Hemispheric Swelling Research Articles

Neuroprotective effects of exosomes derived from bone marrow mesenchymal stem cells treated by Musk Ketone on ischemic stroke

ObjectivesIschemic stroke (IS) is a leading cause of morbidity and mortality globally. This study aimed to investigate the role of exosomes (Exo) derived from bone marrow mesenchymal stem cells (BMSCs) treated with Musk Ketone (Mus treated-Exo) in the development of IS injury. MethodsBMSCs were pretreated with 10 μM Mus for 36 h, and Exo derived from these Mus-treated BMSCs (Mus-treated Exo) were extracted. Rats with middle cerebral artery occlusion (MCAO) were administered either 2 mg/kg of control Exo (Ctrl-Exo), 2 mg/kg of Mus treated-Exo, or 10 μM Mus. Neurological deficit and cerebral infarction in the MCAO rats were assessed utilizing neurological scores and TTC staining. Neuronal apoptosis, activation of microglia/macrophages, and inflammation were evaluated through TUNEL staining, immunofluorescence staining, and western blot analysis, respectively. ResultsOur findings revealed that Mus-treated Exo possessed a more pronounced neuroprotective effect on MCAO rats when compared to Ctrl-Exo and Mus treatment alone. Specifically, Mus treated-Exo effectively ameliorated neurological function, reduced the volume of cerebral infarction, and diminished hemispheric swelling in MCAO rats. Moreover, it inhibited neuronal apoptosis and activation of microglia/macrophages, promoted the expression of the anti-apoptotic protein Bcl-2 while decreasing the expression of pro-apoptotic protein Bax, Cleaved-caspase 3, and pro-inflammatory factors IL-6 and COX-2. ConclusionsThe findings imply that Mus treated-Exo could confer neuroprotection in rats affected by IS, potentially by attenuating apoptosis and neuroinflammation. The underlying mechanisms, however, warrant further investigation. Mus treated-Exo shows potential as a new therapeutic strategy for IS.

Incidence, risk factors, and clinical outcomes of acute brain swelling associated with traumatic acute subdural hematoma: a retrospective study utilizing novel diagnostic criteria.

Post-traumatic acute brain swelling (ABS) is a major cause of elevated intracranial pressure and thus mortality. The current definition of post-traumatic ABS has certain limitations, and there is limited information available regarding ABS associated with traumatic acute subdural hematoma (ASDH). To investigate the incidence, risk factors, and clinical outcomes of ABS associated with traumatic ASDH. Retrospective study. Data for 161 patients diagnosed with traumatic ASDH were retrospectively collected. Novel computed tomography-based criteria were proposed for diagnosing ABS in patients with ASDH and determining its incidence. Univariate and multivariate logistic regression analyses were performed to explore the risk factors of post-traumatic ABS. The Glasgow Outcome Scale (GOS) score, mortality, and functional prognosis of all patients at discharge and the proportion of intraoperative malignant brain bulge in surgical patients were taken as clinical outcome measures. A total of 45 (28%) patients experienced post-traumatic ABS, exhibiting significantly lower Glasgow Coma Scale scores on admission (p < 0.001). The incidence of hemispheric and whole-brain swelling was 8.1% and 19.9%, respectively. Risk factors independently associated with post-traumatic ABS were: (1) age [odds ratio (OR) = 0.917, p < 0.001]; (2) platelet to white blood cell ratio (PWR) (OR = 0.887, p = 0.012); and (3) traumatic subarachnoid hemorrhage (SAH) (OR = 4.346, p = 0.005). The ABS cohort had a lower GOS score [2 (1-3) versus 4 (3-5); p < 0.001], higher mortality (46.7% versus 6.9%; p < 0.001), and higher proportion of unfavorable functional prognosis (75.6% versus 34.5%; p < 0.001) upon discharge compared to the no ABS cohort, along with higher proportion of intraoperative malignant brain bulge (43.8% versus 0%; p < 0.001). The incidence of ABS associated with ASDH is significantly high overall. Patients with ASDH who have young age, low PWR, and traumatic SAH are at an increased risk of developing post-traumatic ABS, and therefore of poor clinical outcomes.

Canagliflozin, an Inhibitor of the Na+-Coupled D-Glucose Cotransporter, SGLT2, Inhibits Astrocyte Swelling and Brain Swelling in Cerebral Ischemia.

