Priorities for clinical research in intracerebral hemorrhage: report from a National Institute of Neurological Disorders and Stroke workshop. Stroke. 2005;36:e23-e41. [PMID: 15692109 DOI: 10.1161/01.str.0000155685.77775.4c]

A potential role of gut microbiota in stroke: mechanisms, therapeutic strategies and future prospective

RATIONALE

Neurological conditions like Stroke and Alzheimer's disease (AD) often include inflammatory responses in the nervous system. Stroke, linked to high disability and mortality rates, poses challenges related to organ-related complications. Recent focus on understanding the pathophysiology of ischemic stroke includes aspects like cellular excitotoxicity, oxidative stress, cell death mechanisms, and neuroinflammation.

OBJECTIVE

The objective of this paper is to summarize and explore the pathophysiology of ischemic stroke, elucidates the gut-brain axis mechanism, and discusses recent clinical trials, shedding light on novel treatments and future possibilities.

RESULTS

Changes in gut architecture and microbiota contribute to dementia by enhancing intestinal permeability, activating the immune system, elevating proinflammatory mediators, altering blood-brain barrier (BBB) permeability, and ultimately leading to neurodegenerative diseases (NDDs). The gut-brain axis's potential role in disease pathophysiology offers new avenues for cell-based regenerative medicine in treating neurological conditions.

CONCLUSION

In conclusion, the gut microbiome significantly impacts stroke prognosis by highlighting the role of the gut-brain axis in ischemic stroke mechanisms. This insight suggests potential therapeutic strategies for improving outcomes.

Influence of Hospital Type on Outcomes of Patients With Acute Spontaneous Intracerebral Hemorrhage: A Population-Based Study

BACKGROUND AND OBJECTIVES

Whether the outcome of patients with spontaneous intracerebral hemorrhage (ICH) differs depending on the type of hospital where they are admitted is uncertain. The objective of this study was to determine influence of hospital type at admission (telestroke center [TSC], primary stroke center [PSC], or comprehensive stroke center [CSC]) on outcome for patients with ICH. We hypothesized that outcomes may be better for patients admitted to a CSC.

METHODS

This is a multicenter prospective observational and population-based study of a cohort of consecutively recruited patients with ICH (March 2020-March 2022). We included all patients with spontaneous ICH in Catalonia (Spain) who had a pre-ICH modified Rankin scale (mRS) score of 0-3 and who were admitted to the hospital within 24 hours of onset. We compared patients admitted to a TSC/PSC (n = 641) or a CSC (n = 1,320) and also analyzed the subgroup of patients transferred (n = 331) or not transferred (n = 310) from a TSC/PSC to a CSC. The main outcome was the 3-month mRS score obtained by blinded investigators. Outcomes were compared using adjusted ordinal logistic regression to estimate the common odds ratio (OR) and 95% CI for a shift in mRS scores. A propensity score matching (PSM) analysis was performed for the subgroup of transferred patients.

RESULTS

Relevant data were obtained from 1961 of a total of 2,230 patients, with the mean (SD) age of 70 (14.1) years, and 713 (38%) patients were women. After adjusting for confounders (age, NIH Stroke Scale score, intraventricular hemorrhage, hematoma volume, and pre-ICH mRS score), type of hospital of initial admission (CSC vs TSC/PSC) was not associated with outcome (adjusted common OR 1.13, 95% CI 0.93-1.38). A PSM analysis indicated that transfer to a CSC was not associated with more favorable outcomes (OR 0.77, 95% CI 0.55-1.10; p = 0.16).

DISCUSSION

In this population-based study, we found that, after adjusting for confounders, hospital types were not associated with functional outcomes. In addition, for patients who were transferred from a TSC/PSC to a CSC, PSM indicated that outcomes were similar to nontransferred patients. Our findings suggest that patient characteristics are more important than hospital characteristics in determining outcome after ICH.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT03956485.

A differential of the left eye and right eye neurological pupil index is associated with discharge modified Rankin scores in neurologically injured patients

Background

Automated infrared pupillometry (AIP) and the Neurological Pupil index (NPi) provide an objective means of assessing and trending the pupillary light reflex (PLR) across a broad spectrum of neurological diseases. NPi quantifies the PLR and ranges from 0 to 5; in healthy individuals, the NPi of both eyes is expected to be ≥ 3.0 and symmetric. AIP values demonstrate emerging value as a prognostic tool with predictive properties that could allow practitioners to anticipate neurological deterioration and recovery. The presence of an NPi differential (a difference ≥ 0.7 between the left and right eye) is a potential sign of neurological abnormality.

Methods

We explored NPi differential by considering the modified Rankin Score at discharge (DC mRS) among patients admitted to neuroscience intensive care units (NSICU) of 4 U.S. and 1 Japanese hospitals and for two cohorts of brain injuries: stroke (including subarachnoid hemorrhage, intracerebral hemorrhage, acute ischemic stroke, and aneurysm, 1,200 total patients) and 185 traumatic brain injury (TBI) patients for a total of more than 54,000 pupillary measurements.

Results

Stroke patients with at least 1 occurrence of an NPi differential during their NSICU stay have higher DC mRS scores (3.9) compared to those without an NPi differential (2.7; P < .001). Patients with TBI and at least 1 occurrence of an NPi differential during their NSICU stay have higher discharge modified Rankin Scale scores (4.1) compared to those without an NPi differential (2.9; P < .001). When patients experience both abnormalities, abnormal (NPi < 3.0) and an NPi differential, the latter has an anticipatory relationship with respect to the former (P < .001 for z-score skewness analysis). Finally, our analysis confirmed ≥ 0.7 as the optimal cutoff value for the NPi differential (AUC = 0.71, P < .001).

Conclusion

The NPi differential is an important factor that clinicians should consider when managing critically ill neurological injured patients admitted to the neurocritical care units.

Trial registration

NCT02804438, Date of Registration: June 17, 2016.

A Multi-Model Pipeline for Translational Intracerebral Haemorrhage Research

Apart from acute and chronic blood pressure lowering, we have no specific medications to prevent intracerebral haemorrhage (ICH) or improve outcomes once bleeding has occurred. One reason for this may be related to particular limitations associated with the current pre-clinical models of ICH, leading to a failure to translate into the clinic. It would seem that a breakdown in the 'drug development pipeline' currently exists for translational ICH research which needs to be urgently addressed. Here, we review the most commonly used pre-clinical models of ICH and discuss their advantages and disadvantages in the context of translational studies. We propose that to increase our chances of successfully identifying new therapeutics for ICH, a bi-directional, 2- or 3-pronged approach using more than one model species/system could be useful for confirming key pre-clinical observations. Furthermore, we highlight that post-mortem/ex-vivo ICH patient material is a precious and underused resource which could play an essential role in the verification of experimental results prior to consideration for further clinical investigation. Embracing multidisciplinary collaboration between pre-clinical and clinical ICH research groups will be essential to ensure the success of this type of approach in the future.

A novel proposed grading system for cerebellar arteriovenous malformations

OBJECTIVE

The objective of this study was to evaluate the existing Spetzler-Martin (SM), Spetzler-Ponce (SP), and Lawton-Young (LY) grading systems for cerebellar arteriovenous malformations (AVMs) and to propose a new grading system to estimate the risks associated with these lesions.

METHODS

Data for patients with cerebellar AVMs treated microsurgically in two tertiary medical centers were retrospectively reviewed. Data from patients at institution 1 were collected from September 1999 to February 2013, and at institution 2 from October 2008 to October 2015. Patient outcomes were classified as favorable (modified Rankin Scale [mRS] score 0-2) or poor (mRS score 3-6) at the time of discharge. Using chi-square and logistic regression analysis, variables associated with poor outcomes were assigned risk points to design the proposed grading system. The proposed system included neurological status prior to treatment (poor, +2 points), emergency surgery (+1 point), age > 60 years (+1 point), and deep venous drainage (deep, +1 point). Risk point totals of 0-1 comprised grade 1, 2-3 grade 2, and 4-5 grade 3.

