Molecular keys to the problems of cerebral vasospasm

A nomogram for predicting the risk of cerebral vasospasm after neurosurgical clipping in patients with aneurysmal subarachnoid hemorrhage

Purpose

Cerebral vasospasm (CVS) is a common complication that occurs after neurosurgical clipping of intracranial aneurysms in patients with aSAH. This complication can lead to clinical deterioration and a poor prognosis. The aim of this study is to explore the risk factors for CVS in aSAH patients who have undergone neurosurgical clipping, develop a nomogram for CVS, and evaluate its performance.

Methods

Patients with aSAH who underwent neurosurgical clipping in the Department of Neurosurgery from January 2018 to January 2023 were selected as the subjects of this research. The clinical data of these patients were retrospectively analyzed. Logistic multivariate regression analysis was employed to identify the independent risk factors of CVS. A clinical prediction model in the form of a nomogram for CVS was developed using the R programming language and subsequently evaluated for its performance and quality.

Results

A total of 156 patients with aSAH were included in the analysis, comprising 109 patients in the training set and 47 patients in the validation set. In the training cohort, 27 patients (24.77%) developed CVS after neurosurgical clipping, while in the validation cohort, 15 patients (31.91%) experienced CVS. Multivariate regression analysis revealed that age, Hcy, WBC, glucose/potassium ratio, aneurysm location, and modified Fisher grade were independent risk factors for CVS. The nomogram exhibited excellent discriminative performance in both the training set (AUC = 0.885) and the validation set (AUC = 0.906).

Conclusion

CVS was a prevalent complication following neurosurgical clipping in patients with aSAH, with a highly intricate pathogenesis and pathophysiological course. Early prediction of CVS represented a significant challenge in clinical practice. In this study, age, Hcy, WBC, glucose/potassium ratio, aneurysm location, and modified Fisher grade emerged as independent risk factors for CVS. The resulting nomogram demonstrated substantial predictive value.

Role of albumin-induced volume expansion therapy for cerebral vasospasm in aneurysmal subarachnoid hemorrhage: A systematic review

Objectives

This study reviews the effect of albumin-induced volume expansion therapy on symptomatic vasospasm and clinical outcome in aneurysmal subarachnoid hemorrhage (aSAH).

Materials and Methods

Computer searches carried out from the Scopus, Medline, Embase, Web of Science, the Cochrane Library, and Internet documents; hand searching of medical journals; and review of reference lists. Randomized controlled trials (RCT) and observational studies (OSs) comparing albumin therapy in combination or alone with crystalloid therapy for the treatment of cerebral vasospasm in aSAH were included in the study. Risk-of-bias assessment was conducted using ROB2.0 and ROBINS-I tools for RCTs and Oss, respectively.

Results

Out of a total of 1078 searches, one RCT (published in two articles) and one observational (retrospective) study were included for final analysis. In RCT, albumin was used for volume expansion therapy with a baseline crystalloid regime and comparison made between hypervolemic and normovolemic groups and it showed no beneficial effects on symptomatic vasospasm and clinical outcomes based on the Glasgow outcome scale. Furthermore, the use of albumin showed a tendency for sodium retention with lowering of glomerular filtration rate, limiting the amount of total fluid required for targeted central venous pressure values, and thereby avoiding fluid overload manifestations. The retrospective study results between albumin versus non-albumin groups (crystalloids only) supported improved outcomes in the former group with lower in-hospital mortality. Cardiorespiratory complications were equivocal in RCT and increased in non-albumin group in the retrospective study. Risk-of-bias assessment analyses revealed "some concerns" in RCT and "serious" limitation in OS due to its retrospective design.

Conclusion

Albumin-induced volume expansion therapy for cerebral vasospasm does not have substantiative evidence to improve cerebral vasospasm and clinical outcomes in aSAH. Studies with well-designed RCTs are required to compare the use of albumin for volume expansion therapy versus standard fluid management using crystalloids to mitigate the scarcity of published data.

Transcatheter Arterial Embolization for Bleeding Related to Pelvic Trauma: Comparison of Technical and Clinical Results between Hemodynamically Stable and Unstable Patients

BACKGROUND

Endovascular intervention is now the primary line of therapy for arterial injury brought on by pelvic trauma since it can significantly reduce considerable morbidity associated with surgery and can swiftly access and control bleeding sites. Despite international guidelines and widespread awareness of the role of angioembolization in clinical practice, robust evidence comparing the outcomes of angioembolization in hemodynamically stable and unstable patients is still lacking. This study aims to directly compare the outcomes of angioembolization for the treatment of pelvic traumatic arterial injury in patients with hemodynamic stability vs. hemodynamic instability.

METHODS

In our multicenter retrospective investigation, we analyzed data from consecutive patients who underwent, from January 2020 to May 2023, angioembolization for traumatic pelvic arterial injury.

RESULTS

In total, 116 angioembolizations were performed. Gelatin sponges (56.9%) and coils (25.9%) were the most widely used embolic agents. The technical and clinical success rates were 100% and 91.4%, respectively. No statistically significant differences were observed between the two groups in terms of technical success, clinical success, procedure-related complication rate, or 30-day bleeding-related mortality.

CONCLUSIONS

Angioembolization is an effective and safe option for the management of traumatic pelvic arterial lesions even in hemodynamically unstable patients, despite technical variations such as greater use of prophylactic angioembolization.

Mechanisms of cerebral vasospasm and cerebral ischaemia in subarachnoid haemorrhage

Subarachnoid haemorrhage (SAH) is a cerebrovascular emergency associated with significant morbidity and mortality. SAH is characterized by heterogeneity, interindividual variation and complexity of pathophysiological responses following extravasation of blood from cerebral circulation. The purpose of this review is to integrate previously established pre-existing factors, pathophysiological pathways and to develop a concept map of mechanisms of SAH-induced cerebral vasospasm and delayed cerebral ischaemia using a systematic approach. We conducted an extensive mapping of a hypothesized sequence of pathophysiological events. Documentation of supporting evidence was done alongside a concept map building. After finalizing the model, we conducted an analysis of the consequences and connections of pathophysiological events. We included the findings of experimental research, focusing on pathophysiological processes. We focused on SAH-induced cerebral vasospasm and delayed cerebral ischaemia as a component of cerebral injury and potential systemic consequences. SAH-induced brain injury occurs within 72 h following haemorrhage. Pathophysiology of cerebral vasospasm may include reduction in NO production, direct activation of calcium channels, upregulating genes involved with inflammation and extracellular matrix remodelling, triggering oxidative stress and free radical damage to smooth muscle and lipid peroxidation of cell membranes, cortical spreading depolarizations, sympathetic activation, finally resulting in the failure of cerebral autoregulation, microthrombosis and cerebral ischaemic injury. This cascade of events might explain why medical therapy often fails to reverse resistant cerebral vasospasm and to prevent cerebral ischaemia.

