlusion rat models, the morphological size of the macrovasculature, microvascular vessel size index (VSI), and microvessel density (MVD) were quantified along with functional perfusion measurements of the relative cerebral blood flow (rCBF) and mean transit time (rMTT) of the corresponding areas (33 cases for each parameter). When compared with typical pseudo-normalization lesions, early pseudo-normalization lesions exhibited larger VSI and rCBF (p < 0.001) at reperfusion days 4 and 7, along with reduced MVD and elongated rMTT (p < 0.001) at reperfusion days 1, 4, and 7. The group median VSI and rCBF exhibited a strong positive correlation (r = 0.92), and the corresponding MVD and rMTT showed a negative correlation (r = -0.48). Light sheet fluorescence microscopy images were used to quantitatively validate the corresponding MRI-derived microvascular size, density, and cerebral blood volume.
Subject(s)
Brain Edema , Cerebrovascular Circulation , Ischemic Stroke , Magnetic Resonance Imaging , Animals , Brain Edema/diagnostic imaging , Brain Edema/physiopathology , Disease Models, Animal , Ischemic Stroke/diagnostic imaging , Ischemic Stroke/physiopathology , Male , Rats , Rats, WistarABSTRACT
Morphofunctional changes of the brain tissues of Wistar rats were studied based on the development of a multifactor cardiovasorenal model of arterial hypertension using MRI. An increase of the signal on the diffusion brain maps was recorded in 3 months, which indicated fluid accumulation in the intra- and extracellular space of the brain tissue. The data characterize the development of the pathogenetic mechanism of the hypervolemic variant of experimental arterial hypertension. The development of endothelial dysfunction in the brain vessels was manifested by predominance of abnormal constrictor reactions. In 6 months after arterial hypertension simulation, structural changes in the brain developed, such as leukoareosis, cystic encephalomalacia with dilated cerebrospinal fluid spaces and limited blood supply to brain tissue in the basins of the large cerebral arteries.
Subject(s)
Brain/diagnostic imaging , Diffusion Magnetic Resonance Imaging , Hypertension/diagnostic imaging , Animals , Brain/blood supply , Brain/pathology , Brain Edema/diagnosis , Brain Edema/pathology , Brain Edema/physiopathology , Brain Mapping/methods , Cerebral Veins/diagnostic imaging , Cerebral Veins/pathology , Hypertension/pathology , Hypertension/physiopathology , Intracranial Pressure/physiology , Male , Rats , Rats, WistarABSTRACT
OBJECTIVE: Decompressive craniectomy (DC) improves functional outcomes in selected patients with malignant hemispheric infarction (MHI), but variability in the surgical technique and occasional complications may be limiting the effectiveness of this procedure. Our aim was to evaluate predefined perioperative CT measurements for association with post-DC midline brain shift in patients with MHI. METHODS: At two medical centers we identified 87 consecutive patients with MHI and DC between January 2007 and December 2019. We used our previously tested methods to measure the craniectomy surface area, extent of transcalvarial brain herniation, thickness of tissues overlying the craniectomy, diameter of the cerebral ventricle atrium contralateral to the stroke, extension of infarction beyond the craniectomy edges, and the pre and post-DC midline brain shifts. To avoid potential confounding from medical treatments and additional surgical procedures, we excluded patients with the first CT delayed >30 hours post-DC, resection of infarcted brain, or insertion of an external ventricular drain during DC. The primary outcome in multiple linear regression analysis was the postoperative midline brain shift. RESULTS: We analyzed 72 qualified patients. The average midline brain shift decreased from 8.7 mm pre-DC to 5.4 post-DC. The only factors significantly associated with post-DC midline brain shift at the p<0.01 level were preoperative midline shift (coefficient 0.32, standard error 0.10, p=0.002) and extent of transcalvarial brain herniation (coefficient -0.20, standard error 0.05, p <0.001). CONCLUSIONS: In patients with MHI and DC, smaller post-DC midline shift is associated with smaller pre-DC midline brain shift and greater transcalvarial brain herniation. This knowledge may prove helpful in assessing DC candidacy and surgical success. Additional studies to enhance the surgical success of DC are warranted.
