Perioperative Management of Aneurysmal Subarachnoid Hemorrhage

Stem Cells Treatment for Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) refers to bleeding in the subarachnoid space, which is a serious neurologic emergency. However, the treatment effects of SAH are limited. In recent years, stem cell (SC) therapy has gradually become a very promising therapeutic method and advanced scientific research area for SAH.

REVIEW SUMMARY

The SCs used for SAH treatment are mainly bone marrow mesenchymal stem cells (BMSCs), umbilical cord mesenchymal stem cells (hUC-MSCs), dental pulp stem cells (DPSCs), neural stem cells (NSCs)/neural progenitor cell (NPC), and endothelial progenitor cell (EPC). The mechanisms mainly included differentiation and migration of SCs for tissue repair; alleviating neuronal apoptosis; anti-inflammatory effects; and blood-brain barrier (BBB) protection. The dosage of SCs was generally 106 orders of magnitude. The administration methods included intravenous injection, nasal, occipital foramen magnum, and intraventricular administration. The administration time is generally 1 hour after SAH modeling, but it may be as late as 24 hours or 6 days. Existing studies have confirmed the neuroprotective effect of SCs in the treatment of SAH.

CONCLUSIONS

SC has great potential application value in SAH treatment, a few case reports have provided support for this. However, the relevant research is still insufficient and there is still a lack of clinical research on the SC treatment for SAH to further evaluate the effectiveness and safety before it can go from experiment to clinical application.

The Predictive Value of PKC and ET-1 Levels in Cerebrospinal Fluid for Vasospasm and Prognosis in Patients with Aneurysmal Subarachnoid Hemorrhage

Objective

To analyze the predictive value of protein kinase C (PKC) and endothelin-1 (ET-1) in cerebrospinal fluid for vasospasm and prognosis in patients with aneurysmal subarachnoid hemorrhage (ASH).

Methods

One hundred and forty-eight ASH patients hospitalized in our hospital during February 2019 to February 2022 were optioned as observation subjects. These subjects were graded into good prognosis group (mRS score 0-2, n = 102) and poor prognosis group (mRS score 3-6, n = 46) according to the Rankin Revised Scale Score (mRS) after 6 months of follow-up. Cerebrospinal fluid was collected from patients to detect the content of ET-1 and PKC. The prognostic factors were analyzed using multifactorial logistic regression. The predictive value was assessed using receiver operating characteristic (ROC) curve.

Results

The patients with poor prognosis had a higher age level and a higher proportion of ≥2 aneurysms, aneurysm diameter ≥6 mm, cerebral vasospasm, and Hunt-Hess grade ≥III than those with good prognosis (P < 0.05). The patients with poor prognosis had higher content of PKC and ET-1 than those with good prognosis (P < 0.05). Age, aneurysm diameter ≥6 mm, cerebral vasospasm, Hunt-Hess classification ≥grade III, PKC and ET-1 were all risk factors related to the prognosis of ASH (P < 0.05). The area under the curve (AUC) of PKC and ET-1 for diagnosing poor prognosis of ASH was 0.803 and 0.720, respectively. The AUC of the combined detection was 0.873 (P < 0.05). Patients with cerebrovascular spasm had higher content of PKC and ET-1 than those without (P < 0.05). The AUC of PKC and ET-1 for diagnosing cerebral vasospasm in ASH was 0.891 and 0.816, respectively, which was 0.932 for combined detection (P < 0.05).

Conclusion

The combination of PKC and ET-1 in cerebrospinal fluid had certain value in predicting the poor prognosis of patients with ASH.

Clinical Characteristics as Predictors of Early and Delayed Cerebral Infarction in Aneurysmal Subarachnoid Hemorrhage Patients: A Meta-Analysis of 4527 Cases

BACKGROUND

Predictors of delayed cerebral infarction (DCI) and early cerebral infraction (ECI) among aneurysmal subarachnoid hemorrhage (aSAH) patients remain unclear. We aimed to systematically review and synthesize the literature on predictors of ECI and DCI among aSAH patients.

METHODS

We systematically searched PubMed, EMBASE, Cochrane Library, and Scopus databases comprehensively from inception through January 2024 for observational cohort studies examining predictors of DCI or ECI following aneurysmal SAH. Studies were screened, reviewed, and meta-analyzed, adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane guidelines. The data were pooled as Odds ratios (OR) with 95% confidence intervals using Review Manager 5.4 software. Methodologic quality was assessed with the Newcastle-Ottawa Scale.

RESULTS

Our meta-analysis included 12 moderate to high-quality cohort studies comprising 4527 patients. Regarding DCI predictors, Higher severity scores (OR = 1.49, 95% confidence interval [1.12, 1.97], P = 0.005) and high Fisher scores (OR = 2.23, 95% confidence interval [1.28, 3.89], P = 0.005) on presentation were significantly associated with an increased risk of DCI. Also, the female sex and the presence of vasospasm were significantly associated with an increased risk of DCI (OR = 3.04, 95% confidence interval [1.35, 6.88], P = 0.007). In contrast, preexisting hypertension (P = 0.94), aneurysm treatment (P = 0.14), and location (P = 0.16) did not reliably predict DCI risk. Regarding ECI, the pooled analysis demonstrated no significant associations between sex (P = 0.51), pre-existing hypertension (P = 0.63), severity (P = 0.51), or anterior aneurysm location versus posterior (P = 0.86) and the occurrence of ECI.

CONCLUSION

Female sex, admission disease severity, presence of vasospasm and Fisher grading can predict DCI risk post-aSAH. Significant knowledge gaps exist for ECI predictors. Further large standardized cohorts are warranted to guide prognosis and interventions.

