Intracranial hemorrhage

A Machine Learning Method for Predicting Acute Kidney Injury in Patients with Intracranial Hemorrhage

Intracranial hemorrhage (ICH) is a critical and urgent condition in clinical practice. Recent research has highlighted acute kidney injury (AKI) that frequently impacts patient prognosis. For clinicians, early intervention is crucial, and the advancement of machine learning brings promising prospects for predicting this disease. Therefore, this study aims to develop innovative machine learning models for the prediction and diagnosis of acute kidney injury (AKI) in patients with intracerebral hemorrhage (ICH). AKI data of ICH patients were extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. To construct the models, we utilized various techniques including random survival forest (RSF), elastic network (Enet), Least Absolute Shrinkage and Selection Operator (Lasso), stepwise logistic regression (stepwise LR), and ten machine learning algorithms. Optimal parameters were obtained through a ten-fold crossover, and training and testing groups were employed for the integrated machine models' training and validation. We conducted a quantitative evaluation of the model's performance and assessed its clinical application to determine its advantages. Furthermore, we compared the base model with traditional models such as the Sequential Organ Failure Assessment (SOFA) and the bespoke Simplified Acute Physiology Score (SAPS) II model. A total of 1856 patients with intracerebral hemorrhage (ICH) were enrolled in the study, consisting of 1633 non-AKI patients and 223 AKI patients. Among the various machine learning models tested, XGBoost exhibited the highest predictive accuracy and demonstrated excellent clinical applicability as a standalone model. When combining integrated models, RSF+XGBoost, LR[forward]+Lasso, LR[forward]+RSF, and Lasso+XGBoost, all achieved the highest AUC values (AUC = 1.000). Machine learning models can serve as valuable diagnostic tools in identifying the occurrence of acute kidney injury (AKI) in intracerebral hemorrhage (ICH) cases. Whether utilized individually or in combination, these models have the potential to assist clinicians in proactively developing effective interventions.

Clinical benefits of invasive intracranial pressure monitoring for spontaneous intracranial hemorrhage: a systematic review and meta-analysis

BACKGROUND

This meta-analysis evaluated the clinical benefits of invasive intracranial pressure (ICP) monitoring for spontaneous intracranial hemorrhage with specific focuses on the hypertensive intracerebral hemorrhage (ICH) subgroup and the outcomes when combined with minimally invasive surgery (MIS).

METHODS

PubMed and Embase were searched to identify studies comparing the clinical outcomes from ICP monitoring vs. non-ICP monitoring. Primary outcomes included in-hospital and 6-month mortality rates. Secondary outcomes were hospital length of stay (LOS), proportion of patients with poor 6-month functional outcomes, and central nervous system (CNS) infection rates. Subgroup analyses were performed on hypertensive ICH subgroup and on MIS vs. non-MIS subgroups. This study was registered in PROSPERO (CRD42024587974).

RESULTS

Thirteen studies involving 4,027 patients with spontaneous intracranial hemorrhage were included. Compared with non-ICP monitoring, ICP monitoring significantly reduced the 6-month mortality rate (43.33% vs. 28.67%, P < 0.00001), the proportion of patients with poor 6-month functional outcomes (70.49% vs. 56.71%, P = 0.0003), and hospital LOS (19.71 vs. 18.15 days, P = 0.001) but increased CNS infection rate (1.56% vs.7.49%, P < 0.00001). The hypertensive ICH subgroup analysis revealed that ICP monitoring significantly reduced in-hospital mortality rate (8.57% vs. 2.78%, P = 0.02), LOS (18.42 vs.14.54 days, P < 0.00001), and the proportion of patients with poor 6-month functional outcomes (60.00% vs. 38.77%, P = 0.001). When used with MIS, ICP monitoring significantly reduced the LOS (16.98 vs. 12.45 days, P < 0.00001) and the proportion of patients with poor 6-month functional outcomes (66.89% vs. 36.22%, P < 0.00001).

CONCLUSION

ICP monitoring improves short- and long-term outcomes in patients with spontaneous intracranial hemorrhage, particularly when combined with MIS therapy.

The burden of cardiovascular disease in children in Asian countries (1990-2021): Systematic analysis and projection of the burden of disease

Background

Cardiovascular disease (CVD) is the leading global cause of death and health loss. The epidemiology and factors influencing CVD in children are unique, making it essential to first evaluate current and future trends to guide interventions and reduce the disease burden.

Objective

To analyze the incidence, mortality, and disability-adjusted life years (DALY) of CVD in children aged 0-14 from 1990 to 2021, and explore global disease burden, risk factors, and trends over the next 30 years. The study focuses on China, Japan, South Korea, India, and Singapore to aid in developing targeted prevention and treatment strategies.

Methods

Using data from the Global Burden of Disease Study (GBD) 1990-2021, we assessed age- and sex-specific morbidity, mortality, and DALY of CVD in Asian children aged 0-14 and computed the EAPC. We analyzed risk factors, specific causes, and projected prevalence trends through 2050 using the Bayesian Age-Period-Cohort (BAPC) model.

Results

From 1990 to 2021, CVD incidence among Asian children aged 0-14 decreased by 8.03 % (95 % UI:13.63 to -4.02). Mortality saw a significant drop of 67.98 % (95 % UI:73.73 to -62.23), with the greatest decline in children aged 2-4, and the highest death rate in those under 1 year. Disability and mortality patterns were similar across gender, age, etiology, and overall trends. In 2021, South Asia had the highest rates of morbidity, mortality, and disability. Rates varied significantly, with Mongolia exhibiting the highest rate and Cyprus the lowest, showing a sixfold difference. Rheumatic heart disease (RHD) and intracerebral hemorrhage were the most critical diseases needed attention. Abnormal temperatures were identified as a risk factor associated with CVD outcomes in children. The burden of CVD is projected to increase in various regions and countries across Asia.