Brain swelling is a major cause of death and disability in ischemic stroke. Drugs of the gliflozin class, which target the Na+-coupled D-glucose cotransporter, SGLT2, are approved for type 2 diabetes mellitus (T2DM) and may be beneficial in other conditions, but data in cerebral ischemia are limited. We studied murine models of cerebral ischemia with middle cerebral artery occlusion/reperfusion (MCAo/R). Slc5a2/SGLT2 mRNA and protein were upregulated de novo in astrocytes. Live cell imaging of brain slices from mice following MCAo/R showed that astrocytes responded to modest increases in D-glucose by increasing intracellular Na+ and cell volume (cytotoxic edema), both of which were inhibited by the SGLT2 inhibitor, canagliflozin. The effect of canagliflozin was studied in three mouse models of stroke: non-diabetic and T2DM mice with a moderate ischemic insult (MCAo/R, 1/24 h) and non-diabetic mice with a severe ischemic insult (MCAo/R, 2/24 h). Canagliflozin reduced infarct volumes in models with moderate but not severe ischemic insults. However, canagliflozin significantly reduced hemispheric swelling and improved neurological function in all models tested. The ability of canagliflozin to reduce brain swelling regardless of an effect on infarct size has important translational implications, especially in large ischemic strokes.

Secondary hyperperfusion injury following surgical evacuation for acute isolated epidural hematoma with concurrent cerebral herniation.

Hemispherical cerebral swelling or even encephalocele after head trauma is a common complication and has been well elucidated previously. However, few studies have focused on the secondary brain hemorrhage or edema occurring regionally but not hemispherically in the cerebral parenchyma just underneath the surgically evacuated hematoma during or at a very early stage post-surgery. In order to explore the characteristics, hemodynamic mechanisms, and optimized treatment of a novel peri-operative complication in patients with isolated acute epidural hematoma (EDH), clinical data of 157 patients with acute-isolated EDH who underwent surgical intervention were reviewed retrospectively. Risk factors including demographic characteristics, admission Glasgow Coma Score, preoperative hemorrhagic shock, anatomical location, and morphological parameters of epidural hematoma, as well as the extent and duration of cerebral herniation on physical examination and radiographic evaluation were considered. It suggested that secondary intracerebral hemorrhage or edema was determined in 12 of 157 patients within 6 h after surgical hematoma evacuation. It was featured by remarkable, regional hyperperfusion on the computed tomography (CT) perfusion images and associated with a relatively poor neurological prognosis. In addition to concurrent cerebral herniation, which was found to be a prerequisite for the development of this novel complication, multivariate logistic regression further showed four independent risk factors contributing to this type of secondary hyperperfusion injury: cerebral herniation that lasted longer than 2 h, hematomas that were located in the non-temporal region, hematomas that were thicker than 40 mm, and hematomas occurring in pediatric and elderly patients. Secondary brain hemorrhage or edema occurring within an early perioperative period of hematoma-evacuation craniotomy for acute-isolated EDH is a rarely described hyperperfusion injury. Because it plays an important prognostic influence on patients' neurological recovery, optimized treatment should be given to block or reduce the consequent secondary brain injuries.

Novel mitoNEET ligand NL-1 improves therapeutic outcomes in an aged rat model of cerebral ischemia/reperfusion injury

Cerebral ischemic stroke is a leading cause of mortality and disability worldwide. Currently, there are a lack of drugs capable of reducing neuronal cell loss due to ischemia/reperfusion-injury after stroke. Previously, we identified mitoNEET, a [2Fe-2S] redox mitochondrial protein, as a putative drug target for ischemic stroke. In this study, we tested NL-1, a novel mitoNEET ligand, in a preclinical model of ischemic stroke with reperfusion using aged female rats. Using a transient middle cerebral artery occlusion (tMCAO), we induced a 2 h ischemic injury and then evaluated the effects of NL-1 treatment on ischemic/reperfusion brain injury at 24 and 72 h. Test compounds were administered at time of reperfusion via intravenous dosing. Results of the study demonstrated that NL-1 (10 mg/kg) treatment markedly improved survival and reduced infarct volume and hemispheric swelling in the brain as compared aged rats treated with vehicle or a lower dose of NL-1 (0.25 mg/kg). Interestingly, the protective effect of NL-1 was significantly improved when encapsulated in PLGA nanoparticles, where a 40-fold lesser dose (0.25 mg/kg) of NL-1 produced an equivalent effect as the 10 mg/kg dose. Evaluation of changes in blood-brain barrier permeability and lipid peroxidation corroborated the protective actions of NL-1 (10 mg/kg) or NL-1 NP treatment demonstrated a reduced accumulation of parenchymal IgG, decreased levels of 4-hydroxynonenal (4-HNE) and a decreased TUNEL positive cells in the brains of aged female rats at 72 h after tMCAO with reperfusion. Our studies indicate that targeting mitoNEET following ischemia/reperfusion-injury is a novel drug target pathway that warrants further investigation.

