The role of the coagulation cascade in brain edema formation after intracerebral hemorrhage

Thrombin Priming Promotes the Neuroprotective Effects of Human Wharton's Jelly-Derived Mesenchymal Stem Cells Via the HGF/AKT/STAT3 Signaling Pathway

Mesenchymal stem cells (MSCs) directly differentiate into neurons and endothelial cells after transplantation, and their secretome has considerable potential for treating brain injuries. Previous studies have suggested that the effects of MSCs priming with exposure to hypoxia, cytokines, growth factors, or chemical agents could optimize the paracrine potency and therapeutic potential of MSCs. Studies have suggested that thrombin-primed Wharton's Jelly-derived mesenchymal stem cells (Th.WJ-MSCs) significantly enhance the neuroprotective beneficial effects of naive MSCs in brain injury such as hypoxic-ischemic brain injury (HIE) and intraventricular hemorrhage (IVH). This study aimed to characterize WJ-MSCs in terms of stem cell markers, differentiation, cell proliferation, and paracrine factors by comparing naive and Th.WJ-MSCs. We demonstrated that compared with naive MSCs, Th.MSCs significantly enhanced the neuroprotective effects in vitro. Moreover, we identified differentially expressed proteins in the conditioned media of naive and Th.WJ-MSCs by liquid chromatography-tandem mass spectrometry analysis. Secretome analysis of the conditioned medium of WJ-MSCs revealed that such neuroprotective effects were mediated by paracrine effects with secretomes of Th.WJ-MSCs, and hepatocyte growth factor was identified as a key paracrine mediator. These results can be applied further in the preclinical and clinical development of effective and safe cell therapeutics for brain injuries such as HIE and IVH.

Brain edema formation and therapy after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) accounts for about 10% of all strokes in the United States of America causing a high degree of disability and mortality. There is initial (primary) brain injury due to the mechanical disruption caused by the hematoma. There is then secondary injury, triggered by the initial injury but also the release of various clot-derived factors (e.g., thrombin and hemoglobin). ICH alters brain fluid homeostasis. Apart from the initial hematoma mass, ICH causes blood-brain barrier disruption and parenchymal cell swelling, which result in brain edema and intracranial hypertension affecting patient prognosis. Reducing brain edema is a critical part of post-ICH care. However, there are limited effective treatment methods for reducing perihematomal cerebral edema and intracranial pressure in ICH. This review discusses the mechanisms underlying perihematomal brain edema formation, the effects of sex and age, as well as how edema is resolved. It examines progress in pharmacotherapy, particularly focusing on drugs which have been or are currently being investigated in clinical trials.

Hemorrhagic Stroke: Endoscopic Aspiration

Intracerebral hemorrhage (ICH) and intraventricular hemorrhage (IVH) carry a very dismal prognosis. Several medical and surgical attempts have been made to reduce mortality and to improve neurological outcomes in survivors. Aggressive surgical treatment of ICH through craniotomy and microsurgical evacuation did not prove to be beneficial to these patients, compared to the best medical treatment. Similarly, the conventional treatment of IVH using an EVD is often effective in controlling ICP only initially, as it is very likely for the EVD to become obstructed by blood clots, requiring frequent replacements with a consequent increase of infection rates.Minimally invasive techniques have been proposed to manage these cases. Some are based on fibrinolytic agents that are infused in the hemorrhagic site through catheters with a single burr hole. Others are possible thanks to the development of neuroendoscopy. Endoscopic removal of ICH through a mini-craniotomy or a single burr hole, and via a parafascicular white matter trajectory, proved to reduce mortality in this population, and further randomized trials are expected to show whether also a better neurological outcome can be obtained in survivors. Moreover, endoscopy offers the opportunity to access the ventricular system to aspirate blood clots in patients with IVH. In such cases, the restoration of patency of the entire CSF pathway has the potential to improve outcome and reduce complications and now it is believed to decrease shunt-dependency.

Assessing the Evolution of Intracranial Hematomas by using Animal Models: A Review of the Progress and the Challenges

Stroke has become the second leading cause of death in people aged higher than 60 years, with cancer being the first. Intracerebral hemorrhage (ICH) is the most lethal type of stroke. Using imaging techniques to evaluate the evolution of intracranial hematomas in patients with hemorrhagic stroke is worthy of ongoing research. The difficulty in obtaining ultra-early imaging data and conducting intensive dynamic radiographic imaging in actual clinical settings has led to the application of experimental animal models to assess the evolution of intracranial hematomas. Herein, we review the current knowledge on primary intracerebral hemorrhage mechanisms, focus on the progress of animal studies related to hematoma development and secondary brain injury, introduce preclinical therapies, and summarize related challenges and future directions.

Nonequilibrium Dynamics of Magnetic Nanoparticles with Applications in Biomedicine

Magnetic nanoparticles are currently the focus of investigation for a wide range of biomedical applications that fall into the categories of imaging, sensing, and therapeutics. A deep understanding of nanoparticle magnetization dynamics is fundamental to optimization and further development of these applications. Here, a summary of theoretical models of nanoparticle dynamics is presented, and computational nonequilibrium models are outlined, which currently represent the most sophisticated methods for modeling nanoparticle dynamics. Nanoparticle magnetization response is explored in depth; the effect of applied field amplitude, as well as nanoparticle size, on the resulting rotation mechanism and timescale is investigated. Two applications in biomedicine, magnetic particle imaging and magnetic fluid hyperthermia, are highlighted.

Perihematomal Edema and Clinical Outcome in Intracerebral Hemorrhage Related to Different Oral Anticoagulants

BACKGROUND

There is a need to examine the effects of different types of oral anticoagulant-associated intracerebral hemorrhage (OAC-ICH) on perihematomal edema (PHE), which is gaining considerable appeal as a biomarker for secondary brain injury and clinical outcome.

METHODS

In a large multicenter approach, computed tomography-derived imaging markers for PHE (absolute PHE, relative PHE (rPHE), edema expansion distance (EED)) were calculated for patients with OAC-ICH and NON-OAC-ICH. Exploratory analysis for non-vitamin-K-antagonist OAC (NOAC) and vitamin-K-antagonists (VKA) was performed. The predictive performance of logistic regression models, employing predictors of poor functional outcome (modified Rankin scale 4-6), was explored.

RESULTS

Of 811 retrospectively enrolled patients, 212 (26.14%) had an OAC-ICH. Mean rPHE and mean EED were significantly lower in patients with OAC-ICH compared to NON-OAC-ICH, p-value 0.001 and 0.007; whereas, mean absolute PHE did not differ, p-value 0.091. Mean EED was also significantly lower in NOAC compared to NON-OAC-ICH, p-value 0.05. Absolute PHE was an independent predictor of poor clinical outcome in NON-OAC-ICH (OR 1.02; 95%CI 1.002-1.028; p-value 0.027), but not in OAC-ICH (p-value 0.45).

CONCLUSION

Quantitative markers of early PHE (rPHE and EED) were lower in patients with OAC-ICH compared to those with NON-OAC-ICH, with significantly lower levels of EED in NOAC compared to NON-OAC-ICH. Increase of early PHE volume did not increase the likelihood of poor outcome in OAC-ICH, but was independently associated with poor outcome in NON-OAC-ICH. The results underline the importance of etiology-specific treatment strategies. Further prospective studies are needed.

