Delayed cerebral ischemia: A look at the role of endothelial dysfunction, emerging endovascular management, and glymphatic clearance

Risk factors for clazosentan-induced fluid retention in subarachnoid hemorrhage from the Japanese adverse event database

BACKGROUND

Clazosentan, a selective endothelin receptor antagonist, is used to prevent cerebral vasospasm. We investigated patient characteristics and concomitant medications associated with an increased risk of clazosentan-induced fluid retention, the risk factors of which remain unknown.

METHODS

We retrospectively reviewed cases of clazosentan-induced adverse drug reactions from the Japanese Adverse Drug Event Report (JADER) database, published by the Pharmaceuticals and Medical Devices Agency. We investigated the time course of fluid retention onset following clazosentan administration before analyzing whether specific patient characteristics and concomitant medications were associated with an increased risk of clazosentan-induced fluid retention.

RESULTS

Among 241 cases of clazosentan use identified, fluid retention occurred in 114 (47.3 %). The median time interval from clazosentan initiation to onset of fluid retention was 3 days, and 88.7 % of fluid retention cases were reported within 1 week of initiation. Patients with fluid retention were older than those without; patients >70 years old accounted for 63.16 % of the cohort with fluid retention vs 44.1 % of the cohort without fluid retention. Fluid retention occurred more frequently in patients with concomitant use of fasudil hydrochloride, a conventional vasospasm drug in Japan, than in those without. Multivariate logistic regression analysis revealed that older age (>70 years) and concomitant use of fasudil hydrochloride remained independent risk factors for fluid retention.

CONCLUSIONS

Clazosentan-induced fluid retention occurred more frequently in older adult patients. Clazosentan combined with fasudil hydrochloride increased the incidence of fluid retention. These findings can guide pharmacological treatment of cerebral vasospasm in patients with subarachnoid hemorrhage.

Quantitative electroencephalography predicts delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage: a retrospective study

PURPOSE

Delayed cerebral ischemia (DCI) is a common complication that occurs in aneurysmal subarachnoid hemorrhage (aSAH). This complication can lead to clinical deterioration and poor prognosis. The aim of this study is to explore the risk factors for DCI in aSAH patients in neurological ICU, develop a nomogram including quantitative electroencephalography (qEEG) parameters, and evaluate its performance.

METHODS

We retrospectively analyzed and processed Severe aneurysmal subarachnoid hemorrhage (SaSAH) patients from June 2022 to May 2024 who underwent bedside qEEG monitoring and analyzed the qEEG indices, brain CT, and clinical data of these patients. Logistic multivariate regression analysis was employed to identify the independent risk factors of DCI. A clinical prediction model in the form of a nomogram for DCI was developed using the R programming language and subsequently evaluated for its performance and quality.

RESULTS

A total of 145 patients with SaSAH were included in the analysis, comprising 101 patients in the training set and 44 patients in the validation set. 77 patients (53.10 %) developed DCI. Multivariate regression analysis revealed that GCS, modified Fisher grade, hypothermia, alpha/delta ratio (ADR) and PAV grade were independent risk factors for DCI. The nomogram exhibited excellent discriminative performance in both the training set (AUC = 0.84) and the validation set (AUC = 0.80).

CONCLUSION

Quantitative EEG can predict DCI following SaSAH, the resulting nomogram demonstrated substantial predictive value and may help target therapies to patients at highest risk of secondary brain injury. It needs to be further confirmed in the future by multi-center large sample studies.

Functional outcomes following endovascular treatment of vasospasm secondary to aneurysmal subarachnoid Hemorrhage: A Single center retrospective analysis

INTRODUCTION

Endovascular treatment of post-hemorrhagic cerebral vasospasm (PHCV) has the potential to improve functional outcomes but there continues to be limited data reported in the literature.

OBJECTIVE

To retrospectively review our institution's experience treating PHCV endovascularly and report clinical outcome data.