Inflammatory Response and Immune Regulation in Brain-Heart Interaction after Stroke

Cerebrocardiac syndrome (CCS) is one of the secondary myocardial injuries after stroke. Cerebrocardiac syndrome may result in a poor prognosis with high mortality. Understanding the mechanism of the brain-heart interaction may be crucial for clinical treatment of pathological changes in CCS. Accumulating evidence suggests that the inflammatory response is involved in the brain-heart interaction after stroke. Systemic inflammatory response syndrome (SIRS) evoked by stroke may injure myocardial cells directly, in which the interplay between inflammatory response, oxidative stress, cardiac sympathetic/parasympathetic dysfunction, and splenic immunoregulation may be also the key pathophysiology factor. This review article summarizes the current understanding of inflammatory response and immune regulation in brain-heart interaction after stroke.

Cannabidiol’s Multifactorial Mechanisms Has Therapeutic Potential for Aneurysmal Subarachnoid Hemorrhage: a Review

Subarachnoid hemorrhage (SAH) is a major health burden that accounts for approximately 5% of all strokes. The most common cause of a non-traumatic SAH is the rupture of a cerebral aneurysm. The most common symptom associated with SAH is a headache, often described as “the worst headache of my life.” Delayed cerebral ischemia (DCI) is a major factor associated with patient mortality following SAH and is often associated with SAH-induced cerebral vasospasm (CV). Cannabidiol (CBD) is emerging as a potential drug for many therapeutic purposes, including epilepsy, anxiety, and pain relief. We aim to review the potential use of CBD as a treatment option for post-SAH critically ill patients. Through a literature review, we evaluated the known pharmacology and physiological effects of CBD and correlated those with the pathophysiological outcomes associated with cerebral vasospasm following subarachnoid hemorrhage. Although overlap exists, data were formatted into three major categories: anti-inflammatory, vascular, and neuroprotective effects. Based on the amount of information known about the actions of CBD, we hypothesize the anti-inflammatory effects are likely to be the most promising therapeutic mechanism. However, its cardiovascular effects through calcium regulation and its neuroprotective effects against cell death, excitotoxicity, and oxidative stress are all plausible mechanisms by which post-SAH critically ill patients may benefit from both early and late intervention with CBD. More research is needed to better understand if and how CBD might affect neurological and vascular functions in the brain following injury such as subarachnoid hemorrhage.

Extravasation and outcomes in computed tomography and angiography in patients with pelvic fractures requiring transcatheter arterial embolization: A single-center observational study

BACKGROUND

Extravasation on contrast-enhanced computed tomography (CECT) is a helpful indicator of the need for transcatheter arterial embolization (TAE) for pelvic fractures. However, previous reports were inconsistent on cases in which angiography is necessary, even though there is no extravasation on computed tomography. This study aimed to describe and analyze the contradictory findings in cases where extravasation is observed on angiography but not on CECT, to contribute to improved management of patients with pelvic fractures.

METHODS

This was a retrospective single-center study. Patients with pelvic fractures who underwent CECT and TAE between 2014 and 2020 were included. We classified the patients into three groups: CECT and angiography with extravasation (CT+Angio+), CECT with no extravasation and angiography with extravasation (CT-Angio+), and CECT with extravasation and angiography without extravasation (CT+Angio-).

RESULTS

A total of 113 patients were included in the study: the CT+Angio+ group had 54 patients, CT-Angio+ group, 47; and CT+Angio- group, 12. The CT-Angio+ group had a significantly longer time from arrival to CECT than the CT+Angio+ group (27 minutes vs. 23 minutes, p < 0.05). The CT-Angio+ group had significantly more blood transfusions (fresh frozen plasma, platelets) within 24 hours than the CT+Angio- group did (p < 0.05), and ventilator management days (p < 0.05) and intensive care unit stays (p < 0.05) were significantly longer.

CONCLUSION

There was no significant difference in outcomes among the three groups. There was no difference in severity, transfusion volume, or mortality in patients with pelvic fractures needing TAE, classified as CT-Angio+, compared with that of CT+Angio+ patients. Even in the absence of extravasation in the pelvic region on CECT, angiography or TAE may still be necessary.

LEVEL OF EVIDENCE

Therapeutic/Care Management, Level IV.

Proposal of standardization of every step of angiographic procedure in bleeding patients from pelvic trauma

Trauma accounts for a third of the deaths in Western countries, exceeded only by cardiovascular disease and cancer. The high risk of massive bleeding, which depends not only on the type of fractures, but also on the severity of any associated parenchymal injuries, makes pelvic fractures one of the most life-threatening skeletal injuries, with a high mortality rate. Therefore, pelvic trauma represents an important condition to correctly and early recognize, manage, and treat. For this reason, a multidisciplinary approach involving trauma surgeons, orthopedic surgeons, emergency room physicians and interventional radiologists is needed to promptly manage the resuscitation of pelvic trauma patients and ensure the best outcomes, both in terms of time and costs. Over the years, the role of interventional radiology in the management of patient bleeding due to pelvic trauma has been increasing. However, the current guidelines on the management of these patients do not adequately reflect or address the varied nature of injuries faced by the interventional radiologist. In fact, in the therapeutic algorithm of these patients, after the word “ANGIO”, there are no reports on the different possibilities that an interventional radiologist has to face during the procedure. Furthermore, variations exist in the techniques and materials for performing angioembolization in bleeding patients with pelvic trauma. Due to these differences, the outcomes differ among different published series. This article has the aim to review the recent literature on optimal imaging assessment and management of pelvic trauma, defining the role of the interventional radiologist within the multidisciplinary team, suggesting the introduction of common and unequivocal terminology in every step of the angiographic procedure. Moreover, according to these suggestions, the present paper tries to expand the previously drafted algorithm exploring the role of the interventional radiologist in pelvic trauma, especially given the multidisciplinary setting.