Relationship Between Non-contrast Computed Tomography Imaging Markers and Perihemorrhagic Edema Growth in Intracerebral Hemorrhage

OBJECTIVES

Perihemorrhagic edema (PHE) growth has been gradually considered as predictor for outcome of Intracerebral hemorrhage (ICH) patients. The aim of our study was to investigate correlation between non-contrast computed tomography (CT) markers and early PHE growth.

METHODS

ICH patients between July 2011 and March 2017 were included in this retrospective analysis. ICH and PHE volumes were measured by using a validated semiautomatic volumetric algorithm. Nonparametric test was used for comparing PHE volume at different time points of non-contrast computed tomography (NCCT) imaging markers. Multivariable linear regression was constructed to study the relationship between NCCT imaging markers and PHE growth over 36 h.

RESULTS

A total of 214 patients were included. Nonparametric test showed that PHE volume was significantly different between patients with and without NCCT imaging markers. (all p < 0.05) In multivariable linear regression analysis adjusted for ICH characteristics, blend sign (p = 0.011), black hole sign (p = 0.002), island sign (p < 0.001), and expansion-prone hematoma (p < 0.001) were correlated with PHE growth. Follow-up PHE volume within 36 h after baseline CT scan was associated with blend sign (p = 0.001), island sign (p < 0.001), and expansion-prone hematoma (p < 0.001).

CONCLUSION

NCCT imaging markers of hematoma expansion are associated with PHE growth. This suggests that early PHE growth can be predicted using radiology markers on admission CT scan.

Intracerebral haemorrhage: from clinical settings to animal models

Spontaneous intracerebral haemorrhage (ICH) is a devastating type of stroke with high mortality and morbidity and for which no effective treatments are available to date. Much experimental and clinical research have been performed to explore its mechanisms regard the subsequent inflammatory cascade and to seek the potential therapeutic strategies. The aim of this review is to discuss insights from clinical settings that have led to the development of numerous animal models of ICH. Some of the current and future challenges for clinicians to understand ICH are also surveyed.

The Role of Thrombin in Brain Injury After Hemorrhagic and Ischemic Stroke

Thrombin is increased in the brain after hemorrhagic and ischemic stroke primarily due to the prothrombin entry from blood either with a hemorrhage or following blood-brain barrier disruption. Increasing evidence indicates that thrombin and its receptors (protease-activated receptors (PARs)) play a major role in brain pathology following ischemic and hemorrhagic stroke (including intracerebral, intraventricular, and subarachnoid hemorrhage). Thrombin and PARs affect brain injury via multiple mechanisms that can be detrimental or protective. The cleavage of prothrombin into thrombin is the key step of hemostasis and thrombosis which takes place in every stroke and subsequent brain injury. The extravascular effects and direct cellular interactions of thrombin are mediated by PARs (PAR-1, PAR-3, and PAR-4) and their downstream signaling in multiple brain cell types. Such effects include inducing blood-brain-barrier disruption, brain edema, neuroinflammation, and neuronal death, although low thrombin concentrations can promote cell survival. Also, thrombin directly links the coagulation system to the immune system by activating interleukin-1α. Such effects of thrombin can result in both short-term brain injury and long-term functional deficits, making extravascular thrombin an understudied therapeutic target for stroke. This review examines the role of thrombin and PARs in brain injury following hemorrhagic and ischemic stroke and the potential treatment strategies which are complicated by their role in both hemostasis and brain.

Intraventricular Hemorrhage and White Matter Injury in Preclinical and Clinical Studies

Germinal matrix-intraventricular hemorrhage (IVH) occurs in nearly half of infants born at less than 26 weeks' gestation. Up to 50% of survivors with IVH develop cerebral palsy, cognitive deficits, behavioral disorders, posthemorrhagic ventricular dilatation, or a combination of these sequelae. After the initial bleeding and the primary brain injury, inflammation and secondary brain injury might lead to periventricular leukomalacia or diffuse white matter injury. Potential factors that are involved include microglia and astrocyte activation, degradation of blood components with release of "toxic" products, infiltration of the brain by systemic immune cells, death of neuronal and glial cells, and arrest of preoligodendrocyte maturation. In addition, impairment of the blood-brain barrier may play a major role in the pathophysiology. A wide range of animal models has been used to explore causes and mechanisms leading to IVH-induced brain injury. Preclinical studies have identified potential targets for enhancing brain repair. However, little has been elucidated about the effectiveness of potential interventions in clinical studies. A systematic review of available preclinical and clinical studies might help identify research gaps and which types of interventions may be prioritized. Future trials should report clinically robust and long-term outcomes after IVH.

Fully Automated Segmentation Algorithm for Perihematomal Edema Volumetry After Spontaneous Intracerebral Hemorrhage

Background and Purpose- Perihematomal edema (PHE) is a promising surrogate marker of secondary brain injury in patients with spontaneous intracerebral hemorrhage, but it can be challenging to accurately and rapidly quantify. The aims of this study are to derive and internally validate a fully automated segmentation algorithm for volumetric analysis of PHE. Methods- Inpatient computed tomography scans of 400 consecutive adults with spontaneous, supratentorial intracerebral hemorrhage enrolled in the Intracerebral Hemorrhage Outcomes Project (2009-2018) were separated into training (n=360) and test (n=40) datasets. A fully automated segmentation algorithm was derived from manual segmentations in the training dataset using convolutional neural networks, and its performance was compared with that of manual and semiautomated segmentation methods in the test dataset. Results- The mean volumetric dice similarity coefficients for the fully automated segmentation algorithm were 0.838±0.294 and 0.843±0.293 with manual and semiautomated segmentation methods as reference standards, respectively. PHE volumes derived from the fully automated versus manual (r=0.959; P<0.0001), fully automated versus semiautomated (r=0.960; P<0.0001), and semiautomated versus manual (r=0.961; P<0.0001) segmentation methods had strong between-group correlations. The fully automated segmentation algorithm (mean 18.0±1.8 seconds/scan) quantified PHE volumes at a significantly faster rate than both of the manual (mean 316.4±168.8 seconds/scan; P<0.0001) and semiautomated (mean 480.5±295.3 seconds/scan; P<0.0001) segmentation methods. Conclusions- The fully automated segmentation algorithm accurately quantified PHE volumes from computed tomography scans of supratentorial intracerebral hemorrhage patients with high fidelity and greater efficiency compared with manual and semiautomated segmentation methods. External validation of fully automated segmentation for assessment of PHE is warranted.

Role of thrombin-PAR1-PKCθ/δ axis in brain pericytes in thrombin-induced MMP-9 production and blood-brain barrier dysfunction in vitro

Thrombin, an essential component in the coagulation cascade, participates in the pathogenesis of brain diseases, such as ischemic stroke, intracerebral hemorrhage, Alzheimer's disease and Parkinson's disease through blood-brain barrier (BBB) dysfunction. It is thought that the thrombin-matrix metalloproteinase (MMP)-9 axis is an important process in the pathogenesis of neurovascular disease, such as BBB dysfunction. We recently reported that brain pericytes are the most MMP-9-releasing cells in response to thrombin stimulation among the BBB-constituting cells. This thrombin-induced MMP-9 release is partially due to protease-activated receptor (PAR1), one of the specific thrombin receptors. Then, we evaluated the intracellular signaling pathways involved in MMP-9 release and the contribution of thrombin-reactive brain pericytes to BBB dysfunction. PKC activator evoked MMP-9 release from brain pericytes. The thrombin-induced MMP-9 release was inhibited by U0126, LY294002, Go6976, and Go6983. However, Go6976 decreased phosphorylation levels of PKCθ and Akt, and Go6983 decreased phosphorylation levels of PKCδ and extracellular signal-regulated kinase (ERK). Additionally, treatment of pericytes with thrombin or PAR1-activating peptide stimulated PKCδ/θ signaling. These substances impaired brain endothelial barrier function in the presence of brain pericytes. Brain pericytes function through two independent downstream signaling pathways via PAR1 activation to release MMP-9 in response to thrombin - the PKCθ-Akt pathway and the PKCδ-ERK1/2 pathway. These pathways participate in PAR1-mediated MMP-9 release from pericytes, which leads to BBB dysfunction. Brain pericytes and their specific signaling pathways could provide novel therapeutic targets for thrombin-induced neurovascular diseases.