Exploring the causal role of immune cells in cerebral aneurysm through single-cell transcriptomics and Mendelian randomization analysis

Cerebral aneurysm (CA) represents a significant clinical challenge, characterized by pathological dilation of cerebral arteries. Recent evidence underscores the crucial involvement of immune cells in CA pathogenesis. This study aims to explore the complex interplay between immune cells and CA formation. We analyzed single-cell RNA sequencing data from the GSE193533 dataset, focusing on unruptured CA and their controls. Comprehensive cell-type identification and pseudo-time trajectory analyses were conducted to delineate the dynamic shifts in immune cell populations. Additionally, a two-sample Mendelian randomization (MR) approach was employed to investigate the causal influence of various immunophenotypes on CA susceptibility and the reciprocal effect of CA formation on immune phenotypes. Single-cell transcriptomic analysis revealed a progressive loss of vascular smooth muscle cells (VSMCs) and an increase in monocytes/macrophages (Mo/MΦ) and other immune cells, signifying a shift from a structural to an inflammatory milieu in CA evolution. MR analysis identified some vital immunophenotypes, such as CD64 on CD14+ CD16+ monocytes (OR: 1.236, 95% CI: 1.064-1.435, P = 0.006), as potential risk factors for CA development, while others, like CD28- CD8br %CD8br (OR: 0.883, 95% CI: 0.789-0.988, P = 0.030), appeared protective. Reverse MR analysis demonstrated that CA formation could modulate specific immunophenotypic expressions, highlighting a complex bidirectional interaction between CA pathology and immune response. This study underscores the pivotal role of immune cells in this process through the integration of single-cell transcriptomics with MR analysis, offering a comprehensive perspective on CA pathogenesis, and potentially guiding future therapeutic strategies targeting specific immune pathways.

A Survey on Monitoring and Management of Cerebral Vasospasm and Delayed Cerebral Ischemia After Subarachnoid Hemorrhage: The Mantra Study

INTRODUCTION

Cerebral infarction from delayed cerebral ischemia (DCI) is a leading cause of poor neurological outcome after aneurysmal subarachnoid hemorrhage (aSAH). We performed an international clinical practice survey to identify monitoring and management strategies for cerebral vasospasm associated with DCI in aSAH patients requiring intensive care unit admission.

METHODS

The survey questionnaire was available on the European Society of Intensive Care Medicine (May 2021-June 2022) and Neurocritical Care Society (April - June 2022) websites following endorsement by these societies.

RESULTS

There were 292 respondents from 240 centers in 38 countries. In conscious aSAH patients or those able to tolerate an interruption of sedation, neurological examination was the most frequently used diagnostic modality to detect delayed neurological deficits related to DCI caused by cerebral vasospasm (278 respondents, 95.2%), while in unconscious patients transcranial Doppler/cerebral ultrasound was most frequently used modality (200, 68.5%). Computed tomography angiography was mostly used to confirm the presence of vasospasm as a cause of DCI. Nimodipine was administered for DCI prophylaxis by the majority of the respondents (257, 88%), mostly by an enteral route (206, 71.3%). If there was a significant reduction in arterial blood pressure after nimodipine administration, a vasopressor was added and nimodipine dosage unchanged (131, 45.6%) or reduced (122, 42.5%). Induced hypertension was used by 244 (85%) respondents as first-line management of DCI related to vasospasm; 168 (59.6%) respondents used an intra-arterial procedure as second-line therapy.

CONCLUSIONS

This survey demonstrated variability in monitoring and management strategies for DCI related to vasospasm after aSAH. These findings may be helpful in promoting educational programs and future research.

Acute Respiratory Failure in Severe Acute Brain Injury

Acute respiratory failure is commonly encountered in severe acute brain injury due to a multitude of factors related to the sequelae of the primary injury. The interaction between pulmonary and neurologic systems in this population is complex, often with competing priorities. Many treatment modalities for acute respiratory failure can result in deleterious effects on cerebral physiology, and secondary brain injury due to elevations in intracranial pressure or impaired cerebral perfusion. High-quality literature is lacking to guide clinical decision-making in this population, and deliberate considerations of individual patient factors must be considered to optimize each patient's care.

A Global Review of the Perioperative Care of Patients With Aneurysmal Subarachnoid Hemorrhage Undergoing Microsurgical Repair of Ruptured Intracerebral Aneurysm

INTRODUCTION

To describe the perioperative care of patients with aneurysmal subarachnoid hemorrhage (aSAH) who undergo microsurgical repair of a ruptured intracerebral aneurysm.

METHODS

An English language survey examined 138 areas of the perioperative care of patients with aSAH. Reported practices were categorized as those reported by <20%, 21% to 40%, 41% to 60%, 61% to 80%, and 81% to 100% of participating hospitals. Data were stratified by Worldbank country income level (high-income or low/middle-income). Variation between country-income groups and between countries was presented as an intracluster correlation coefficient (ICC) and 95% confidence interval (CI).

RESULTS

Forty-eight hospitals representing 14 countries participated in the survey (response rate 64%); 33 (69%) hospitals admitted ≥60 aSAH patients per year. Clinical practices reported by 81 to 100% of the hospitals included placement of an arterial catheter, preinduction blood type/cross match, use of neuromuscular blockade during induction of general anesthesia, delivering 6 to 8 mL/kg tidal volume, and checking hemoglobin and electrolyte panels. Reported use of intraoperative neurophysiological monitoring was 25% (41% in high-income and 10% in low/middle-income countries), with variation between Worldbank country-income group (ICC 0.15, 95% CI 0.02-2.76) and between countries (ICC 0.44, 95% CI 0.00-0.68). The use of induced hypothermia for neuroprotection was low (2%). Before aneurysm securement, variable in blood pressure targets was reported; systolic blood pressure 90 to 120 mm Hg (30%), 90 to 140 mm Hg (21%), and 90 to 160 mmHg (5%). Induced hypertension during temporary clipping was reported by 37% of hospitals (37% each in high and low/middle-income countries).

CONCLUSIONS

This global survey identifies differences in reported practices during the perioperative management of patients with aSAH.

Red blood cell transfusion in neurocritical patients: a systematic review and meta-analysis

BACKGROUND

Anemia can lead to secondary brain damage by reducing arterial oxygen content and brain oxygen supply. Patients with acute brain injury have impaired self-regulation. Brain hypoxia may also occur even in mild anemia. Red blood cell (RBC) transfusion is associated with increased postoperative complications, poor neurological recovery, and mortality in critically ill neurologic patients. Balancing the risks of anemia and red blood cell transfusion-associated adverse effects is challenging in neurocritical settings.

METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and MEDLINE (PubMed) from inception to January 31, 2024. We included all randomized controlled trials (RCTs) assessing liberal versus restrictive RBC transfusion strategies in neurocritical patients. We included all relevant studies published in English. The primary outcome was mortality at intensive care unit (ICU), discharge, and six months.