RESULTS

A total of 125 cerebellar AVMs of 1328 brain AVMs were reviewed in 125 patients, 120 of which were treated microsurgically and included in the study. With our proposed grading system, we found poor outcomes differed significantly between each grade (p < 0.001), while with the SM, SP, and LY grading systems they did not (p = 0.22, p = 0.25, and p = 1, respectively). Logistic regression revealed grade 2 had 3.3 times the risk of experiencing a poor outcome (p = 0.008), while grade 3 had 9.9 times the risk (p < 0.001). The proposed grading system demonstrated a superior level of predictive accuracy (area under the receiver operating characteristic curve [AUROC] of 0.72) compared with the SM, SP, and LY grading systems (AUROC of 0.61, 0.57, and 0.51, respectively).

CONCLUSIONS

The authors propose a novel grading system for cerebellar AVMs based on emergency surgery, venous drainage, preoperative neurological status, and age that provides a superior prognostication power than the formerly proposed SM, SP, and LY grading systems. This grading system is clinically predictive of patient outcomes and can be used to better guide vascular neurosurgeons in clinical decision-making.

Advancements in Managing Intracerebral Hemorrhage: Transition from Nihilism to Optimism

There have been significant advancements in the management of intracerebral hemorrhage (ICH) stemming from new knowledge on its pathogenesis. Major clinical trials, such as Surgical Trial in Lobar Intracerebral Hemorrhage (STICH I and II), have shown only a small, albeit clinically relevant, advantage of surgical interventions in specific subsets of patients suffering from ICH. Currently, the aim is to use a minimally invasive and safe trajectory in removing significant brain hematomas with the aid of neuro-endoscopy or precise guidance through neuro-navigation, thereby avoiding a collateral damage to the surrounding normal brain tissue. A fundamental rational to such approach is to safely remove hematoma, preventing the ongoing mass effect resulting in brain herniation, and to minimize deleterious effects of iron released from hematoma to brain cells. The clot lysis process is facilitated with the adjunctive use of recombinant tissue plasminogen activator and sonolysis. Revised recommendations for the management of ICH focus on a holistic approach, with special emphasis on early patient mobilization and graded rehabilitative process. There has been a paradigm shift in the management algorithm, putting emphasis on early and safe removal of brain hematoma and then focusing on the improvement of patients' quality of life. We have made significant progress in transition from nihilism toward optimism, based on evidence-based management of such a severe global health scourge as intracranial hemorrhage.

Transcranial Doppler combined with quantitative EEG brain function monitoring and outcome prediction in patients with severe acute intracerebral hemorrhage

Background

Neurological deterioration after intracerebral hemorrhage (ICH) is thought to be closely related to increased intracranial pressure (ICP), decreased cerebral blood flow (CBF), and brain metabolism. Transcranial Doppler (TCD) is increasingly used as an indirect measure of ICP, and quantitative EEG (QEEG) can reflect the coupling of CBF and metabolism. We aimed to combine TCD and QEEG to comprehensively assess brain function after ICH and provide prognostic diagnosis.

Methods

We prospectively enrolled patients with severe acute supratentorial (SAS)-ICH from June 2015 to December 2016. Mortality was assessed at 90-day follow-up. We collected demographic data, serological data, and clinical factors, and performed neurophysiological tests at study entry. Quantitative brain function monitoring was performed using a TCD-QEEG recording system at the patient’s bedside (NSD-8100; Delica, China). Univariate and multivariable analyses and receiver operating characteristic (ROC) curves were employed to assess the relationships between variables and outcome.

Results

Forty-seven patients (67.3 ± 12.6 years; 23 men) were studied. Mortality at 90 days was 55.3%. Statistical results showed there were no significant differences in brain symmetry index between survivors and nonsurvivors, nor between patients and controls (all p > 0.05). Only TCD indicators of the pulsatility index from unaffected hemispheres (UPI) (OR 2.373, CI 1.299–4.335, p = 0.005) and QEEG indicators of the delta/alpha ratio (DAR) (OR 5.306, CI 1.533–18.360, p = 0.008) were independent predictors for clinical outcome. The area under the ROC curve after the combination of UPI and DAR was 0.949, which showed better predictive accuracy compared to individual variables.

Conclusions

In patients with SAS-ICH, multimodal neuromonitoring with TCD combined with QEEG indicated that brain damage caused diffuse changes, and the predictive accuracy after combined use of TCD-QEEG was statistically superior in performance to any single variable, whether clinical or neurophysiological.

Aggressive blood pressure treatment of hypertensive intracerebral hemorrhage may lead to global cerebral hypoperfusion: Case report and imaging perspective

Hypoperfusion injury related to blood pressure decrease in acute hypertensive intracerebral hemorrhage continues to be a controversial topic. Aggressive treatment is provided with the intent to stop the ongoing bleeding. However, there may be additional factors, including autoregulation and increased intracranial pressure, that may limit this approach. We present here a case of acute hypertensive intracerebral hemorrhage, in which aggressive blood pressure management to levels within the normal range led to global cerebral ischemia within multiple border zones. Global cerebral ischemia may be of concern in the management of hypertensive hemorrhage in the presence of premorbid poorly controlled blood pressure and increased intracranial pressure.

White Matter Injury after Intracerebral Hemorrhage: Pathophysiology and Therapeutic Strategies

Intracerebral hemorrhage (ICH) accounts for 10%–30% of all types of stroke. Bleeding within the brain parenchyma causes gray matter (GM) destruction as well as proximal or distal white matter (WM) injury (WMI) due to complex pathophysiological mechanisms. Because WM has a distinct cellular architecture, blood supply pattern and corresponding function, and its response to stroke may vary from that of GM, a better understanding of the characteristics of WMI following ICH is essential and may shed new light on treatment options. Current evidence using histological, radiological and chemical biomarkers clearly confirms the spatio-temporal distribution of WMI post- ICH. Although certain types of pathological damage such as inflammatory, oxidative and neuro-excitotoxic injury to WM have been identified, the exact molecular mechanisms remain unclear. In this review article, we briefly describe the constitution and physiological function of brain WM, summarize evidence regarding WMI, and focus on the underlying pathophysiological mechanisms and therapeutic strategies.

Neurovascular Cell Sheet Transplantation in a Canine Model of Intracranial Hemorrhage

Cell-based therapy for intracerebral hemorrhage (ICH) has a great therapeutic potential. However, methods to effectively induce direct regeneration of the damaged neural tissue after cell transplantation have not been established, which, if done, would improve the efficacy of cell-based therapy. In this study, we aimed to develop a cell sheet with neurovasculogenic potential and evaluate its usefulness in a canine ICH model. We designed a composite cell sheet made of neural progenitors derived from human olfactory neuroepithelium and vascular progenitors from human adipose tissue-derived stromal cells. We also generated a physiologic canine ICH model by manually injecting and then infusing autologous blood under arterial pressure. We transplanted the sheet cells (cell sheet group) or saline (control group) at the cortex over the hematoma at subacute stages (2 weeks from ICH induction). At 4 weeks from the cell transplantation, cell survival, migration, and differentiation were evaluated. Hemispheric atrophy and neurobehavioral recovery were also compared between the groups. As a result, the cell sheet was rich in extracellular matrices and expressed neurotrophic factors as well as the markers for neuronal development. After transplantation, the cells successfully survived for 4 weeks, and a large portion of those migrated to the perihematomal site and differentiated into neurons and pericytes (20% and 30% of migrated stem cells, respectively). Transplantation of cell sheets alleviated hemorrhage-related hemispheric atrophy (p = 0.042) and showed tendency for improving functional recovery (p = 0.062). Therefore, we concluded that the cell sheet transplantation technique might induce direct regeneration of neural tissue and might improve outcomes of intracerebral hemorrhage.

Treatment with FTY720 has no beneficial effects on short-term outcome in an experimental model of intracerebral hemorrhage

BACKGROUND

No evidence-based therapy is available for patients with acute intracerebral hemorrhage (ICH). In view of the profound inflammatory reaction in the perilesional tissue, we investigated in a well-characterized experimental model whether the administration of the immunomodulator fingolimod (FTY720) is neuroprotective in acute ICH.

METHODS

ICH was induced by means of a stereotactic intrastriatal injection of collagenase type VII-S. FTY720 (1 mg/kg) was administered intraperitoneally 1 h after ICH induction. Hematoma volume was assessed spectrophotometrically at 24 h after ICH induction. The following endpoints were determined at 24 and 72 h, respectively: mortality rate and neurologic outcomes, edema formation, and MMP-9 activity.

