Vanessa Magdalena Swiatek

Background/Objectives: Aneurysmal subarachnoid hemorrhage (aSAH) carries high morbidity and mortality, with delayed cerebral ischemia (DCI) as a major secondary complication. Although infection has increasingly been implicated in DCI pathogenesis, the role of central nervous system (CNS) infection remains unclear. We evaluated CNS infection-related parameters for predicting DCI and functional outcome after aSAH using machine learning. Methods: This retrospective single-center study included 191 patients with confirmed aSAH treated in the intensive care unit between 2019 and 2024. Demographic, clinical, radiographic, treatment-related, microbiological, cerebrospinal fluid (CSF), and longitudinal laboratory data were extracted from electronic records. DCI was analyzed as a binary outcome, and discharge functional outcome was dichotomized using the modified Rankin Scale (0–2 vs. 3–6). Twelve feature selection methods and twelve classifiers were evaluated using five-fold cross-validation. Results: For DCI prediction, the models achieved a mean accuracy of 0.96, F1-score of 0.96, and AUC of 0.98. Key predictors included antibiotic therapy, aneurysm treatment modality, history of thrombosis, and EVD revision, along with mean albumin, red cell distribution width, INR, minimum aspartate aminotransferase, and CSF glucose, lactate, nucleated cell count, and cellular debris. For functional outcome prediction, accuracy was 0.948, F1-score 0.95, and AUC was 0.97. Predictors comprised cerebral vasospasm, number of spasmolysis procedures, pre-admission anticoagulation, CSF pathogen detection and type, aPTT, fibrinogen, aspartate aminotransferase, lactate dehydrogenase, and CSF mononuclear cell proportion, leukocyte count, and glucose concentration. Conclusions: Machine learning models integrating clinical, systemic, and CSF-derived parameters demonstrated excellent performance in predicting both DCI and functional outcome after aSAH. The identified predictors highlight the importance of the neurocritical care course, including infection-related and thromboinflammatory processes, and extend beyond traditional vasospasm-centered paradigms. These findings may inform risk stratification, although the temporal relationship between several predictors and outcome onset means the models should be regarded as hypothesis-generating rather than tools for early clinical prediction.

Background/Objectives: Delayed cerebral ischemia (DCI) is a major cause of poor outcome after aneurysmal subarachnoid hemorrhage (aSAH). Beyond large-vessel vasospasm, DCI reflects a systemic, multifactorial process involving inflammation, hematologic dysregulation, and organ dysfunction. Stroke-associated pneumonia (SAP), a frequent aSAH complication linked to stroke-induced immunodepression, may aggravate secondary ischemic injury. Unlike prior studies focusing on classical predictors alone, we included pneumonia and longitudinal respiratory parameters alongside inflammatory, hematologic, and renal markers. Using machine learning, this study aimed to identify predictors of DCI and functional outcome from routinely collected intensive care data. Methods: In this retrospective single-center study, 182 aSAH patients treated in a neurosurgical intensive care unit were included. Clinical data, SAP status, and longitudinal inflammatory, hematologic, renal, and respiratory parameters were extracted. DCI and functional outcome were assessed. Continuous variables were summarized as minimum, maximum, and mean values. Supervised machine learning models combining 12 feature selection methods and 12 classifiers were trained using five-fold cross-validation and evaluated by accuracy, F1-score, and AUC. Results: DCI occurred in 22% of patients, and SAP in 27%. The machine learning models achieved a mean accuracy of 59.7% (F1-score 58.8%, AUC 59.7%) for DCI prediction. No single dominant feature emerged; predictive patterns included leukocyte counts, CRP, erythrocyte indices, platelet variability, renal function, and oxygenation metrics. Functional outcome prediction performed moderately better (mean AUC 65.7%) and shared overlapping predictors. Conclusions: DCI reflects systemic instability in aSAH, with longitudinal inflammatory and respiratory variability outperforming static thresholds. Dynamic risk stratification may enable earlier detection of deterioration, supporting future time-series modeling and external validation.