Novel mitoNEET ligand NL‐1 improves therapeutic outcomes in an aged rat model of cerebral ischemia/reperfusion injury

Cerebral ischemic stroke is a leading cause of mortality and disability worldwide. Currently, there are a lack of drugs capable of reducing neuronal cell loss after ischemia/reperfusion‐injury after stroke. Previously, we identified mitoNEET, a [2Fe‐2S] redox mitochondrial protein, as a putative drug target for stroke. In this study, we tested the novel mitoNEET ligand, NL‐1, in a preclinical model of ischemic stroke with reperfusion using aged female rats. Using a transient middle cerebral artery occlusion (tMCAO), we induced a 2 h ischemic injury and then evaluated the effects of NL‐1 treatment on ischemic/reperfusion brain injury at 24 and 72 h. Test drugs were administered at time of reperfusion via IV dosing. Results demonstrated that NL‐1 (10 mg/kg) treatment markedly reduced infarct volume and hemispheric swelling in the brain as compared rats treated with vehicle or a lower concentration of NL‐1 (0.25 mg/kg). Surprisingly, the protective effect of NL‐1 was significantly improved when encapsulated in PLGA nanoparticles, where a 40‐fold lesser dose (0.25 mg/kg) of NL‐1 produced an equivalent effect as the 10 mg/kg dose. Evaluation of changes in blood‐brain barrier permeability and oxidative stress using immunohistochemical staining corroborated the protective actions of NL‐1, showing reduced extravasation of IgG and decreased levels of 4‐hydroxynonenal (4‐HNE) in the brains of aged female rats at 72 h after tMCAO with reperfusion. Our studies indicate that targeting mitoNEET following ischemia/reperfusion‐injury is a novel drug target pathway that warrants further investigation.

Long term delivery of glibenclamide from in situ forming microparticles for the treatment of ischemic stroke

Glibenclamide, sulfonylurea receptor inhibitor, is reported to be neuroprotective in ischemic stroke by reducing cytotoxic edema, which is the primary cause of morbidity. As neurological worsening in stroke occurs from 3 to 10 days post-injury, there is a need to develop a system that would provide the release of glibenclamide for 10–15 days in a sustained manner in order to y improve the neurological functions effectively. In situ forming microparticles (ISFM) of glibenclamide was developed using PLGA 50:50 as a biodegradable polymer and by applying RSM I-Optimal design. In vitro evaluation studies were carried out for optimized formulation. In vivo pharmacological assessments and pharmacokinetics studies were performed in the Bilateral common carotid artery occlusion model (BCCAO) in Wistar rats. In vitro drug release studies showed a minimum burst release at 12 h and maximum release on 15th day. In vivo results showed a significant improvement in neurological functions, reduction in the infarct area, and hemispheric swelling in glibenclamide ISFM treated animals as compared to diseased animals. From in vitro and in vivo animal studies, it was concluded that long-acting ISFM of glibenclamide was successfully developed, which showed drug release pattern in a sustained manner for up to 15 days for preventing the neurological worsening in stroke.

Lindsay tumour

The follicular tumours with nuclear features of papillary carcinoma are categorised as follicular variant of papillary thyroid carcinoma (FVPTC). They exhibit biologic and molecular properties that are different from conventional papillary thyroid cancer. Solid encapsulated follicular variant of papillary carcinoma of thyroid is termed as Lindsay tumour. Since they are encapsulated, they follow an indolent course. We present a case of Lindsay tumour in a 34-year-old female, who presented with swelling in the neck for six months. She had no other specific complaints. On local examination of her neck, there was a hemispherical swelling of size 6×5×2 cm, found in the midline which moves with deglutition. The swelling was firm in consistency and its surface was nodular. There were no palpable lymph nodes in the neck. The ultrasonogram of her neck revealed multinodular goitre. The fine needle aspiration cytology from neck swelling revealed colloid goitre with cystic degeneration. Her thyroid function tests were within normal limit. She was then, proceeded with total thyroidectomy. Her postoperative recovery was uneventful. Her histopathological report revealed an encapsulated follicular variant of papillary carcinoma of thyroid. She was then kept on half yearly follow-up with serum thyroglobulin. Therefore, this case provides an opportunity to review the encapsulated follicular variant of papillary carcinoma thyroid (Lindsay tumour) and its management.