RESULTS

Twenty-four hour after ICH induction, hematoma volume was not statistically different between groups. No difference was found in mortality and neurologic outcomes at 24 and 72 h between FTY720 treated mice and controls. Edema formation was present in both groups on the ipsilateral side with no statistical difference between groups at both time points. No difference was found in MMP-9 levels after 24 and 72 h between groups.

CONCLUSIONS

Our results suggest that FTY720 has no beneficial effects in the acute phase of experimental ICH.

Prophylactic Antiepileptic Drug Use and Outcome in the Ethnic/Racial Variations of Intracerebral Hemorrhage Study

BACKGROUND AND PURPOSE

The role of antiepileptic drug (AED) prophylaxis after intracerebral hemorrhage (ICH) remains unclear. This analysis describes prevalence of prophylactic AED use, as directed by treating clinicians, in a prospective ICH cohort and tests the hypothesis that it is associated with poor outcome.

METHODS

Analysis included 744 patients with ICH enrolled in the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study before November 2012. Baseline clinical characteristics and AED use were recorded in standardized fashion. ICH location and volume were recorded from baseline neuroimaging. We analyzed differences in patient characteristics by AED prophylaxis, and we used logistic regression to test whether AED prophylaxis was associated with poor outcome. The primary outcome was 3-month modified Rankin Scale score, with 4 to 6 considered poor outcome.

RESULTS

AEDs were used for prophylaxis in 289 (39%) of the 744 subjects; of these, levetiracetam was used in 89%. Patients with lobar ICH, craniotomy, or larger hematomas were more likely to receive prophlyaxis. Although prophylactic AED use was associated with poor outcome in an unadjusted model (odds ratio, 1.40; 95% confidence interval, 1.04-1.88; P=0.03), this association was no longer significant after adjusting for clinical and demographic characteristics (odds ratio, 1.11; 95% confidence interval, 0.74-1.65; P=0.62).

CONCLUSIONS

We found no evidence that AED use (predominantly levetiracetam) is independently associated with poor outcome. A prospective study is required to assess for a more modest effect of AED use on outcome after ICH.

Efficacy of Surgery Combined with Autologous Bone Marrow Stromal Cell Transplantation for Treatment of Intracerebral Hemorrhage

Bone marrow stromal cells (BMSCs) may differentiate into nerve cells under a certain condition; however, the clinical application for treating nervous system disease remains unclear. The aim is to assess the safety profile, feasibility, and effectiveness of surgery combined with autologous BMSCs transplantation for treating ICH. 206 ICH patients who had received surgical procedure were divided into transplantation (n = 110) or control group (n = 96). For transplantation group, BMSCs were injected into the perihemorrhage area in the base ganglia through an intracranial drainage tube 5.5 (3.01–6.89) days after surgery, followed by a second injection into the subarachnoid space through lumbar puncture 4 weeks later. Neurologic impairment and daily activities were assessed with National Institute Stroke Scale (NIHSS), Barthel index, and Rankin scale before transplantation and 6 months and 12 months after transplantation. Our results revealed that, compared with control group, NIHSS score and Rankin scale were both significantly decreased but Barthel index was increased in transplantation group after 6 months. Interestingly, no significant difference was observed between 12 months and 6 months. No transplantation-related adverse effects were investigated during follow-up assessments. Our findings suggest that surgery combined with autologous BMSCs transplantation is safe for treatment of ICH, providing short-term therapeutic benefits.

Experimental subarachnoid haemorrhage results in multifocal axonal injury

The great majority of acute brain injury results from trauma or from disorders of the cerebrovasculature, i.e. ischaemic stroke or haemorrhage. These injuries are characterized by an initial insult that triggers a cascade of injurious cellular processes. The nature of these processes in spontaneous intracranial haemorrhage is poorly understood. Subarachnoid haemorrhage, a particularly deadly form of intracranial haemorrhage, shares key pathophysiological features with traumatic brain injury including exposure to a sudden pressure pulse. Here we provide evidence that axonal injury, a signature characteristic of traumatic brain injury, is also a prominent feature of experimental subarachnoid haemorrhage. Using histological markers of membrane disruption and cytoskeletal injury validated in analyses of traumatic brain injury, we show that axonal injury also occurs following subarachnoid haemorrhage in an animal model. Consistent with the higher prevalence of global as opposed to focal deficits after subarachnoid haemorrhage and traumatic brain injury in humans, axonal injury in this model is observed in a multifocal pattern not limited to the immediate vicinity of the ruptured artery. Ultrastructural analysis further reveals characteristic axonal membrane and cytoskeletal changes similar to those associated with traumatic axonal injury. Diffusion tensor imaging, a translational imaging technique previously validated in traumatic axonal injury, from these same specimens demonstrates decrements in anisotropy that correlate with histological axonal injury and functional outcomes. These radiological indicators identify a fibre orientation-dependent gradient of axonal injury consistent with a barotraumatic mechanism. Although traumatic and haemorrhagic acute brain injury are generally considered separately, these data suggest that a signature pathology of traumatic brain injury-axonal injury-is also a functionally significant feature of subarachnoid haemorrhage, raising the prospect of common diagnostic, prognostic, and therapeutic approaches to these conditions.

Stem cell-based therapies for intracerebral hemorrhage in animal model: a meta-analysis

Stem cell to be a new intervention for treating intracerebral hemorrhage (ICH) might benefit humans. Therefore, we collected animal studies to find the effect of this innovative treatment. In July 2014, we searched Medline (from 1950), Embase (from 1980), China Biology Medicine disk (from 1978) for studies on stem cells used for treating experimental ICH in animal models that reported neurobehavioral and structural outcome. We evaluated the quality of these studies and used a weighted mean difference random affects model for the meta-analysis. We have collected 30 studies from 650 publications identified through systematic review describing the effects of 5 different type of stem cells on 12 different neurobehavioral scales with 1101 rodents or monkeys. Although there is lack of uniformity of the evaluation methods, these researches showed consistent improvements both in neurobehavioral function and structural outcomes. Besides, the quality of these studies needs to be raised. In conclusion, stem cells hold extensive potential in treating ICH, which should be further evaluated with more evidence-based, high-quality animal studies.

Toxic role of prostaglandin E2 receptor EP1 after intracerebral hemorrhage in mice

Inflammatory mechanisms mediated by prostaglandins may contribute to the progression of intracerebral hemorrhage (ICH)-induced brain injury, but they are not fully understood. In this study, we examined the effect of prostaglandin E2 receptor EP1 (EP1R) activation and inhibition on brain injury in mouse models of ICH and investigated the underlying mechanism of action. ICH was induced by injecting collagenase, autologous blood, or thrombin into the striatum of middle-aged male and female mice and aged male mice. Effects of selective EP1R agonist ONO-DI-004, antagonist SC51089, and nonspecific Src family kinase inhibitor PP2 were evaluated by a combination of histologic, magnetic resonance imaging (MRI), immunofluorescence, molecular, cellular, and behavioral assessments. EP1R was expressed primarily in neurons and axons but not in astrocytes or microglia after ICH induced by collagenase. In middle-aged male mice subjected to collagenase-induced ICH, EP1R inhibition mitigated brain injury, brain edema, cell death, neuronal degeneration, neuroinflammation, and neurobehavioral deficits, whereas its activation exacerbated these outcomes. EP1R inhibition also was protective in middle-aged female mice and aged male mice after collagenase-induced ICH and in middle-aged male mice after blood- or thrombin-induced ICH. EP1R inhibition also reduced oxidative stress, white matter injury, and brain atrophy and improved functional outcomes. Histologic results were confirmed by MRI. Src kinase phosphorylation and matrix metalloproteinase-9 activity were increased by EP1R activation and decreased by EP1R inhibition. EP1R regulated matrix metalloproteinase-9 activity through Src kinase signaling, which mediated EP1R toxicity after collagenase-induced ICH. We conclude that prostaglandin E2 EP1R activation plays a toxic role after ICH through mechanisms that involve the Src kinases and the matrix metalloproteinase-9 signaling pathway. EP1R inhibition could be a novel therapeutic strategy to improve outcomes after ICH.

