Rethinking brain injury after subarachnoid hemorrhage

The Great Mimicker: A Unique Case of Diffuse Subarachnoid Haemorrhage Simulating Acute Myocardial Infarction

Subarachnoid haemorrhage (SAH) is a rare yet consequential medical emergency that may mimic an acute myocardial infarction (MI). SAH causes enhanced sympathetic activity, culminating in the development of neurogenic stunned myocardium (NSM), which presents as ST-segment deviations, prolonged QT intervals, T-wave inversions or Q-waves. Reperfusion therapy is contraindicated for SAH because of an increased risk of bleeding and death. Therefore, a prompt diagnosis is crucial. Here, we report a unique case of massive SAH presenting as diffuse ST-segment deviation simulating an acute MI. Our patient was brought to the emergency department after a cardiac arrest and died on day 2 of admission.

LEARNING POINTS

Subarachnoid haemorrhage (SAH) can present with EKG changes and significant rise in troponin, mimicking acute coronary syndrome.SAH should be included in the differential diagnosis for patients presenting with neurological symptoms, ST-segment deviations or prolonged QT intervals.Misdiagnosis of SAH as acute coronary syndrome can lead to inappropriate use of anticoagulants or delays in necessary neurological interventions.

The Role of Early Serum Biomarkers and Clinical Rating Scales in the Prediction of Delayed Cerebral Ischaemia and Short-Term Outcome after Aneurysmal Subarachnoid Haemorrhage: Single Centre Experience

Considering the variety of complications that arise after aneurysmal subarachnoid haemorrhage (aSAH) and the complex pathomechanism of delayed cerebral ischaemia (DCI), the task of predicting the outcome assumes a profound complexity. Therefore, there is a need to develop early predictive and decision-making models. This study explores the effect of serum biomarkers and clinical scales on patients' outcomes and their interrelationship with DCI and systemic complications in aSAH. This was a retrospective analysis including aSAH patients admitted to the Wroclaw University Hospital (Wrocław, Poland) from 2011 to 2020. A good outcome was defined as a modified Rankin Scale (mRS) score of 0-2. The prediction of the development of DCI and poor outcome was conducted using logistic regression as a standard model (SM) and random forest as a machine learning method (ML). A cohort of 174 aSAH patients were included in the analysis. DCI was diagnosed in 79 (45%) patients. Significant differences between patients with poor vs. good outcome were determined from their levels of albumin (31 ± 7 vs. 35 ± 5 (g/L); p < 0.001), D-dimer (3.0 ± 4.5 vs. 1.5 ± 2.8 (ng/mL); p < 0.001), procalcitonin (0.2 ± 0.4 vs. 0.1 ± 0.1 (ng/mL); p < 0.001), and glucose (169 ± 69 vs. 137 ± 48 (nmol/L); p < 0.001). SM for DCI prediction included the Apache II scale (odds ratio [OD] 1.05; 95% confidence interval [CI] 1.00-1.09) and albumin level (OD 0.88; CI 0.82-0.95). ML demonstrated that low albumin level, high Apache II scale, increased D-dimer and procalcitonin levels had the highest predictive values for DCI. The integration of clinical parameters and scales with a panel of biomarkers may effectively facilitate the stratification of aSAH patients, identifying those at high risk of secondary complications and poor outcome.

Early Brain Injury After Subarachnoid Hemorrhage: Incidence and Mechanisms

Aneurysmal subarachnoid hemorrhage is a devastating condition causing significant morbidity and mortality. While outcomes from subarachnoid hemorrhage have improved in recent years, there continues to be significant interest in identifying therapeutic targets for this disease. In particular, there has been a shift in emphasis toward secondary brain injury that develops in the first 72 hours after subarachnoid hemorrhage. This time period of interest is referred to as the early brain injury period and comprises processes including microcirculatory dysfunction, blood-brain-barrier breakdown, neuroinflammation, cerebral edema, oxidative cascades, and neuronal death. Advances in our understanding of the mechanisms defining the early brain injury period have been accompanied by improved imaging and nonimaging biomarkers for identifying early brain injury, leading to the recognition of an elevated clinical incidence of early brain injury compared with prior estimates. With the frequency, impact, and mechanisms of early brain injury better defined, there is a need to review the literature in this area to guide preclinical and clinical study.

Calcitonin gene-related peptide and neurologic injury: An emerging target for headache management

Calcitonin gene-related peptide (CGRP) is a 37-amino acid neuropeptide known to be involved in the trigeminovascular system and to function as a potent vasodilator. Although it has emerged as a viable target for headache management with targeted treatments developed for migraine, a highly disabling neurovascular disorder, less is known about CGRP's role in other neurologic conditions such as traumatic brain injury and subarachnoid hemorrhage. The literature has shown that during these injury cascades, CGRP receptors are modulated in varying ways. Therefore, CGRP or its receptors might be viable targets to manage secondary injuries following acute brain injury. In this review, we highlight the pathophysiology of the CGRP pathway and its relation to migraine pathogenesis. Using these same principles, we assess the existing preclinical data for CGRP and its role in acute brain injury. The findings are promising, and set the basis for further work, with specific focus on the therapeutic benefit of CGRP modulation following neurologic injury.

C-reactive protein elevation predicts in-hospital deterioration after aneurysmal subarachnoid hemorrhage: a retrospective observational study

Background

There is increasing evidence that inflammation plays a role in the pathogenesis of aneurysmal subarachnoid hemorrhage (aSAH) and in the development of delayed cerebral ischemia (DCI). However, the assessment and interpretation of classically defined inflammatory parameters is difficult in aSAH patients. The objective of this study was to investigate the relationship between easily assessable findings (hyperventilation, fever, white blood cell count (WBC), and C-reactive protein (CRP)) and the occurrence of DCI and unfavorable neurological outcome at discharge in aSAH patients.