RESULTS

Of 5195 records retrieved, 84 full-text articles were reviewed, and five eligible studies were included. There was no significant difference between the restrictive and liberal transfusion groups in ICU mortality (RR: 2.53, 95% CI: 0.53 to 12.13), in-hospital mortality (RR: 2.34, 95% CI: 0.50 to 11.00), mortality at six months (RR: 1.42, 95% CI: 0.42 to 4.78) and long-term mortality (RR: 1.22, 95% CI: 0.64 to 2.33). The occurrence of neurological adverse events and most major non-neurological complications was similar in the two groups. The incidence of deep venous thrombosis was lower in the restrictive strategy group (RR: 0.41, 95% CI: 0.18 to 0.91).

CONCLUSIONS

Due to the small sample size of current studies, the evidence is insufficiently robust to confirm definitive conclusions for neurocritical patients. Therefore, further investigation is encouraged to define appropriate RBC transfusion thresholds in the neurocritical setting.

Construction and verification of risk predicting models to evaluate the possibility of hydrocephalus following aneurysmal subarachnoid hemorrhage

BACKGROUND

Hydrocephalus following a ruptured aneurysm portends a poor prognosis. The authors aimed to establish a nomogram to predict the risk of hydrocephalus after aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

A total of 421 patients with aSAH who were diagnosed by digital subtraction angiography in The General Hospital of Northern Theater Command center from January 2020 to June 2021 were screened to establish the training cohort. An additional 135 patients who enrolled between July 2021 and May 2022 were used for the validation cohort. Variate difference analysis and stepwise logistic regression (model A) and univariate and multivariate logistic regressions (model B) were respectively used to construct two models. Then, the net reclassification improvement (NRI), integrated discrimination improvement (IDI), and receiver operating characteristic (ROC) curve were used to compare the predictive abilities of the two models. Finally, two nomograms were constructed and externally validated.

RESULTS

After screening, 556 patients were included. The area under the ROC curve of models A and B in the training cohort were respectively 0.884 (95 % confidence interval [CI]: 0.847-0.921) and 0.834 (95 % CI: 0.787-0.881). The prediction ability of the model A was superior to model B (NRI > 0, IDI > 0, p < 0.05). The C-index of models A and B was 0.8835 and 0.8392, respectively. Regarding clinical usefulness, the two models offered a net benefit with a threshold probability of between 0.12 and 1 in the decision curve analysis, suggesting that the two models can accurately predict hydrocephalus events.

CONCLUSIONS

Both models have good prediction accuracy. Compared with model B, model A has better discrimination and calibration. Further, the easy-to-use nomogram can help neurosurgeons to make rapid clinical decisions and apply early treatment measures in high-risk groups, which ultimately benefits patients.

Rehabilitation of Traumatic Acute Subdural Hematoma and Subarachnoid Hemorrhage: A Case Report

A head injury or cerebrovascular illness may be the cause of acute intracranial hemorrhage. Making a precise diagnosis is challenging since diagnostic imaging might be challenging in both situations. In this case report, an aneurysmal rupture related head injury resulted in an acute subdural hematoma (SHD) after the patient lost consciousness. A 54-year-old male was found in a state of unconsciousness on the ground and was brought to the nearest hospital. Computed tomography (CT) scan showed an oblique fracture involving the bilateral frontal and right parietal bones along with underlying SDH, subarachnoid hemorrhage (SAH), and hemorrhagic contusion along with midline shift. The case report highlights the rehabilitation journey of a patient with acute SDH and SAH. The patient can now sit independently and stand with minimal assistance. Vasospasm detection, prevention, and treatment need to be the norm at that time. This case demonstrates the effectiveness of a comprehensive rehabilitation approach in promoting mobility and independence for patients with traumatic brain injuries.

T817MA Regulates Mitochondrial Dynamics via Sirt1 and Arc Following Subarachnoid Hemorrhage

Spontaneous subarachnoid hemorrhage (SAH) is an acute neurologic emergency with poor outcomes, and mitochondrial dysfunction is known as one of the key pathological mechanisms underlying the SAH-induced early brain injury (EBI). 1-{3-[2-(1-benzothiophen-5-yl)ethoxy]propyl} azetidin-3-ol maleate (T817MA) is a newly synthesized neurotrophic compound that has been demonstrated to exert protective effects against brain injury. Here, we investigated the effect of T817MA in neuronal injury following experimental SAH both in vitro and in vivo. Primary cultured cortical neurons were treated with oxyhemoglobin (OxyHb) to mimic SAH in vitro, and T817MA at concentrations higher than 0.1 μM reduced OxyHb-induced neuronal injury. T817MA treatment significantly inhibited lipid peroxidation, reduced neuronal apoptosis and attenuated mitochondrial fragmentation. The results of western blot showed that T817MA markedly reduced the expression of mitochondrial fission proteins, fission protein 1 (Fis-1) and dynamin-related GTPase-1 (Drp-1), but prolonged the expression of the postsynaptic protein activity-regulated cytoskeleton-associated protein (Arc). In addition, T817MA significantly increased the expression of sirtuin 1 (Sirt1), which was accompanied by preserved enzymatic of isocitrate dehydrogenase (IDH2) and superoxide dismutase (SOD). Knockdown of Sirt1 and Arc via small interfere RNA (siRNA) transfection partially prevented the T817MA-induced protection in cortical neurons. Furthermore, treatment with T817MA in vivo significantly reduced brain damage and preserved neurological function in rats. The decreased expression of Fis-1 and Drp-1, as well as the increased expression of Arc and Sirt1 were also observed in vivo. Taken together, these data indicate that the neuroprotective agent T817MA protects against SAH-induced brain injury via Sirt1- and Arc-mediated regulation of mitochondrial dynamics.

Evaluation of markers of cerebral oxygenation and metabolism in patients undergoing clipping of cerebral aneurysm under total intravenous anesthesia versus inhalational anesthesia: A prospective randomized trial (COM-IVIN trial)

INTRODUCTION

Anesthetic goals in patients undergoing clipping of cerebral aneurysm include maintenance of cerebral blood flow, oxygenation, and metabolism to avoid cerebral ischemia and maintenance of hemodynamic stability. We intend to study the influence of anesthetic agents on the outcome of aneurysmal subarachnoid hemorrhage (SAH).