Seizure activity occurs in the collagenase but not the blood infusion model of striatal hemorrhagic stroke in rats

Seizures are a frequent complication of brain injury, including intracerebral hemorrhage (ICH), where seizures occur in about a third of patients. Rodents are used to study pathophysiology and neuroprotective therapies after ICH, but there have been no studies assessing the occurrence of seizures in these models. Thus, we compared seizure incidence and characteristics after infusing collagenase (0.14 U), which degrades blood vessels, and autologous blood (100 μL) into the striatum of rats. Saline was infused in others as a negative control, whereas iron, a by-product of degrading erythrocytes, served as a positive control. Ipsilateral and contralateral electroencephalographic (EEG) activity was continuously monitored with telemetry probes for a week after the stroke. There were no electrographic abnormalities during baseline recordings. As expected, saline did not elicit any epileptiform activity whereas iron caused seizure activity. Seizures occurred in 66 % of the collagenase group between 10 and 36 h, their duration ranged from 5 to 90 s, and these events were mostly observed bilaterally. No such activity occurred after blood infusion despite comparable lesion sizes of 32.5 and 40.9 mm³ in the collagenase and blood models, respectively (p = 0.222). Therefore, seizures are a common acute occurrence in the collagenase but not whole blood models of striatal ICH (p = 0.028, for incidence). These findings have potential implications for ICH studies such as for understanding model differences, helping select which model to use, and determining how seizures may affect or be affected by treatments applied after stroke.

Intrastriatal injection of autologous blood or clostridial collagenase as murine models of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a common form of cerebrovascular disease and is associated with significant morbidity and mortality. Lack of effective treatment and failure of large clinical trials aimed at hemostasis and clot removal demonstrate the need for further mechanism-driven investigation of ICH. This research may be performed through the framework provided by preclinical models. Two murine models in popular use include intrastriatal (basal ganglia) injection of either autologous whole blood or clostridial collagenase. Since, each model represents distinctly different pathophysiological features related to ICH, use of a particular model may be selected based on what aspect of the disease is to be studied. For example, autologous blood injection most accurately represents the brain's response to the presence of intraparenchymal blood, and may most closely replicate lobar hemorrhage. Clostridial collagenase injection most accurately represents the small vessel rupture and hematoma evolution characteristic of deep hemorrhages. Thus, each model results in different hematoma formation, neuroinflammatory response, cerebral edema development, and neurobehavioral outcomes. Robustness of a purported therapeutic intervention can be best assessed using both models. In this protocol, induction of ICH using both models, immediate post-operative demonstration of injury, and early post-operative care techniques are demonstrated. Both models result in reproducible injuries, hematoma volumes, and neurobehavioral deficits. Because of the heterogeneity of human ICH, multiple preclinical models are needed to thoroughly explore pathophysiologic mechanisms and test potential therapeutic strategies.

In vivo testing of a non-invasive prototype device for the continuous monitoring of intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is a stroke subtype with the highest mortality rate. Hematoma expansion and re-bleeding post-ICH are common and exacerbate the initial cerebral insult. There is a need for continuous monitoring of the neurologic status of patients with an ICH injury.

NEW METHOD

A prototype device for non-invasive continuous monitoring of an ICH was developed and tested in vivo using a porcine ICH model. The device consists of receiving and transmitting antennae in the 400-1000 MHz frequency range, placed directly in line with the site of the ICH. The device exploits the differences in the dielectric properties and geometry of tissue media of a healthy brain and a brain with an ICH injury. The power received by the receiving antenna is measured and the percent change in power received immediately after infusion of blood and 30 min after the infusion, allowing for the blood to clot, is calculated.

RESULTS

An increase in the received power in the presence of an ICH is observed at 400 MHz, consistent with previous in vitro studies. Frequency sweep experiments show a maximum percent change in received power in the 750-1000 MHz frequency range.

COMPARISON WITH EXISTING METHODS

Currently, CT, MRI and catheter angiography (CA) are the main clinical neuroimaging modalities. However, these techniques require specialized equipment and personnel, substantial time, and patient-transportation to a radiology suite to obtain results. Moreover, CA is invasive and uses intra-venous dye or vascular catheters to accomplish the imaging.

CONCLUSIONS

The device has the potential to significantly improve neurologic care in the critically ill brain-injured patient.

An in vivo, MRI-integrated real-time model of active contrast extravasation in acute intracerebral hemorrhage

BACKGROUND AND PURPOSE

The "spot sign" or contrast extravasation is strongly associated with hematoma formation and growth. An animal model of contrast extravasation is important to test existing and novel therapeutic interventions to inform present and future clinical studies. The purpose of this study was to create an animal model of contrast extravasation in acute intracerebral hemorrhage.

MATERIALS AND METHODS

Twenty-eight hemispheres of Yorkshire male swine were insonated with an MR imaging-guided focused sonography system following lipid microsphere infusion and mean arterial pressure elevation. The rate of contrast leakage was quantified by using dynamic contrast-enhanced MR imaging and was classified as contrast extravasation or postcontrast leakage by using postcontrast T1. Hematoma volume was measured on gradient recalled-echo MR imaging performed 2 hours postprocedure. Following this procedure, sacrificed brain was subjected to histopathologic examination. Power level, burst length, and blood pressure elevation were correlated with leakage rate, hematoma size, and vessel abnormality extent.

RESULTS

Median (intracerebral hemorrhage) contrast extravasation leakage was higher than postcontrast leakage (11.3; 6.3-23.2 versus 2.4; 1.1-3.1 mL/min/100 g; P<.001). Increasing burst length, gradient recalled-echo hematoma (ρ=0.54; 95% CI, 0.2-0.8; P=.007), and permeability were correlated (ρ=0.55; 95% CI, 0.1-0.8; P=.02). Median permeability (P=.02), gradient recalled-echo hematoma (P=.02), and dynamic contrast-enhanced volumes (P=.02) were greater at 1000 ms than at 10 ms. Within each burst-length subgroup, incremental contrast leakage was seen with mean arterial pressure elevation (ρ=0.2-0.8).

CONCLUSIONS

We describe a novel MR imaging-integrated real-time swine intracerebral hemorrhage model of acute hematoma growth and contrast extravasation.

Neuropathologic analysis of hematomas evacuated from patients with spontaneous intracerebral hemorrhage

Spontaneous intracerebral hemorrhage (ICH) is a devastating cause of morbidity and mortality. Intraparenchymal hematomas are often surgically evacuated. This generates fragments of perihematoma brain tissue that may elucidate their etiology. The goal of this study is to analyze the value of these specimens in providing a possible etiology for spontaneous ICH as well as the utility of using immunohistochemical markers to identify amyloid angiopathy. Surgically resected hematomas from 20 individuals with spontaneous ICH were examined with light microscopy. Hemorrhage locations included 11 lobar and nine basal ganglia hemorrhages. Aβ immunohistochemistry and Congo red stains were used to confirm the presence of amyloid angiopathy, when this was suspected. Evidence of cerebral amyloid angiopathy (CAA) was observed in eight of the 20 specimens, each of which came from lobar locations. Immunohistochemistry confirmed CAA in the brain fragments from these eight individuals. Patients with immunohistochemically confirmed CAA were older than patients without CAA, and more likely to have lobar hemorrhages (OR 3.0 and 3.7, respectively). Evidence of CAA was not found in any of the basal ganglia specimens. One specimen showed evidence of CAA-associated angiitis, with formation of a microaneurysm in an inflamed segment of a CAA-affected arteriole, surrounded by acute hemorrhage. In another specimen, Aβ immunohistochemistry showed the presence of senile plaques suggesting concomitant Alzheimer's disease (AD) changes. Surgically evacuated hematomas from patients with spontaneous ICH should be carefully examined, paying special attention to any fragments of included brain parenchyma. These fragments can provide evidence of the etiology of the hemorrhage. Markers such as Aβ 1-40 can help to identify underlying CAA, and should be utilized when microangiopathy is suspected. Given the association of (Aβ) CAA with AD, careful examination of entrapped brain fragments may also provide evidence of AD in a given patient.