Conclusion

The burden of CVD continues to challenge children aged 0-14 in Asia. Enhancing our understanding of pediatric CVD epidemiology, addressing risk factors, and reinforcing prevention and control measures are essential for reducing this burden.

Periodic Table of Immunomodulatory Elements and Derived Two-Dimensional Biomaterials

Periodic table of chemical elements serves as the foundation of material chemistry, impacting human health in many different ways. It contributes to the creation, growth, and manipulation of functional metallic, ceramic, metalloid, polymeric, and carbon-based materials on and near an atomic scale. Recent nanotechnology advancements have revolutionized the field of biomedical engineering to tackle longstanding clinical challenges. The use of nano-biomaterials has gained traction in medicine, specifically in the areas of nano-immunoengineering to treat inflammatory and infectious diseases. Two-dimensional (2D) nanomaterials have been found to possess high bioactive surface area and compatibility with human and mammalian cells at controlled doses. Furthermore, these biomaterials have intrinsic immunomodulatory properties, which is crucial for their application in immuno-nanomedicine. While significant progress has been made in understanding their bioactivity and biocompatibility, the exact immunomodulatory responses and mechanisms of these materials are still being explored. Current work outlines an innovative "immunomodulatory periodic table of elements" beyond the periodic table of life, medicine, and microbial genomics and comprehensively reviews the role of each element in designing immunoengineered 2D biomaterials in a group-wise manner. It recapitulates the most recent advances in immunomodulatory nanomaterials, paving the way for the development of new mono, hybrid, composite, and hetero-structured biomaterials.

Impact of Dataset Size on 3D CNN Performance in Intracranial Hemorrhage Classification

Background: This study aimed to evaluate the effect of sample size on the development of a three-dimensional convolutional neural network (3DCNN) model for predicting the binary classification of three types of intracranial hemorrhage (ICH): intraparenchymal, subarachnoid, and subdural (IPH, SAH, SDH, respectively). Methods: During the training, we compiled all images of each brain computed tomography scan into a single 3D image, which was then fed into the model to classify the presence of ICH. We divided the non-hemorrhage quantities into 20, 30, 40, 50, 100, and 150 and the ICH quantities into 20, 30, 40, and 50. Cross-validation was performed to compute the average area under the curve (AUC) over the last five iterations. The AUC and accuracy were used to evaluate the performance of the models. Results: Fifty patients, each with the three ICH types, and 150 non-hemorrhage cases were enrolled. Larger sample sizes achieved stable and acceptable performance in the artificial intelligence (AI) models, whereas training with a limited number of cases posed the risk of falsely high AUC values or accuracy. The overall trends and fluctuations in AUC values were similar between IPH and SDH but different for SAH. The accuracy of the results was relatively consistent among the three ICH types. Conclusions: The 3DCNN technique can be used to develop AI models capable of detecting ICH from limited case numbers. However, a minimal case number must be provided. The performance of AI models varies across different ICH types and is more stable with larger sample sizes.

Emergency neurosurgical hybrid operating platform for acute intracranial hemorrhage (E-HOPE)

BACKGROUND

Precise diagnosis and rapid treatment for acute complex intracranial hemorrhage (ICH) are crucial. The neurosurgical hybrid operating platform integrates traditional open neurosurgery operating room functionalities with endovascular therapy capabilities and is developing in the neurosurgical practice. However, its effect on the emergent complicated neurovascular cases needs pilot exploration.

METHODS

In this prospective study, a total of 103 cases of both spontaneous and non-spontaneous ICH were consecutively recruited between June 2019 and June 2023. Demographic data, including age, gender distribution, and types of hemorrhage, were collected. Surgical interventions were tailored based on DSA, including spontaneous and non-spontaneous hemorrhages. Functional outcomes were assessed using the modified Rankin Scale (mRS) preoperatively and postoperatively.

RESULTS

Over the study period from June 2019 to June 2023, a cohort of 103 ICH cases underwent emergency hybrid surgical treatment utilizing the E-HOPE platform. Among these cases, 88 were classified as spontaneous ICH, while 15 were non-spontaneous. The mean age at diagnosis for the entire cohort was 54.0 ± 3.7 years, with a slight predominance of male patients. Spontaneous ICH encompassed a diverse spectrum of etiologies, including arteriovenous malformations, aneurysms, arteriovenous fistulas, cavernous malformations, moyamoya disease, and cryptogenic hemorrhages. Surgical interventions were tailored to address the specific pathology. Notably, improvements in mRS scores were observed in a majority of cases, with some patients experiencing stabilization or deterioration postoperatively. Non-spontaneous cases (n = 15) were primarily iatrogenic (n = 13) due to tumors adjacent to the internal carotid artery, necessitating stent graft deployment. Surgical approaches, including stent graft deployment and middle meningeal artery embolization, were effective in managing these cases. Postoperative functional outcomes varied depending on the nature of the hemorrhage, with a subset of patients demonstrating improvement in mRS scores while others showed no significant change.

CONCLUSIONS

Emergency hybrid surgical treatment utilizing the E-HOPE platform offers promising outcomes for ICH patients. Tailored surgical approaches result in favorable postoperative functional outcomes, highlighting the importance of a multidisciplinary approach in managing these complex cases.