Repeat Catheter Angiography in Patients with Aneurysmal-Pattern Angiographically Negative Subarachnoid Hemorrhage

BACKGROUND

A significant proportion of patients with subarachnoid hemorrhage have a normal cerebral angiogram. Patients with angiographically negative subarachnoid hemorrhage (anSAH) with either perimesencephalic- (panSAH) or aneurysmal-pattern hemorrhage (aanSAH, also known as diffuse anSAH) have an excellent prognosis, but only if underlying vascular abnormalities are completely excluded. The rate of occult aneurysms in patients with aanSAH varies widely across studies. The purpose of this study was to quantify the value of repeat DSA in these patients.

METHODS

We reviewed the records of all patients initially diagnosed with aanSAH after a screening DSA at a single tertiary neurovascular referral center from January 2006-April 2018. Patients with panSAH and traumatic SAH were excluded. We also performed a systematic review and meta-analysis of positive second DSAs in previously published case series of patients with aanSAH who underwent two serial DSAs. For meta-analysis, PubMed Central, MEDLINE and Cochrane Library databases were searched for pertinent studies up to November 2019. The rate of aneurysm detection on repeat angiography was extracted from each study. Pooled rates for positive second angiogram were calculated as untransformed proportions in a binary random-effects model meta-analysis. Inter-study heterogeneity was calculated using an I² statistic.

RESULTS

Three of 27 patients (11.1%) with aanSAH and at least two DSAs were subsequently found to have a cerebral aneurysm in our institutional dataset. Twenty-six studies in our systematic review met inclusion criteria, and the pooled rate of positive second angiogram was 10.4% (95% CI 7.3%-13.5%, P < 0.001). Substantial inter-study heterogeneity was observed in the meta-analysis (I² = 61.7%, P < 0.001).

CONCLUSIONS

One in 10 patients with aanSAH has an occult ruptured aneurysm. A second-look DSA should be strongly considered in these cases.

Fluid metabolic pathways after subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating cerebrovascular disease with high mortality and morbidity. In recent years, a large number of studies have focused on the mechanism of early brain injury (EBI) and delayed cerebral ischemia (DCI), including vasospasm, neurotoxicity of hematoma and neuroinflammatory storm, after aSAH. Despite considerable efforts, no novel drugs have significantly improved the prognosis of patients in phase III clinical trials, indicating the need to further re-examine the multifactorial pathophysiological process that occurs after aSAH. The complex pathogenesis is reflected by the destruction of the dynamic balance of the energy metabolism in the nervous system after aSAH, which prevents the maintenance of normal neural function. This review focuses on the fluid metabolic pathways of the central nervous system (CNS), starting with ruptured aneurysms, and discusses the dysfunction of blood circulation, cerebrospinal fluid (CSF) circulation and the glymphatic system during disease progression. It also proposes a hypothesis on the metabolic disorder mechanism and potential therapeutic targets for aSAH patients.

Stoichiometric Analysis of Shifting in Subcellular Compartmentalization of HSP70 within Ischemic Penumbra

The heat shock protein (HSP) 70 is considered the main hallmark in preclinical studies to stain the peri-infarct region defined area penumbra in preclinical models of brain ischemia. This protein is also considered as a potential disease modifier, which may improve the outcome of ischemic damage. In fact, the molecule HSP70 acts as a chaperonine being able to impact at several level the homeostasis of neurons. Despite being used routinely to stain area penumbra in light microscopy, the subcellular placement of this protein within area penumbra neurons, to our knowledge, remains undefined. This is key mostly when considering studies aimed at deciphering the functional role of this protein as a determinant of neuronal survival. The general subcellular placement of HSP70 was grossly reported in studies using confocal microscopy, although no direct visualization of this molecule at electron microscopy was carried out. The present study aims to provide a direct evidence of HSP70 within various subcellular compartments. In detail, by using ultrastructural morphometry to quantify HSP70 stoichiometrically detected by immuno-gold within specific organelles we could compare the compartmentalization of the molecule within area penumbra compared with control brain areas. The study indicates that two cell compartments in control conditions own a high density of HSP70, cytosolic vacuoles and mitochondria. In these organelles, HSP70 is present in amount exceeding several-fold the presence in the cytosol. Remarkably, within area penumbra a loss of such a specific polarization is documented. This leads to the depletion of HSP70 from mitochondria and mostly cell vacuoles. Such an effect is expected to lead to significant variations in the ability of HSP70 to exert its physiological roles. The present findings, beyond defining the neuronal compartmentalization of HSP70 within area penumbra may lead to a better comprehension of its beneficial/detrimental role in promoting neuronal survival.

Neuroprotective Strategies in Aneurysmal Subarachnoid Hemorrhage (aSAH)

Aneurysmal subarachnoid hemorrhage (aSAH) remains a disease with high mortality and morbidity. Since treating vasospasm has not inevitably led to an improvement in outcome, the actual emphasis is on finding neuroprotective therapies in the early phase following aSAH to prevent secondary brain injury in the later phase of disease. Within the early phase, neuroinflammation, thromboinflammation, disturbances in brain metabolism and early neuroprotective therapies directed against delayed cerebral ischemia (DCI) came into focus. Herein, the role of neuroinflammation, thromboinflammation and metabolism in aSAH is depicted. Potential neuroprotective strategies regarding neuroinflammation target microglia activation, metalloproteases, autophagy and the pathway via Toll-like receptor 4 (TLR4), high mobility group box 1 (HMGB1), NF-κB and finally the release of cytokines like TNFα or IL-1. Following the link to thromboinflammation, potential neuroprotective therapies try to target microthrombus formation, platelets and platelet receptors as well as clot clearance and immune cell infiltration. Potential neuroprotective strategies regarding metabolism try to re-balance the mismatch of energy need and supply following aSAH, for example, in restoring fuel to the TCA cycle or bypassing distinct energy pathways. Overall, this review addresses current neuroprotective strategies in aSAH, hopefully leading to future translational therapy options to prevent secondary brain injury.

A Highly Predictive MicroRNA Panel for Determining Delayed Cerebral Vasospasm Risk Following Aneurysmal Subarachnoid Hemorrhage

Approximately one-third of aneurysmal subarachnoid hemorrhage (aSAH) patients develop delayed cerebral vasospasm (DCV) 3-10 days after aneurysm rupture resulting in additional, permanent neurologic disability. Currently, no validated biomarker is available to determine the risk of DCV in aSAH patients. MicroRNAs (miRNAs) have been implicated in virtually all human diseases, including aSAH, and are found in extracellular biofluids including plasma and cerebrospinal fluid (CSF). We used a custom designed TaqMan Low Density Array miRNA panel to examine the levels of 47 selected brain and vasculature injury related miRNAs in CSF and plasma specimens collected from 31 patients with or without DCV at 3 and 7 days after aSAH, as well as from eight healthy controls. The analysis of the first 18-patient cohort revealed a striking differential expression pattern of the selected miRNAs in CSF and plasma of aSAH patients with DCV from those without DCV. Importantly, this differential expression was observed at the early time point (3 days after aSAH), before DCV event occurs. Seven miRNAs were identified as reliable DCV risk predictors along with a prediction model constructed based on an array of additional 19 miRNAs on the panel. These chosen miRNAs were then used to predict the risk of DCV in a separate, testing cohort of 15 patients. The accuracy of DCV risk prediction in the testing cohort reached 87%. The study demonstrates that our novel designed miRNA panel is an effective predictor of DCV risk and has strong applications in clinical management of aSAH patients.