Methods

Retrospective analysis of prospectively collected data from a single center cohort. We evaluated the potential of clinical signs of inflammation (hyperventilation, fever) and simple inflammatory laboratory parameters CRP and WBC to predict unfavorable outcomes at discharge and DCI in a multivariate analysis. A cutoff value for CRP was calculated by Youden’s J statistic. Outcome was measured using the modified Rankin score at discharge, with an unfavorable outcome defined as modified Rankin scale (mRS) > 3.

Results

We included 97 consecutive aSAH patients (63 females, 34 males, mean age 58 years) in the analysis. Twenty-one (22%) had major disability or died by the time of hospital discharge. Among inflammatory parameters, CRP over 100 mg/dl on day 2 was an independent predictor for worse neurological outcome at discharge. The average C-reactive protein level in the first 14 days was higher in patients with a worse neurological outcome (96.6, SD 48.3 vs 56.3 mg/dl, SD 28.6) in the first 14 days after aSAH. C-reactive protein on day 2 was an indicator of worse neurological outcome. No inflammatory parameter was an independent predictor of DCI. After multivariate adjustment, DCI, increased age, and more than 1 day of mechanical ventilation were significant predictors of worse neurological outcome.

Conclusions

Early elevated CRP levels were a significant predictor of worse neurological outcome at hospital discharge and may be a useful marker of later deterioration in aSAH.

Angiotensin-(1-7) as a Potential Therapeutic Strategy for Delayed Cerebral Ischemia in Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a substantial cause of mortality and morbidity worldwide. Moreover, survivors after the initial bleeding are often subject to secondary brain injuries and delayed cerebral ischemia, further increasing the risk of a poor outcome. In recent years, the renin-angiotensin system (RAS) has been proposed as a target pathway for therapeutic interventions after brain injury. The RAS is a complex system of biochemical reactions critical for several systemic functions, namely, inflammation, vascular tone, endothelial activation, water balance, fibrosis, and apoptosis. The RAS system is classically divided into a pro-inflammatory axis, mediated by angiotensin (Ang)-II and its specific receptor AT₁R, and a counterbalancing system, presented in humans as Ang-(1-7) and its receptor, MasR. Experimental data suggest that upregulation of the Ang-(1-7)/MasR axis might be neuroprotective in numerous pathological conditions, namely, ischemic stroke, cognitive disorders, Parkinson's disease, and depression. In the presence of SAH, Ang-(1-7)/MasR neuroprotective and modulating properties could help reduce brain damage by acting on neuroinflammation, and through direct vascular and anti-thrombotic effects. Here we review the role of RAS in brain ischemia, with specific focus on SAH and the therapeutic potential of Ang-(1-7).

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.

Psychological distress after subarachnoid haemorrhage: A systematic review and meta-analysis

OBJECTIVE

Psychological distress is a common complication in patients after Subarachnoid haemorrhage (SAH) which often has significant impact on the prognosis. The objective of this study was to determine the pooled prevalence of anxiety symptoms and depressive symptoms in patients after SAH and identify relevant risk factors.

METHODS

The study adopted a systematic review and meta-analysis protocol. Multiple databases including EMBASE, Medline, PsychInfo, and Web of Science were searched for publications before 1st January 2020. Screening, data extraction, and quality assessment were undertaken following the PRISMA guidelines for preferred reporting of systematic reviews and meta-analysis. The random-effects model was used to calculate pooled prevalence rates. Meta-analysis was conducted using Comprehensive Meta-analysis software. The review protocol was registered on PROSPERO (CRD42020182594).

RESULTS

42 studies reporting anxiety symptoms and 64 studies reporting depressive symptoms were included. The pooled short term(<3 years) and long term(≥3 years) prevalence rates of anxiety symptoms were 31.4%(95% CI: 23.6%, 40.4%) and 40.4%(95% CI: 31.6%, 49.8%), respectively, whereas the pooled short term and long term prevalence rates of depressive symptoms were 25.2%(95%CI: 17.8%, 34.5%) and 35.8%(95%CI: 28.6%, 43.6%), respectively. Gender and pre-existing psychiatric conditions were identified as potential risk factors.

CONCLUSIONS

The high prevalence of anxiety symptoms and depressive symptoms after SAH highlights the need for appropriate assessment and management of psychological stress in patients after SAH. Further research is warranted to explore potential underlying mechanisms and to develop holistic interventions that incorporate understanding of both the biological and psychological impact of SAH.

Transcriptome Analysis of Microglia Reveals That the TLR2/IRF7 Signaling Axis Mediates Neuroinflammation After Subarachnoid Hemorrhage

Microglia-mediated neuroinflammatory response in the early brain injury after subarachnoid hemorrhage (SAH) has been reported to have an impact on progress, and the mechanism is not completely understood. Here, we performed genome-wide transcriptome analysis of microglia purified from damaged hemisphere of adult mice at 3 days after SAH or sham operation. Robust transcriptional changes were observed between SAH-induced and healthy microglia, indicating rapid activation of microglia after suffering from SAH. We identified 1576 differentially expressed genes (DEGs; 928 upregulated and 648 downregulated) in SAH-induced microglia compared with sham microglia, representing a strong alteration of the genome (6.85% of total ∼23,000 genes). Functional enrichment of these DEGs indicated that cell division, inflammatory response, cytokine production, and leukocyte chemotaxis were strongly activated in SAH-induced microglia. Moreover, we identified and proved that the TLR2/IRF7 signaling axis was involved in the regulation of this microglia-mediated inflammation in SAH mice by performing flow cytometry and immunofluorescence. Together, these results provided a perspective of microglia-mediated neuroinflammatory response in the early stage of SAH and might give a new therapeutic target for SAH.