Clinical and genetic analysis of 5 pediatric patients with hemiplegic migraine presenting as acute encephalopathy

Objective: To analyze the clinical and genetic characteristics, diagnosis and treatment of hemiplegic migraine (HM) manifested as acute encephalopathy in children, so as to improve the understanding of this disease. Methods: The clinical data of 5 children diagnosed with HM characterized by acute encephalopathy who were admitted to Beijing Children's Hospital affiliated to Capital Medical University from August 2018 to June 2020 were retrospectively analyzed. Results: Among the 5 cases, 3 were males and 2 females with an age of 9.7 (3.9-12.7) years. The age of disease onset was 7.0(2.1-12.7) years. The peak symptoms of 5 children showed encephalopathy such as drowsiness and coma, as well as other clinical manifestations including headache, visual abnormality, hemiplegia, aphasia, convulsions, and fever, etc. The time to reach the peak was on the 2nd-6th day of the course of the disease. Before the onset of the disease 2 cases were found to have mild brain trauma and 2 cases had similar attacks in the past. Brain magnetic resonance imaging (MRI) showed hemispheric or partial cerebral cortex swelling and restricted diffusion of subcortical white matter in all cases, and cerebellar atrophy in 3 cases. All children received symptomatic treatment, and 2 of them were also treated with low-dose corticosteroids in the meantime. Finally all cases recovered clinically from the attack, but one had atrophic changes left in the affected area on brain MRI. Whole exon sequencing revealed variations of CACNA1A gene in all cases, among which 4 were de novo mutations and 1 case inherited from the mother who had migraine without aura. After the diagnosis, the 5 children were treated with long-term flunarizine and followed up for 22(7-29) months by telephone or in the outpatient clinic. Before the last follow-up, none of them showed weakness or encephalopathy, but one still had intermittent headaches and occasional transient right limb numbness. Conclusions: Hemipleg is often accompanied by impaired consciousness in addition to headache, hemiplegia, aphasia, visual abnormality, etc. Most patients recover completely after a short period, while a few recover slowly and may suffer sequelae such as brain atrophy and cognitive impairment and even death. CACNA1A gene variation is the most common genetic variation. Flunarizine could prevent recurrence of severe attack.

Sporadic Hemiplegic Migraine Type 1 and Congenital Ataxia due to a Single Amino Acid Deletion (ΔF1502) in CACNA1A: A Challenging Diagnosis

AbstractMutations in the CACNA1A gene have been classically related to three neurologic disorders: hemiplegic migraine type 1 (both familiar and sporadic FHM1/SHM1), episodic ataxia type 2 (EA2), and spinocerebellar ataxia type 6 (SCA6). More recently, pathogenic variants in CACNA1A have been recognized as causative of an early-onset cerebellar syndrome consistent with the definition of congenital ataxia (CA), variably associated with paroxysmal symptoms. Early recognition of congenital ataxia is challenging because the presenting symptoms, such as hypotonia, weak deep tendon reflexes, and delayed motor milestones, are unspecific while clear signs of a cerebellar syndrome which are usually not seen before the second or third year. Here, we report on a case of nonepisodic ataxia of congenital onset and severe SHM1 where the diagnosis of congenital ataxia was made retrospectively after the identification of the ΔF1502 pathogenic variant in CACNA1A by an hemiplegic migraine multigene panel, conducted for the onset of hemiplegic migraine attacks associated with hemispheric swelling. A significant reduction in migraine attacks frequency was achieved with acetazolamide.

Magnetic Resonance Imaging and Gait Analysis Indicate Similar Outcomes Between Yucatan and Landrace Porcine Ischemic Stroke Models.