Matrix Metalloproteinase in Blood-Brain Barrier Breakdown in Dementia

The neurovascular unit, which consists of astrocytic end-feet, neurons, pericytes, and endothelial cells, plays a key role in maintaining brain homeostasis by forming the blood-brain barrier and carefully controlling local cerebral blood flow. When the blood-brain barrier is disrupted, blood components can leak into the brain, damage the surrounding tissue and lead to cognitive impairment. This disruption in the blood-brain barrier and subsequent impairment in cognition are common after stroke and during cerebral amyloid angiopathy and Alzheimer's disease. Matrix metalloproteinases are proteases that degrade the extracellular matrix as well as tight junctions between endothelial cells and have been implicated in blood-brain barrier breakdown in neurodegenerative diseases. This review will focus on the roles of MMP2 and MMP9 in dementia, primarily post-stroke events that lead to dementia, cerebral amyloid angiopathy, and Alzheimer's disease.

Protease activated receptor 1 (PAR1) enhances Src-mediated tyrosine phosphorylation of NMDA receptor in intracerebral hemorrhage (ICH)

It has been demonstrated that Src could modulate NMDA receptor, and PAR1 could also affect NMDAR signaling. However, whether PAR1 could regulate NMDAR through Src under ICH has not yet been investigated. In this study, we demonstrated the role of Src-PSD95-GluN2A signaling cascades in rat ICH model and in vitro thrombin challenged model. Using the PAR1 agonist SFLLR, antagonist RLLFS and Src inhibitor PP2, electrophysiological analysis showed that PAR1 regulated NMDA-induced whole-cell currents (INMDA) though Src in primary cultured neurons. Both in vivo and in vitro results showed the elevated phosphorylation of tyrosine in Src and GluN2A and enhanced interaction of the Src-PSD95-GluN2A under model conditions. Treatment with the PAR1 antagonist RLLFS, AS-PSD95 (Antisense oligonucleotide against PSD95) and Src inhibitor PP2 inhibited the interaction among Src-PSD95-GluN2A, and p-Src, p-GluN2A. Co-application of SFLLR and AS-PSD95, PP2, or MK801 (NMDAR inhibitor) abolished the effect of SF. In conclusion, our results demonstrated that activated thrombin receptor PAR1 induced Src activation, enhanced the interaction among Src-PSD95-GluN2A signaling modules, and up-regulated GluN2A phosphorylation after ICH injury. Elucidation of such signaling cascades would possibly provide novel targets for ICH treatment.

Dynamic regulation of aquaporin-4 water channels in neurological disorders

Aquaporin-4 water channels play a central role in brain water regulation in neurological disorders. Aquaporin-4 is abundantly expressed at the astroglial endfeet facing the cerebral vasculature and the pial membrane, and both its expression level and subcellular localization significantly influence brain water transport. However, measurements of aquaporin-4 levels in animal models of brain injury often report opposite trends of change at the injury core and the penumbra. Furthermore, aquaporin-4 channels play a beneficial role in brain water clearance in vasogenic edema, but a detrimental role in cytotoxic edema and exacerbate cell swelling. In light of current evidence, we still do not have a complete understanding of the role of aquaporin-4 in brain water transport. In this review, we propose that the regulatory mechanisms of aquaporin-4 at the transcriptional, translational, and post-translational levels jointly regulate water permeability in the short and long time scale after injury. Furthermore, in order to understand why aquaporin-4 channels play opposing roles in cytotoxic and vasogenic edema, we discuss experimental evidence on the dynamically changing osmotic gradients between blood, extracellular space, and the cytosol during the formation of cytotoxic and vasogenic edema. We conclude with an emerging picture of the distinct osmotic environments in cytotoxic and vasogenic edema, and propose that the directions of aquaporin-4-mediated water clearance in these two types of edema are distinct. The difference in water clearance pathways may provide an explanation for the conflicting observations of the roles of aquaporin-4 in edema resolution.

Application of the Ommaya Reservoir in Managing Ventricular Hemorrhage

BACKGROUND

Intraventricular hemorrhage (IVH) is associated with high morbidity and mortality. This study evaluated the safety and efficacy of the combined treatment of an Ommaya reservoir and conventional external ventricular drainage (EVD) using urokinase in the management of IVH.

METHODS

We performed a prospective controlled study. Sixty eligible patients with IVH received conventional EVD alone (group A) or combined EVD and Ommaya reservoir (group B) between January 2010 and January 2015. Clinical, cerebrospinal fluid, and radiographic data were used to assess clot clearance, clinical outcomes, and complications between the groups.

RESULTS

There were no significant differences in gender, age, blood pressure, Glasgow Coma Scale, Graeb score, intracerebral hemorrhage volume on admission, and IVH volume before surgery between groups A and B (P > 0.05). The number of injections of urokinase (20,000 IU/dose) were significantly different in group B compared with group A (P < 0.05). Repeated computed tomography scans 3 days, 6 days, and 10 days after surgery revealed that clot clearance rates at each time point were significantly increased in group B compared with group A (P < 0.05). The conventional catheter-based EVD duration time was shortened to 5 (4-6) days in group B compared with 7 (5-9) days in group A (P < 0.05). The total drainage time was prolonged to 9 (8-11) days in group B compared with 7 (5-9) days in group A (P < 0.05). Ventriculitis was not significantly different between the 2 groups (P > 0.05). The hydrocephalus incidence and mortality revealed significant differences between the 2 groups (P < 0.05). The 30-day Glasgow Outcome Scale score was significantly increased in group B compared with group A (P < 0.05).

CONCLUSIONS

The combined treatment approach of an Ommaya reservoir and EVD with intraventricular urokinase is safe and effective in patients with IVH. It increased clot clearance, shortened conventional catheter-based EVD duration, prolonged total drainage time, reduced the hydrocephalus incidence and mortality, and contributed to good clinical outcomes. The Ommaya reservoir provides a safe way to increase the injection times of urokinase, which accelerated clot resolution and did not increase the risk for ventriculitis infection.

Brain pericytes are the most thrombin-sensitive matrix metalloproteinase-9-releasing cell type constituting the blood-brain barrier in vitro

In the acute phase of intracerebral hemorrhage (ICH), hemorrhagic transformation and brain edema are associated with blood-brain barrier (BBB) disruption. Elevated levels of thrombin, a coagulation factor, contribute to the development of brain edema during ICH through matrix metalloproteinase (MMP)-9 production. Thrombin directly induces a variety of cellular responses through its specific receptors known as protease-activated receptors (PARs). However, it remains unclear which cell types constituting the BBB mainly produce MMP-9 in response to thrombin. Here, we compared the MMP-9 release induced by thrombin using primary cultures of rat brain microvascular endothelial cells, astrocytes, and pericytes. Brain pericytes exhibited the highest levels of MMP-9 release due to thrombin stimulation among the BBB cells. The pattern of PAR mRNA expression in pericytes was characterized by high expression of PAR1 and moderate expression of PAR4. Heat-inactivated thrombin failed to stimulate pericytes to release MMP-9. A selective PAR1 inhibitor SCH79797 blocked the thrombin-induced MMP-9 release from pericytes. These findings suggest that both PAR1 and PAR4 mediate thrombin-induced MMP-9 release from pericytes. The present study raises the possibility that brain pericytes could play a pivotal role as a highly thrombin-sensitive and MMP-9-producing cell type at the BBB in brain damage including ICH.