Tumor necrosis factor α antagonism improves neurological recovery in murine intracerebral hemorrhage

Background

Intracerebral hemorrhage (ICH) is a devastating stroke subtype characterized by a prominent neuroinflammatory response. Antagonism of pro-inflammatory cytokines by specific antibodies represents a compelling therapeutic strategy to improve neurological outcome in patients after ICH. To test this hypothesis, the tumor necrosis factor alpha (TNF-α) antibody CNTO5048 was administered to mice after ICH induction, and histological and functional endpoints were assessed.

Methods

Using 10 to 12-week-old C57BL/6J male mice, ICH was induced by collagenase injection into the left basal ganglia. Brain TNF-α concentration, microglia activation/macrophage recruitment, hematoma volume, cerebral edema, and rotorod latency were assessed in mice treated with the TNF-α antibody, CNTO5048, or vehicle.

Results

After ICH induction, mice treated with CNTO5048 demonstrated reduction in microglial activation/macrophage recruitment compared to vehicle-treated animals, as assessed by unbiased stereology (P = 0.049). This reduction in F4/80-positive cells was associated with a reduction in cleaved caspase-3 (P = 0.046) and cerebral edema (P = 0.026) despite similar hematoma volumes, when compared to mice treated with vehicle control. Treatment with CNTO5048 after ICH induction was associated with a reduction in functional deficit when compared to mice treated with vehicle control, as assessed by rotorod latencies (P = 0.024).

Conclusions

Post-injury treatment with the TNF-α antibody CNTO5048 results in less neuroinflammation and improved functional outcomes in a murine model of ICH.

Ablation of astrocytic laminin impairs vascular smooth muscle cell function and leads to hemorrhagic stroke

Ablation of astrocytic laminin disrupted the interaction between vascular smooth muscle cells and astrocytes, down-regulated contractile protein expression, and weakened vascular integrity in deep brain regions, leading to hemorrhage.

Astrocytes express laminin and assemble basement membranes (BMs) at their endfeet, which ensheath the cerebrovasculature. The function of astrocytic laminin in cerebrovascular integrity is unknown. We show that ablation of astrocytic laminin by tissue-specific Cre-mediated recombination disrupted endfeet BMs and led to hemorrhage in deep brain regions of adult mice, resembling human hypertensive hemorrhage. The lack of astrocytic laminin led to impaired function of vascular smooth muscle cells (VSMCs), where astrocytes have a closer association with VSMCs in small arterioles, and was associated with hemorrhagic vessels, which exhibited VSMC fragmentation and vascular wall disassembly. Acute disruption of astrocytic laminin in the striatum of adult mice also impaired VSMC function, indicating that laminin is necessary for VSMC maintenance. In vitro, both astrocytes and astrocytic laminin promoted brain VSMC differentiation. These results show that astrocytes regulate VSMCs and vascular integrity in small vessels of deep brain regions. Therefore, astrocytes may be a possible target for hemorrhagic stroke prevention and therapy.

Quantitative CT densitometry for predicting intracerebral hemorrhage growth

BACKGROUND AND PURPOSE

Intracerebral hemorrhage growth independently predicts disability and death. We hypothesized that noncontrast quantitative CT densitometry reflects active bleeding and improves predictive models of growth.

MATERIALS AND METHODS

We analyzed 81 of the 96 available baseline CT scans obtained <3 hours post-ICH from the placebo arm of the phase IIb trial of recombinant factor VIIa. Fifteen scans could not be analyzed for technical reasons, but baseline characteristics were not statistically significantly different. Hounsfield unit histograms for each ICH were generated. Analyzed qCTD parameters included the following: mean, SD, coefficient of variation, skewness (distribution asymmetry), and kurtosis ("peakedness" versus "flatness"). These densitometry parameters were examined in statistical models accounting for baseline volume and time-to-scan.

RESULTS

The coefficient of variation of the ICH attenuation was the most significant individual predictor of hematoma growth (adjusted R(2) = 0.107, P = .002), superior to BV (adjusted R(2) = 0.08, P = .006) or TTS (adjusted R(2) = 0.03, P = .05). The most significant combined model incorporated coefficient of variation, BV, and TTS (adjusted R(2) = 0.202, P = .009 for coefficient of variation) compared with BV and TTS alone (adjusted R(2) = 0.115, P < .05). qCTD increased the number of growth predictions within ±1 mL of actual 24-hour growth by up to 47%.

CONCLUSIONS

Heterogeneous ICH attenuation on hyperacute (<3 hours) CT imaging is predictive of subsequent hematoma expansion and may reflect an active bleeding process. Further studies are required to determine whether qCTD can be incorporated into standard imaging protocols for predicting ICH growth.

Evaluation of the hematoma consequences, neurobehavioral profiles, and histopathology in a rat model of pontine hemorrhage

OBJECT

Primary pontine hemorrhage (PPH) represents approximately 7% of all intracerebral hemorrhages (ICHs) and is a clinical condition of which little is known. The aim of this study was to characterize the early brain injury, neurobehavioral outcome, and long-term histopathology in a novel preclinical rat model of PPH.

METHODS

The authors stereotactically infused collagenase (Type VII) into the ventral pontine tegmentum of the rats, in accordance with the most commonly affected clinical region. Measures of cerebrovascular permeability (brain water content, hemoglobin assay, Evans blue, collagen Type IV, ZO-1, and MMP-2 and MMP-9) and neurological deficit were quantified at 24 hours postinfusion (Experiment 1). Functional outcome was measured over a 30-day period using a vertebrobasilar scale (the modified Voetsch score), open field, wire suspension, beam balance, and inclined-plane tests (Experiment 2). Neurocognitive ability was determined at Week 3 using the rotarod (motor learning), T-maze (working memory), and water maze (spatial learning and memory) (Experiment 3), followed by histopathological analysis 1 week later (Experiment 4).

RESULTS

Stereotactic collagenase infusion caused dose-dependent elevations in hematoma volume, brain edema, neurological deficit, and blood-brain barrier rupture, while physiological variables remained stable. Functional outcomes mostly normalized by Week 3, whereas neurocognitive deficits paralleled the cystic cavitary lesion at 30 days. Obstructive hydrocephalus did not develop despite a clinically relevant 30-day mortality rate (approximately 54%).

CONCLUSIONS

These results suggest that the model can mimic several translational aspects of pontine hemorrhage in humans and can be used in the evaluation of potential preclinical therapeutic interventions.

Etiology of stroke and choice of models

Animal models of stroke contribute to the development of better stroke prevention and treatment through studies investigating the pathophysiology of different stroke subtypes and by testing promising treatments before trials in humans. There are two broad types of animal models: those in which stroke is induced through artificial means, modeling the consequences of a vascular insult but not the vascular pathology itself; and those in which strokes occur spontaneously. Most animal models of stroke are in rodents due to cost, ethical considerations, availability of standardized neurobehavioral assessments, and ease of physiological monitoring. While there are similarities in cerebrovascular anatomy and pathophysiology between rodents and humans, there are also important differences, including brain size, length and structure of perforating arteries, and gray to white matter ratio, which is substantially lower in humans. The wide range of rodent models of stroke includes models of global and focal ischemia, and of intracerebral and sub-arachnoid hemorrhage. The most widely studied model of spontaneous stroke is the spontaneously hypertensive stroke-prone rat, in which the predominant lesions are small subcortical infarcts resulting from a vascular pathology similar to human cerebral small vessel disease. Important limitations of animal models of stroke - they generally model only certain aspects of the disease and do not reflect the heterogeneity in severity, pathology and comorbidities of human stroke - and key methodological issues (especially the need for adequate sample size, randomization, and blinding in treatment trials) must be carefully considered for the successful translation of pathophysiological concepts and therapeutics from bench to bedside.

Transplantation of adipose-derived stem cells is associated with neural differentiation and functional improvement in a rat model of intracerebral hemorrhage

AIMS

To examine whether transplantation of adipose-derived stem cells (ADSCs) induces neural differentiation and improves neural function in a rat intracerebral hemorrhage (ICH) model.