METHODS

Patients who experienced nontraumatic subarachnoid hemorrhage (SAH) and were treated with endovascular therapy were identified using ICD and CPT codes. Demographic, clinical, and outcome variables were then collected via review of electronic medical records. The primary outcome measure was rate of modified Rankin Score (mRS) ≤ 2 at discharge as well as 1, 3, and 6 months after discharge. Discharge disposition, angiographic response to treatment, and complication rates were secondary outcomes. A subgroup analysis was performed on patients treated with retrievable stents.

RESULTS

In a 12.5 year period, 1396 patients with nontraumatic SAH were treated, and of these 82/1396 (5.9 %) were treated endovascularly for vasospasm. 200 total interventions were performed on 82 patients. 29.7 % of patients had radiographic delayed cerebral ischemia. The complication rates were 3.5 % per procedure and 4.9 % per patient. 40.7 % of patients had good neurologic outcomes (mRS ≤ 2) at any time point. In-hospital mortality was 11 % and 6-month mortality was 21 %. Higher presenting Glasgow Coma Score (GCS) predicted good neurologic outcome in univariable logistic regression (OR = 1.33, p = 0.026). Patients that underwent mechanical angioplasty were significantly younger than those who did not (46 years vs 53 years, p = 0.003). 11 cases of retrievable stent angioplasty were performed, yielding a complication rate of 9 % which was comparable to the complication rate of patients treated with balloon angioplasty (4.3 %, p = 0.54).

CONCLUSIONS

Our experience with endovascular treatment of PHCV results in similar functional outcomes and complication rates to the literature. Better presenting GCS predicts good functional outcomes in patients with PHCV treated endovascularly. Patients undergoing mechanical angioplasty tended to be younger. Retrievable stents produced similar rates of complications and good functional outcomes to balloon angioplasty patients.

Altered Pattern of Serum N-Glycome in Subarachnoid Hemorrhage and Cerebral Vasospasm

Background: Subarachnoid hemorrhage is a serious condition caused by ruptured intracranial aneurysms, resulting in severe disability mainly in young adults. Cerebral vasospasm is one of the most common complication of subarachnoid hemorrhage; thus, active prevention is key to improve the prognosis. The glycosylation of proteins is a critical quality attribute which is reportedly altered in patients diagnosed with acute ischemic stroke. In this study, we examined the N-glycosylation profile of serum glycoproteins in patients with subarachnoid hemorrhage without vasospasm compared to patients with vasospasm. Methods: The serum N-glycans were released by PNGase F (Peptide: N-glycosidase F) digestion and subsequently labeled by procainamide via reductive amination. The samples were analyzed by hydrophilic-interaction liquid chromatography after solid-phase extraction-based sample purification. Results: Besides the glycosylation pattern, we also investigated the biomarkers following subarachnoid hemorrhage. Multiple statistical analyses were performed in order to find significant differences and identify potential prediction factors of cerebral vasospasm. Significant differences were identified such as higher sialylation on bi-, tri-, and tetra-antennary structures in patients with subarachnoid hemorrhage and cerebral vasospasm. Conclusions: Our results suggest that glycosylation analysis can improve the identification of patients with cerebral vasospasm in combination with laboratory parameters.

Association of dynamic changes in arterial partial pressure of carbon dioxide with neurological outcomes in aneurysmal subarachnoid hemorrhage

Background

Cerebral blood flow (CBF) is closely regulated by carbon dioxide (CO2). In patients with aneurysmal subarachnoid hemorrhage (aSAH), abnormal arterial partial pressure of CO2 (PaCO2) might deteriorate brain injuries. Nevertheless, the impact of dynamic PaCO2 fluctuations on neurological outcomes in aSAH patients has not been extensively studied. Our study aimed to investigate the association between dynamic PaCO2 levels and unfavorable neurological outcomes in aSAH patients.

Methods

In this retrospective observational study, we consecutively enrolled 159 aSAH patients from December 2019 to July 2021. Arterial blood gas measurements within 10 days after intensive care unit (ICU) admission for each patient were recorded to calculate the time-weighted average (TWA)-PaCO2, an indicator representing the dynamic changes in PaCO2 levels. For the association between TWA-PaCO2 levels and unfavorable neurological outcomes in aSAH patients, multivariable logistic analysis was used to explore TWA-PaCO2 levels as categorical variables, and restricted cubic spline (RCS) was used to explore TWA-PaCO2 levels as continuous variables.