Causal Relationships Between Gut Microbiota, Inflammatory Cells/Proteins, and Subarachnoid Hemorrhage: A Multi-omics Bidirectional Mendelian Randomization Study and Meta-analysis

Subarachnoid hemorrhage (SAH) is a neurological emergency that can lead to fatal outcomes. It occurs when bleeding happens in the subarachnoid space, a small gap between the arachnoid and pia mater. This condition results from the rupture of diseased or damaged blood vessels at the brain's base or surface. This study combined various omics approaches with Mendelian randomization analysis, including MR-IVW, MR Egger, MR weight median, and MR weight mode, to generate preliminary results. It also employed reverse Mendelian randomization, treating SAH as the exposure. Finally, a meta-analysis was conducted to summarize these findings. The study found positive correlations between SAH and both GBPA-Pyridoxal 5 phosphate biosynthesis I (OR=1.48, 95% CI, 1.04-2.12) and GBPA-glucose biosynthesis I (OR=0.68, 95% CI, 0.52-0.90). Increased levels of urokinase-type plasma activator were also associated with SAH (OR=1.17, 95% CI, 1.04-1.32). Associations were observed with SAH for CD80 on CD62L+ plasmacytoid dendritic cells, CD80 on plasmacytoid dendritic cells, CD123 on CD62L+ plasmacytoid dendritic cells, and SSC-A on plasmacytoid dendritic cells. This study, through Mendelian randomization and meta-analysis, established links between SAH and four inflammatory cells, one inflammatory protein, and two gut microbiota-related pathways. These findings suggest potential treatment targets for SAH, highlighting the importance of modulating gut microbiota and utilizing anti-inflammatory drugs in its management.

NADPH Oxidases in Neurodegenerative Disorders: Mechanisms and Therapeutic Opportunities

Significance: The nicotinamide adenine dinucleotide phosphate oxidase (NOX) enzyme family, located in the central nervous system, is recognized as a source of reactive oxygen species (ROS) in the brain. Despite its importance in cellular processes, excessive ROS generation leads to cell death and is involved in the pathogenesis of neurodegenerative disorders. Recent advances: NOX enzymes contribute to the development of neurodegenerative diseases, such as Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and stroke, highlighting their potential as targets for future therapeutic development. This review will discuss NOX's contribution and therapeutic targeting potential in neurodegenerative diseases, focusing on PD, AD, ALS, and stroke. Critical issues: Homeostatic and physiological levels of ROS are crucial for regulating several processes, such as development, memory, neuronal signaling, and vascular homeostasis. However, NOX-mediated excessive ROS generation is deeply involved in the damage of DNA, proteins, and lipids, leading to cell death in the pathogenesis of a wide range of diseases, namely neurodegenerative diseases. Future directions: It is essential to understand the role of NOX homologs in neurodegenerative disorders and the pathological mechanisms undergoing neurodegeneration mediated by increased levels of ROS. This further knowledge will allow the development of new specific NOX inhibitors and their application for neurodegenerative disease therapeutics. Antioxid. Redox Signal. 41, 522-541.

Nrdp1-mediated Macrophage Phenotypic Regulation Promotes Functional Recovery in Mice with Mild Neurological Impairment after Intracerebral Hemorrhage

Neuregulin receptor degradation protein 1 (Nrdp1) is a ring finger E3 ubiquitin ligase involved in some inflammation through ubiquitination, including macrophage polarization following cerebral hemorrhage. However, there is limited understanding regarding the mechanisms through which Nrdp1 modulates macrophage polarization and the potential impact of this modulation on neurological function. Using stereotactic injection and adenoviral transfection techniques, the corresponding animal models were constructed through injecting adenovirus, saline, or blood into the mouse striatum at different periods of time in this research. The alteration in the ratio of various M1/M2 phenotype-associated markers (e.g., CD86, CD206, IL-6, IL-10, etc.) was evaluated through immunohistochemistry, immunofluorescence, western blotting, and elisa assays. Additionally, neurological function scores and behavioral tests were utilized to evaluate changes in neurological function in mice after cerebral hemorrhage. Our results show that overexpression of Nrdp1 promotes the expression of a variety of M2 macrophage-associated markers and enhance transcriptional activity of arginase-1 (Arg1) protein through ubiquitination for early regulation M2 macrophage polarization. Additionally, Nrdp1 promotes hematoma absorption, increases IL-10 expression, inhibits inducible nitric oxide synthase (iNOS), IL-6, and TNF-α production, alleviates neurological impairment and brain edema, and accelerates functional recovery. These findings suggest that modulating macrophage polarization through Nrdp1 could be a therapeutic strategy for neurofunctional impairment in cerebral hemorrhage.

Clinical features and associated factors of coexisting intracerebral hemorrhage in patients with cerebral small vessel disease: a cross-sectional study

Intracerebral hemorrhage (ICH) is generally considered to be closely related to cerebral small vessel disease (CSVD), leading to a poor prognosis. However, the coexistence of ICH in general CSVD patients and related factors remain underreported. In our cross-sectional study, we screened 414 CSVD patients from a database at the Department of Neurology, First Affiliated Hospital of Zhengzhou University (September 2018 to April 2022). Imaging biomarkers of CSVD and coexisting ICH lesion were assessed. Factors associated with coexisting ICH in CSVD were determined using multivariate logistic regression analysis. ICH was observed in 59 patients (14.3%). Multivariate logistic regression showed that previous history of ischemic stroke or transient ischemic attack (OR 5.189, 95%CI 2.572-10.467, P < 0.001), high-grade perivascular space in the basal ganglia (n > 10) (OR 2.051, 95%CI 1.044-4.027, P = 0.037) and low adjusted calcium-phosphorus product (OR 0.728 per 1 [mmol/L]2 increase, 95%CI 0.531-0.998, P = 0.049) were associated with coexisting ICH in CSVD patients. The considerable proportion of coexisting ICH and revelation of associated factors in general CSVD patients alert physicians of the potential risk of the reoccurrence of ICH, and might have a significant impact on therapeutic strategies.