MATERIALS AND METHODS

This is a prospective, randomized, parallel, single-center pilot trial approved by the Institutional Ethics Committee and is prospectively registered with the Clinical Trial Registry of India. Patients with aneurysmal SAH (aSAH) admitted to our institution for surgical clipping, fulfilling the trial inclusion criteria, will be randomized in a 1:1 allocation ratio utilizing a computerized random allocation sequence to receive either total intravenous anesthesia (n = 25) or inhalational anesthesia (n = 25). Our primary objective is to study the effects of these anesthetic techniques on cerebral oxygenation and metabolism in patients with aSAH. Our secondary objective is to evaluate the impact of these anesthetic techniques on the incidence of delayed cerebral ischemia and long-term patient outcomes in patients with aSAH. The Modified Rankin Score and Glasgow Outcome Scale (GOS) at discharge and 3 months following hospital discharge will be evaluated. An observer blinded to the study intervention will assess the outcome measures.

DISCUSSION

This study will provide more insight as to which is the ideal anesthetic agent that offers a better neurophysiological profile regarding intraoperative cerebral oxygenation and metabolism, thereby contributing to better postoperative outcomes in aSAH patients.

Risk factors associated with vasospasm after non-traumatic subarachnoid hemorrhage: a retrospective analysis of 456 patients

BACKGROUND

The pathophysiology of vasospasm (VS) after non-traumatic subarachnoid hemorrhage is not completely understood. Several risk factors associated with VS were previously reported, partially with conflicting results. The aim of this study was to identify patients at increased risk for VS.

METHODS

Retrospective analysis of data from all patients treated in our institutional intensive care unit (ICU) between 2010 and 2016 after non-traumatic subarachnoid hemorrhage. Possible contributing factors for VS studied were: age, sex, aneurysm-localization, treatment option, ICU-stay, ICU mortality, pre-existing condition, medication history, World Federation of Neurosurgical Societies (WFNS) grading system, modified Fisher scale.

RESULTS

We obtained data from 456 patients. 184 were male and 272 female patients, respectively. Mean age was 57.7±13.9 and was not different between sexes. In 119 patients, VS was diagnosed after subarachnoid hemorrhage. Incidence of VS was not different between sexes (male: 22.3%, female: 28.7%, P=0.127). Patients with VS were significantly younger (mean age 52.2 vs. 59.7, P<0.001), meanwhile patients aged 36-40 yrs. had the highest incidence of VS. Most VS were found after rupture of middle cerebral artery-aneurysms. Higher incidence of VS was found after aneurysm clipping compared to coiling. VS developed more often in patients with more severe WFNS grade and Fisher scale. In multivariate analysis, age, previous drug abuse and history of anticoagulants were associated with the incidence of VS.

CONCLUSIONS

Younger age, middle cerebral artery-aneurysms, aneurysm clipping, previous drug abuse and history of anticoagulants were associated with a higher incidence of VS after non-traumatic subarachnoid hemorrhage. No gender difference was found.

Prognostic nomogram for predicting lower extremity deep venous thrombosis in ruptured intracranial aneurysm patients who underwent endovascular treatment

Background

Lower extremity deep vein thrombosis (DVT) is one of the major postoperative complications in patients with ruptured intracranial aneurysms (RIA) who underwent endovascular treatment (EVT). However, patient-specific predictive models are still lacking. This study aimed to construct and validate a nomogram model for estimating the risk of lower extremity DVT for RIA patients who underwent EVT.

Methods

This cohort study enrolled 471 RIA patients who received EVT in our institution between 1 January 2020 to 4 February 2022. Perioperative information on participants is collected to develop and validate a nomogram for predicting lower extremity DVT in RIA patients after EVT. Predictive accuracy, discriminatory capability, and clinical effectiveness were evaluated by concordance index (C-index), calibration curves, and decision curve analysis.

Result

Multivariate logistic regression analysis showed that age, albumin, D-dimer, GCS score, middle cerebral artery aneurysm, and delayed cerebral ischemia were independent predictors for lower extremity DVT. The nomogram for assessing individual risk of lower extremity DVT indicated good predictive accuracy in the primary cohort (c-index, 0.92) and the validation cohort (c-index, 0.85), with a wide threshold probability range (4-82%) and superior net benefit.

Conclusion

The present study provided a reliable and convenient nomogram model developed with six optimal predictors to assess postoperative lower extremity DVT in RIA patients, which may benefit to strengthen the awareness of lower extremity DVT control and supply appropriate resources to forecast patients at high risk of RIA-related lower extremity DVT.

Role of multimodal monitoring in the management of patients undergoing complex intracranial bypass procedures - A case series and literature review

Patients undergoing complex intracranial neurovascular procedures continue to have a high mortality rate. Individualised goal-directed cerebral resuscitation employing multimodality neuromonitoring may impact these patients' treatment and prognosis. Advanced monitoring methods aid in the early identification of secondary brain insults and serve as endpoints for goal-directed therapy in the perioperative period. Unfortunately, there is a paucity of literature exploring the impact of multimodality monitoring and its outcome in these patients. We aim to present this case series wherein the patients had a favourable outcome post-intracranial complex bypass procedure, owing to goal-directed management guided by multimodality monitoring in the perioperative period.

Mathematical Analysis of the Effectiveness of Screening for Intracranial Aneurysms in First-Degree Relatives of Persons with Subarachnoid Hemorrhage

OBJECTIVE

Population screening for aneurysms in patients with risk factors and preventive surgical treatment are beneficial according to numerous studies. One of the most significant risk factors is heredity, namely, the presence of first-degree relatives (FDR) with aneurysmal subarachnoid hemorrhage (aSAH). Nevertheless, there are still no generally accepted approaches or evidence bases regarding the benefits of the aneurysm screening strategy.

METHODS

Mathematical modeling of the dynamics of aneurysm development in the population was carried out using an algorithm implementing a discrete Markov's chain. To implement the model, all probabilities of events and distributions are taken from available literature sources. Three-dimensional time of flight noncontrast magnetic resonance angiography was chosen as a screening method. Patients underwent preventive surgical treatment if an aneurysm was detected.