Vasorelaxing cell permeant phosphopeptide mimetics for subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) due to rupture of an intracranial aneurysm leads to vasospasm resulting in delayed cerebral ischemia. Therapeutic options are currently limited to hemodynamic optimization and nimodipine, which have marginal clinical efficacy. Nitric oxide (NO) modulates cerebral blood flow through activation of the cGMP-Protein Kinase G (PKG) pathway. Our hypothesis is that SAH results in downregulation of signaling components in the NO-PKG pathway which could explain why treatments for vasospasm targeting this pathway lack efficacy and that treatment with a cell permeant phosphopeptide mimetic of downstream effector prevents delayed vasospasm after SAH. Using a rat endovascular perforation model, reduced levels of NO-PKG pathway molecules were confirmed. Additionally, it was determined that expression and phosphorylation of a PKG substrate: Vasodilator-stimulated phosphoprotein (VASP) was downregulated. A family of cell permeant phosphomimetic of VASP (VP) was wasdesigned and shown to have vasorelaxing property that is synergistic with nimodipine in intact vascular tissuesex vivo. Hence, treatment targeting the downstream effector of the NO signaling pathway, VASP, may bypass receptors and signaling elements leading to vasorelaxation and that treatment with VP can be explored as a therapeutic strategy for SAH induced vasospasm and ameliorate neurological deficits.

Unstable Hemodynamics is not Always Predictive of Failed Nonoperative Management in Blunt Splenic Injury

BACKGROUND

The advanced technology of interventional radiology may contribute to a rapid and timely angioembolization for hemostasis. We hypothesized that unstable hemodynamics is no longer an absolute contraindication of nonoperative management (NOM) in blunt splenic injury patients using rapid angioembolization.

METHODS

From January 2009 to December 2019, blunt splenic injury patients with unstable hemodynamics [initial pulse >120 beats/min or systolic blood pressure <90 mm Hg] were included. Either emergency surgery or angioembolization was performed for hemostasis because of their unstable status. The characteristics of patients who underwent angioembolization or surgery were compared in each group (all patients, patients with hypotension, patients without response to resuscitation and hypotensive patients without response to resuscitation).

RESULTS

A total of 73 patients were included in the current study. With respect to all patients, 68.5% (N = 50) of patients underwent NOM with angioembolization for hemostasis. Patients who underwent angioembolization for hemostasis had a significantly lower base deficit (5.3 ± 3.8 vs. 8.3 ± 5.2 mmol/L, p = 0.006) and a higher proportion of response to resuscitation (82.0% vs. 30.4%, p < 0.001) than did patients who underwent surgery. However, there was no significant difference in the proportion of hypotension (58.0% vs. 65.2%, p = 0.558) between these two groups. There were 44 patients with hypotension, and the angioembolization could be performed in 65.9% (N = 29) of them. Patients who underwent angioembolization had a significantly higher proportion of response to resuscitation than did patients who underwent surgery (89.7% vs. 33.3%, p < 0.001). In hypotensive patients without response to resuscitation (N = 13), 23.1% (N = 3) of the patients underwent angioembolization successfully. There was no significant difference in time to hemostasis procedure between patients who underwent angioembolization or surgery (24.7 ± 2.1 vs. 26.3 ± 16.7 min, p = 0.769). The demographics, vital signs, blood transfusion amount, injury severity, mortality rate and length of stay of patients who underwent angioembolization were not significantly different from patients who underwent surgery in each group.

CONCLUSIONS

With a short preparation time of angioembolization, the NOM could be performed selectively for hemodynamically unstable patients with blunt splenic injury. The base deficit serves as an early detector of the requirement of surgical treatment.

Bibliometric Analysis of the Top 100 Most Cited Articles on Cerebral Vasospasm

OBJECTIVE

Bibliometric analysis reflects the scientific recognition and influential performance of a published article within its field. Our aim is to identify and analyze the top 100 most-cited articles on cerebral vasospasm.

METHODS

A title-specific search was carried out using the Scopus database. The top 100 cited articles including the keywords "Cerebral Vasospasm" AND "Vasospasm" were retrieved and stratified in a descending order: title, authors, institution, publishing journal, country of origin, year of publication, and topic of each article were studied.

RESULTS

The top 100 articles have an accumulative citation count of 20,972, with 209 average citations per article. Publication dates ranged from 1968 to 2012, with the most productive years between 1998 and 2005. Clinical studies are the most frequent category, followed by pathophysiology. The list includes 7 clinical trials, which received accumulative citations of 1525. The top cited article had received 2109 citations, with 52.7 citations per year. The top 100 articles were published across 14 countries, with most originating from the United States. The lead research institution was the University of Alberta. The most used journal was Journal of Neurosurgery.

CONCLUSIONS

Bibliometric analysis has garnered major interest in recent years. It shows the publication trends, knowledge evolution, and evidence-based practice throughout the years. The collection of highly cited articles may assist physicians in gaining a better understanding of the nature of cerebral vasospasm and optimize their clinical practice.

Inflammatory Pathways Following Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is an acute cerebrovascular emergency resulting from the rupture of a brain aneurysm. Despite only accounting for 5% of all strokes, SAH imposes a significant health burden on society due to its relatively young age at onset. Those who survive the initial bleed are often afflicted with severe disabilities thought to result from delayed cerebral ischemia (DCI). Consequently, elucidating the underlying mechanistic pathways implicated in DCI development following SAH remains a priority. Neuroinflammation has recently been implicated as a promising new theory for the development of SAH complications. However, despite this interest, clinical trials have failed to provide consistent evidence for the use of anti-inflammatory agents in SAH patients. This may be explained by the complexity of SAH as a plethora of inflammatory pathways have been shown to be activated in the disease. By determining how these pathways may overlap and interact, we hope to better understand the developmental processes of SAH complications and how to prevent them. The goal of this review is to provide insight into the available evidence regarding the molecular pathways involved in the development of inflammation following SAH and how SAH complications may arise as a result of these inflammatory pathways.

