Prediction of delayed cerebral ischemia followed aneurysmal subarachnoid hemorrhage. A machine-learning based study.

INTRODUCTION: Delayed Cerebral Ischemia (DCI) is a significant complication following aneurysmal subarachnoid hemorrhage (aSAH) that can lead to poor outcomes. Machine learning techniques have shown promise in predicting DCI and improving risk stratification. METHODS: In this study, we aimed to develop machine learning models to predict the occurrence of DCI in patients with aSAH. Patient data, including various clinical variables and co-factors, were collected. Six different machine learning models, including logistic regression, multilayer perceptron, decision tree, random forest, gradient boosting machine, and extreme gradient boosting (XGB), were trained and evaluated using performance metrics such as accuracy, area under the curve (AUC), precision, recall, and F1 score. RESULTS: After data augmentation, the random forest model demonstrated the best performance, with an AUC of 0.85. The multilayer perceptron neural network model achieved an accuracy of 0.93 and an F1 score of 0.85, making it the best performing model. The presence of positive clinical vasospasm was identified as the most important feature for predicting DCI. CONCLUSIONS: Our study highlights the potential of machine learning models in predicting the occurrence of DCI in patients with aSAH. The multilayer perceptron model showed excellent performance, indicating its utility in risk stratification and clinical decision-making. However, further validation and refinement of the models are necessary to ensure their generalizability and applicability in real-world settings. Machine learning techniques have the potential to enhance patient care and improve outcomes in aSAH, but their implementation should be accompanied by careful evaluation and validation.

Metal allergy and neurovascular stenting: A systematic review.

BACKGROUND: Intracranial stents and flow diverters contain significant amounts of metals, notably nickel, which can cause allergic reactions in a considerable portion of the population. These allergic responses may lead to complications like in-stent stenosis (ISS) and TIA/Stroke in patients receiving stents or flow diverters for intracranial aneurysms. METHODS: We conducted a systematic review of studies from inception until July 2023, which reported outcomes of patients with metal allergy undergoing neurovascular stenting. The skin patch test was used to group patients into those with positive, negative, or absent patch test results but with a known history of metal allergy. RESULTS: Our review included seven studies with a total of 39 patients. Among them, 87% had a history of metal allergy before treatment. Most aneurysms (89%) were in the anterior circulation and the rest (11%) were in the posterior circulation. Skin patch tests were performed in 59% of patients, with 24% showing positive results and 33% negative. Incidental ISS was observed in 18% of patients, and the rate of TIA/Stroke was reported in 21%. The pooled rates of ISS and TIA/Stroke were higher in the first group (43% and 38%) compared to the second (18% and 9%) and third groups (15% and 15%), but these differences were not statistically significant. CONCLUSIONS: The current neurosurgical literature does not provide a conclusive association between metal allergy and increased complications among patients undergoing neurovascular stenting. Further studies are necessary to gain a more comprehensive understanding of this topic.

Balloon-assisted U-turn Technique to Access Cortical Vein for Transvenous Embolization of Mixed Dural-pial Arteriovenous Malformation.

Cerebral arteriovenous malformations can be classified into pure pial, mixed dural-pial, and pure dural types. Mixed pial-dural AVMs (DPAVM) are rare and often receive blood supply from dural meningeal arteries, including branches of the internal carotid, external carotid, and vertebral arteries.1- 6 DPAVMs, which are usually large and complex, require delicate endovascular and surgical treatment methods. The cure rate is low, and recurrence is very common, leading to high morbidity and mortality. In this case video, we present a case of PDAVM that recurred after initial endovascular onyx embolization, requiring additional endovascular coiling which resulted in obliteration of the DPAVM.

Natural History, Pathophysiology, and Recent Management Modalities of Intraventricular Hemorrhage.

Intraventricular hemorrhage (IVH) is a clinical challenge observed among 40-45% of intracerebral hemorrhage (ICH) cases. IVH can be classified according to the source of the hemorrhage into primary and secondary IVH. Primary intraventricular hemorrhage (PIVH), unlike secondary IVH, involves only the ventricles with no hemorrhagic parenchymal source. Several risk factors of PIVH were reported which include hypertension, smoking, age, and excessive alcohol consumption. IVH is associated with high mortality and morbidity and several prognostic factors were identified such as IVH volume, number of ventricles with blood, involvement of fourth ventricle, baseline Glasgow Coma Scale score, and hydrocephalus. Prompt management of patients with IVH is required to stabilize the clinical status of patients upon admission. Nevertheless, further advanced management is crucial to reduce the morbidity and mortality associated with intraventricular bleeding. Recent treatments showed promising outcomes in the management of IVH patients such as intraventricular anti-inflammatory drugs, lumbar drainage, and endoscopic evacuation of IVH, however, their safety and efficacy are still in question. This literature review presents the epidemiology, physiopathology, risk factors, and outcomes of IVH in adults with an emphasis on recent treatment options.

Peripheral Monocytosis at Admission to Predict Cerebral Infarct and Poor Functional Outcomes in Subarachnoid Hemorrhage Patients.

OBJECTIVE: Increasing evidence points monocytes' role to be larger than thought in developing cerebral infarction (CI) after subarachnoid hemorrhage (SAH). However, there is no clinical evidence of the relationship between peripheral monocytes and CI and clinical outcomes. Therefore we determine whether an increase in monocytes in the acute phase is useful to predict CI and functional outcomes in SAH patients. METHODS: We included 204 patients with an SAH diagnosis. We collected patient-related factors, comorbidities, Hunt-Hess grade, modified Fisher grade, treatment, delayed cerebral ischemia, CI, aneurysm characteristics, and peripheral monocytes from vein blood at admission. Poor outcomes were defined as modified Rankin Scale score ≥3. RESULTS: Fifty (24.5%) patients had CI before discharge. In a multivariate model, increased monocytes at admission were significantly associated with CI after adjusting for IV-V Hunt-Hess grade and delayed cerebral ischemia (odds ratio: 3.193, 95% confidence interval: 1.069-9.532, P = 0.037). In receiver operating characteristic curve analysis, a monocyte count of 0.60 was identified as the best cutoff value to discriminate the development of CI (area under the curve = 0.622, P = 0.010; CI for monocytes <0.60 17.4% vs. CI for monocytes ≥0.60 29.1% P = 0.046). Admission monocytes ≥0.60 predicted poor functional outcomes at discharge (monocytes <0.60 52% vs. monocytes ≥0.60 64.7%) and at 12 months (monocytes <0.60 29.4% vs. monocytes ≥0.60 70.6%). CONCLUSIONS: Increased peripheral monocytes at admission is a risk factor for developing CI after SAH. Moreover, short- and long-term poor clinical outcomes were associated with higher monocyte count. Therefore monocytes could be a convenient biomarker for prognosis unfavorable outcomes and a possible target for new therapeutic strategies.