Analysis of Cynandione A's Anti-Ischemic Stroke Effects from Pathways and Protein-Protein Interactome

Ischemic stroke is the third leading cause of death in the world. Our previous study found that cynandione A (CYNA), the main component from the root of Cynanchum bungei, exhibits anti-ischemic stroke activity. In this work, we investigated the therapeutic mechanisms of CYNA to ischemic stroke at protein network level. First, PC12 cells and cerebellar granule neurons were prepared to validate the effects of CYNA against glutamate injury. Our experiments suggested that CYNA could dose-dependently mitigate glutamate-induced neurons neurotoxicity and inhibit glutamate-induced upregulation of KHSRP and HMGB1, further confirming the neuroprotective effects of CYNA in vivo. Then, on the pathway sub-networks, which present biological processes that can be impacted directly or in periphery nodes by drugs via their targets, we found that CYNA regulates 11 pathways associated with the biological process of thrombotic or embolic occlusion of a cerebral artery. Meanwhile, by defining a network-based anti-ischemic stroke effect score, we showed that CYNA has a significantly higher effect score than random counterparts, which suggests a synergistic effect of CYNA to ischemic stroke. This study may shed new lights on the study of network based pharmacology.

CCR2+ Ly6C(hi) inflammatory monocyte recruitment exacerbates acute disability following intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating type of stroke that lacks a specific treatment. An intense immune response develops after ICH, which contributes to neuronal injury, disability, and death. However, the specific mediators of inflammation-induced injury remain unclear. The objective of the present study was to determine whether blood-derived CCR2+ Ly6C(hi) inflammatory monocytes contribute to disability. ICH was induced in mice and the resulting inflammatory response was quantified using flow cytometry, confocal microscopy, and neurobehavioral testing. Importantly, blood-derived monocytes were distinguished from resident microglia by differential CD45 staining and by using bone marrow chimeras with fluorescent leukocytes. After ICH, blood-derived CCR2+ Ly6C(hi) inflammatory monocytes trafficked into the brain, outnumbered other leukocytes, and produced tumor necrosis factor. Ccr2(-/-) mice, which have few circulating inflammatory monocytes, exhibited better motor function following ICH than control mice. Chimeric mice with wild-type CNS cells and Ccr2(-/-) hematopoietic cells also exhibited early improvement in motor function, as did wild-type mice after inflammatory monocyte depletion. These findings suggest that blood-derived inflammatory monocytes contribute to acute neurological disability. To determine the translational relevance of our experimental findings, we examined CCL2, the principle ligand for the CCR2 receptor, in ICH patients. Serum samples from 85 patients were collected prospectively at two hospitals. In patients, higher CCL2 levels at 24 h were independently associated with poor functional outcome at day 7 after adjusting for potential confounding variables. Together, these findings suggest that inflammatory monocytes worsen early disability after murine ICH and may represent a therapeutic target for patients.

Preconditioning provides neuroprotection in models of CNS disease: paradigms and clinical significance

Preconditioning is a phenomenon in which brief episodes of a sublethal insult induce robust protection against subsequent lethal injuries. Preconditioning has been observed in multiple organisms and can occur in the brain as well as other tissues. Extensive animal studies suggest that the brain can be preconditioned to resist acute injuries, such as ischemic stroke, neonatal hypoxia/ischemia, surgical brain injury, trauma, and agents that are used in models of neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. Effective preconditioning stimuli are numerous and diverse, ranging from transient ischemia, hypoxia, hyperbaric oxygen, hypothermia and hyperthermia, to exposure to neurotoxins and pharmacological agents. The phenomenon of "cross-tolerance," in which a sublethal stress protects against a different type of injury, suggests that different preconditioning stimuli may confer protection against a wide range of injuries. Research conducted over the past few decades indicates that brain preconditioning is complex, involving multiple effectors such as metabolic inhibition, activation of extra- and intracellular defense mechanisms, a shift in the neuronal excitatory/inhibitory balance, and reduction in inflammatory sequelae. An improved understanding of brain preconditioning should help us identify innovative therapeutic strategies that prevent or at least reduce neuronal damage in susceptible patients. In this review, we focus on the experimental evidence of preconditioning in the brain and systematically survey the models used to develop paradigms for neuroprotection, and then discuss the clinical potential of brain preconditioning.

Analysis of combined coiling and neuroendoscopy in the treatment of intraventricular hemorrhage due to ruptured aneurysm

BACKGROUND

Subarachnoid hemorrhage (SAH) with intraventricular hemorrhage (IVH) is associated with poor outcomes. The aim of this study was to evaluate the effectiveness of combined coiling and neuroendoscopy to treat severe SAH with massive IVH.

METHOD

Between April 2008 and March 2012, 13 patients had massive IVH with a ruptured aneurysm treated at the Department of Neurosurgery, Fukuoka University, Japan. All 13 patients were treated within 2 days of onset by coiling and neuroendoscopic removal of the IVH, including the fourth ventricle.

RESULTS

No rebleeding or acute hydrocephalus were noted. Glasgow Outcome Scale scores (GOS) at discharge were: good recovery (two patients), moderate disability (three patients), severe disease (one patient), vegetative state (four patients), and dead (three patients). A good modified Rankin Scale score (mRS) (0-2) at 6 months was observed in six patients and a poor mRS score (3-6) occurred in seven. The pre- and post-operative Graeb scores were significantly lower in the good mRS group (p = 0.020 and 0.033, respectively, Mann-Whitney U-test). GOS scores at discharge were significantly associated with mRS score at 6 months (p = 0.011, Fisher's Exact Test).

CONCLUSIONS

Combined coiling and neuroendoscopic removal of the IVH, including the fourth ventricle, were feasible procedures and achieved preferable outcomes in approximately half of the cases.

Human amniotic epithelial stem cells inhibit microglia activation through downregulation of tumor necrosis factor-α, interleukin-1β and matrix metalloproteinase-12 in vitro and in a rat model of intracerebral hemorrhage

BACKGROUND AIMS

The molecular mechanisms by which stem cell transplantation improves functional recovery after intracerebral hemorrhage (ICH) are not well understood. Accumulating evidence suggests that microglia cells are activated shortly after ICH and that this activation contributes to secondary ICH-induced brain injury. We studied the effect of human amniotic epithelial stem cells (HAESCs) on microglia activation.

METHODS

To study the effect of HAESCs in vitro, we used thrombin to activate the microglia cells. Twenty-four hours after thrombin treatment, the levels of tumor necrosis factor-α and interleukin-1β were measured by enzyme-linked immunosorbent assay. In vivo, the HAESCs were transplanted into the rat striatum 1 day after collagenase-induced ICH. The expression levels of matrix metalloproteinase (MMP)-12 and microglia infiltration in the peri-hematoma tissues were determined 7 days after ICH through the use of reverse transcriptase-polymerase chain reaction and immunohistochemical analysis, respectively.