Mitophagy in intracerebral hemorrhage: a new target for therapeutic intervention

Intracerebral hemorrhage is a life-threatening condition with a high fatality rate and severe sequelae. However, there is currently no treatment available for intracerebral hemorrhage, unlike for other stroke subtypes. Recent studies have indicated that mitochondrial dysfunction and mitophagy likely relate to the pathophysiology of intracerebral hemorrhage. Mitophagy, or selective autophagy of mitochondria, is an essential pathway to preserve mitochondrial homeostasis by clearing up damaged mitochondria. Mitophagy markedly contributes to the reduction of secondary brain injury caused by mitochondrial dysfunction after intracerebral hemorrhage. This review provides an overview of the mitochondrial dysfunction that occurs after intracerebral hemorrhage and the underlying mechanisms regarding how mitophagy regulates it, and discusses the new direction of therapeutic strategies targeting mitophagy for intracerebral hemorrhage, aiming to determine the close connection between mitophagy and intracerebral hemorrhage and identify new therapies to modulate mitophagy after intracerebral hemorrhage. In conclusion, although only a small number of drugs modulating mitophagy in intracerebral hemorrhage have been found thus far, most of which are in the preclinical stage and require further investigation, mitophagy is still a very valid and promising therapeutic target for intracerebral hemorrhage in the long run.

Hemorrhage Evaluation and Detector System for Underserved Populations: HEADS-UP

Objective

To create a rapid, cloud-based, and deployable machine learning (ML) method named hemorrhage evaluation and detector system for underserved populations, potentially across the Mayo Clinic enterprise, then expand to involve underserved areas and detect the 5 subtypes of intracranial hemorrhage (IH).

Methods

We used Radiological Society of North America dataset for IH detection. We made 4 total iterations using Google Cloud Vertex AutoML. We trained an AutoML model with 2000 images, followed by 6000 images from both IH positive and negative classes. Pixel values were measured by the Hounsfield units, presenting a width of 80 Hounsfield and a level of 40 Hounsfield as the bone window. This was followed by a more detailed image preprocessing approach by combining the pixel values from each of the brain, subdural, and soft tissue window-based gray-scale images into R(red)-channel, G(green)-channel, and B(blue)-channel images to boost the binary IH classification performance. Four experiments with AutoML were applied to study the effects of training sample size and image preprocessing on model performance.

Results

Out of the 4 AutoML experiments, the best-performing model was the fourth experiment, where 95.80% average precision, 91.40% precision, and 91.40% recall were achieved. On the basis of this analysis, our binary IH classifier hemorrhage evaluation and detector system for underserved populations appeared both accurate and performed well.

Conclusion

Hemorrhage evaluation and detector system for underserved populations is a rapid, cloud-based, deployable ML method to detect IH. This tool can help expedite the care of patients with IH in resource-limited hospitals.

Intracranial hemorrhages in patients with COVID-19: a systematic review of the literature, regarding six cases in an Amazonian population

BACKGROUND

 Coronavirus disease 2019 (COVID-19) has emerged as a public health emergency worldwide, predominantly affecting the respiratory tract. However, evidence supports the involvement of extrapulmonary sites, including reports of intracranial hemorrhages.

OBJECTIVE

 To describe six original cases and review the literature on intracranial hemorrhages in patients diagnosed with COVID-19 by molecular methods.

METHODS

 A systematic literature review was performed on MEDLINE, PubMed, and NCBI electronic databases to identify eligible studies. Of the total 1,624 articles retrieved, only 53 articles met the inclusion criteria.

RESULTS

 The overall incidence of intracranial hemorrhage in patients hospitalized for COVID-19 was 0.26%. In this patient group, the mean age was 60 years, and the majority were male (68%) with initial respiratory symptoms (73%) and some comorbidity. Before the diagnosis of hemorrhage, 43% of patients were using anticoagulants, 47.3% at therapeutic doses. The intraparenchymal (50%) was the most affected compartment, followed by the subarachnoid (34%), intraventricular (11%), and subdural (7%). There was a predominance of lobar over non-lobar topographies. Multifocal or multicompartmental hemorrhages were described in 25% of cases. Overall mortality in the cohort studies was 44%, while around 55% of patients were discharged from hospital.

CONCLUSION

 Despite the unusual association, the combination of these two diseases is associated with high rates of mortality and morbidity, as well as more severe clinicoradiological presentations. Further studies are needed to provide robust evidence on the exact pathophysiology behind the occurrence of intracranial hemorrhages after COVID-19 infection.

Therapeutic review: The role of tranexamic acid in management of traumatic brain injury, nontraumatic intracranial hemorrhage, and aneurysmal subarachnoid hemorrhage

PURPOSE

To summarize current literature evaluating tranexamic acid in the management of intracranial bleeding associated with traumatic and nontraumatic brain injuries and implications for clinical practice.

SUMMARY

Intracranial hemorrhage, regardless of etiology, is associated with high morbidity and mortality. Tranexamic acid is an antifibrinolytic with anti-inflammatory properties shown to reduce mortality in trauma patients with extracranial injuries. In traumatic brain injury, a large randomized trial found no difference in outcomes when tranexamic acid was compared to placebo; however, subgroup analyses suggested that it may reduce head injury-related mortality in the context of mild-to-moderate injury if treatment occurs within 1 hour of symptom onset. More recent out-of-hospital data have disputed these findings and even suggested harm in severely injured patients. In spontaneous, nontraumatic intracranial hemorrhage, treatment with tranexamic acid did not result in a difference in functional status; however, rates of hematoma expansion, even though modest, were significantly reduced. In aneurysmal subarachnoid hemorrhage, tranexamic acid may prevent rebleeding, but has not led to improved outcomes or reduced mortality, and there is concern for increased incidence of delayed cerebral ischemia. Overall, tranexamic acid has not been shown to result in increased risk of thromboembolic complications across these classes of brain injury.

CONCLUSION

Despite its favorable safety profile overall, tranexamic acid does not seem to improve functional outcomes and cannot be routinely recommended. More data are needed to determine which head injury subpopulations are most likely to benefit from tranexamic acid and which patients are at increased risk for harm.

Resource utilization in management of spontaneous intracerebral hemorrhage without systemic risk factors. Does early surgical decompression matter?