Background/Objectives: Holocord astrocytomas are exceptionally rare intramedullary tumors, especially in adults, and often present with extensive longitudinal growth. Because only a small number of cases have been described, management strategies remain insufficiently defined. This report presents an adult patient treated with a staged surgical approach and provides an updated review of the literature. Methods: A 31-year-old male presented with progressive paraparesis, sensory deficits, and sphincter dysfunction. MRI demonstrated an intramedullary tumor extending from T3 to the conus medullaris. The patient underwent a planned two-stage resection with intraoperative neurophysiological monitoring. Histopathological and DNA-methylation analyses were performed. Additionally, a systematic review of previously reported holocord astrocytoma cases was conducted. Results: The two-stage surgical strategy enabled extensive debulking across multiple spinal segments while preserving neurological function. The patient demonstrated marked postoperative improvement, including restoration of sphincter control, improved motor function, and better mobility. Histopathological analyses confirmed a high-grade astrocytoma with piloid features. The literature review identified 28 previously reported cases, including only 5 in adults. Reported neurological outcomes across adult cases are variable, reflecting the heterogeneity and rarity of this tumor entity. Conclusions: Holocord astrocytomas in adults are extremely rare and pose particular diagnostic and therapeutic challenges. This case demonstrates that a carefully planned, staged surgical approach can achieve meaningful neurological recovery, even in patients presenting with severe preoperative deficits. The report expands the limited body of evidence available for adult holocord astrocytomas and may support future management strategies.

Backround: The flow characteristics of bifurcation aneurysms in the posterior communicating artery (PCOM) have rarely been studied. The likelihood of a complete PCOM aneurysm occlusion after endovascular treatment is reduced with the presence of a fetal posterior communicating artery (fPCOM). As a result, anatomical variations in PCOM aneurysms represent a major challenge for the endovascular treatment. This study addresses hemodynamic variations in PCOM aneurysms of either fetal or adult type. Methods: 3D-DSA data of 14 patients with bifurcation aneurysms located in the PCOM junction were collected. Nine patients presented with a fPCOM and five patients an adult PCOM (aPCOM). Patient-specific 3D models containing at least one bifurcation distal the aneurysm in the anterior circulation as well as the PCOM itself were extracted using image-based blood flow simulations. Seven hemodynamic parameters were calculated for all aneurysm models to characterize the intra-aneurysmal blood flow. The PCOM outflow was artificially varied to represent both fPCOM and aPCOM conditions for each model resulting in 28 simulations. Results: Fetal‑type PCOM showed higher intra‑aneurysmal mean velocity (median 0.09 vs. 0.06 m/s), maximum velocity (0.17 vs. 0.14 m/s), averaged wall shear stress (1.67 vs. 1.27 Pa), neck inflow rate (40.9 vs. 22.4 ml/min), and inflow concentration index (0.56 vs. 0.40), with lower pulsatility index (1.73 vs. 1.89). Those differences were significant whereas mean oscillatory shear index did not differ significantly. Conclusion: The presence of anatomical variations affects the hemodynamic parameters of PCOM bifurcation aneurysms. In particular, the presence of an fPCOM has an unfavorable effect on the intra-aneurysmal flow dynamics.

Background: Head-mounted augmented reality (AR) displays are a promising innovation in neurosurgical visualization, offering the potential to improve ergonomics and team coordination compared to traditional operating microscopes. Surgeons frequently experience physical strain due to fixed postures during long procedures, contributing to work-related musculoskeletal disorders. This technical note reports on the first clinical use of an AR headset during convexity meningioma resection. Methods: An 82-year-old female patient underwent surgical resection of a left convexity meningioma using an AR visualization system (Leica MyVeo). The headset displayed the microscope feed directly into the surgeon’s and assistant’s field of view, allowing both to maintain ergonomic postures throughout the operation. A post-procedural questionnaire and rapid entire body assessment (REBA) scores were used to evaluate ergonomics and workflow. Results: The AR headset was rated positively for improving team coordination and visualization continuity. Both surgeon and assistant reported increased comfort and reduced strain during the procedure. REBA scores indicated low ergonomic risk (3 for the surgeon, 2 for the assistant), suggesting an improvement over typical scores reported for microscope-based surgery. The tumor was completely resected without complications, and the patient had an uneventful postoperative course. Conclusion: This initial experience demonstrates that AR headsets can be safely integrated into neurosurgical workflows, offering significant ergonomic and collaborative advantages. These findings support further investigation into AR-assisted visualization as a complementary tool to traditional operative microscopy.

BACKGROUND: Thrombosed intracranial aneurysms are rare in pediatric populations and pose significant diagnostic challenges due to their atypical imaging features, which often mimic neoplasms. These lesions can present with mass effect, contrast enhancement, and calcifications, leading to potential misdiagnosis and inappropriate management. Accurate differentiation through advanced imaging is essential to prevent surgical complications and ensure optimal outcomes. OBSERVATIONS: The authors describe the case of a 15-year-old boy with severe acute headaches and an MRI finding of a contrast-enhancing lesion in the left cerebellar tonsil abutting the medulla oblongata, suggestive of a neoplasm. Neurological examination was normal, and there was no significant medical history. Despite negative angiographic findings, the unclear etiology warranted surgical intervention. A median suboccipital craniotomy revealed a capsule-like lesion with arterial feeders from the posterior inferior cerebellar artery. Complete resection was achieved, and histopathology confirmed a thrombosed aneurysm. Postoperative recovery was uneventful, and 1-year follow-up showed full symptom resolution without recurrence. LESSONS: This case highlights the importance of considering thrombosed aneurysms in pediatric patients with atypical intracranial lesions. Multidisciplinary collaboration and advanced imaging are crucial for accurate diagnosis and effective management. Documenting such cases enhances understanding, refines diagnostic strategies, and improves patient care. https://thejns.org/doi/10.3171/CASE2592