METHODS

Adipose-derived stem cells cells were isolated from inguinal fat pad of rat. ICH was induced by injection of collagenase type IV into the right basal ganglia of rat. Forty-eight hours after ICH, ADSCs cells (10 μL of 2-4 × 10(7) cells/mL) were injected into the right lateral cerebral ventricle. The differentiation of ADSCs was detected in vitro and in vivo. The neural function was evaluated with Zea Longa 5-grade scale at day 1, 3, 7, 14, or 28.

RESULTS

Our data demonstrated that ADSCs differentiated into cells that shared the similarities of neurons or astrocytes in vitro. Transplantation of ADSCs decreased cell apoptosis and the transplanted ADSCs were able to differentiate into neuron-like and astrocyte-like cells around the hematoma, accompanied with upregulation of vascular endothelial growth factor expression and improvement of neural function.

CONCLUSIONS

Our data suggest that transplantation of ADSCs could be a therapeutic approach for ICH stroke.

Autologous bone marrow mononuclear cell implantation for intracerebral hemorrhage-a prospective clinical observation

BACKGROUND

This study was designed to assess the clinical effect of bone marrow mononuclear cells including mesenchymal stem cell (MSCs) in patients with intracerebral hemorrhage (ICH).

METHODS

One hundred patients were divided into a study (n=60) or a control group (n=40). Bone marrow mononuclear cells from the same patient were injected to the perihemorrhage area in the base ganglia through an intracranial drainage tube 5.9 days after ICH. National Institute Stroke Scale (NIHSSS) and Barthel index was used to assess neurologic impairment and daily activities, respectively, before and 6 months after intervention.

RESULTS

Six months after implantation, the NIHSS score in the study group was lower than in the control group (10.09 ± 8.86 vs 14.35 ± 10.14, P<0.01), whereas the Barthel scores were higher (57.39 ± 23.51 vs 46.90 ± 20.29, P<0.01). Neurological and functional improvement was observed in 52 (86.7%) of the study group patients, and in 17 (42.5%) of the control group patients (P=0.001). No allergic or other adverse effects were observed in the study group.

CONCLUSION

Autologous bone marrow mononuclear cell implantation reduced neurological impairment and improved activities of daily living in a selected group of ICH patients. Further studies are required to ascertain the long-term safety and efficacy of this treatment.

Translating basic science research to clinical application: models and strategies for intracerebral hemorrhage

Preclinical stroke models provide insights into mechanisms of cellular injury and potential therapeutic targets. Renewed efforts to standardize preclinical practices and adopt more rigorous approaches reflect the assumption that a better class of compounds will translate into clinical efficacy. While the need for novel therapeutics is clear, it is also critical that diagnostics be improved to allow for more rapid treatment upon hospital admission. Advances in imaging techniques have aided in the diagnosis of stroke, yet current limitations and expenses demonstrate the need for new and complementary approaches. Intracerebral hemorrhage (ICH) exhibits the highest mortality rate, displays unique pathology and requires specialized treatment strategies relative to other forms of stroke. The aggressive nature and severe consequences of ICH underscore the need for novel therapeutic approaches as well as accurate and expeditious diagnostic tools. The use of experimental models will continue to aid in addressing these important issues as the field attempts to translate basic science findings into the clinical setting. Several preclinical models of ICH have been developed and are widely used to recapitulate human pathology. Because each model has limitations, the burden lies with the investigator to clearly define the question being asked and select the model system that is most relevant to that question. It may also be necessary to optimize and refine pre-existing paradigms, or generate new paradigms, as the future success of translational research is dependent upon the ability to mimic human sequelae and assess clinically relevant outcome measures as means to evaluate therapeutic efficacy.

A critical appraisal of experimental intracerebral hemorrhage research

The likelihood of translating therapeutic interventions for stroke rests on the quality of preclinical science. Given the limited success of putative treatments for ischemic stroke and the reasons put forth to explain it, we sought to determine whether such problems hamper progress for intracerebral hemorrhage (ICH). Approximately 10% to 20% of strokes result from an ICH, which results in considerable disability and high mortality. Several animal models reproduce ICH and its underlying pathophysiology, and these models have been widely used to evaluate treatments. As yet, however, none has successfully translated. In this review, we focus on rodent models of ICH, highlighting differences among them (e.g., pathophysiology), issues with experimental design and analysis, and choice of end points. A Pub Med search for experimental ICH (years: 2007 to 31 July 2011) found 121 papers. Of these, 84% tested neuroprotectants, 11% tested stem cell therapies, and 5% tested rehabilitation therapies. We reviewed these to examine study quality (e.g., use of blinding procedures) and choice of end points (e.g., behavioral testing). Not surprisingly, the problems that have plagued the ischemia field are also prevalent in ICH literature. Based on these data, several recommendations are put forth to facilitate progress in identifying effective treatments for ICH.

Minimally invasive procedures reduce perihematomal endothelin-1 levels and the permeability of the BBB in a rabbit model of intracerebral hematoma

To observe the effects of minimally invasive procedures for the evacuation of intracerebral hematomas on perihematomal ET-1 expression and their correlation with blood-brain barrier (BBB) permeability. Forty-five rabbits (2.8-3.4 kg body weight) were randomly divided into a normal control group (NC group, 15 rabbits), a model control group (MC group, 15 rabbits) and a minimally invasive group (MI group, 15 rabbits). A model of intracerebral hemorrhage (ICH) was prepared in the MC and MI groups by infusing autologous arterial blood into the rabbits' brains; the same procedure was also performed in the NC group but without infusing blood into the rabbits' brains. The intracerebral hematomas were evacuated by a stereotactic procedure in the minimally invasive group 6 h after the model was established. The neurological functions, ET-1 expression and the perihematomal BBB permeability were determined and analyzed in all of the animals. The number of endothelial cells with ET-1-positive expression and the perihematomal BBB permeability significantly increased 1, 3, and 7 days after the ICH model was prepared successfully, as compared to the NC group. In the MI group, however, both measurements decreased markedly compared with the MC group at the same time point. A positive correlation between the number of endothelial cells with ET-1-positive expression and BBB permeability was observed. Increased BBB permeability might be associated with perihematomal ET-1 levels. Minimally invasive procedures for the evacuation of intracerebral hematomas could significantly decrease BBB permeability in perihematomal brain tissues, likely by reducing the production of ET-1.

Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH) II: design, methods, and rationale

The December 2003 report from the National Institute of Neurological Disorders and Stroke (NINDS) Workshop on priorities for clinical research in intracerebral hemorrhage (ICH) recommended clinical trials for evaluation of blood pressure management in acute ICH as a leading priority. The Special Writing Group of the Stroke Council of the American Heart Association in 1999 and 2007 emphasized the need for clinical trials to ensure evidence-based treatment of acute hypertensive response in ICH. To address important gaps in knowledge, we conducted a pilot study funded by the NINDS, Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH) I Trial, during 2004-2008 to determine the appropriate level of systolic blood pressure (SBP) reduction. We now have initiated a multi-center, randomized Phase III trial, the ATACH II Trial, to definitively determine the efficacy of early, intensive, antihypertensive treatment using intravenous (IV) nicardipine initiated within 3 h of onset of ICH and continued for the next 24 h in subjects with spontaneous supratentorial ICH. The primary hypothesis of this large (N = 1,280), streamlined, and focused trial is that SBP reduction to ≤140 mm Hg reduces the likelihood of death or disability at 3 months after ICH, defined by modified Rankin scale score of 4-6, by at least 10% absolute compared to standard SBP reduction to ≤180 mm Hg. The ATACH II trial is a natural extension of numerous case series, the subsequent ATACH I pilot trial, and a preliminary, randomized, and controlled trial in this patient population funded by the Australian National Health and Medical Research Council. Both trials recently confirmed the safety and tolerability of both the regimen and goals of antihypertensive treatment in acutely hypertensive patients with ICH, as proposed in the present trial. The underlying mechanism for this expected beneficial effect of intensive treatment is presumably mediated through reduction of the rate and magnitude of hematoma expansion observed in approximately 73% of the patients with acute ICH. The Australian trial provided preliminary evidence of attenuation of hematoma expansion with intensive SBP reduction. The ATACH II trial will have important public health implications by providing evidence of, or lack thereof, regarding the efficacy and safety of acute antihypertensive treatment in subjects with ICH. This treatment represents a strategy that can be made widely available without the need for specialized equipment and personnel, and therefore, can make a major impact upon clinical practice for treating patients with ICH.