BACKGROUND

Even though different subtypes of spontaneous ICH are frequently linked to a poor prognosis, their causes, pathological features, and prognoses vary. Atypical intracerebral hemorrhage is the subtype of spontaneous ICH that usually occurs due to an underlying localized vascular lesion. It is unrelated to systemic vascular risk factors, mostly affects children and young adults and is associated with a relatively good outcome. This fact should be considered when planning the evaluation and treatment. Investigating the cause of this subtype is fundamental to providing optimal management. However, if resources do not allow completing the investigations, the cause will be more difficult to discover. Treatment decisions will be made under stress to save the patient's life, especially with rapidly deteriorating patients.

METHODS

We described three cases of spontaneous ICH without systemic risk factors where the bleeding source could not be determined before surgery due to a lack of resources, preventing preoperative vascular investigation. Knowing that the atypical ICH has a distinct identity, regarding etiology and prognosis, encouraged the surgeons to resort to early surgical decompression as an alternative plan. We reviewed the literature searching for supporting evidence.

RESULTS

The results of treatment of the presented cases were satisfactory. The lack of reported similar cases was brought to light by a literature analysis that sought to provide backing for the proposed management strategy. In the end, we supplied two graphic organizers to help readers remember the different types and treatment of hemorrhagic stroke.

CONCLUSION

There isn't enough evidence to show that there are other ways to treat atypical intracerebral haemorrhage when resources are limited. The presented cases highlight the importance of decisionmaking in resource-constrained situations when patient outcomes can be improved.

Inflammation and immune cell abnormalities in intracranial aneurysm subarachnoid hemorrhage (SAH): Relevant signaling pathways and therapeutic strategies

Intracranial aneurysm subarachnoid hemorrhage (SAH) is a cerebrovascular disorder associated with high overall mortality. Currently, the underlying mechanisms of pathological reaction after aneurysm rupture are still unclear, especially in the immune microenvironment, inflammation, and relevant signaling pathways. SAH-induced immune cell population alteration, immune inflammatory signaling pathway activation, and active substance generation are associated with pro-inflammatory cytokines, immunosuppression, and brain injury. Crosstalk between immune disorders and hyperactivation of inflammatory signals aggravated the devastating consequences of brain injury and cerebral vasospasm and increased the risk of infection. In this review, we discussed the role of inflammation and immune cell responses in the occurrence and development of aneurysm SAH, as well as the most relevant immune inflammatory signaling pathways [PI3K/Akt, extracellular signal-regulated kinase (ERK), hypoxia-inducible factor-1α (HIF-1α), STAT, SIRT, mammalian target of rapamycin (mTOR), NLRP3, TLR4/nuclear factor-κB (NF-κB), and Keap1/nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/ARE cascades] and biomarkers in aneurysm SAH. In addition, we also summarized potential therapeutic drugs targeting the aneurysm SAH immune inflammatory responses, such as nimodipine, dexmedetomidine (DEX), fingolimod, and genomic variation-related aneurysm prophylactic agent sunitinib. The intervention of immune inflammatory responses and immune microenvironment significantly reduces the secondary brain injury, thereby improving the prognosis of patients admitted to SAH. Future studies should focus on exploring potential immune inflammatory mechanisms and developing additional therapeutic strategies for precise aneurysm SAH immune inflammatory regulation and genomic variants associated with aneurysm formation.

Automatic Brain Midline Surface Delineation on 3D CT Images With Intracranial Hemorrhage

Brain midline delineation plays an important role in guiding intracranial hemorrhage surgery, which still remains a challenging task since hemorrhage shifts the normal brain configuration. Most previous studies detected brain midline on 2D plane and did not handle hemorrhage cases well. We propose a novel and efficient hemisphere-segmentation framework (HSF) for 3D brain midline surface delineation. Specifically, we formulate the brain midline delineation as a 3D hemisphere segmentation task, and employ an edge detector and a smooth regularization loss to generate the midline surface. We also introduce a distance-weighted map to keep the attention on the midline. Furthermore, we adopt rectification learning to handle various head poses. Finally, considering the complex situation of ventricle break-in for hemorrhages in bilateral intraventricular (B-IVH) cases, we identify those cases via a classification model and design a midline correction strategy to locally adjust the midline. To our best knowledge, it is the first study focusing on delineating the brain midline surface on 3D CT images of hemorrhage patients and handling the situation of ventricle break-in. Extensive validation on our large in-house datasets (519 patients) and the public CQ500 dataset (491 patients), demonstrates that our method outperforms state-of-the-art methods on brain midline delineation.

Mechanisms and Biomarker Potential of Extracellular Vesicles in Stroke

Simple Summary

A stroke occurs when there is a lack of blood flow to the brain. Stroke injures the brain and can have devastating outcomes depending on the size and location of the brain tissue affected. Currently, there are only a limited number of treatment options for stroke. Extracellular vesicles are small vesicles secreted by cells. Importantly, extracellular vesicles have specific markers indicating the cell they were released from and can pass from the brain into the blood. For these reasons, assessing extracellular vesicles in the blood may create a window into changes occurring in the brain. Assessing changes in extracellular vesicles in the blood during stroke may produce new insight into the cellular changes in the brain causing injury during stroke. This in turn may generate potential targets for the development of future treatments. We summarize what is known about changes in brain-cell-specific extracellular vesicles during stroke and stress the importance of continuing to study these changes.