Background/Objectives: Perioperative strokes are a rare but recognized complication of cerebral aneurysm surgeries, often influenced by patient-specific factors. Amphetamine abuse, known for its vasospastic effects, is an underexplored risk factor in the neurosurgical setting. This report highlights the clinical and perioperative challenges associated with acute undisclosed amphetamine abuse in a patient undergoing elective clipping of an unruptured middle cerebral artery (MCA) aneurysm. Methods: A 46-year-old male presented with a 3 mm broad-based unruptured aneurysm in the proximal M1 segment of the right MCA. The patient reported a history of illicit drug use, including intravenous consumption. Upon further questioning, he admitted to intermittent use of amphetamines, although he denied any recent use. Elective aneurysm clipping via a transsylvian approach was performed after multidisciplinary consensus. Postoperatively, the patient developed anisocoria, prompting an emergency CT with perfusion and angiography, showing significant findings. Further imaging revealed a bilateral superior cerebellar artery territory infarction. Given the patient’s medical history, a toxicology screening later confirmed recent amphetamine use. Conclusions: This case highlights the need for preoperative evaluation, including routine toxicology screening, in patients with a history of substance abuse. Amphetamine use may present perioperative challenges and increase the risk of complications like vasospasm and stroke.

Brain arteriovenous malformations (bAVMs) are complex vascular lesions with significant clinical risks. The Hippo signaling pathway, particularly its downstream effector YAP, plays a crucial role in angiogenesis and vascular remodeling. This study investigates the role of YAP and related molecular markers in bAVMs, focusing on the effects of embolization. Immunohistochemical analysis was conducted on tissue samples from bAVM patients (n = 127), as well as on healthy blood vessels (n = 17). YAP, HIF-1α, FGFR1, CTGF, and CYR61 expression were quantified and correlated with clinical parameters. Results: In healthy vessels, YAP exhibited nuclear localization in (sub)endothelial cells and the tunica media, while CTGF and CYR61 were detected in the cytoplasm and extracellular matrix. The expression of YAP, CTGF, and CYR61 was significantly lower in bAVM tissues. Embolized bAVMs exhibited significantly higher expression of YAP, CTGF, and CYR61 compared to non-embolized tissues, suggesting a link between embolization and pro-angiogenic signaling. Additionally, FGFR1 was upregulated in embolized tissues. These results suggest that upregulation of YAP expression via the Hippo pathway might play a key role in bAVM pathophysiology. Embolization may further promote vascular remodeling. Dysregulation of YAP and related molecules in bAVMs warrants further studies to explore potential therapeutic strategies targeting the Hippo pathway.

Background and Objectives: Realistic surgical simulation models are essential for neurosurgical training, particularly in glioma resection. We developed a patient-specific simulation model designed for fluorescence-guided glioma resection, providing an anatomically accurate and reusable platform for surgical education. While insular gliomas were used as an example, the model can be adapted to simulate gliomas in other brain regions, making it a versatile training tool. Methods: Using open-source 3D software, we created a digitally reconstructed skull, brain, and cerebral vessels, including a fluorescent insular glioma. The model was produced through additive manufacturing and designed with input from neurosurgeons to ensure a realistic and reusable representation of the Sylvian fissure and bone structures. The simulator’s educational effectiveness and usability were evaluated by two senior physicians, four assistant physicians, and six medical students using actual microsurgical instruments. Assessments were based on subjective and objective criteria. Results: Subjective evaluations, using a 5-point Likert scale, showed high face and content validity. Objective measures demonstrated strong construct validity, accurately reflecting the participant’s skills. Medical students and resident neurosurgeons showed marked improvement in their learning curve over three attempts, with progressive improvement in performance. Conclusions: This simulation model addresses advanced neurosurgical training needs by providing a highly realistic, cost- effective, and adaptable platform for fluorescence-guided glioma resection. Its effectiveness in enhancing surgical skills suggests significant potential for broader integration into neurosurgical training programs. Further studies are warranted to explore its applications in different glioma localizations and training settings.