The role and therapeutic potential of heat shock proteins in haemorrhagic stroke

Heat shock proteins (HSPs) are induced after haemorrhagic stroke, which includes subarachnoid haemorrhage (SAH) and intracerebral haemorrhage (ICH). Most of these proteins function as neuroprotective molecules to protect cerebral neurons from haemorrhagic stroke and as markers to indicate cellular stress or damage. The most widely studied HSPs in SAH are HSP70, haeme oxygenase-1 (HO-1), HSP20 and HSP27. The subsequent pathophysiological changes following SAH can be divided into two stages: early brain injury and delayed cerebral ischaemia, both of which determine the outcome for patients. Because the mechanisms of HSPs in SAH are being revealed and experimental models in animals are continually maturing, new agents targeting HSPs with limited side effects have been suggested to provide therapeutic potential. For instance, some pharmaceutical agents can block neuronal apoptosis signals or dilate cerebral vessels by modulating HSPs. HO-1 and HSP70 are also critical topics for ICH research, which can be attributed to their involvement in pathophysiological mechanisms and therapeutic potential. However, the process of HO-1 metabolism can be toxic owing to iron overload and the activation of succedent pathways, for example, the Fenton reaction and oxidative damage; the overall effect of HO-1 in SAH and ICH tends to be protective and harmful, respectively, given the different pathophysiological changes in these two types of haemorrhagic stroke. In the present study, we focus on the current understanding of the role and therapeutic potential of HSPs involved in haemorrhagic stroke. Therefore, HSPs may be potential therapeutic targets, and new agents targeting HSPs are warranted.

KV channel trafficking and control of vascular tone

Membrane potential is a principal regulator of arterial contractility. Arterial smooth muscle cells express several different types of ion channel that control membrane potential, including K_V channels. K_V channel activation leads to membrane hyperpolarization, resulting in inhibition of voltage-dependent Ca²⁺ channels, a reduction in [Ca²⁺ ]_i , and vasodilation. In contrast, K_V channel inhibition leads to membrane depolarization and vasoconstriction. The ability of K_V channels to regulate arterial contractility is dependent upon the number of plasma membrane-resident channels and their open probability. Here, we will discuss mechanisms that alter the surface abundance of K_V channel proteins in arterial smooth muscle cells and the functional consequences of such regulation. Cellular processes that will be described include those that modulate K_V channel transcription, retrograde and anterograde trafficking, and protein degradation.

Trans-arterial embolisation (TAE) in haemorrhagic pelvic injury: review of management and mid-term outcome of a major trauma centre

BACKGROUND

Management of pelvic fracture associated haemorrhage is often complex with high morbidity and mortality rates. Different treatment options are used to control bleeding with an on-going discussion in the trauma community regarding the best management algorithm.

MAIN BODY

Recent studies have shown trans-arterial embolisation (TAE) to be a safe and effective technique to control pelvic fracture associated haemorrhage. Computed tomography (CT) evidence of active bleeding, haemodynamic instability, and pelvic fracture patterns are amongst important indicators for TAE.

CONCLUSION

Herein, we aim to provide a comprehensive literature review of the effectiveness of TAE in controlling haemorrhage secondary to pelvic fracture according to the indications, technique and embolic agents, and outcomes, whilst incorporating our Level 1 major trauma centre's (MTC) results between 2014-2017.

Unique Contribution of Haptoglobin and Haptoglobin Genotype in Aneurysmal Subarachnoid Hemorrhage

Survivors of cerebral aneurysm rupture are at risk for significant morbidity and neurological deficits. Much of this is related to the effects of blood in the subarachnoid space which induces an inflammatory cascade with numerous downstream consequences. Recent clinical trials have not been able to reduce the toxic effects of free hemoglobin or improve clinical outcome. One reason for this may be the inability to identify patients at high risk for neurologic decline. Recently, haptoglobin genotype has been identified as a pertinent factor in diabetes, sickle cell, and cardiovascular disease, with the Hp 2-2 genotype contributing to increased complications. Haptoglobin is a protein synthesized by the liver that binds free hemoglobin following red blood cell lysis, and in doing so, prevents hemoglobin induced toxicity and facilitates clearance. Clinical studies in patients with subarachnoid hemorrhage indicate that Hp 2-2 patients may be a high-risk group for hemorrhage related complications and poor outcome. We review the relevance of haptoglobin in subarachnoid hemorrhage and discuss the effects of genotype and expression levels on the known mechanisms of early brain injury (EBI) and cerebral ischemia after aneurysm rupture. A better understanding of haptoglobin and its role in preventing hemoglobin related toxicity should lead to novel therapeutic avenues.

Spinal dural arteriovenous fistula presenting with subarachnoid hemorrhage: A case report

RATIONALE

Subarachnoid hemorrhage (SAH) is a common and serious disease and one of the most important differential diagnoses in the emergency department.

PATIENT CONCERNS

A 39-year-old female patient with a 12 years' history of migraine, presented with a sudden headache combined with motor aphasia. Physical examination suggested probable positive neck resistance. SAH was confirmed by magnetic resonance imaging. In addition, spinal digital subtraction angiography and spinal vascular computed tomography angiography indicated spinal arteriovenous malformation (SAVM).

DIAGNOSES

The final diagnosis was spinal dural arteriovenous fistula presenting with SAH.

INTERVENTIONS

Following diagnosis, appropriate drugs were administered, but the therapeutic effect was poor. Then the patient was then transferred to a superior hospital where she was treated with interventional embolization.

OUTCOMES

Through 2 years of follow-up, intermittent migraine was found in the patient, but the symptoms of occipital pain, nausea, and vomiting did not occur again.

LESSONS

For patients who have been diagnosed with SAH but have no definite cause, we should pay attention to the etiological screening of SAH, and the possibility of the spinal cord SAH should be vigilant. The pain in the chest and back and the signs of spinal cord may be an important breakthrough in patients with spinal cord SAH, and medical history and physical examination are particularly important.

Deep brain stimulation could cause delayed and recurrent cerebral ischemia: a case report

A 40-year-old male who had a severe tremor, bradykinesia, and rigidity for 6 years underwent bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) at our hospital. The patient did not have any prior ischemia events or any risk factors in his medical history. Six and 9 months post-operation, this patient was admitted to the hospital twice for lower left limb involuntary twitching. Two magnetic resonance imaging (MRI) scans showed cerebral ischemia surrounding the implanted electrode. To our knowledge, this is the first case of recurrent cerebral ischemia associated with DBS. Reports in the literature of cerebral ischemia associated with DBS were reviewed, and the mechanism was discussed.