Results

In multivariable logistic analysis, after adjusting confounders, when TWA-PaCO2 35-45 mmHg was as a reference, TWA-PaCO2 < 35 mmHg (odds ratio [OR] 2.15, 95 % confidence interval [CI] 0.83-5.55, P = 0.113) and TWA-PaCO2 > 45 mmHg (OR 8.31, 95 % CI 0.72-96.14, P = 0.090) were not independently associated with unfavorable neurological outcomes (modified Rankin score of 3-6). The RCS shows a "U" shape curve between TWA-PaCO2 levels and unfavorable neurological outcomes, with a nonlinear P-value of 0.023. The lowest ORs of unfavorable neurological outcomes were within PaCO2 32.8-38.1 mmHg.

Conclusions

Both lower and higher PaCO2 levels are harmful to aSAH patients. PaCO2 in the range of 32.8-38.1 mmHg is associated with lowest unfavorable neurological outcomes.

Melatonin Improves Vasogenic Edema via Inhibition to Water Channel Aquaporin-4 (AQP4) and Metalloproteinase-9 (MMP-9) Following Permanent Focal Cerebral Ischemia

Background: The efficacy of melatonin in reducing vasogenic and cytotoxic edema was investigated using a model of permanent middle cerebral artery occlusion (pMCAO). Methods: Rats underwent pMCAO, followed by intravenous administration of either melatonin (5 mg/kg) or a vehicle 10 min post-insult. Brain infarction and edema were assessed, and Western blot analyses were conducted to examine the expression levels of aquaporin-4 (AQP4), metalloproteinase-9 (MMP-9), and the neurovascular tight-junction protein ZO-1 upon sacrifice. The permeability of the blood-brain barrier (BBB) was measured using spectrophotometric quantification of Evans blue dye leakage. Results: Compared to controls, melatonin-treated rats exhibited a significant reduction in infarct volume by 26.9% and showed improved neurobehavioral outcomes (p < 0.05 for both). Melatonin treatment also led to decreased Evans blue dye extravasation and brain edema (p < 0.05 for both), along with lower expression levels of AQP4 and MMP-9 proteins and better preservation of ZO-1 protein (p < 0.05 for all). Conclusions: Therefore, melatonin offers neuroprotection against brain swelling induced by ischemia, possibly through its modulation of AQP4 and MMP-9 activities in glial cells and the extracellular matrix (ECM) during the early phase of ischemic injury.

Identification of key genes and immune infiltration in peripheral blood biomarker analysis of delayed cerebral ischemia: Valproic acid as a potential therapeutic drug

BACKGROUND

Delayed cerebral ischemia (DCI) is a common and serious complication of subarachnoid hemorrhage (SAH). Its pathogenesis is not fully understood. Here, we developed a predictive model based on peripheral blood biomarkers and validated the model using several bioinformatic multi-analysis methods.

METHODS

Six datasets were obtained from the GEO database. Characteristic genes were screened using weighted correlation network analysis (WGCNA) and differentially expressed genes. Three machine learning algorithms, elastic networks-LASSO, support vector machines (SVM-RFE) and random forests (RF), were also used to construct diagnostic prediction models for key genes. To further evaluate the performance and predictive value of the diagnostic models, nomogram model were constructed, and the clinical value of the models was assessed using Decision Curve Analysis (DCA), Area Under the Check Curve (AUC), Clinical Impact Curve (CIC), and validated in the mouse single-cell RNA-seq dataset. Mendelian randomization(MR) analysis explored the causal relationship between SAH and stroke, and the intermediate influencing factors. We validated this by retrospectively analyzing the qPCR levels of the most relevant genes in SAH and SAH-DCI patients. This experiment demonstrated a statistically significant difference between SAH and SAH-DCI and normal group controls. Finally, potential small molecule compounds interacting with the selected features were screened from the Comparative Toxicogenomics Database (CTD).