The Stroke Therapy Academic Industry Roundtable (STAIR) has recommended that novel therapeutics be tested in a large animal model with similar anatomy and physiology to humans. The pig is an attractive model due to similarities in brain size, organization, and composition relative to humans. However, multiple pig breeds have been used to study ischemic stroke with potentially differing cerebral anatomy, architecture and, consequently, ischemic stroke pathologies. The objective of this study was to characterize brain anatomy and assess spatiotemporal gait parameters in Yucatan (YC) and Landrace (LR) pigs pre- and post-stroke using magnetic resonance imaging (MRI) and gait analysis, respectively. Ischemic stroke was induced via permanent middle cerebral artery occlusion (MCAO). MRI was performed pre-stroke and 1-day post-stroke. Structural and diffusion-tensor sequences were performed at both timepoints and analyzed for cerebral characteristics, lesion diffusivity, and white matter changes. Spatiotemporal and relative pressure gait measurements were collected pre- and 2-days post-stroke to characterize and compare acute functional deficits. The results from this study demonstrated that YC and LR pigs exhibit differences in gross brain anatomy and gait patterns pre-stroke with MRI and gait analysis showing statistical differences in the majority of parameters. However, stroke pathologies in YC and LR pigs were highly comparable post-stroke for most evaluated MRI parameters, including lesion volume and diffusivity, hemisphere swelling, ventricle compression, caudal transtentorial and foramen magnum herniation, showing no statistical difference between the breeds. In addition, post-stroke changes in velocity, cycle time, swing percent, cadence, and mean hoof pressure showed no statistical difference between the breeds. These results indicate significant differences between pig breeds in brain size, anatomy, and motor function pre-stroke, yet both demonstrate comparable brain pathophysiology and motor outcomes post-stroke. The conclusions of this study suggest pigs of these different breeds generally show a similar ischemic stroke response and findings can be compared across porcine stroke studies that use different breeds.

Intracisternal administration of tanshinone IIA-loaded nanoparticles leads to reduced tissue injury and functional deficits in a porcine model of ischemic stroke.

BackgroundThe absolute number of new stroke patients is annually increasing and there still remains only a few Food and Drug Administration (FDA) approved treatments with significant limitations available to patients. Tanshinone IIA (Tan IIA) is a promising potential therapeutic for ischemic stroke that has shown success in pre-clinical rodent studies but lead to inconsistent efficacy results in human patients. The physical properties of Tan-IIA, including short half-life and low solubility, suggests that Poly (lactic-co-glycolic acid) (PLGA) nanoparticle-assisted delivery may lead to improve bioavailability and therapeutic efficacy. The objective of this study was to develop Tan IIA-loaded nanoparticles (Tan IIA-NPs) and to evaluate their therapeutic effects on cerebral pathological changes and consequent motor function deficits in a pig ischemic stroke model.ResultsTan IIA-NP treated neural stem cells showed a reduction in SOD activity in in vitro assays demonstrating antioxidative effects. Ischemic stroke pigs treated with Tan IIA-NPs showed reduced hemispheric swelling when compared to vehicle only treated pigs (7.85 ± 1.41 vs. 16.83 ± 0.62%), consequent midline shift (MLS) (1.72 ± 0.07 vs. 2.91 ± 0.36 mm), and ischemic lesion volumes (9.54 ± 5.06 vs. 12.01 ± 0.17 cm3) when compared to vehicle-only treated pigs. Treatment also lead to lower reductions in diffusivity (−37.30 ± 3.67 vs. −46.33 ± 0.73%) and white matter integrity (−19.66 ± 5.58 vs. −30.11 ± 1.19%) as well as reduced hemorrhage (0.85 ± 0.15 vs 2.91 ± 0.84 cm3) 24 h post-ischemic stroke. In addition, Tan IIA-NPs led to a reduced percentage of circulating band neutrophils at 12 (7.75 ± 1.93 vs. 14.00 ± 1.73%) and 24 (4.25 ± 0.48 vs 5.75 ± 0.85%) hours post-stroke suggesting a mitigated inflammatory response. Moreover, spatiotemporal gait deficits including cadence, cycle time, step time, swing percent of cycle, stride length, and changes in relative mean pressure were less severe post-stroke in Tan IIA-NP treated pigs relative to control pigs.ConclusionThe findings of this proof of concept study strongly suggest that administration of Tan IIA-NPs in the acute phase post-stroke mitigates neural injury likely through limiting free radical formation, thus leading to less severe gait deficits in a translational pig ischemic stroke model. With stroke as one of the leading causes of functional disability in the United States, and gait deficits being a major component, these promising results suggest that acute Tan IIA-NP administration may improve functional outcomes and the quality of life of many future stroke patients.

An integrative multivariate approach for predicting functional recovery using magnetic resonance imaging parameters in a translational pig ischemic stroke model.