RESULTS

Screening and preventive treatment in the general population reduces the prevalence of aneurysms by 1.74% (3.44% in the FDR group) and the prevalence of aSAH by 14.36% (37.48% in the FDR group). Mortality due to aSAH was reduced by 14.44%. The number of disabilities also decreases. The occurrence of deep disability was reduced by 20.2% in the FDR group. Economic analysis of the part of the population consisting of FDRs showed annual savings of ies also decr CONCLUSIONS: The mathematical model demonstrated that screening and preventive treatment of cerebral aneurysms can reduce aSAH-associated morbidity and mortality. In the FDR group, there was decrease in the prevalence of aSAH and decrease in associated mortality. Screening for cerebral aneurysms is cost-effective.

2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage: A Guideline From the American Heart Association/American Stroke Association

AIM

The "2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage" replaces the 2012 "Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage." The 2023 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with aneurysmal subarachnoid hemorrhage.

METHODS

A comprehensive search for literature published since the 2012 guideline, derived from research principally involving human subjects, published in English, and indexed in MEDLINE, PubMed, Cochrane Library, and other selected databases relevant to this guideline, was conducted between March 2022 and June 2022. In addition, the guideline writing group reviewed documents on related subject matter previously published by the American Heart Association. Newer studies published between July 2022 and November 2022 that affected recommendation content, Class of Recommendation, or Level of Evidence were included if appropriate. Structure: Aneurysmal subarachnoid hemorrhage is a significant global public health threat and a severely morbid and often deadly condition. The 2023 aneurysmal subarachnoid hemorrhage guideline provides recommendations based on current evidence for the treatment of these patients. The recommendations present an evidence-based approach to preventing, diagnosing, and managing patients with aneurysmal subarachnoid hemorrhage, with the intent to improve quality of care and align with patients' and their families' and caregivers' interests. Many recommendations from the previous aneurysmal subarachnoid hemorrhage guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

Inadequate Adenosine-Induced Flow Arrest During Intraoperative Basilar Aneurysm Surgery

Aneurysmal subarachnoid hemorrhage (SAH) is an acute neurologic emergency. We report the case of a 48-year-old male with a massive SAH caused by a ruptured aneurysm of the vertebrobasilar transition. During an urgent craniotomy, due to an aneurysm re-rupture, adenosine was given for flow arrest but no sinus pause was observed. Esmolol was administered and strategies for cerebral protection were implemented. The surgeon was able to clip the aneurysm and the patient was discharged after 78 days without sequelae. The highest adenosine dose given did not result in an efficient cardiac pause. Atropine given one hour before could have contributed to this. This case highlights a successfully managed case of ruptured aneurysm with refractory adenosine-induced flow arrest.

Effect of xenon on brain injury, neurological outcome, and survival in patients after aneurysmal subarachnoid hemorrhage-study protocol for a randomized clinical trial

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a neurological emergency, affecting a younger population than individuals experiencing an ischemic stroke; aSAH is associated with a high risk of mortality and permanent disability. The noble gas xenon has been shown to possess neuroprotective properties as demonstrated in numerous preclinical animal studies. In addition, a recent study demonstrated that xenon could attenuate a white matter injury after out-of-hospital cardiac arrest.

METHODS

The study is a prospective, multicenter phase II clinical drug trial. The study design is a single-blind, prospective superiority randomized two-armed parallel follow-up study. The primary objective of the study is to explore the potential neuroprotective effects of inhaled xenon, when administered within 6 h after the onset of symptoms of aSAH. The primary endpoint is the extent of the global white matter injury assessed with magnetic resonance diffusion tensor imaging of the brain.

DISCUSSION

Despite improvements in medical technology and advancements in medical science, aSAH mortality and disability rates have remained nearly unchanged for the past 10 years. Therefore, new neuroprotective strategies to attenuate the early and delayed brain injuries after aSAH are needed to reduce morbidity and mortality.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04696523. Registered on 6 January 2021. EudraCT, EudraCT Number: 2019-001542-17. Registered on 8 July 2020.

[Surgical treatment of intracranial aneurysms in acute period of hemorrhage in Hunt-Hess grade IV-V patients at Burdenko Neurosurgical Center between 2006 and 2020]

BACKGROUND

Management of patients in acute period of aneurysmal subarachnoid hemorrhage Hunt-Hess grade IV-V is still a complex and unsolved problem, especially regarding surgical treatment and various complications.

OBJECTIVE

To analyze postoperative outcomes in patients undergoing surgery in acute period of aneurysmal subarachnoid hemorrhage Hunt-Hess grade IV-V between 2006 and 2020, as well as to assess various factors influencing treatment outcomes.

MATERIAL AND METHODS

We analyzed 163 patients who underwent surgery within 21 days after aneurysmal subarachnoid hemorrhage Hunt-Hess grade IV-V. All patients were divided into 2 groups depending on the period: 2006-2011 (group 1) and 2012-2020 (group 2).

RESULTS

Mortality reduced from 28.6% in group 1 to 8.3% in group 2. At the same time, incidence of vegetative state (GOS grade 2) increased from 4.8% to 17.4%. Incidence of outcomes GOS grade 3 - 5 was similar.

CONCLUSION

Large or giant aneurysm, repeated preoperative subarachnoid hemorrhage, intraoperative aneurysm rupture and prolonged temporary clipping can impair postoperative outcomes in patients with hemorrhage Hunt-Hess grade IV-V. External ventricular drainage, intraarterial injection of verapamil, intracisternal administration of calcium channel blockers and active surgical tactics improve postoperative outcomes and reduce mortality.

[Screening of patients with cerebral aneurysms: mathematical analysis and economic justification]

Subarachnoid hemorrhages due to rupture of cerebral aneurysms have a high risk of disability and mortality. Screening of the population to detect aneurysms in patients with risk factors is currently not carried out in Russia. However, the detection of clinically silent aneurysms and their subsequent prophylactic surgical treatment are justified, according to numerous studies.

BACKGROUND

Demonstrate the clinical and economic feasibility of screening the population (including first-line relatives) for cerebral aneurysms using an economic and mathematical model of the RF virtual population.