RESULTS

Thrombin-activated microglia expression of tumor necrosis factor-α, interleukin-1β and MMP-12 was significantly reduced through contact-dependent and paracrine mechanisms when the HAESCs were co-cultured with microglia cells. After transplantation of HAESCs in rat brains, the expression levels of MMP-12 and microglia infiltration in the peri-hematoma tissues were significantly reduced.

CONCLUSIONS

Our observations suggest that microglia activation could be inhibited by HAESCs both in vitro and in vivo, which may be an important mechanism by which the transplantation of HAESCs reduces brain edema and ameliorates the neurologic deficits after ICH. Therefore, we hypothesize that methods for suppressing the activation of microglia and reducing the inflammatory response can be used for designing effective treatment strategies for ICH.

A multicenter, randomized, double-blinded, placebo-controlled phase III study of Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR III)

BACKGROUND

In adults, intraventricular thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) facilitates resolution of intraventricular haemorrhage (IVH), reduces intracranial pressure, decreases duration of cerebrospinal fluid diversion, and may ameliorate direct neural injury. We hypothesize that patients with small parenchymal haematoma volumes (<30 cc) and relatively large IVH causing acute obstructive hydrocephalus would have improved clinical outcomes when given injections of low-dose rtPA to accelerate lysis and evacuation of IVH compared with placebo.

METHODS

The Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage III trial is an investigator-initiated, phase III, randomized, multicenter, double-blind, placebo-controlled study comparing the use of external ventricular drainage (EVD) combined with intraventricular injection of rtPA to EVD plus intraventricular injection of normal saline (placebo) for the treatment of IVH. Patients with known symptom onset within 24 h of the computed tomography scan confirmed IVH and third or fourth ventricle obstruction, with or without supratentorial intracerebral haemorrhage volume <30 cc, who require EVD are screened with a computed tomography scan at least six hours after EVD placement and, if necessary, at consecutive 12-h intervals until stabilization of any intracranial bleeding has been established. Patients who meet clinical and imaging criteria (no ongoing coagulopathy and no suspicion of aneurysm, arteriovenous malformation, or any other vascular anomaly) will be randomized to either intraventricular rtPA or placebo.

RESULTS

The primary outcome measure is dichotomized modified Rankin Scale 0-3 vs. 4-6 at 180 days. Clinical secondary outcomes include additional modified Rankin Scale dichotomizations at 180 days (0-4 vs. 5-6), ordinal modified Rankin Scale (0-6), mortality and safety events at 30 days, mortality at 180 days, functional status measures, type and intensity of intensive care unit management, rate and extent of ventricular blood clot removal, and quality of life measures.

Safety of intraventricular hemorrhage (IVH) thrombolysis based on CT localization of external ventricular drain (EVD) fenestrations and analysis of EVD tract hemorrhage

BACKGROUND

The purpose of the study is to review the CT findings associated with ventriculostomy placement in regards to the safety of an EVD plus recombinant tissue plasminogen activator (rt-PA) for IVH.

METHODS

A retrospective review was conducted for patients receiving intraventricular rt-PA for IVH from January 2004 to September 2009. Safety was assessed by the presence of EVD tract hemorrhage by CT at baseline after EVD placement, worsening hemorrhage after rt-PA, and CSF infection. IVH volumetrics were assessed by the Le Roux score and outcomes by Glasgow Outcome Scale and modified Rankin Scale.

RESULTS

Twenty-seven patients received rt-PA for IVH. Median dose was 2 mg (range 0.3-8) and a median of two doses (range 1-17) were given. Worsening EVD catheter tract hemorrhage after rt-PA was 46.7 %, with a significantly higher incidence of worsening tract hemorrhage seen with incorrectly placed EVDs (p = 0.04). IVH hematoma burden decreased by a median Le Roux score of 10 (range 3-16) prior to rt-PA to 4 (range 0-16) after rt-PA. There were no central nervous system bacterial infections.

CONCLUSION

Intraventricular rt-PA appears to be relatively safe especially when all EVD fenestrations are within the ventricle and reduces IVH burden similar to other studies. We describe a CT-based EVD tract hemorrhage grading scale to evaluate EVD tract hemorrhage before and after thrombolysis, and a bone-window technique to evaluate EVD fenestrations prior to IVH thrombolysis. Further research is needed evaluating these imaging techniques in regard to intraventricular thrombolytic safety and EVD tract hemorrhage.

Safety and feasibility of combined coiling and neuroendoscopy for better outcomes in the treatment of severe subarachnoid hemorrhage accompanied by massive intraventricular hemorrhage

Subarachnoid hemorrhage (SAH) with intraventricular hemorrhage (IVH) is associated with poor outcomes. The aim of this study was to evaluate the safety and feasibility of combined coiling and neuroendoscopy for treating severe SAH with massive IVH. Between April 2008 and June 2011, 49 patients with a severe SAH were treated at the Department of Neurosurgery, Fukuoka University, Japan; 10 of these patients had a massive IVH with a ruptured aneurysm. All 10 patients (three men and seven women; mean age, 63.1±8.5 years) were treated with coiling and neuroendoscopic removal of the IVH within 2 days of onset. Coiling was successfully performed at a mean volume embolization ratio of 21.8±5.5%. Neuroendoscopic removal of the IVH reduced the mean Graeb score from 10.5±2.0 to 4.8±2.5 (p=0.005). All external drains were removed on day 3. No rebleeding or acute hydrocephalus was noted. The Glasgow Outcome Scale scores at discharge indicated two patients with good recovery, three with moderate disability, four in a vegetative state, and one dead. A good modified Rankin Scale (mRS) score (0-2) at least 6 months later (mean follow-up period, 15.4±9.2 months) was observed for five patients (50%), and a poor mRS score (3-6) was observed for the remaining four patients. Neuroendoscopically removing the IVH from all of the ventricles between the lateral and the fourth ventricle and coiling the ruptured aneurysm is a safe, feasible approach for treating severe SAH with massive IVH.

Thrombin-induced TGF-β1 pathway: a cause of communicating hydrocephalus post subarachnoid hemorrhage

The mechanism of communicating hydrocephalus after subarachnoid hemorrhage (SAH) remains unclear. Revealing a signaling cascade may provide significant insights into the molecular etiology of the accumulation of cerebrospinal fluid (CSF) in cerebral compartments during SAH. To investigate the mechanism of the communicating hydrocephalus following SAH, we infused CSF with thrombin (TH), resulting in proinflammatory and proliferative responses in rat meninges of SAH. The effect of TH could be completely blocked by a transforming growth factor β1 (TGF-β1) inhibitor, SB-431542, suggesting that TH-stimulated proliferation of meninges is through the TGF-β1 signaling pathway. The cascade of TGF β1-Smad3 was significantly upregulated by TH, which, in turn, stimulated the proliferation of subarachnoid meninges. TH-induced overexpression of TGF-β1 and activation of its downstream factors might be a mechanism of communicating hydrocephalus after SAH.

Computed tomography and transcranial Doppler findings in acute and subacute phases of intracerebral hemorrhagic stroke

BACKGROUND AND PURPOSE

The hematoma volume is an important determinant of outcome and a predictor of clinical deterioration in patients with intracerebral hemorrhage (ICH). Our goal was to evaluate alterations in the cerebral circulation, in respect to hemorrhage and edema volume changes, using transcranial Doppler (TCD).