Magnetic resonance imaging (MRI) is a clinically relevant, real-time imaging modality that is frequently utilized to assess stroke type and severity. However, specific MRI biomarkers that can be used to predict long-term functional recovery are still a critical need. Consequently, the present study sought to examine the prognostic value of commonly utilized MRI parameters to predict functional outcomes in a porcine model of ischemic stroke. Stroke was induced via permanent middle cerebral artery occlusion. At 24 hours post-stroke, MRI analysis revealed focal ischemic lesions, decreased diffusivity, hemispheric swelling, and white matter degradation. Functional deficits including behavioral abnormalities in open field and novel object exploration as well as spatiotemporal gait impairments were observed at 4 weeks post-stroke. Gaussian graphical models identified specific MRI outputs and functional recovery variables, including white matter integrity and gait performance, that exhibited strong conditional dependencies. Canonical correlation analysis revealed a prognostic relationship between lesion volume and white matter integrity and novel object exploration and gait performance. Consequently, these analyses may also have the potential of predicting patient recovery at chronic time points as pigs and humans share many anatomical similarities (e.g., white matter composition) that have proven to be critical in ischemic stroke pathophysiology. The study was approved by the University of Georgia (UGA) Institutional Animal Care and Use Committee (IACUC; Protocol Number: A2014-07-021-Y3-A11 and 2018-01-029-Y1-A5) on November 22, 2017.

Caveolin-1 Regulates Perivascular Aquaporin-4 Expression After Cerebral Ischemia.

Edema is a hallmark of many brain disorders including stroke. During vasogenic edema, blood-brain barrier (BBB) permeability increases, contributing to the entry of plasma proteins followed by water. Caveolae and caveolin-1 (Cav-1) are involved in these BBB permeability changes. The expression of the aquaporin-4 (AQP4) water channel relates to brain swelling, however, its regulation is poorly understood. Here we tested whether Cav-1 regulates AQP4 expression in the perivascular region after brain ischemia in mice. We showed that Cav-1 knockout mice had enhanced hemispheric swelling and decreased perivascular AQP4 expression in perilesional and contralateral cortical regions compared to wild-type. Glial fibrillary acidic protein-positive astrocytes displayed less branching and ramification in Cav-1 knockout mice compared to wild-type animals. There was a positive correlation between the area of perivascular AQP4-immunolabelling and branch length of Glial fibrillary acidic protein-positive astrocytes in wild-type mice, not seen in Cav-1 knockout mice. In summary, we show for the first time that loss of Cav-1 results in decreased AQP4 expression and impaired perivascular AQP4 covering after cerebral ischemia associated with altered reactive astrocyte morphology and enhanced brain swelling. Therapeutic approaches targeting Cav-1 may provide new opportunities for improving stroke outcome.Significance StatementSevere brain edema worsens outcome in stroke patients. Available treatments for stroke-related edema are not efficient and molecular and cellular mechanisms are poorly understood. Cellular water channels, aquaporins (AQPs), are mainly expressed in astrocytes in the brain and play a key role in water movements and cerebral edema, while endothelial caveolins have been suggested to play a role in vasogenic edema. Here we used an integrative approach to study possible interaction between AQP4 and caveolin-1 (Cav-1) after stroke. Absence of Cav-1 was associated with perivascular changes in AQP4 expression and enhanced brain swelling at 3 days after cerebral ischemia. The present work indicates a direct or indirect effect of Cav-1 on perivascular AQP4, which may lead to novel edema therapy.

Visualization of cortical cerebral blood flow dynamics during craniotomy in acute subdural hematoma using laser speckle imaging in a rat model

Mass evacuation with decompressive craniotomy is considered a standard intervention for acute subdural hematoma (ASDH). However, hemispheric swelling complicates the intraoperative and postoperative management of ASDH patients, and previous studies have revealed that this approach can damage ischemic/reperfusion (I/R) injury. Few studies have focused on the cerebrovascular response following traumatic brain injury (TBI). To characterize the relative cerebral blood flow (rCBF) before and after removal of the hematoma, rats were injured by a subdural infusion of 400 μL of venous blood or paraffin oil. MRI scans were performed. Then, we monitored cortical rCBF during hematoma removal in real time using laser speckle imaging (LSCI) in ASDH rats. The CBF of arteriovenous and capillary regions were quantified and normalized to their own baseline values via a custom algorithm. In the sham group, the cortical CBF was higher post-craniotomy than pre-craniotomy. However, in the hematoma injection group, the CBF of arteries and capillaries was higher while the venous CBF was lower post-craniotomy than pre-craniotomy. The difference in the changes in vein CBF that occurred between the two groups was statistically significant. The three components of the vascular system showed heterogeneous responses to craniotomy, which may be the basis for secondary brain injury.