Abstract

Stoke is a prevalent and devastating neurologic condition with limited options for therapeutic management. Since brain tissue is rarely accessible clinically, peripheral biomarkers for the central nervous system’s (CNS’s) cellular response to stroke may prove critical for increasing our understanding of stroke pathology and elucidating novel therapeutic targets. Extracellular vesicles (EVs) are cell-derived, membrane-enclosed vesicles secreted by all cell types within the CNS that can freely pass the blood-brain barrier (BBB) and contain unique markers and content linked to their cell of origin. These unique qualities make brain-derived EVs novel candidates for non-invasive blood-based biomarkers of both cell specificity and cell physiological state during the progression of stroke and recovery. While studies are continuously emerging that are assessing the therapeutic potential of EVs and profiling EV cargo, a vast minority of these studies link EV content to specific cell types. A better understanding of cell-specific EV release during the acute, subacute, and chronic stages of stroke is needed to further elucidate the cellular processes responsible for stroke pathophysiology. Herein, we outline what is known about EV release from distinct cell types of the CNS during stroke and the potential of these EVs as peripheral biomarkers for cellular function in the CNS during stroke.

A model to visualize the fate of iron after intracranial hemorrhage using isotopic tracers and elemental bioimaging

Hemoglobin-iron is a red-blood-cell toxin contributing to secondary brain injury after intracranial bleeding. We present a model to visualize an intracerebral hematoma and secondary hemoglobin-iron distribution by detecting 58Fe-labeled hemoglobin (Hb) with laser ablation-inductively coupled plasma-mass spectrometry on mouse brain cryosections after stereotactic whole blood injection for different time periods. The generation of 58Fe-enriched blood and decisive steps in the acute hemorrhage formation and evolution was evaluated. The model allows to visualize and quantify 58Fe with high spatial resolution and striking signal-to-noise ratio. Script-based evaluation of the delocalization-depth revealed ongoing 58Fe delocalization in the brain even six days after hematoma induction. Collectively, the model can quantify the distribution of Hb-derived iron post-bleeding, providing a methodological framework to study the pathophysiological basis of cell-free Hb toxicity in hemorrhagic stroke.

The protective effects of activating Sirt1/NF-κB pathway for neurological disorders

Sirt1, a member of the sirtuins family, is a nicotinamide adenosine dinucleotide (NAD⁺)-dependent deacetylase. It can be involved in the regulation of several processes including inflammatory response, apoptosis, oxidative stress, energy metabolism, and autophagy by exerting deacetylation. Nuclear factor-κB (NF-κB), a crucial nuclear transcription factor with specific DNA binding sequences, exists in almost all cells and plays a vital role in several biological processes involving inflammatory response, immune response, and apoptosis. As the hub of multiple intracellular signaling pathways, the activity of NF-κB is regulated by multiple factors. Sirt1 can both directly deacetylate NF-κB and indirectly through other molecules to inhibit its activity. We would like to emphasize that Sirt1/NF-κB is a signaling pathway that is closely related to neuroinflammation. Many recent studies have demonstrated the neuroprotective effects of Sirt1/NF-κB signaling pathway activation applied to the treatment of neurological related diseases. In this review, we focus on new advances in the neuroprotective effects of the Sirt1/NF-κB pathway. First, we briefly review Sirt1 and NF-κB, two key molecules of cellular metabolism. Next, we discuss the connection between NF-κB and neuroinflammation. In addition, we explore how Sirt1 regulates NF-κB in nerve cells and relevant evidence. Finally, we analyze the therapeutic effects of the Sirt1/NF-κB pathway in several common neuroinflammation-related diseases.

Modified ICH score was superior to original ICH score for assessment of 30-day mortality and good outcome of non-traumatic intracerebral hemorrhage

INTRODUCTION

Intracerebral hemorrhage (ICH) score has been widely used as a consistent and reliable clinical grading scale for predicting mortality. However, ICH score had not been used to predict good outcome or significant disability for those who were alive. We intended to address whether any modifications would increase prediction accuracy for mortality as well as the extent of morbidity for those who survived.

METHODS

We conducted a retrospective cohort study, involving all non-traumatic ICH patients admitted to our hospital between September 2018 and July 2020. All non-traumatic ICH patients who were admitted to the stroke unit and registered in our stroke database had their medical records, neuroimaging, and laboratory test results reviewed. Only patients with complete medical records and available CT imaging and laboratory test results were included in our study. Independent predictors of mortality (modified Rankin scale/mRS of 6) or good outcome vs. significant disability (mRS≤2 vs. mRS 3-5, respectively) were identified by logistic regression. A modified ICH (mICH) score was compared with the original ICH (oICH) score for its diagnostic performance (DP). Overall DPs were graded and ranked according to Youden Index (YI).

RESULTS

As many as 311 patients were eligible with both 39.9% rate of 30-day mortality and good outcome. Factors independently associated with mortality were low GCS and high NIHSS on admission (P = 0.002, <0.001, respectively), and presence of respiratory failure (P < 0.001). Independent factors for good outcome were low NIHSS on admission and mass effect (midline shift > 5 mm) [both P < 0.001]. A modification of ICH score from the original was made by substituting GCS with NIHSS (0 -10 = 1; 11 - 20 = 2; >20 = 3), changing age cut-off point to > 55 years old (= 1), and adding respiratory failure (= 1), and mass effect (= 1). Overall, mICH scored better over oICH score with respect to sensitivity and had comparable specificity for both 30-day mortality and good outcome (sensitivity 80.6% vs. 50.8%; specificity 88.7% vs. 89.3%; YI 0.69 vs. 0.40, respectively) and good outcome (sensitivity 86.3% vs. 77.4%; specificity 74.6% vs. 77.8%; YI of 0.61 vs. 0.55, respectively). There was only one patient with oICH and none on mICH score of 0, who died and none survived with oICH and mICH score of ≥ 5 and ≥ 7, respectively. The proportion of 30-day mortality and good outcome increased in a more linear fashion with mICH score.

CONCLUSIONS

The mICH score was proven to be reliable and consistent as a risk grading assessment for non-traumatic ICH patients. The mICH was statistically superior to oICH score in predicting 30-day mortality and good outcome.