METHODS

Twenty patients with acute supratentorial ICH were examined. Brain, hematoma, and edema volumes were calculated from CT scans performed at admission and 2 weeks later. Data were compared with those obtained from bilateral TCD recordings of the middle cerebral arteries.

RESULTS

During TCD examination, blood flow velocities did not change, cerebral perfusion pressure (CPP) and resistance area product (RAP) decreased (P = .006, P = .002) while cerebral blood flow index (CBFI) remained constant on the affected side. Although hemorrhage volume did not correlate with RAP in the acute phase, correlation was found in the subacute phase (r = -.44, P = .04).

CONCLUSIONS

TCD monitoring sensitively demonstrates the hemodynamic change caused by ICH but the severity of the changes does not correlate with the volume of the ICH in acute stage. The CPP, RAP, and CBFI values are more sensitive parameters than the absolute velocity values, therefore they contribute more to the understanding of hemodynamic changes developed after spontaneous ICH.

The Molecular Mechanisms that Promote Edema After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a devastating type of stroke with no effective therapies. Clinical advances in ICH treatment are limited by an incomplete understanding of the molecular mechanisms responsible for secondary injury and poor outcome. Increasing evidence suggests that cerebral edema is a major contributor to secondary injury and poor outcome in ICH. ICH activates specific signaling pathways that promote edema and damage neuronal tissue. By increasing our understanding of these pathways, we may be able to target them pharmaceutically to reduce edema in ICH patients. In this review, we focus on three major signaling pathways that promote edema after ICH: (1) the coagulation cascade and thrombin, (2) the inflammatory response and matrix metalloproteinases, and (3) the complement cascade and hemoglobin toxicity. We will describe the experimental evidence that confirms these pathways promote edema in ICH, discuss potential targets for new therapies, and comment on important directions for future research.

Association of Interleukin-11 with Mortality in Patients with Spontaneous Basal Ganglia Haemorrhage

This study evaluated interleukin (IL)-11 as an independent prognostic marker of mortality following intracerebral haemorrhage (ICH). Plasma IL-11 levels in patients with ICH were significantly higher than in healthy controls. Multivariate analysis indicated that plasma IL-11 level was an independent predictor for mortality within 1 week of ICH onset and was positively associated with haematoma volume. Receiver operating characteristic curve analysis identified that a baseline plasma IL-11 level > 20.9 pg/ml predicted mortality within 1 week of ICH onset with 81.2% sensitivity and 74.1% specificity. The area under the curve for IL-11 level was significantly smaller than that for the Glasgow Coma Scale score, but similar to that for haematoma volume. IL-11 did not, however, significantly improve the predictive value of the Glasgow Coma Scale or haematoma volume. Thus, IL-11 may be considered as a new independent prognostic marker of mortality and an additional valuable tool for risk stratification and decision-making in the acute phase of ICH.

Time course of plasma microparticle concentrations after acute spontaneous basal ganglia hemorrhage

OBJECTIVES

To examine the changes in plasma microparticle (MP) levels in patients after intracerebral hemorrhage (ICH) and assess their association with outcome along with biological markers of the acute phase response.

MATERIALS AND METHODS

Thirty healthy controls and 86 patients with acute ICH were recruited. Plasma samples were obtained on admission and at days 1, 2, 3, 5, and 7 after ICH. MPs with procoagulant potential were measured with a prothrombinase assay.

RESULTS

Plasma MP levels in patients were substantially higher than those in healthy controls during the 7-day period. Plasma MP levels were strongly associated with outcome and with biological markers of the acute phase response. Multivariate analysis showed baseline plasma MP level was a good predictor of 1-week mortality (odds ratio, 1.930; 95% confidence interval, 1.229-3.031; P=0.004). A receiver operating characteristic curve identified the plasma MP cutoff level (8.4 nmol/l phosphatidylserine equivalent) that predicted 1-week mortality with high sensitivity (90.6%) and specificity (68.5.0%) (P<0.001).

CONCLUSIONS

Increased membrane microparticle levels occur after ICH and may contribute to the subsequent brain injury, in association with a poor clinical outcome.

Analysis of thrombin-antithrombin complex contents in plasma and hematoma fluid of hypertensive intracerebral hemorrhage patients after clot removal

BACKGROUND AND PURPOSE

  Animal experiments indicate that the cerebral thrombin is associated with secondary brain damage after intracerebral hemorrhage (ICH). This study was aimed to investigate the concentrations of thrombin-antithrombin complex (TAT) in hematoma fluid and plasma of the patients with ICH after surgery and analyze the correlation between TAT complex levels and severity of ICH.

METHODS

  Sixty patients with ICH were enrolled. Craniotomy for removal of intracranial blood clot was performed within 24h after ICH. Hematoma fluid and plasma were collected on postoperative days 1, 2, and 4. The plasma obtained from healthy subjects and cerebrospinal fluid from patients without cerebrovascular diseases served as controls, respectively. Enzyme-linked immunosorbent assay was used to determine the concentrations of TAT complex in the patients and controls.

RESULTS

  TAT complex concentrations in both postoperative plasma and hematoma fluid of patients with ICH were significantly higher than those of the controls (P<0.01). In patients with ICH, hematoma fluid had a higher TAT complex level than plasma (P<0.01). The preoperative hemorrhage volume and postoperative TAT complex levels in plasma and hematoma fluid correlated positively with National Institutes of Health stroke scale and negatively with Glasgow coma score (P<0.01).

CONCLUSION

  This study indicates that TAT complex levels of plasma and hematoma fluid correlate positively with the severity of ICH. Determination of the plasma TAT complex concentration is helpful for the evaluation of the severity of post-ICH brain injury.

Alteplase (rtPA) treatment of intraventricular hematoma (IVH): safety of an efficient methodological approach for rapid clot removal

Intraventricular hemorrhage (IVH) subsequent to intracerebral hemorrhage (ICH) or subarachnoid hemorrhage (SAH) is associated with high mortality and morbidity. The use of fibrinolytic agents to treat this condition has previously been reported in small clinical trials with limited numbers of patients. Variability regarding inclusion criteria, method of administration and outcome have made it difficult to draw firm conclusions regarding the efficacy of antifibrinolytic therapy. Nine patients with CT-diagnosed IVH were treated with Alteplase intrathecally for 3 to 5 days according to the CT-verified clearance of IVH. After the treatment period, a repeat CT scan was performed to evaluate treatment effect.In this safety study, we achieved rapid removal of IVH compared to retrospective controls, without incidents of re-bleeding, with only 33% permanent shunt placements and a neurological outcome of GOS of 4-5 in 44% of the patients. Based on the above results, the treatment protocol was considered safe and highly effective. A prospective randomized national multicenter trial has been initiated in order to evaluate the efficacy of this novel method also in terms of outcome and shunt dependency.

The action of thrombin in intracerebral hemorrhage induced brain damage is mediated via PKCα/PKCδ signaling

The present study investigates the role of protein kinase C alpha/delta (PKCα/PKCδ) in brain injury induced by intracerebral hemorrhage (ICH) by utilizing a rat model that received intracerebral injections of autologous blood and thrombin (TM). The activation and expression of PKC and PKCδ were analyzed by Western blot and immunohistochemistry. A PKC inhibitor, dihydrochloride (H7), was administrated intraperitoneally after injury to evaluate the effect of inhibition of PKC on ICH and TM induced brain damage. Our data indicate that both ICH and TM increased the expression of PKCα/PKCδ in the brain tissue, and PKCα expression peaked at 6h, while PKCδ expression reached its maximum value at 72h post-injury. Administration of H7 significantly reduced the inflammatory cells infiltrate, permeability of brain-blood barrier (BBB), brain edema, and neuronal death. We conclude that both PKCα and PKCδ play important roles in ICH and TM-induced brain injury, and dihydrochloride (H7) can attenuate brain damage after ICH.