Subject(s)
Brain Edema/surgery , Cerebral Infarction/surgery , Decompressive Craniectomy , Hernia/prevention & control , Adult , Brain Edema/diagnostic imaging , Brain Edema/physiopathology , Cerebral Infarction/diagnostic imaging , Cerebral Infarction/physiopathology , Clinical Decision-Making , Decompressive Craniectomy/adverse effects , Female , Georgia , Hernia/diagnostic imaging , Hernia/etiology , Humans , Male , Middle Aged , Recovery of Function , Registries , Retrospective Studies , Risk Assessment , Risk Factors , Tomography, X-Ray Computed , Treatment Outcome , VirginiaABSTRACT
Ischemic stroke is an injury caused by temporary or permanent cerebral vascular occlusion. It has a high incidence, mortality, and disability rate in clinical practice, and thus poses a considerable threat to public health as one of the top three major conditions endangering human health. Vascular endothelial growth factor is a specific mitogen of endothelial cells and a protein factor that is closely related to ischemic stroke. Vascular endothelial growth factor plays an important role in a multitude of physiological and pathological conditions. As a potential angiogenic protein for the treatment of ischemic stroke, vascular endothelial growth factor plays a role in promoting angiogenesis and neuroprotection and regeneration. At the same time, it plays a role in brain edema, collateral artery formation, and atherosclerosis. An increase in vascular endothelial growth factor levels contributes to the early pathological changes in patients with stroke and is closely related to the formation of cerebral edema in ischemic stroke complications. In theory, the neuroprotective and angiogenic effects of vascular endothelial growth factor make it an ideal candidate for the treatment of stroke. Here, we review the mechanism by which vascular endothelial growth factor participates in various stages of ischemic stroke and its prospects for use in the treatment of ischemic stroke.
Subject(s)
Brain Edema/physiopathology , Ischemic Stroke/physiopathology , Vascular Endothelial Growth Factor A/metabolism , Angiogenesis Inducing Agents/pharmacology , Animals , Brain Edema/drug therapy , Humans , Ischemic Stroke/drug therapy , Neovascularization, Physiologic/drug effects , Neovascularization, Physiologic/physiology , Neuroprotective Agents/pharmacology , Vascular Endothelial Growth Factor A/therapeutic useABSTRACT
BACKGROUND: Interest is growing in the role played by intestinal flora in the pathogeneses of diseases and in the possibility of treating disease by altering intestinal flora compositions. Recent studies have focused on the relationship between the intestinal microbiome and brain function as proposed by the brain-gut axis hypothesis. OBJECTIVES: To investigate the relation between ischemic stroke and plasma equol monosulfate levels (a soy isoflavone metabolite) in a middle cerebral artery occlusion (MCAO) mouse model. METHODS: Mice (C57BL/6) were subjected to MCAO for various times (30 min to 24 h), and degrees of cerebral damage were assessed using total infarction volumes, brain edema severities and neurological deficit scores. Hematoxylin and eosin and cresyl violet staining were used to observe morphological changes in ischemic brains. Levels of equol monosulfate in plasma and the relationships between these and degree of brain injury were investigated. RESULTS: Infarction volumes, brain edema severity and neurological deficit scores were significantly correlated with ischemic time, and morphological deteriorations of brain neuronal cells also increased with ischemic duration. Equol monosulfate contents were ischemic-time dependently lower in MCAO treated animals than in sham-operated controls. CONCLUSION: Ischemic stroke may time-dependently reduce plasma levels of equol monosulfate by lowering the metabolic rate of equol in MCAO-induced mice. This study provides indirect support of the brain-gut axis hypothesis.
Subject(s)
Brain-Gut Axis/physiology , Equol/blood , Gastrointestinal Microbiome , Ischemic Stroke/blood , Animals , Brain Edema/blood , Brain Edema/immunology , Brain Edema/pathology , Brain Edema/physiopathology , Brain-Gut Axis/immunology , CA1 Region, Hippocampal/pathology , Cerebral Cortex/pathology , Disease Models, Animal , Hippocampus/pathology , Infarction, Middle Cerebral Artery/blood , Infarction, Middle Cerebral Artery/immunology , Infarction, Middle Cerebral Artery/pathology , Infarction, Middle Cerebral Artery/physiopathology , Ischemic Stroke/immunology , Ischemic Stroke/pathology , Ischemic Stroke/physiopathology , Mice , Mice, Inbred C57BL , Neurons/pathology , Sulfates/blood , Time FactorsABSTRACT
BACKGROUND: The mu-opioid agonist methadone is administered orally and used in opioid detoxification and in the treatment of moderate-to-severe pain. Acute oral methadone-use and -abuse have been associated with inflammatory and toxic central nervous system (CNS) damage in some cases and cognitive deficits can develop in long-term methadone users. In contrast, reports of intravenous methadone adverse effects are rare. CASE PRESENTATION: Here, we report a patient who developed acute bilateral hearing loss, ataxia and paraparesis subsequently to intravenous methadone-abuse. While the patient gradually recovered from these deficits, widespread magnetic resonance imaging changes progressed and delayed-onset encephalopathy with signs of cortical dysfunction persisted. This was associated with changes in the composition of monocyte and natural killer cell subsets in the cerebrospinal fluid. CONCLUSION: This case suggests a potential bi-phasic primary toxic and secondary inflammatory CNS damage induced by intravenous methadone.