The Role of Omega-3 Polyunsaturated Fatty Acids in Stroke

Stroke is the third commonest cause of death following cardiovascular diseases and cancer. In particular, in recent years, the morbidity and mortality of stroke keep remarkable growing. However, stroke still captures people attention far less than cardiovascular diseases and cancer. Past studies have shown that oxidative stress and inflammation play crucial roles in the progress of cerebral injury induced by stroke. Evidence is accumulating that the dietary supplementation of fish oil exhibits beneficial effects on several diseases, such as cardiovascular diseases, metabolic diseases, and cancer. Omega-3 polyunsaturated fatty acids (n-3 PUFAs), the major component of fish oil, have been found against oxidative stress and inflammation in cardiovascular diseases. And the potential of n-3 PUFAs in stroke treatment is attracting more and more attention. In this review, we will review the effects of n-3 PUFAs on stroke and mainly focus on the antioxidant and anti-inflammatory effects of n-3 PUFAs.

The Risks of Sumatriptan Administration in Patients with Unrecognized Subarachnoid Haemorrhage (SAH)

Administration of sumatriptan in subarachnoid haemorrhage (SAH) patients, misdiagnosed as migraine patients, may induce symptomatic cerebral vasospasm with potentially dangerous consequences. Over a 5-year period, we observed three patients with a 3-15-year history of migraine, who received sumatriptan for acute headache. Two patients received 6 mg sumatriptan subcutaneously on days 4 and 6, and one patient 3 x 100 mg sumatriptan orally on day 1 after an acute headache episode. In all three cases, an alleviation of headache intensity from severe to moderate was observed. When headache recurred and meningeal signs appeared, SAH was diagnosed by computed tomography in all three cases. No neurological deficits occurred during the further course of the disease. In both patients with a SAH caused by an aneurysm, transcranial Doppler sonography demonstrated vasospasm of the basal cerebral arteries. An antinociceptive effect of sumatriptan can be observed in SAH patients in good clinical condition, which suggests a specific craniovascular antinociceptive action. This may lead to mis- diagnosis as migraine and delayed appropriate diagnosis and treatment.

Aneurysmal Subarachnoid Hemorrhage and Neuroinflammation: A Comprehensive Review

Aneurysmal subarachnoid hemorrhage (SAH) can lead to devastating outcomes including vasospasm, cognitive decline, and even death. Currently, treatment options are limited for this potentially life threatening injury. Recent evidence suggests that neuroinflammation plays a critical role in injury expansion and brain damage. Red blood cell breakdown products can lead to the release of inflammatory cytokines that trigger vasospasm and tissue injury. Preclinical models have been used successfully to improve understanding about neuroinflammation following aneurysmal rupture. The focus of this review is to provide an overview of how neuroinflammation relates to secondary outcomes such as vasospasm after aneurysmal rupture and to critically discuss pharmaceutical agents that warrant further investigation for the treatment of subarachnoid hemorrhage. We provide a concise overview of the neuroinflammatory pathways that are upregulated following aneurysmal rupture and how these pathways correlate to long-term outcomes. Treatment of aneurysm rupture is limited and few pharmaceutical drugs are available. Through improved understanding of biochemical mechanisms of injury, novel treatment solutions are being developed that target neuroinflammation. In the final sections of this review, we highlight a few of these novel treatment approaches and emphasize why targeting neuroinflammation following aneurysmal subarachnoid hemorrhage may improve patient care. We encourage ongoing research into the pathophysiology of aneurysmal subarachnoid hemorrhage, especially in regards to neuroinflammatory cascades and the translation to randomized clinical trials.

Endovascular Perforation Murine Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a subtype of stroke with disastrous outcomes of high disability and mortality. A variety of endeavors have been developed to explore a SAH animal model for investigation of the disease. Among these models, the endovascular perforation SAH model was considered to be the most simulative to the clinical human SAH because it reproduces several pathophysiology procedures and presents some of the most important post-hemorrhage features. An applicable SAH animal model should have the characteristics of low mortality rate, limited surgical manipulation, and adaptation to many species, which permits reproducibility and standardization. An intensive discussion of how to improve the techniques and refine the procedure has taken place in the last decade. This report describes our experiences with a murine model of SAH. We aim to standardize and optimize the procedures to establish a relatively stable animal model for SAH research.

Signaling Pathway in Cerebral Vasospasm After Subarachnoid Hemorrhage: News Update

Subarachnoid hemorrhage (SAH) caused by ruptured intracranial aneurysms is a serious threat to human health and life. Although advances in surgical and anesthetic techniques have improved the prognosis of patients with aneurysms, the rate of death and disability caused by SAH remains high, predominantly due to cerebral vasospasm (CVS) after SAH and early brain damage. In particular, CVS is a common complication after SAH. However, its pathogenesis has not yet been fully elucidated, and clinically effective prevention and treatment measures are still lacking. Spasm of blood vessels can decrease cerebral blood flow, leading to ischemia and hypoxia in brain tissues and ultimately severe neurological dysfunction. Currently, there is no comprehensive theory that can fully explain the mechanisms underlying SAH-caused CVS. However, studies on signal transduction, apoptosis, and glial cell-mediated mechanisms in recent years have shed new light on the treatment of CVS.

Mechanisms of magnesium-induced vasodilation in cerebral penetrating arterioles

We investigated in cerebral penetrating arterioles the signaling mechanisms and dose-dependency of extracellular magnesium-induced vasodilation and also its vasodilatory effects in vessels preconstricted with agonists associated with delayed cerebral vasospasm following SAH. Male rat penetrating arterioles were cannulated. Their internal diameters were monitored. To investigate mechanisms of magnesium-induced vasodilation, inhibitors of endothelial function, potassium channels and endothelial impairment were tested. To simulate cerebral vasospasm we applied several spasmogenic agonists. Increased extracellular magnesium concentration produced concentration-dependent vasodilation, which was partially attenuated by non-specific calcium-sensitive potassium channel inhibitor tetraethylammonium, but not by other potassium channel inhibitors. Neither the nitric oxide synthase inhibitor L-NNA nor endothelial impairment induced by air embolism reduced the dilation. Although the magnesium-induced vasodilation was slightly attenuated by the spasmogen ET-1, neither application of PF2α nor TXA2 analog effect the vasodilation. Magnesium induced a concentration- and smooth muscle cell-dependent dilation in cerebral penetrating arterioles. Calcium-sensitive potassium channels of smooth muscle cells may play a key role in magnesium-induced vasodilation. Magnesium also dilated endothelium-impaired vessels as well as vessels preconstricted with spasmogenic agonists. These results provide a fundamental background for the clinical use of magnesium, especially in treatment against delayed cerebral ischemia or vasospasm following SAH.