RESULTS

The fGSEA results showed that activation of Toll-like receptor signaling and leukocyte transendothelial cell migration pathways were positively correlated with the DCI phenotype, whereas cytokine signaling pathways and natural killer cell-mediated cytotoxicity were negatively correlated. Consensus feature selection of DEG genes using WGCNA and three machine learning algorithms resulted in the identification of six genes (SPOCK2, TRRAP, CIB1, BCL11B, PDZD8 and LAT), which were used to predict DCI diagnosis with high accuracy. Three external datasets and the mouse single-cell dataset showed high accuracy of the diagnostic model, in addition to high performance and predictive value of the diagnostic model in DCA and CIC. MR analysis looked at stroke after SAH independent of SAH, but associated with multiple intermediate factors including Hypertensive diseases, Total triglycerides levels in medium HDL and Platelet count. qPCR confirmed that significant differences in DCI signature genes were observed between the SAH and SAH-DCI groups. Finally, valproic acid became a potential therapeutic agent for DCI based on the results of target prediction and molecular docking of the characterized genes.

CONCLUSION

This diagnostic model can identify SAH patients at high risk for DCI and may provide potential mechanisms and therapeutic targets for DCI. Valproic acid may be an important future drug for the treatment of DCI.

Interventional Treatment of Symptomatic Vasospasm in the Setting of Traumatic Brain Injury: A Systematic Review of Reported Cases

Traumatic subarachnoid hemorrhage (tSAH) is frequently comorbid with traumatic brain injury (TBI) and may induce secondary injury through vascular changes such as vasospasm and subsequent delayed cerebral ischemia (DCI). While aneurysmal SAH is well studied regarding vasospasm and DCI, less is known regarding tSAH and the prevalence of vasospasm and DCI, the consequences of vasospasm in this setting, when treatment is indicated, and which management strategies should be implemented. In this article, a systematic review of the literature that was conducted for cases of symptomatic vasospasm in patients with TBI is reported, association with tSAH is reported, risk factors for vasospasm and DCI are summarized, and commonalities in diagnosis and management are discussed. Clinical characteristics and treatment outcomes of 38 cases across 20 studies were identified in which patients with TBI with vasospasm underwent medical or endovascular management. Of the patients with data available for each category, the average age was 48.7 ± 20.3 years (n = 31), the Glasgow Coma Scale score at presentation was 10.6 ± 4.5 (n = 35), and 100% had tSAH (n = 29). Symptomatic vasospasm indicative of DCI was diagnosed on average at postinjury day 8.4 ± 3.0 days (n = 30). Of the patients, 56.6% (n = 30) had a new ischemic change associated with vasospasm confirming DCI. Treatment strategies are discussed, with 11 of 12 endovascularly treated and 19 of 26 medically treated patients surviving to discharge. tSAH is associated with vasospasm and DCI in moderate and severe TBI, and patients with clinical and radiographic evidence of symptomatic vasospasm and subsequent DCI may benefit from endovascular or medical management strategies.

Cerebral Blood Deoxygenation by a Postural Change Detected by Near-Infrared Spectroscopy Has a Close Association with Cerebral Infarction

BACKGROUND

The recent introduction of near-infrared spectroscopy has enabled the monitoring of cerebral blood flow in real-time. Previous studies have shown that blood flow velocity is a predictor of cardiovascular disease. We hypothesized that cerebral oxygenation with a change in posture is a predictor for cerebral infarction. We designed a cross-sectional study to investigate the relationship between postural-related changes in cerebral oxygenation and a history of chronic cerebral infarction.

METHODS

A total of 100 consecutive participants were enrolled in this study. We evaluated changes in cerebral oxygenation with a change in posture from the supine to the upright position in the bilateral forehead. The association between a decline in cerebral oxygenation and chronic cerebral infarction was analyzed with multiple logistic regression adjusted for covariates.

RESULTS

Cerebral blood oxygenation increased in 52 participants and decreased in 48 participants with a postural change. The prevalence of decreased cerebral oxygenation was 76.3% in participants with chronic cerebral infarction. Multiple logistic regression analysis showed that a decline in cerebral oxygenation upon a postural change was strongly associated with chronic cerebral infarction (adjusted odds ratio: 3.42, p = 0.025).

CONCLUSIONS

Cerebral blood oxygenation upon a postural change could be a useful predictor for cerebral infarction.