Neuroimaging in stroke and non-stroke pusher patients

Pusher behavior (PB) is a disorder of postural control affecting patients with encephalic lesions. This study has aimed to identify the brain substrates that are critical for the occurrence of PB, to analyze the influence of the midline shift (MS) and hemorrhagic stroke volume (HSV) on the severity and prognosis of the PB. We identified 31 pusher patients of a neurological unit, mean age 67.4±11.89, 61.3% male. Additional neurological and functional examinations were assessed. Neuroimaging workup included measurement of the MS, the HSV in patients with hemorrhagic stroke, the analysis of the vascular territory, etiology and side of the lesion. Lesions in the parietal region (p=0.041) and thalamus (p=0.001) were significantly more frequent in PB patients. Neither the MS nor the HSV were correlated with the PB severity or recovery time.

Experimental intracerebral hemorrhage: avoiding pitfalls in translational research

Intracerebral hemorrhage (ICH) has the highest mortality of all stroke subtypes, yet treatments are mainly limited to supportive management, and surgery remains controversial. Despite significant advances in our understanding of ICH pathophysiology, we still lack preclinical models that accurately replicate the underlying mechanisms of injury. Current experimental ICH models (including autologous blood and collagenase injection) simulate different aspects of ICH-mediated injury but lack some features of the clinical condition. Newly developed models, notably hypertension- and oral anticoagulant therapy-associated ICH models, offer added benefits but further study is needed to fully validate them. Here, we describe and discuss current approaches to experimental ICH, with suggestions for changes in how this condition is studied in the laboratory. Although advances in imaging over the past few decades have allowed greater insight into clinical ICH, there remains an important role for experimental models in furthering our understanding of the basic pathophysiologic processes underlying ICH, provided limitations of animal models are borne in mind. Owing to differences in existing models and the failed translation of benefits in experimental ICH to clinical practice, putative neuroprotectants should be trialed in multiple models using both histological and functional outcomes until a more accurate model of ICH is developed.

Antiplatelet pretreatment does not increase hematoma volume in experimental intracerebral hemorrhage

While oral anticoagulants are associated with greater hematoma expansion and higher mortality rates in patients with intracerebral hemorrhage (ICH), there is ongoing discussion whether pretreatment with antiplatelet drugs also worsens prognosis. Using an experimental model of ICH, we investigated the effects of antiplatelet pretreatment on hematoma volume and functional outcome. CD-1 mice were treated with acetyl-salicylic acid (ASA, 60 mg/kg per 24 hours), clopidogrel (22.5 mg/kg per 24 hours), or both (ASA+clopidogrel) through drinking water for 3 days (n=20 per group). Thereafter, platelet aggregation was found to be significantly reduced. Untreated mice and mice pretreated with warfarin served as controls. A stereotactic injection of collagenase into the right striatum was used to induce ICH. Twenty-four hours after ICH induction, hematoma volume was measured to be 15.0 ± 4.4 μL in controls, 14.1 ± 5.3 μL in ASA mice, 16.8 ± 5.1 μL in clopidogrel mice, and 16.4 ± 5.1 μL in ASA+clopidogrel animals. These differences were not statistically significant. However, mice pretreated with warfarin revealed largely increased hematoma volumes (25.0 ± 7.4 μL versus controls, P=0.001). Neurologic outcome was not different between antiplatelet-pretreated animals and untreated controls. Our results suggest that plasmatic coagulation rather than platelet function is the most critical element for preventing hematoma expansion in acute ICH. Future therapeutic strategies may take these findings into account.

Neuroprotective effects of bone marrow stem cells overexpressing glial cell line-derived neurotrophic factor on rats with intracerebral hemorrhage and neurons exposed to hypoxia/reoxygenation

BACKGROUND

Intracerebral hemorrhage (ICH) represents at least 15% of all strokes in the Western population and a considerably higher proportion at 50% to 60% in the Oriental population.

OBJECTIVE

To investigate whether administration of bone marrow stem cells (BMSCs) overexpressing glial cell line-derived neurotrophic factor (GDNF) provides more efficient neuroprotection for rats with ICH and neurons exposed to hypoxia/reoxygenation.

METHODS

Primary rat BMSCs were transfected with rat GDNF gene using virus vector (GDNF/BMSCs) and blank virus plasmid (BVP/BMSCs). Primary rat cortical neurons of rats were exposed to hypoxia and then reoxygenated with GDNF/BMSCs (GDNF/BMSCs group) or BVP/BMSCs (BMSCs group) treatment for 12 hours and 1, 2, 3, and 5 days. Hoechst 33258 staining was used to evaluate apoptosis. GDNF/BMSCs, BVP/BMSCs, and saline (GDNF/BMSCs, BMSCs, and control groups) were injected into the right striatum 3 days after rat ICH induced by injecting collagenase. Modified neurological severity scores and hematoxylin and eosin staining were performed to evaluate neurological function and lesion volume at 1 and 2 weeks after transplantation. Immunostaining was used to observe differentiation of grafted cells (neurofilament-200 for neurons, glial fibrillary acidic protein for astrocytes). The GDNF level and apoptosis were evaluated by Western blotting and terminal deoxynucleotidyl transferase dUTP nick-end labeling, respectively.

RESULTS

The GDNF/BMSCs group had significantly lowered apoptosis compared with the BMSCs group at the given time. The GDNF/BMSCs group had significantly improved functional deficits and reduced lesion volume compared with the BMSCs group. Stable GDNF expression in the GDNF/BMSCs group was detected at the given time in the host brain. The neurofilament-positive grafted cells in the GDNF/BMSCs group were more numerous than in the BMSCs group. The GDNF/BMSCs group had significantly decreased apoptotic cells compared with the BMSCs group.

CONCLUSION

These results suggest that GDNF/BMSCs provide better neuroprotection for rats with ICH and neurons exposed to hypoxia/reoxygenation.

Minimally invasive evacuation of spontaneous intracerebral hemorrhage using sonothrombolysis

OBJECT

Catheter-based evacuation is a novel surgical approach for the treatment of brain hemorrhage. The object of this study was to evaluate the safety and efficacy of ultrasound in combination with recombinant tissue plasminogen activator (rt-PA) delivered through a microcatheter directly into spontaneous intraventricular (IVH) or intracerebral (ICH) hemorrhage in humans.

METHODS

Thirty-three patients presenting to the Swedish Medical Center in Seattle, Washington, with ICH and IVH were screened between November 21, 2008, and July 13, 2009, for entry into this study. Entry criteria included the spontaneous onset of intracranial hemorrhage ≥ 25 ml and/or IVH producing ventricular obstruction. Nine patients (6 males and 3 females, with an average age of 63 years [range 38-83 years]) who met the entry criteria consented to participate and were entered into the trial. A ventricular drainage catheter and an ultrasound microcatheter were stereotactically delivered together, directly into the IVH or ICH. Recombinant tissue plasminogen activator and 24 hours of continuous ultrasound were delivered to the clot. Gravity drainage was performed. In patients with IVHs, 3 mg of rt-PA was injected; in patients with intraparenchymal hemorrhages, 0.9 mg of rt-PA was injected. The rt-PA was delivered in 3 doses over 24 hours.

RESULTS

All patients had significant volume reductions in the treated hemorrhage. The mean percentage volume reduction after 24 hours of therapy, as determined on CT and compared with pretreatment stability scans, was 59 ± 5% (mean ± SEM) for ICH and 45.1 ± 13% for IVH (1 patient with ICH was excluded from analysis because of catheter breakage). There were no intracranial infections and no significant episodes of rebleeding according to clinical or CT assessment. One death occurred by 30 days after admission. Clinical improvements as determined by a decrease in the National Institutes of Health Stroke Scale score were demonstrated at 30 days after treatment in 7 of 9 patients. The rate of hemorrhage lysis was compared between 8 patients who completed treatment, and patient cohorts treated for IVH and ICH using identical doses of rt-PA and catheter drainage but without the ultrasound (courtesy of the MISTIE [Minimally Invasive Surgery plus T-PA for Intracerebral Hemorrhage Evacuation] and CLEAR II [Clot Lysis Evaluating Accelerated Resolution of Intraventricular Hemorrhage II] studies). Compared with the MISTIE and CLEAR data, the authors observed a faster rate of lysis during treatment for IVH and ICH in the patients treated with sonolysis plus rt-PA versus rt-PA alone.