Effects of Clot Removal by Meticulous Irrigation and Continuous Low-Dose Intravenous Nicardipine on Symptomatic Cerebral Vasospasm in Patients with Aneurysmal Subarachnoid Hemorrhage Treated by Clipping

BACKGROUND

Symptomatic cerebral vasospasm (SCV) is the second most common of morbidity and mortality in aneurysmal subarachnoid hemorrhage (aSAH) after rebleeding. Blood breakdown products are one of the leading causes of vasospasm. We hypothesized that meticulous subarachnoid clot removal in addition to continuous low-dose intravenous nicardipine (CLIN) could reduce the incidence of SCV.

METHODS

SCV was defined as new focal neurologic signs, consciousness deterioration, or both when the cause was believed to be ischemia attributable to vasospasm after other possible causes of worsening were excluded. Initial brain damage was defined as continued consciousness disturbance after clipping without acute hydrocephalus, ischemic lesions, or focal sign before clipping. Poor outcome was defined as a Glasgow Outcome Scale score of 3-5 at 30 days. We compared the variables for 460 aSAH patients with and without SCV, and with and without poor outcome by multivariate analysis.

RESULTS

All patients underwent clipping with meticulous irrigation for clot removal, and SCV was observed in 56 patients (12%). SCV was observed in 2 patients (2.9%) among 70 patients treated with CLIN. There was a higher proportion of patients who were older than 65 years (P = 0.032) and female (P = 0.038), and a lower proportion of patients with CLIN (P = 0.026) among patients with SCV. The outcomes for 109 patients (27%) were poor; age greater than 65 years (P < 0.0001) and initial brain damage (P = 0.008) were related to the poor outcomes.

CONCLUSIONS

The present study showed that meticulous irrigation for clot removal and CLIN might reduce the incidence of SCV in patients with aSAH.

The effectiveness of lumbar cerebrospinal fluid drainage to reduce the cerebral vasospasm after surgical clipping for aneurysmal subarachnoid hemorrhage

Objective

Removal of blood from subarachnoid space with a lumbar drainage (LD) may decrease development of cerebral vasospasm. We evaluated the effectiveness of a LD for a clinical vasospasm and outcomes after clipping of aneurysmal subarachnoid hemorrhage (SAH).

Methods

Between July 2008 and July 2013, 234 patients were included in this study. The LD group consisted of 126 patients, 108 patients in the non LD group. We investigated outcomes as follow : 1) clinical vasospasm, 2) angioplasty, 3) cerebral infarction, 4) Glasgow outcome scale (GOS) score at discharge, 5) GOS score at 6-month follow-up, and 6) mortality.

Results

Clinical vasospasm occurred in 19% of the LD group and 42% of the non LD group (p<0.001). Angioplasty was performed in 17% of the LD group and 38% of the non LD group (p=0.001). Cerebral infarctions were detected in 29% and 54% of each group respectively (p<0.001). The proportion of GOS score 5 at 6 month follow-up in the LD group was 69%, and it was 58% in the non LD group (p=0.001). Mortality rate showed 5% and 10% in each group respectively. But, there was no difference in shunt between the two groups.

Conclusion

LD after aneurysmal SAH shows marked reduction of clinical vasospasm and need for angioplasty. With this technique we have shown favorable GOS score at 6 month follow-up.

Cerebrospinal fluid from patients with subarachnoid haemorrhage and vasospasm enhances endothelin contraction in rat cerebral arteries

INTRODUCTION

Previous studies have suggested that cerebrospinal fluid from patients with subarachnoid hemorrhage (SAH) leads to pronounced vasoconstriction in isolated arteries. We hypothesized that only cerebrospinal fluid from SAH patients with vasospasm would produce an enhanced contractile response to endothelin-1 in rat cerebral arteries, involving both endothelin ETA and ETB receptors.

METHODS

Intact rat basilar arteries were incubated for 24 hours with cerebrospinal fluid from 1) SAH patients with vasospasm, 2) SAH patients without vasospasm, and 3) control patients. Arterial segments with and without endothelium were mounted in myographs and concentration-response curves for endothelin-1 were constructed in the absence and presence of selective and combined ETA and ETB receptor antagonists. Endothelin concentrations in culture medium and receptor expression were measured.

RESULTS

Compared to the other groups, the following was observed in arteries exposed to cerebrospinal fluid from patients with vasospasm: 1) larger contractions at lower endothelin concentrations (p<0.05); 2) the increased endothelin contraction was absent in arteries without endothelium; 3) higher levels of endothelin secretion in the culture medium (p<0.05); 4) there was expression of ETA receptors and new expression of ETB receptors was apparent; 5) reduction in the enhanced response to endothelin after ETB blockade in the low range and after ETA blockade in the high range of endothelin concentrations; 6) after combined ETA and ETB blockade a complete inhibition of endothelin contraction was observed.

CONCLUSIONS

Our experimental findings showed that in intact rat basilar arteries exposed to cerebrospinal fluid from patients with vasospasm endothelin contraction was enhanced in an endothelium-dependent manner and was blocked by combined ETA and ETB receptor antagonism. Therefore we suggest that combined blockade of both receptors may play a role in counteracting vasospasm in patients with SAH.

Proximal arterial diameters on CT angiography and digital subtraction angiography correlate both at admission and in the vasospasm period after aneurysmal subarachnoid hemorrhage

BACKGROUND

Comparison of artery diameters between CT angiography (CTA) and subtraction arteriography (DSA) has the limitation that measurements on DSA are provided as relative units, making a quantitative comparison difficult. On CTA, artery diameters may depend on windowing settings and may lead to false measurements. This study assesses the correlation between CTA and DSA based on measurements in a basic imaging viewer using normalized DSA values, and assesses whether the validity is time dependent.

METHODS

Patients with aneurysmal subarachnoid hemorrhage (aSAH) were included if they underwent both CTA and DSA within 24 h. The analysis was performed using the basic imaging application Centricity Enterprise PACS viewer (GE Healthcare). A total of 15 arterial locations were assessed on CTA and DSA and a specific measurement protocol with normalization of all artery diameters to the cavernous segment of the internal carotid artery was used. Pearson correlation analysis was calculated to access the correlation of normalized arterial diameters measured with both methods at admission and at clinical onset of CVS.