MATERIAL AND METHODS

Mathematical modeling was carried out using an algorithm that implements a discrete Markov chain. The virtual population consisted of 145 million people (the population of the Russian Federation). Magnetic resonance angiography 3DTOF was chosen as a screening method. Virtual patients underwent preventive surgical treatment in case of detection of aneurysm during screening. The number of aneurysms in the population, the number of aneurysmal subarachnoid hemorrhage (aSAH), the cost and outcomes of treatment, and the risk of disability were calculated.

RESULTS

In the case of screening and preventive surgical treatment of aneurysms, there is a decrease in the number of aSAH by 14.3% (37.5% in first-line relatives (RPLR), which affects the reduction in mortality due to aSAH by 14.4% (24.1% in The total number of disabled people is reduced by 1.5% (5.1% for the RPHR). A shift in the structure of disability towards greater labor and social adaptation of patients was noted. An economic analysis for the entire population showed that screening saves 7.7 billion annually rubles, including in the population consisting of RPLR - 4.9 billion rubles.

CONCLUSION

The created mathematical model of the virtual population demonstrated that screening and prophylactic treatment of cerebral aneurysms makes it possible to reduce the number of aSAH and associated mortality among the entire population and in the RPLR group. The number of individuals with severe disabilities is decreasing. Thus, population screening for the detection of cerebral aneurysms may be clinically effective and cost-effective in the general population, especially in RPCR.

Cromolyn prevents cerebral vasospasm and dementia by targeting WDR43

Background

Cerebral vasospasm (CV) can cause inflammation and damage to neuronal cells in the elderly, leading to dementia.

Purpose

This study aimed to investigate the genetic mechanisms underlying dementia caused by CV in the elderly, identify preventive and therapeutic drugs, and evaluate their efficacy in treating neurodegenerative diseases.

Methods

Genes associated with subarachnoid hemorrhage and CV were acquired and screened for differentially expressed miRNAs (DEmiRNAs) associated with aneurysm rupture. A regulatory network of DEmiRNAs and mRNAs was constructed, and virtual screening was performed to evaluate possible binding patterns between Food and Drug Administration (FDA)-approved drugs and core proteins. Molecular dynamics simulations were performed on the optimal docked complexes. Optimally docked drugs were evaluated for efficacy in the treatment of neurodegenerative diseases through cellular experiments.

Results

The study found upregulated genes (including WDR43 and THBS1) and one downregulated gene associated with aneurysm rupture. Differences in the expression of these genes indicate greater disease risk. DEmiRNAs associated with ruptured aortic aneurysm were identified, of which two could bind to THBS1 and WDR43. Cromolyn and lanoxin formed the best docking complexes with WDR43 and THBS1, respectively. Cellular experiments showed that cromolyn improved BV2 cell viability and enhanced Aβ42 uptake, suggesting its potential as a therapeutic agent for inflammation-related disorders.

Conclusion

The findings suggest that WDR43 and THBS1 are potential targets for preventing and treating CV-induced dementia in the elderly. Cromolyn may have therapeutic value in the treatment of Alzheimer's disease and dementia.

A predictive model using risk factor categories for hospital-acquired pneumonia in patients with aneurysmal subarachnoid hemorrhage

Objectives

To identify risk factors for hospital-acquired pneumonia (HAP) in patients with aneurysmal subarachnoid hemorrhage (aSAH) and establish a predictive model to aid evaluation.

Methods

The cohorts of 253 aSAH patients were divided into the HAP group (n = 64) and the non-HAP group (n = 189). Univariate and multivariate logistic regression were performed to identify risk factors. A logistic model (Model-Logit) was established based on the independent risk factors. We used risk factor categories to develop a model (Model-Cat). Receiver operating characteristic curves were generated to determine the cutoff values. Areas under the curves (AUCs) were calculated to assess the accuracy of models and single factors. The Delong test was performed to compare the AUCs.

Results

The multivariate logistic analysis showed that the age [p = 0.012, odds ratio (OR) = 1.059, confidence interval (CI) = 1.013-1.107], blood glucose (BG; >7.22 mmol/L; p = 0.011, OR = 2.781, CI = 1.263-6.119), red blood distribution width standard deviation (RDW-SD; p = 0.024, OR = 1.118, CI = 1.015-1.231), and Glasgow coma scale (GCS; p < 0.001, OR = 0.710, CI = 0.633-0.798) were independent risk factors. The Model-Logit was as follows: Logit(P) = -5.467 + 0.057 * Age + 1.023 * BG (>7.22 mmol/L, yes = 1, no = 0) + 0.111 * RDW-SD-0.342 * GCS. The AUCs values of the Model-Logit, GCS, age, BG (>7.22 mmol/L), and RDW-SD were 0.865, 0.819, 0.634, 0.698, and 0.625, respectively. For clinical use, the Model-Cat was established. In the Model-Cat, the AUCs for GCS, age, BG, and RDW-SD were 0.850, 0.760, 0.700, 0.641, and 0.564, respectively. The AUCs of the Model-Logit were insignificantly higher than the Model-Cat (Delong test, p = 0.157). The total points from -3 to 4 and 5 to 14 were classified as low- and high-risk levels, respectively.

Conclusions

Age, BG (> 7.22 mmol/L), GCS, and RDW-SD were independent risk factors for HAP in aSAH patients. The Model-Cat was convenient for practical evaluation. The aSAH patients with total points from 5 to 14 had a high risk for HAP, suggesting the need for more attention during treatment.

Effect of Cross Theoretical Model of Behaviour Change and Motivation Interview on Self-Management Behaviour

Objective

To evaluate the effects of a trans-theoretical model (TTM) of behavioural change plus motivational interviewing on self-management behavior and quality of life (QoL) in patients with intracranial aneurysm.

Methods

A total of 94 patients with intracranial aneurysm treated in the First Affiliated Hospital of Wenzhou Medical University from 2019 to 04/2021-04 were retrospectively analyzed. Among them, 49 patients used TTM + motivational interview as the observation group (Obs group), and 45 patients used the traditional method as the control group (Con group). The Self-Management Behavior Scale for Patients with Intracranial Aneurysm was used for analyzing the changes in the self-management behavior of the two groups of patients, and the MOS 36-item Short Form Health Survey (SF-36) was used to analyze the changes in the QoL of the patients. The incidence of adverse events after 6 months of intervention was counted. In addition, the Barthel Index (BI) and Montreal Cognitive Assessment Scale (MOCA) were used to evaluate the recovery effects of patients. Logistic regression was conducted for analyzing the risk factors of adverse cerebrovascular events.