Thrombin antithrombin complex and IL-18 serum levels in stroke patients

The complex picture of inflammation and coagulation alterations comes to life in acute stroke phases. Increasing evidence points to a strong interaction and extensive crosstalk between the inflammation and coagulation systems: the interest towards this relationship has increased since recent experimental research showed that the early administration of antithrombin III (ATIII) decreases the volume of ischemia in mice and might be neuroprotective, playing an antiinflammatory role.

We aimed to establish the extent of the relationship among markers of inflammation (S100B and IL-18) and procoagulant and fibrinolytic markers (ATIII, thrombin-antithrombin III complex (TAT), Fibrin Degradation Products (FDP), D-dimer) in 13 comatose patients affected by focal cerebral ischemia.

Plasma levels of TAT, D-dimer and FDP, IL18 and S100B were increased. IL-18 and S100B high serum levels in ischemic patients suggest an early activation of the inflammatory cascade in acute ischemic injury.

The basic principles of the interaction between inflammatory and coagulation systems are revised, from the perspective that simultaneous modulation of both coagulation and inflammation, rather than specific therapies aimed at one of these systems could be more successful in stroke therapy.

Management of acute intracranial and intraventricular hemorrhage

OBJECTIVE

Acute intracranial hemorrhage and intraventricular hemorrhage are devastating disorders. The goal of this review is to familiarize clinicians with recent information pertaining to the acute care of intracranial hemorrhage and intraventricular hemorrhage.

DATA SOURCES

PubMed search and review of the relevant medical literature.

SUMMARY

The management of intracranial hemorrhage and intraventricular hemorrhage is complex. Effective treatment should include strategies designed to reduce hematoma expansion and limit the medical consequences of intracranial hemorrhage and intraventricular hemorrhage. At present, there are a number of new approaches to treatment that may reduce mortality and improve clinical outcomes. Clinicians should recognize that patients with large hematomas may make a substantial recovery.

CONCLUSIONS

Patients with intracranial hemorrhage and intraventricular hemorrhage should be cared for in an intensive care unit. New therapies designed to stabilize hematoma growth and reduce hematoma burden may improve outcomes.

Increase in brain thrombin activity after experimental intracerebral hemorrhage

Thrombin has been shown to play a major role in brain injury after intracerebral hemorrhage (ICH). In this study, we measured thrombin activity in the perihematomal zone and examined the role of thrombin in ICH-induced brain tissue loss. There were 2 experiments in this study. In the first part, adult male Sprague-Dawley rats received 100 microL of either autologous whole blood or saline. The rats were killed at 1 h or 24 h later for thrombin activity measurement. Thrombin activity was measured using the thrombin-specific chromogenic substrate, S2238. In the second part, rats received a 50-microL intracaudate injection of either thrombin or saline, and the rats were killed at days 1, 3, or 28 for determination of neuronal death and brain tissue loss. We found that brain thrombin activity was elevated in ipsilateral basal ganglia 1 h after ICH. Intracerebral injection of thrombin rather than saline caused significant neuronal death at days 1 and 3, and resulted in significant brain tissue loss at day 28. These results suggest that thrombin inhibition in the acute phase may reduce ICH-induced brain damage.

An emerging role of mast cells in cerebral ischemia and hemorrhage

Mast cells (MCs) are perivascularly located resident cells of hematopoietic origin, recognized as effectors in inflammation and immunity. Their subendothelial location at the boundary between the intravascular and extravascular milieus, and their ability to rapidly respond to blood- and tissue-borne stimuli via release of potent vasodilatatory, proteolytic, fibrinolytic, and proinflammatory mediators, render MCs with a unique status to act in the first-line defense in various pathologies. We review experimental evidence suggesting a role for MCs in the pathophysiology of brain ischemia and hemorrhage. In new-born rats, MCs contributed to brain damage in hypoxic-ischemic insults. In experimental cerebral ischemia/reperfusion, MCs regulated permeability of the blood-brain barrier, brain edema formation, and the intensity of local neutrophil infiltration. MCs were reported to play a role in the tissue plasminogen activator-mediated cerebral hemorrhages after experimental ischemic stroke, and to be involved in the expansion of hematoma and edema following intracerebral hemorrhage. Importantly, the MC-stabilizing drug cromoglycate inhibited MC-mediated adverse effects on brain pathology and improved survival of experimental animals. This brings us to a position to consider MC stabilization as a novel initial adjuvant therapy in the prevention of brain injuries in hypoxia-ischemia in new-borns, as well as in ischemic stroke and intracerebral hemorrhage in adults.

Fibrinolytic therapy in spontaneous intraventricular haemorrhage: efficacy and safety of the treatment

Intraventricular haemorrhage (IVH) is associated with a poor outcome. Simple external ventricular drainage has not modified the high morbidity and mortality of these patients. Our objective was to review our experience using intraventricular urokinase (UK) in treating patients with moderate to severe IVH. Prospective analysis of medical records of 14 patients diagnosed with spontaneous IVH who received ventriculostomy and intraventricular infusion of UK from January 2002 to December 2005. Patients with the following characteristics were included: 18-70 years of age, GCS between 5 and 14, and moderate to severe IVH (Graeb > or = 6) without simultaneous intraparenchymal haematoma > 30 ml. The final results were compared to historic control group (14 patients) treated between January 1999 to December 2001 with ventriculostomy alone. All 28 patients accomplished the inclusion criteria. Patient age, initial GCS and Graeb classification of IVH were similar in the two groups of treatment. There was higher ventriculostomy obstruction rate in the non-UK group (33.3 vs. 0%; p > 0.05), a higher rate of intracranial hypertension in the non-UK group (66.6 vs. 16.6%; p = 0.036) and a lower mortality rate in the UK group (25 vs. 58.3%, p > 0.05). There was no rebleeding associated with UK treatment. Intraventricular UK appears to be a safe treatment. It is effective in the prevention of catheter blockage, speeding the clearance of IVH, and it is associated with lower rate of intracranial hypertension and death.

Recombinant hirudin treatment modulates aquaporin-4 and aquaporin-9 expression after intracerebral hemorrhage in vivo

Edema formation has been linked to thrombin toxicity induced by blood clot at the acute stage of intracerebral hemorrhage. Thrombin induces cell toxicity in neuron, microglia and astrocyte. Aquaporin (AQP) 4 and 9 are proteins expressed on astrocyte in rat brain and involved in the brain water accumulation in brain edema. Recombinant hirudin (r-Hirudin) is a direct inhibitor of thrombin that can block the toxicitic effect of thrombin. In this study, we demonstrated that autologous whole blood infusion in caudate nucleus up-regulates the expression of AQP4 and AQP9 mRNAs and proteins. AQP4 and AQP9 mRNAs expression peaked at about 6 h after blood infusion. The AQP4 protein peaked at about 48 h while AQP9 at about 24 h after blood infusion. Thrombin induced up-regulation of AQP4 and AQP9 were inhibited by r-Hirudin administration and significantly decreased the expression of both AQPs. We further investigated the relationship between edema formation and expression of AQP4 and AQP9. The data presented here may be helpful in optimizing r-Hirudin as an anti-thrombin drug in the treatment of edema at the acute stage of ICH.