RESULTS

A total of 627 arteries in 38 patients were analyzed in both CTA and DSA. There was a significant correlation coefficient (R = 0.706) of artery diameters between CTA and DSA measures (p < 0.0001). This correlation remained high when comparing CTA and DSA at admission (correlation coefficient: 0.641; p < 0.0001) vs. in the vasospasm period (0.835; p < 0.0001). The correlation was good in all proximal artery segments and lost significance only when distal vessel segments were considered.

CONCLUSION

Using basic imaging viewers, mostly accessible for clinicians, CTA is a noninvasive and reliable method to assess proximal arterial diameters of the brain in the management of cerebral vasospasm in the acute phase after aSAH. Significance is reached, independent of whether CTA is obtained in the acute phase or during the period of vasospasm, by normalization of basal cerebral artery diameters to a non-variable anatomic landmark, i.e., the petrous or cavernous internal carotid artery diameter.

Blood pressure changes after aneurysmal subarachnoid hemorrhage and their relationship to cerebral vasospasm and clinical outcome

OBJECTIVE

Cerebral vasospasm (VS) and resulting delayed ischemic brain injury constitute the most severe secondary complication after subarachnoid hemorrhage (SAH). Identification of early clinical predictors of developing vasospasm and poor outcome has remained a major challenge in neurointensive care medicine. Aim of the present study was analyze the relevance of spontaneous changes in blood pressures and their predictive value for predicting vasospasm as well as adverse clinical outcome.

METHODS

98 aneurysmal SAH patients were analyzed retrospectively. Patients were divided into two study groups: (1) VS+ (developing VS) and (2) VS- (not developing VS). Repeat-angiography was routinely performed on day 8 after SAH or earlier if clinical signs were suggestive for overt vasospasm. Systolic, diastolic and mean blood pressures were averaged hourly and plotted over time. Secondly, blood pressure (BP)-progression was analyzed with respect to clinical outcomes as assessed by the Glasgow outcome scale.

RESULTS

Mean, systolic, and diastolic blood pressure values progressed in both VS- and VS+ cohorts over time. However, as early as 4 days after SAH a significant dissociation of RR curves was observed between the groups with patients in the VS+ group displaying a significantly higher slope coefficient of blood pressure elevation. An increase of mean arterial pressure >20% within the first 4 days was predictive of developing vasospasm. Elevation of mean arterial blood pressure in the VS+ group was mainly attributable to changes in diastolic pressure. Elevation of mean arterial blood pressure >25% within the first week after SAH was associated with unfavorable outcome.

CONCLUSIONS

SAH leads to spontaneous and progressive elevations in mean arterial blood pressure. Vasospasm might be anticipated by identifying early elevations of mean arterial blood pressure. Finally, spontaneous elevations of mean arterial blood pressure correlate with poorer outcomes.

To look beyond vasospasm in aneurysmal subarachnoid haemorrhage

Delayed cerebral vasospasm has classically been considered the most important and treatable cause of mortality and morbidity in patients with aneurysmal subarachnoid hemorrhage (aSAH). Secondary ischemia (or delayed ischemic neurological deficit, DIND) has been shown to be the leading determinant of poor clinical outcome in patients with aSAH surviving the early phase and cerebral vasospasm has been attributed to being primarily responsible. Recently, various clinical trials aimed at treating vasospasm have produced disappointing results. DIND seems to have a multifactorial etiology and vasospasm may simply represent one contributing factor and not the major determinant. Increasing evidence shows that a series of early secondary cerebral insults may occur following aneurysm rupture (the so-called early brain injury). This further aggravates the initial insult and actually determines the functional outcome. A better understanding of these mechanisms and their prevention in the very early phase is needed to improve the prognosis. The aim of this review is to summarize the existing literature on this topic and so to illustrate how the presence of cerebral vasospasm may not necessarily be a prerequisite for DIND development. The various factors determining DIND that worsen functional outcome and prognosis are then discussed.

Dramatic intracerebral hemorrhagic presentations of reversible cerebral vasoconstriction syndrome: three cases and a literature review

Reversible cerebral vasoconstriction syndrome (RCVS) refers to a number of disorders characterized by severe and sudden-onset (“thunderclap”) headaches and angiographic features of reversible, segmental, multifocal vasoconstriction of cerebral arteries. Although RCVS generally resolves without significant sequelae, a rare and possibly underrecognized hemorrhagic presentation has a worse potential course. We report three cases of hemorrhagic RCVS and review the literature. Three females (42, 54, and 33 years old, resp.) presented with severe headache, neurological deficits, and dramatic intracerebral hemorrhage (ICH). Patient 1 presented comatose with a 9 × 4 × 6.6 cm left deep intraparenchymal hemorrhage (IPH) and 1 cm midline shift. She underwent emergent surgical intervention. Patient 2 had a 3.3 × 1.5 cm left superior frontal IPH that enlarged to 4 × 2.5 cm within 12 hours with worsening headache and neurological deficits. She was successfully managed nonoperatively. Patient 3, after uncomplicated pregnancy and delivery, presented with a 1.5 cm left superior parietal IPH on postpartum day 7. Two days later, she acutely developed right hemiplegia. Repeat CT demonstrated a new 3.3 × 1.7 cm left frontal IPH. She was also successfully managed nonoperatively. Many diverse conditions are grouped within the category of RCVS. Dramatic ICH remains a rare and possibly underrecognized presenting feature. Prompt diagnosis and management are essential for obtaining the best outcome.

Transcranial Doppler ultrasound: a review of the physical principles and major applications in critical care

Transcranial Doppler (TCD) is a noninvasive ultrasound (US) study used to measure cerebral blood flow velocity (CBF-V) in the major intracranial arteries. It involves use of low-frequency (≤2 MHz) US waves to insonate the basal cerebral arteries through relatively thin bone windows. TCD allows dynamic monitoring of CBF-V and vessel pulsatility, with a high temporal resolution. It is relatively inexpensive, repeatable, and portable. However, the performance of TCD is highly operator dependent and can be difficult, with approximately 10-20% of patients having inadequate transtemporal acoustic windows. Current applications of TCD include vasospasm in sickle cell disease, subarachnoid haemorrhage (SAH), and intra- and extracranial arterial stenosis and occlusion. TCD is also used in brain stem death, head injury, raised intracranial pressure (ICP), intraoperative monitoring, cerebral microembolism, and autoregulatory testing.