CONCLUSIONS

Lysis and drainage of spontaneous ICH and IVH with a reduction in mass effect can be accomplished rapidly and safely through sonothrombolysis using stereotactically delivered drainage and ultrasound catheters via a bur hole. A larger clinical trial with catheters specifically designed for brain blood clot removal is warranted.

Semi-automatic volumetric assessment of perihemorrhagic edema with computed tomography

BACKGROUND AND PURPOSE

Magnetic resonance imaging (MRI) shows perihemorrhagic edema (PHE) after intracerebral hemorrhage (ICH) with high contrast, but the procedure is often difficult or not available for clinical use. The aim of the present study was to establish and validate an observer independent method for quantification of PHE on computed tomography (CT) by comparing with simultaneously performed MRI.

METHODS

Patients with spontaneous supratentorial ICH were included. Twenty-two patients received coregistered MRI and CT on day 1, and 27 patients on day 5 after admission. Volumes for PHE and ICH were measured (i) manually on CT, (ii) manually on MRI (fluid-attenuated inversion recovery sequence), and (iii) threshold based on CT. To identify optimal threshold values (Hounsfield units) for best correlation of CT with MRI, upper and lower thresholds were adjusted gradually until the PHE volume on CT best fitted the PHE volume on MRI. The established threshold range was prospectively validated in another 15 patients.

RESULTS

A threshold range 5-33 Hounsfield units (HU) resulted in best correlation both on days 1 and 5. Using these thresholds in the validation group, PHE volumes on CT and MRI were highly comparable (31 ± 26 ml vs. 30 ± 27 ml) with good correlation (R(2) = 0.96, P < 0.01) and high inter- (0.96) and intraobserver (0.96) reliability. Manually traced PHE on CT was significantly larger (37.3 ± 37 ml vs. 30 ± 27 ml, P < 0.01) with worse inter- (0.89) and intraobserver (0.90) reliability.

CONCLUSIONS

Threshold-based CT volumetry of PHE with a threshold range 5-33 HU is a reliable and observer independent method for quantification of PHE after spontaneous ICH.

Treatment of intracerebral hemorrhage in animal models: meta-analysis

OBJECTIVE

Interventions that improve functional outcome after acute intracerebral hemorrhage (ICH) in animals might benefit humans. Therefore, we systematically reviewed the literature to find studies of nonsurgical treatments tested in animal models of ICH.

METHODS

In July 2009 we searched Ovid Medline (from 1950), Embase (from 1980), and ISI Web of Knowledge (from 1969) for controlled animal studies of nonsurgical interventions given after the induction of ICH that reported neurobehavioral outcome. We assessed study quality and performed meta-analysis using a weighted mean difference random effects model.

RESULTS

Of 13,343 publications, 88 controlled studies described the effects of 64 different medical interventions (given a median of 2 hours after ICH induction) on 38 different neurobehavioral scales in 2,616 treated or control animals (median 14 rodents per study). Twenty-seven (31%) studies randomized treatment allocation, and 7 (8%) reported allocation concealment; these studies had significantly smaller effect sizes than those without these attributes (p < 0.001). Of 64 interventions stem cells, calcium channel blockers, anti-inflammatory drugs, iron chelators, and estrogens improved both structural outcomes and neurobehavioral scores in >1 study. Meta-regression revealed that together, structural outcome and the intervention used accounted for 65% of the observed heterogeneity in neurobehavioral score (p < 0.001, adjusted r(2) = 0.65).

INTERPRETATION

Further animal studies of the interventions that we found to improve both functional and structural outcomes in animals, using better experimental designs, could target efforts to translate effective treatments for ICH in animals into randomized controlled trials in humans.

The postpartum period of pregnancy worsens brain injury and functional outcome after cerebellar hemorrhage in rats

BACKGROUND

Intracerebral hemorrhage (ICH) is one of the most common causes of maternal deaths related to the postpartum period. This is a devastating form of stroke for which there is no available treatment. Although premenopausal females tend to have better outcomes after most forms of brain injury, the effects of pregnancy and child birth lead to wide maternal physiological changes that may predispose the mother to an increased risk for stroke and greater initial injury.

METHODS

Three different doses of collagenase were used to generate models of mild, moderate and severe cerebellar hemorrhage in postpartum female and male control rats. Brain water, blood-brain barrier rupture, hematoma size and neurological evaluations were performed 24 h later.

RESULTS

Postpartum female rats had worsened brain water, blood-brain barrier rupture, hematoma size and neurological evaluations compared to their male counterparts.

CONCLUSION

The postpartum state reverses the cytoprotective effects commonly associated with the hormonal neuroprotection of (premenopausal) female gender, and leads to greater initial injury and worsened neurological function after cerebellar hemorrhage. This experimental model can be used for the study of future treatment strategies after postpartum brain hemorrhage, to gain a better understanding of the mechanistic basis for stroke in this important patient subpopulation.

A novel preclinical model of germinal matrix hemorrhage using neonatal rats

BACKGROUND

Germinal matrix hemorrhage (GMH) is a neurological disorder associated with very low birth weight premature infants. This event can lead to post-hemorrhagic hydrocephalus, cerebral palsy, and mental retardation. This study developed a novel animal model for pre-clinical investigations.

METHODS

Neonatal rats underwent infusion of clostridial collagenase into the right germinal matrix (anterior caudate) region using stereotaxic techniques. Developmental milestones were evaluated over 10 days, cognitive function at 3 weeks, and sensorimotor function at 4 weeks after collagenase infusion. This was accomplished by anthropometric quantifications of cranial, cerebral, cardiac, and splenic growths.

RESULTS

Collagenase infusion led to delays in neonatal developmental milestones, followed by cognitive and sensorimotor dysfunctions in the juvenile animals. Cranial growth was accelerated during the first week after injury, and this was followed by significant brain atrophy, splenomegaly, and cardiac hypertrophy 3 weeks later.

CONCLUSION

This study characterized the developmental delays, mental retardation, and cerebral palsy features resembling the long-term clinical course after germinal matrix hemorrhage in premature infants. Pre-clinical testing of therapeutics in this experimental model could lead to improved patient outcomes while expanding upon the pathophysiological understanding of this disease.

Natural history of perihematomal edema after intracerebral hemorrhage measured by serial magnetic resonance imaging

BACKGROUND AND PURPOSE

knowledge on the natural history and clinical impact of perihematomal edema (PHE) associated with intracerebral hemorrhage is limited. We aimed to define the time course, predictors, and clinical significance of PHE measured by serial magnetic resonance imaging.

METHODS

patients with primary supratentorial intracerebral hemorrhage ≥ 5 cm(3) underwent serial MRIs at prespecified intervals during the first month. Hematoma (H(v)) and PHE (E(v)) volumes were measured on fluid-attenuated inversion recovery images. Relative PHE was defined as E(v)/H(v). Neurologic assessments were performed at admission and with each MRI. Barthel Index, modified Rankin scale, and extended Glasgow Outcome scale scores were assigned at 3 months.

RESULTS

twenty-seven patients with 88 MRIs were prospectively included. Median H(v) and E(v) on the first MRI were 39 and 46 cm(3), respectively. Median peak absolute E(v) was 88 cm(3). Larger hematomas produced a larger absolute E(v) (r(2)=0.6) and a smaller relative PHE (r(2)=0.7). Edema volume growth was fastest in the first 2 days but continued until 12 ± 3 days. In multivariate analysis, a higher admission hematocrit was associated with a greater delay in peak PHE (P=0.06). Higher admission partial thromboplastin time was associated with higher peak rPHE (P=0.02). Edema volume growth was correlated with a decline in neurologic status at 48 hours (81 vs 43 cm(3), P=0.03) but not with 3-month functional outcome.

CONCLUSIONS

PHE volume measured by MRI increases most rapidly in the first 2 days after symptom onset and peaks toward the end of the second week. The timing and magnitude of PHE volume are associated with hematologic factors. Its clinical significance deserves further study.