The characteristics of brain injury following cerebral venous infarction induced by surgical interruption of the cortical bridging vein in mice

Cerebral venous infarction (CVI) caused by the injury of cortical bridging veins (CBVs), is one of the most serious complications following neurosurgical craniotomy. Different from cerebral artery infarction, this CVI pathological process is more complicated, accompanied by acute venous hypertension, brain edema, cerebral ischemia and hemorrhage in the veins bridged brain area. Therefore, a reliable and stable small animal model is particularly important for the pathological study of CVI induced by surgical CBV interruption (CBVi). A mouse model established by cutting off the right CBVs from bregma to lambda with microsurgical technique is used for the assessment of the pathological process. Adult male mice underwent craniotomy after transection of the parietal skin under anesthesia. The right CBVs were exposed by removing the right skull along the right lateral edge of the sagittal sinus (forming a 4 mm × 3 mm bone window from bregma to lambda) with a drill under the operating microscope. Following the final inspection of the cerebral veins, the CBVs (30% one, 60% two, 10% none) were sacrificed using bipolar coagulation technique. Intracranial pressure (ICP) monitoring, motor function examination, brain edema assessment and brain histopathological observation after perfusion were performed at different time points (6 h, 12 h, 24 h, and 48 h) in the postoperative mice. Cerebral hemisphere swelling, midline shift and subcortical petechial hemorrhage were found on histological sections 6 h after CBVs dissection. The change of ICP was consistent with cerebral edema and peaked at 12 h after surgery, as well as the disruption of the blood–brain barrier assessed by Evans Blue staining. Tissue necrosis, nerve cell loss and monocytes infiltration were also dynamically increased in the postoperative hemispheric cortex. Behavioral tests showed obvious somato- and forelimb-motor dysfunction, and severe somatosensory disorder on the operative mice at 12 h, which were substantially recovered at 48 h. Our study provided a novel mouse model of CVI caused by surgical CBVi that was close to clinical practice, and preliminarily confirmed its pathological process. This model might become an important tool to study the clinical pathology and the molecular mechanism of nerve injury following CVI.

Acute encephalopathy after head trauma in a patient with a RHOBTB2 mutation.

ObjectiveDe novo missense mutations in the RHOBTB2 gene have been described as causative for developmental and epileptic encephalopathy.MethodsThe clinical phenotype of this disorder includes early-onset epilepsy, severe intellectual disability, postnatal microcephaly, and movement disorder. Three RHOBTB2 patients have been described with acute encephalopathy and febrile epileptic status. All showed severe EEG abnormalities during this episode and abnormal MRI with hemisphere swelling or reduced diffusion in various brain regions.ResultsWe describe the episode of acute encephalopathy after head trauma in a 5-year-old RHOBTB2 patient. At admission, Glasgow coma scale score was E4M4V1. EEG was severely abnormal showing a noncontinuous pattern with slow activity without epileptic activity indicating severe encephalopathy. A second EEG on day 8 was still severely slowed and showed focal delta activity frontotemporal in both hemispheres. Gradually, he recovered, and on day 11, he had regained his normal reactivity, behavior, and mood. Two months after discharge, EEG showed further decrease in slow activity and increase in normal electroencephalographic activity. After discharge, parents noted that he showed more hyperkinetic movements compared to before this period of encephalopathy. Follow-up MRI showed an increment of hippocampal atrophy. In addition, we summarize the clinical characteristics of a second RHOBTB2 patient with increase of focal periventricular atrophy and development of hemiparesis after epileptic status.ConclusionsAcute encephalopathy in RHOBTB2 patients can also be triggered by head trauma.

Characterization of tissue and functional deficits in a clinically translational pig model of acute ischemic stroke

The acute stroke phase is a critical time frame used to evaluate stroke severity, therapeutic options, and prognosis while also serving as a major tool for the development of diagnostics. To further understand stroke pathophysiology and to enhance the development of treatments, our group developed a translational pig ischemic stroke model. In this study, the evolution of acute ischemic tissue damage, immune responses, and functional deficits were further characterized. Stroke was induced by middle cerebral artery occlusion in Landrace pigs. At 24 h post-stroke, magnetic resonance imaging revealed a decrease in ipsilateral diffusivity, an increase in hemispheric swelling resulting in notable midline shift, and intracerebral hemorrhage. Stroke negatively impacted white matter integrity with decreased fractional anisotropy values in the internal capsule. Like patients, pigs showed a reduction in circulating lymphocytes and a surge in neutrophils and band cells. Functional responses corresponded with structural changes through reductions in open field exploration and impairments in spatiotemporal gait parameters. Characterization of acute ischemic stroke in pigs provided important insights into tissue and functional-level assessments that could be used to identify potential biomarkers and improve preclinical testing of novel therapeutics.