An association of prior statin use with decreased perihematomal edema

OBJECTIVE

To investigate the impact of statins on perihematomal edema following spontaneous supratentorial intracerebral hemorrhage (ICH).

BACKGROUND

Hematoma expansion and evolution of perihematomal edema are most commonly responsible for neurological deterioration following ICH. A possible role of statins in reducing perihematomal edema has been suggested based on studies in animal models.

METHODS

Records of consecutive ICH patients admitted to The Johns Hopkins Hospital from 1999 to 2006 were reviewed. Patients with ICH related to trauma or underlying lesions (e.g., brain tumors, aneurysms, and arterio-venous malformations) and of infratentorial location were excluded. Absolute and relative perihematomal edema were assessed on initial head CT. Using regression analysis, the impact of prior statin use on absolute and relative edema at presentation was assessed correcting for other factors possibly impacting perihematomal edema, such as age, coagulopathy, aspirin use, admission mean arterial pressure (MAP), and blood glucose.

RESULTS

A total of 125 consecutive ICH patients were studied. Patients with prior statin exposure had a mean edema volume of 13.2 +/- 9.2 cc compared to 22.3 +/- 18.3 cc in patients who were not using statins at the time of ICH. Following multiple linear regression analysis, we have identified a statistically significant association between prior statin use with reduced early absolute perihematomal edema (P = 0.035). Mean relative perihematomal edema was significantly lower in patients on statins at presentation (0.44) as opposed to 0.81 in patients with no prior statin use. This difference remained statistically significant (P = 0.021) after correcting for other variables.

CONCLUSIONS

We report the association between statin use prior to ICH and decreased absolute and relative perihematomal edema. A prospective study analyzing the role of statins in perihematomal edema reduction and the resultant effect on mortality and functional outcomes following ICH is warranted.

Early edema in warfarin-related intracerebral hemorrhage

BACKGROUND AND PURPOSE

The pathophysiology and clinical significance of perihematomal edema (PHE), a cause of secondary neuronal injury after intracerebral hemorrhage (ICH), is poorly understood. A leading theory proposes that early PHE results from activation of the clotting cascade. We sought to test this theory by examining the relationship between early PHE and warfarin use in ICH patients.

METHODS

ICH and PHE volumes were measured in consecutive patients with warfarin-related ICH and compared to those of controls with non-coagulopathic ICH. Subjects were identified from a prospective database of ICH patients. Clinical and radiological predictors of PHE volume and relative PHE (PHE volume/ICH volume) were identified. The relationship between PHE volume and 90-day mortality was determined.

RESULTS

For the 49 consecutive warfarin-related ICH patients and 49 matched controls: median INRs (interquartile ranges) were 3.2 (2.3, 4.1) and 1.1 (1.08, 1.2); median hematoma volumes were 37.8 cm(3) (6.7, 102.9) and 18.1 cm(3) (9, 51) (P = 0.18); median PHE volumes were 12 cm(3) (3.7, 36.7), and 11 cm(3) (4.1, 24) (P = 0.87); and median relative PHE was 0.38 (0.28, 0.52) and 2 (1.37, 3.06), respectively. In multivariable analysis, ICH volume and warfarin use independently predicted PHE volume. There was an association between higher PHE volume and decreased 90-day mortality.

CONCLUSIONS

Warfarin-related ICH is associated with less early relative edema than non-coagulopathic ICH. This is consistent with the theory that coagulation contributes to early edema. Early edema may be associated with improved functional outcome.

Thrombin-induced cell proliferation and platelet-derived growth factor-AB release from A172 human glioblastoma cells

BACKGROUND

In a previous study, we found that thrombin induced proliferation of TM-1 and T98G human glioma cells and that the mitogenic effect was abolished by hirudin.

OBJECTIVES

We investigated thrombin's effects on the proliferation of A172 human glioblastoma cells and the induction of growth factors. Furthermore, we examined whether or not the expression of heparin cofactor II (HCII) in A172 cells using adenovirus vector could suppress thrombin's effects.

METHODS

The effect of thrombin on cell proliferation was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. The amount of growth factors in the conditioned medium was measured by enzyme-linked immunosorbent assay. The level of platelet-derived growth factor (PDGF)-B mRNA was assessed by reverse transcriptase-polymerase chain reaction analysis.

RESULTS

Thrombin-induced proliferation of A172 cells primarily depended on the enhanced secretion of PDGF-AB by thrombin. The action of thrombin depended on its proteolytic activity. However, thrombin-induced PDGF-AB secretion was not abolished by anti-protease-activated receptor (PAR) antibody. The PAR-1 agonist peptide had no effect on cell growth and PDGF-AB levels. Thrombin did not increase PDGF-B gene expression. Expression of HCII effectively suppressed thrombin-induced PDGF-AB release.

CONCLUSIONS

These results indicate that thrombin may play an important role in the proliferation of A172 cells by inducing PDGF-AB secretion and that thrombin's action is mediated by its proteolytic activity. Inhibition of thrombin's proteolytic activity may be a new therapeutic method for gliomas.

Comparison of brain cell death and inflammatory reaction in three models of intracerebral hemorrhage in adult rats

Intracerebral hemorrhage (ICH) is associated with stroke and head trauma. Different experimental models are used, but it is unclear to what extent the tissue responses are comparable. The purpose of this study was to compare the temporal responses to brain hemorrhages created by injection of autologous whole blood, collagenase digestion of blood vessels, and avulsion of cerebral blood vessels. Adult rats were subjected to ICH. Rats were perfusion fixed with paraformaldehyde 1 hour to 28 days later. Hematoxylin and eosin, Fluoro-Jade, immunohistochemical, and TUNEL staining were used to allow quantification of damaged and dying neurons, neutrophils, CD8alpha immunoreactive lymphocytes, and RCA-1 positive microglia/macrophages, adjacent to the hemorrhagic lesion. In all models, eosinophilic neurons peaked between 2 and 3 days. TUNEL positive cells were observed maximal at 2 days in blood injection model, 3 days in vessel avulsion model, between 1 and 7 days in the collagenase injection model, and were evident in small quantities in 21 to 28 days in 3 models. Neutrophils appeared briefly from 1 to 3 days in all models, but they were substantially lower in the cortical vessel avulsion model, perhaps owing to the devitalized nature of the tissue. Influx of CD8alpha immunoreactive lymphocytes were maximal at 2 to 3 days in the autologous injection model, 3 to 7 days in other 2 models, and persisted for 21 to 28 days in all models. The microglial/macrophage reaction peaked between 2 and 3 days in the blood injection model and at 3 to 7 days in other 2 models, and persisted for weeks in all groups. These results suggest that different models of ICH are associated with similar temporal patterns of cell death and inflammation. However, the relative magnitude of these changes differs.

Brain edema after intracerebral hemorrhage: mechanisms, treatment options, management strategies, and operative indications

Primary intracerebral hemorrhage (ICH) is associated with a high mortality rate and severe morbidity. The treatment of choice is still controversial, given that data from several clinical trials have not provided convincing evidence to support the efficacy of surgical clot removal. Favoring early clot removal is evidence that the limited release of specific neurotoxins associated with the breakdown products of hemoglobin underlies secondary brain injury. Attention has therefore shifted to perilesional brain injury, especially brain edema, as a potential target for therapeutic intervention in patients with ICH. In this review the authors address current understanding of the causes of edema formation following ICH and the treatment options, which are mostly supportive in nature.