Many Good Reasons to Switch from Vitamin K Antagonists to Non-Vitamin K Antagonists in Patients with Non-Valvular Atrial Fibrillation

Non-vitamin K oral anticoagulants (NOACs) are the first choice for prophylaxis of cardioembolism in patients with non-valvular atrial fibrillation (AF) who are anticoagulant-naïve, as well as the preferable anticoagulation strategy in those who are on vitamin K antagonists (VKAs), but with a low time in therapeutic range (TTR). Nonetheless, there are many good reasons to consider switching from VKAs to NOACs also when TTR is >70%. From the pharmacological standpoint, anticoagulation with VKAs may remain erratic even in those patients who have high TTR values, owing to the mode of action of this drug class. Furthermore, experimental data suggest that, unlike VKAs, NOACs favorably modulate the effects of factor Xa and thrombin in the cardiovascular system through the protease-activated receptor family. Clinically, the most striking advantage provided by NOACs over VKAs, irrespective of the TTR, is the substantially lower risk of intracranial hemorrhage. NOACs have also been associated with less deterioration of renal function as compared with VKAs and may confer protection against cardiovascular events not strictly related to AF, especially the acute complications of peripheral artery disease. In this narrative review, we discuss the evidence according to which it is warranted to systematically substitute NOACs for VKAs for the prevention of AF-related stroke and systemic embolism.

The role of complement in brain injury following intracerebral hemorrhage: A review

Intracerebral hemorrhage (ICH) is a significant cause of death and disability and current treatment is limited to supportive measures to reduce brain edema and secondary hematoma expansion. Current evidence suggests that the complement cascade is activated early after hemorrhage and contributes to brain edema/injury in multiple ways. The aim of this review is to summarize the most recent literature about the role of the complement cascade after ICH. Primary literature demonstrating complement mediated brain edema and neurologic injury through the membrane attack complex (MAC) as well as C3a and C5a are reviewed. Further, attenuation of brain edema and improved functional outcomes are demonstrated after inhibition of specific components of the complement cascade. Conversely, complement also plays a significant role in neurologic recovery after ICH and in other neurologic disorders. We conclude that the role of complement after ICH is complex. Understanding the role of complement after ICH is essential and may elucidate possible interventions to reduce brain edema and injury.

Distant Organ Damage in Acute Brain Injury

Acute brain injuries pose a great threat to global health, having significant impact on mortality and disability. Patients with acute brain injury may develop distant organ failure, even if no systemic diseases or infection is present. The severity of non-neurologic organs' dysfunction depends on the extremity of the insult to the brain. In this comprehensive review we sought to describe the organ-related consequences of acute brain injuries. The clinician should always be aware of the interplay between central nervous system and non-neurological organs, that is constantly present. Cerebral injury is not only a brain disease, but also affects the body as whole, and thus requires holistic therapeutical approach.

Intracranial Hemorrhage Detection in Head CT Using Double-Branch Convolutional Neural Network, Support Vector Machine, and Random Forest

Brain hemorrhage is a severe threat to human life, and its timely and correct diagnosis and treatment are of great importance. Multiple types of brain hemorrhage are distinguished depending on the location and character of bleeding. The main division covers five subtypes: subdural, epidural, intraventricular, intraparenchymal, and subarachnoid hemorrhage. This paper presents an approach to detect these intracranial hemorrhage types in computed tomography images of the head. The model trained for each hemorrhage subtype is based on a double-branch convolutional neural network of ResNet-50 architecture. It extracts features from two chromatic representations of the input data: a concatenation of the image normalized in different intensity windows and a stack of three consecutive slices creating a 3D spatial context. The joint feature vector is passed to the classifier to produce the final decision. We tested two tools: the support vector machine and the random forest. The experiments involved 372,556 images from 11,454 CT series of 9997 patients, with each image annotated with labels related to the hemorrhage subtypes. We validated deep networks from both branches of our framework and the model with either of two classifiers under consideration. The obtained results justify the use of a combination of double-source features with the random forest classifier. The system outperforms state-of-the-art methods in terms of F1 score. The highest detection accuracy was obtained in intraventricular (96.7%) and intraparenchymal hemorrhages (93.3%).

Comparison of hemorrhagic and ischemic stroke after allogeneic hematopoietic stem cell transplantation

Stroke is an important complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Nevertheless, few studies have been published to analyzed the occurrence and prognosis of stroke after allo-HSCT. From January 2007 to December 2018 in Peking University People's Hospital, 6449 patients received HSCT and there were 2.3% of patients diagnosed with stroke after allo-HSCT (hemorrhagic: 1.0%, ischemic: 1.3%). The median time to hemorrhagic and ischemic stroke after HSCT was 161 days and 137 days, respectively. In total, 8.4% of patients experienced neurological sequelae. The outcome was much worse in patients with stroke than in control subjects. The comparison of prognosis showed no statistical differences between patients with hemorrhagic stroke and those with ischemic stroke. Significant risk factors for hemorrhagic stroke were pretransplant central nervous system leukemia (CNSL), and delayed platelet engraftment. Risk factors associated with the occurrence of ischemic stroke included high-risk disease, prior venous thromboembolism (VTE), grade III-IV acute graft-versus-host disease (aGVHD), and thrombotic microangiopathy (TMA). Haplo-identical transplantation was not a risk factor for stroke and had no impact on the prognosis compared with HLA-matched HSCT. Altogether, these results show that stroke is a severe complication after allo-HSCT. The prognosis of posttransplant stroke did not differ between hemorrhagic and ischemic stroke.

Multi-frequency difference method for intracranial hemorrhage detection by magnetic induction tomography

OBJECTIVE

Frequency-difference magnetic induction tomography (fdMIT) is a promising technique for the continuous monitoring of intracranial hemorrhage. The dual-frequency difference MIT (dfdMIT) will sometimes produce artefacts in the reconstructed images. To overcome this problem, a multi-frequency difference MIT (mfdMIT) method is proposed.