Abstract 111: Myeloid Specific Deletion of CD36 Increases Microglia-Like CD45 Low Subset and Exacerbates Stroke-Induced Brain Injury

Objective: CD36 regulates biological and pathological processes including inflammation, resolution, phagocytosis, and angiogenesis. Highly expressed in monocytes/macrophages (MM), MM CD36 has been implicated in both detrimental and beneficial effects in acute stroke outcome and recovery. Using myeloid specific deficiency of CD36 (CD36KO MM ) mice, the present study addresses the role of MM CD36 on subset composition of MM in the acute and recovery phases of stroke. Methods: WT (CD36 fl/fl ) and CD36KO MM (M/F, 12w old) mice were subjected to transient focal ischemia. Brain immune cells were collected at 3d, 7d and 2m (n=8-12/timepoint). Infarct volume and hemispheric swelling were measured at 3d (n=13/genotype). In the isolated brain immune cells, CD11b+ cells were further distinguished by CD45 Hi and CD45 Low subsets. The extent of MM trafficking was determined by an intravenous infusion of control GFP+ splenocytes into the stroked WT and CD36KO MM mice 1d prior to sacrifice and MM subset analyses. Results: Compared to WT mice, CD36KO MM mice showed no difference in CD45 Low subset at 3d, 7d and 2m after stroke. However, CD36KO MM mice displayed a significant reduction of CD45 Hi subset, presumably infiltrating cells, at these time points (n=4-8 /group, P&lt;0.01). Adoptive transfer of control GFP+ splenocytes to stroked CD36KO MM mice resulted in an increase of GFP+ cells in CD45 Low but a profound reduction in CD45 Hi subset. Despite the near absence of CD45 Hi and increased CD45 Low population in the post-ischemic brain, CD36KO MM mice displayed exacerbation of brain injury (15.1±13.7 vs 25.8±17.5 mm 3 , p&lt;0.05) and brain swelling (12.1±10.3 vs 18.4±12.7 %, p=0.1). Conclusion: The observed reduction of CD45 Hi subset and exacerbation of brain injury in CD36KO MM mice suggests a beneficial role of infiltrated CD45 Hi MMs in limiting stroke injury. The sustained trafficking at 2m indicates potential involvement of MM CD36 in the recovery process. Further studies to assess long-term outcomes of CD36KO MM mice will provide critical insights on the role of macrophage CD36 in stroke recovery.

EVENTS ASSOCIATED WITH THE OCCURRENCE OF INTRACRANIAL HYPERTENSION IN PEDIATRIC PATIENTS WITH SEVERE CRANIOENCEPHALIC TRAUMA AND MONITORING OF INTRACRANIAL PRESSURE.

ABSTRACTObjective:To determine the events associated with the occurrence of intracranial hypertension (ICH) in pediatric patients with severe cranioencephalic trauma.Methods:This was a prospective cohort study of patients 18 years old and younger with cranioencephalic trauma, scores below nine on the Glasgow Coma Scale, and intracranial pressure monitoring. They were admitted between September, 2005 and March, 2014 into a Pediatric Intensive Care Unit. ICH was defined as an episode of intracranial pressure above 20 mmHg for more than five minutes that needed treatment.Results:A total of 198 children and adolescents were included in the study, of which 70.2% were males and there was a median age of nine years old. ICH occurred in 135 (68.2%) patients and maximum intracranial pressure was 36.3 mmHg, with a median of 34 mmHg. A total of 133 (97.8%) patients with ICH received sedation and analgesia for treatment of the condition, 108 (79.4%) received neuromuscular blockers, 7 (5.2%) had cerebrospinal fluid drainage, 105 (77.2%) received mannitol, 96 (70.6%) received hyperventilation, 64 (47.1%) received 3% saline solution, 20 (14.7%) received barbiturates, and 43 (31.9%) underwent a decompressive craniectomy. The events associated with the occurrence of ICH were tomographic findings at the time of admission of diffuse or hemispheric swelling (edema plus engorgement). The odds ratio for ICH in patients with Marshall III (diffuse swelling) tomography was 14 (95%CI 2.8–113; p<0.003), and for those with Marshall IV (hemispherical swelling) was 24.9 (95%CI 2.4–676, p<0.018). Mortality was 22.2%.Conclusions:Pediatric patients with severe cranioencephalic trauma and tomographic alterations of Marshall III and IV presented a high chance of developing ICH.