Results

After treatment, the Con group got lower self-management behavior score than the Obs group (P < 0.05), and also got lower SF-36 scores, BI, and MOCA scores than the Obs group (P < 0.05). Age and a history of hypertension were independent risk factors for adverse events. The Hosmer-Lemeshow test was adopted for testing the goodness of fit of the regression equation (P=0.903). With the established model, the area under the receiver operating characteristic curve for predicting adverse events in patients with intracranial aneurysm was determined to be 0.851, indicating that the model performed well as a risk prediction model.

Conclusion

TTM + motivational interviewing can help improve the self-management behavior and QoL of patients with intracranial aneurysm without increasing the occurrence of adverse events.

Ultra-early endovascular treatment improves prognosis in High grade aneurysmal subarachnoid hemorrhage: A single-center retrospective study

Background

The long-term survival prognosis of patients with high-grade (Hunt-Hess grade IV–V or World Federation of Neurosurgical Societies grade IV–V) aneurysmal subarachnoid hemorrhage (aSAH) is generally poor, and the association between endovascular treatment timing and the prognosis of high-grade aSAH has not been explored in depth. This retrospective cohort study aimed to determine whether endovascular treatment within 24 h of high-grade aSAH is associated with a better prognosis.

Methods

We retrospectively analyzed the clinical data of patients with high-grade aSAH who were admitted to our institution between January 2018 and January 2021. The Modified Rankin Scale score was used to assess the 6-month prognosis of patients. Univariate and multivariate logistic regression analyses were used to identify the factors associated with prognosis. The area under the receiver operating characteristic (ROC) curve was used to assess the model's discriminatory ability.

Results

Eighty-six patients were included in the study. In the multivariate analysis, the timing of endovascular treatment (odds ratio = 7.003 [1.800–27.242], P = 0.005) was an independent risk factor for prognosis. The ROC curve showed that the predictive power of the timing of endovascular treatment was 0.744, the best cut-off value was 12.5 h, and the corresponding sensitivity and specificity were 71.4 and 70.5%, respectively. Hydrocephalus (P = 0.005) and pulmonary infection (P = 0.029) were also associated with prognosis. In addition, cerebrospinal fluid drainage immediately after endovascular treatment had a significant effect on reducing hydrocephalus formation.

Conclusions

Endovascular therapy within 24 h is feasible and improves the prognosis of patients with high-grade aSAH.

Deep Learning-Based Magnetic Resonance Imaging in Diagnosis and Treatment of Intracranial Aneurysm

This study was focused on the positioning of the intracranial aneurysm in the magnetic resonance imaging (MRI) images using the deep learning-based U-Net model, to realize the computer-aided diagnosis of the intracranial aneurysm. First, a network was established based on the three-dimensional (3D) U-Net model, and the collected image data were input into the network to realize the automatic location and segmentation of the aneurysm. The 3D convolutional neural network (CNN) network can extract the aneurysm blood vessels to locate and identify the areas of possible aneurysms. Next, 40 patients highly suspected of intracranial aneurysm were selected as research subjects, and they were subjected to magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) examinations. The results showed that based on the U-Net algorithm model, 40 patients' hemangiomas were completely contained in the labeling bounding box, one patient's hemangioma was at the edge of the labeling bounding box, and 4 patients' hemangiomas were outside the labeling box. The final accuracy coefficient was 88.9%, and it was in good agreement with the doctor's manual labelling results. Under the 3D CNN network test, the sensitivity, specificity, and accuracy of DSA for intracranial aneurysm were 91.46%, 86.01%, and 90.2%, respectively; the sensitivity, specificity, and accuracy of MRA for intracranial aneurysm were 95.87%, 100%, and 97.19%, respectively. In conclusion, the 3D CNN can successfully realize the positioning of intracranial aneurysm in MRA images, providing a certain theoretical basis for subsequent imaging diagnosis of aneurysm.

Role of hydrogen sulfide in subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a common acute and severe disease worldwide, which imposes a heavy burden on families and society. However, the current therapeutic strategies for SAH are unsatisfactory. Hydrogen sulfide (H2 S), as the third gas signaling molecule after carbon monoxide and nitric oxide, has been widely studied recently. There is growing evidence that H2 S has a promising future in the treatment of central nervous system diseases. In this review, we focus on the effects of H2 S in experimental SAH and elucidate the underlying mechanisms. We demonstrate that H2 S has neuroprotective effects and significantly reduces secondary damage caused by SAH via antioxidant, antiinflammatory, and antiapoptosis mechanisms, and by alleviating cerebral edema and vasospasm. Based on these findings, we believe that H2 S has great potential in the treatment of SAH and warrants further study to promote its early clinical application.

Early management of patients with aneurysmal subarachnoid hemorrhage in a hospital with neurosurgical/neuroendovascular facilities: a consensus and clinical recommendations of the Italian Society of Anesthesia and Intensive Care (SIAARTI)-part 2

BACKGROUND

Questions remain on the optimal management of subarachnoid hemorrhage (SAH) patients once they are admitted to the referring center, before and after the aneurysm treatment. To address these issues, we created a consensus of experts endorsed by the Italian Society of Anesthesia and Intensive Care (SIAARTI) to provide clinical guidance regarding this topic. Specifically, in this manuscript (part 2), we aim to provide a list of experts' recommendations regarding the management of SAH patients in a center with neurosurgical/neuroendovascular facilities after aneurysm treatment.

METHODS

A multidisciplinary consensus panel composed by 24 physicians selected for their established clinical and scientific expertise in the acute management of SAH patients with different specializations (anesthesia/intensive care, neurosurgery, and interventional neuroradiology) was created. A modified Delphi approach was adopted.

RESULTS

A total of 33 statements were discussed, voted, and approved. Consensus was reached on 30 recommendations (28 strong and 2 weak). In 3 cases, where consensus could not be agreed upon, no recommendation was provided.