APPROACH

To test the performance of this algorithm, 2D head models comprising six tissue types with different hemorrhage sizes were simulated, and images of the hemorrhage were reconstructed by mfdMIT and dfdMIT. Imaging errors and correlation coefficients were calculated with different levels of added phase noise and conductivity noise.

MAIN RESULTS

A hemorrhage with a diameter of 20 mm can be reconstructed with 20 dB noise by the mfdMIT method, and the imaging error is reduced by about 60%. The results show that the conductivity of brain tissues changing with frequency will cause artefacts on the reconstructed images of the hemorrhage by dfdMIT, but the artefacts can be effectively suppressed with mfdMIT by separating the hemorrhage from other brain tissues.

SIGNIFICANCE

The mfdMIT method increases the reconstructed image precision, which promotes the development of medical imaging by MIT.

On-site Rapid Diagnosis of Intracranial Hematoma using Portable Multi-slice Microwave Imaging System

Rapid, on-the-spot diagnostic and monitoring systems are vital for the survival of patients with intracranial hematoma, as their conditions drastically deteriorate with time. To address the limited accessibility, high costs and static structure of currently used MRI and CT scanners, a portable non-invasive multi-slice microwave imaging system is presented for accurate 3D localization of hematoma inside human head. This diagnostic system provides fast data acquisition and imaging compared to the existing systems by means of a compact array of low-profile, unidirectional antennas with wideband operation. The 3D printed low-cost and portable system can be installed in an ambulance for rapid on-site diagnosis by paramedics. In this paper, the multi-slice head imaging system’s operating principle is numerically analysed and experimentally validated on realistic head phantoms. Quantitative analyses demonstrate that the multi-slice head imaging system is able to generate better quality reconstructed images providing 70% higher average signal to clutter ratio, 25% enhanced maximum signal to clutter ratio and with around 60% hematoma target localization compared to the previous head imaging systems. Nevertheless, numerical and experimental results demonstrate that previous reported 2D imaging systems are vulnerable to localization error, which is overcome in the presented multi-slice 3D imaging system. The non-ionizing system, which uses safe levels of very low microwave power, is also tested on human subjects. Results of realistic phantom and subjects demonstrate the feasibility of the system in future preclinical trials.

Design and Experimental Evaluation of a Non-Invasive Microwave Head Imaging System for Intracranial Haemorrhage Detection

An intracranial haemorrhage is a life threatening medical emergency, yet only a fraction of the patients receive treatment in time, primarily due to the transport delay in accessing diagnostic equipment in hospitals such as Magnetic Resonance Imaging or Computed Tomography. A mono-static microwave head imaging system that can be carried in an ambulance for the detection and localization of intracranial haemorrhage is presented. The system employs a single ultra-wideband antenna as sensing element to transmit signals in low microwave frequencies towards the head and capture backscattered signals. The compact and low-profile antenna provides stable directional radiation patterns over the operating bandwidth in both near and far-fields. Numerical analysis of the head imaging system with a realistic head model in various situations is performed to realize the scattering mechanism of haemorrhage. A modified delay-and-summation back-projection algorithm, which includes effects of surface waves and a distance-dependent effective permittivity model, is proposed for signal and image post-processing. The efficacy of the automated head imaging system is evaluated using a 3D-printed human head phantom with frequency dispersive dielectric properties including emulated haemorrhages with different sizes located at different depths. Scattered signals are acquired with a compact transceiver in a mono-static circular scanning profile. The reconstructed images demonstrate that the system is capable of detecting haemorrhages as small as 1 cm³. While quantitative analyses reveal that the quality of images gradually degrades with the increase of the haemorrhage’s depth due to the reduction of signal penetration inside the head; rigorous statistical analysis suggests that substantial improvement in image quality can be obtained by increasing the data samples collected around the head. The proposed head imaging prototype along with the processing algorithm demonstrates its feasibility for potential use in ambulances as an effective and low cost diagnostic tool to assure timely triaging of intracranial hemorrhage patients.

Use of plasma in the management of central nervous system bleeding: evidence-based consensus recommendations

INTRODUCTION

Central nervous system (CNS) hemorrhage is a potentially life-threatening condition, especially in patients with acquired coagulopathy. In this setting, treatment of CNS bleeding includes hemostatic therapy to replenish coagulation factors. There is currently a debate over the hemostatic efficacy of plasma in many clinical settings, alongside increasing concern about transfusion-associated adverse events. Despite these concerns, plasma is widely used. Moreover, plasma transfusion practice is variable and there is currently no uniform approach to treatment of traumatic, surgical or spontaneous CNS hemorrhage. This study addresses the need for guidance on the indications and potential risks of plasma transfusion in these settings. An Expert Consensus Panel was convened to develop recommendations guiding the use of plasma to treat bleeding and/or coagulopathy associated with CNS hemorrhage. The panel did not advise on the best treatment available but rather proposed recommendations to be used in the formulation of local procedures to support emergency physicians in their decision-making process.

METHODS

Evidence was systematically gathered from the literature and rated using methods established by the Scottish Intercollegiate Guidelines Network. The evidence was used to develop graded consensus recommendations, which are presented along with the evidence-based rationale for each in this report.

RESULTS

Sixty-five articles were identified covering both vitamin K antagonist-anticoagulation reversal and treatment of bleeding/coagulopathy in non-anticoagulated patients. Recommendations were then developed in four clinical scenarios within each area, and agreed on unanimously by all members of the panel.

CONCLUSION

The Panel considered plasma to be reasonable therapy for CNS hemorrhage requiring urgent correction of coagulopathy, although physicians should be prepared for potential cardiopulmonary complications, and evidence suggests that alternative therapies have superior risk-benefit profiles. Plasma could not be recommended in the absence of hemorrhage or coagulopathy. Consideration of the absolute risks and benefits of plasma therapy before transfusion is imperative.