CONCLUSIONS

This consensus provides practical recommendations (and not mandatory standard of practice) to support clinician's decision-making in the management of SAH patients in centers with neurosurgical/neuroendovascular facilities after aneurysm securing.

Early management of patients with aneurysmal subarachnoid hemorrhage in a hospital with neurosurgical/neuroendovascular facilities: a consensus and clinical recommendations of the Italian Society of Anesthesia and Intensive Care (SIAARTI)-Part 1

BACKGROUND

Issues remain on the optimal management of subarachnoid hemorrhage (SAH) patients once they are admitted to the referring center, before and after the aneurysm treatment. To address these issues, we created a consensus of experts endorsed by the Italian Society of Anesthesia and Intensive Care (SIAARTI). In this manuscript, we aim to provide a list of experts' recommendations regarding the early management of SAH patients from hospital admission, in a center with neurosurgical/neuro-endovascular facilities, until securing of the bleeding aneurysm.

METHODS

A multidisciplinary consensus panel composed of 24 physicians selected for their established clinical and scientific expertise in the acute management of SAH patients with different background (anesthesia/intensive care, neurosurgery, and interventional neuroradiology) was created. A modified Delphi approach was adopted.

RESULTS

Among 19 statements discussed. The consensus was reached on 18 strong recommendations. In one case, consensus could not be agreed upon and no recommendation was provided.

CONCLUSIONS

This consensus provides practical recommendations for the management of SAH patients in hospitals with neurosurgical/neuroendovascular facilities until aneurysm securing. It is intended to support clinician's decision-making and not to mandate a standard of practice.

Efficacy and Safety of Tranexamic Acid in Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Tranexamic acid has been shown to reduce rebleeding after aneurysmal subarachnoid hemorrhage; however, whether it can reduce mortality and improve clinical outcomes is controversial. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of the tranexamic acid in aneurysmal subarachnoid hemorrhage. We conducted a comprehensive literature search of PubMed, Embase, Web of Science, and Cochrane Library from inception to March 2021 for randomized controlled trials (RCTs) comparing tranexamic acid and placebo in adults with aneurysmal subarachnoid hemorrhage. The risk of bias was evaluated using the Cochrane Handbook, and the quality of evidence was evaluated using the GRADE approach. This meta-analysis included 13 RCTs, involving 2,888 patients. In patients with aneurysmal subarachnoid hemorrhage tranexamic acid had no significant effect on all-cause mortality (RR = 0.96; 95% CI = 0.84–1.10, p = 0.55, I² = 44%) or poor functional outcome (RR = 1.04; 95% CI = 0.95–1.15, p = 0.41) compared with the control group. However, risk of rebleeding was significantly lower (RR = 0.59; 95% CI = 0.43–0.80, p = 0.0007, I² = 53%). There were no significant differences in other adverse events between tranexamic acid and control treatments, including cerebral ischemia (RR = 1.17; 95% CI = 0.95–1.46, p = 0.15, I² = 53%). At present, routine use of tranexamic acid after subarachnoid hemorrhage cannot be recommended. For a patient with subarachnoid hemorrhage, it is essential to obliterate the aneurysm as early as possible. Additional higher-quality studies are needed to further assess the effect of tranexamic acid on patients with subarachnoid hemorrhage.

Early management of patients with aneurysmal subarachnoid hemorrhage in a hospital without neurosurgical/neuroendovascular facilities: a consensus and clinical recommendations of the Italian Society of Anesthesia and Intensive Care (SIAARTI)

Background

The immediate management of subarachnoid hemorrhage (SAH) patients in hospitals without neurosurgical/neurointerventional facilities and their transfer to a specialized center is challenging and not well covered in existing guidelines. To address these issues, we created a consensus of experts endorsed by the Italian Society of Anesthesia and Intensive Care (SIAARTI) to provide clinical guidance.

Methods

A multidisciplinary consensus panel composed by 19 physicians selected for their established clinical and scientific expertise in the acute management of SAH patients with different specializations (anesthesia/intensive care, neurosurgery and interventional neuroradiology) was created. A modified Delphi approach was adopted.

Results

A total of 14 statements have been discussed. Consensus was reached on 11 strong recommendations and 2 weak recommendations. In one case, where consensus could not be agreed upon, no recommendation could be provided.

Conclusions

Management of SAH in a non-specialized setting and early transfer are difficult and may have a critical impact on outcome. Clinical advice, based on multidisciplinary consensus, might be helpful. Our recommendations cover most, but not all, topics of clinical relevance.

The surgical management of intraoperative intracranial internal carotid artery injury in open skull base surgery-a systematic review

Intraoperative internal carotid artery (ICA) injury during open skull base surgery is a catastrophic complication. Multiple techniques and management strategies have been reported for endoscopic skull base surgery; however, the literature on managing this complication in open skull base surgery is limited. To perform a systematic review and give an overview of the different techniques described to manage this complication intraoperatively, a systematic review was conducted in PubMed, Ovid Medline, Ovid Embase and Scopus for literature published until July 2021. Titles and abstracts were screened. Studies meeting prespecified inclusion criteria were reviewed in full. PRISMA guidelines were strictly adhered to. Out of 4492 articles, only 12 articles could be included, reflecting an underreporting of open skull base ICA injuries. Multiple techniques can be used depending on the location and size of the injury as well as the surgeon's experience. Described techniques include the following: a primary repair via a micro-suture or nonpenetrating clips; wrapping or plugging; coating; occlusion of the parent artery with or without a bypass; packing with further endovascular management. A treatment algorithm is proposed.

Year in Review: Synopsis of Selected Articles in Neuroanesthesia and Neurocritical Care from 2020

This review is a synopsis of selected articles from neuroscience, neuroanesthesia, and neurocritical care from the year 2020 (January–December 2020). The journals reviewed include anesthesia journals, critical care medicine journals, neurology and neurosurgical journals, as well as high-impact medical journals such as the Lancet, Journal of American Medical Association, New England Journal of Medicine, and Stroke. This summary of important articles will serve to update the knowledge of anesthesiologists and other perioperative physicians who provide care to neurosurgical and neurocritical care patients. In addition, some of the important narrative reviews that are of interest to neuroanesthesiologists are also listed.

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.