Purpose This study compared laminectomy and hemilaminectomy for resection of spinal (sHBs), evaluating extent of resection, 12-month postoperative functional outcomes, perioperative complications overall, with particular attention to postoperative bleeding. Material and methods This retrospective international multicenter study included 280 primary sHB patients from 13 neuro-oncological centers who underwent either laminectomy (n = 125) or hemilaminectomy (n = 155). The endpoints were the extent of resection, functional outcomes at 12 months, and postoperative bleeding requiring retreatment. Multivariable logistic regression analysis was performed to determine independent risk factors associated with these outcomes. Results The rate of complete resection was similar between both surgical approaches, with 86.4% in the laminectomy group and 90.3% in the hemilaminectomy group (p = 0.35). Independent predictors of incomplete resection included preoperative modified McCormick >2 (OR: 4.29, p = 0.001), combined intra- and extramedullary tumor location (OR: 2.91, p = 0.03), and cervical or thoracic tumor location (OR: 3.38, p = 0.01). Functional outcomes at 12 months did not differ significantly between the laminectomy- and hemilaminectomy-groups (p = 0.97). Postoperative bleeding was more frequently observed in tumors involving two or more spinal segments (OR: 14.6, p = 0.01). The choice of surgical approach did not impact the incidence of postoperative bleeding (p = 0.55). Conclusion Laminectomy and hemilaminectomy result in comparable outcomes of sHB. Tumors affecting multiple spinal segments are associated with an increased risk of postoperative bleeding, while combined intra- and extramedullary growth, impaired preoperative functioning and non-lumbar location were associated with incomplete resection. Given the comparable outcomes, the selection of the surgical approach may be guided by surgeon preference and individual patient anatomy.

OBJECTIVES:To validate whether cerebrospinal fluid oxyhaemoglobin (CSF-Hb), measured from external ventricular or lumbar drains, is associated with secondary brain injury (SAH-SBI) after aneurysmal subarachnoid haemorrhage (aSAH) and to assess its value as a real-time monitoring biomarker. DESIGN:Pre-registered multicentre prospective observational cohort study. SETTING:Eight neurosurgical tertiary centres in Switzerland, Germany and Austria between August 2021 and June 2024. PARTICIPANTS:366 patients with aSAH (mean age 58 years; 65% women). Of these, 260 provided cerebrospinal fluid (CSF) samples via external ventricular drain (EVD; 2467 samples, median 10 days per patient) and 66 via lumbar drain (LD; 379 samples, median 6 days). INTERVENTIONS:Daily CSF samples were collected via EVD or LD from day 1 to day 14 after haemorrhage; no therapeutic interventions were tested. MAIN OUTCOME MEASURES:CSF-Hb and its metabolites were analysed post hoc in a blinded manner. The primary outcome was SAH-SBI, defined as a composite of angiographic vasospasm (aVSP), delayed cerebral ischaemia (DCI) and delayed ischaemic neurological deficits (DIND), assessed daily over 14 days. Secondary outcomes included temporal CSF-Hb profiles and associations with aneurysm location, haematoma volume, intraventricular haemorrhage, chronic hydrocephalus and 3 month functional outcome. RESULTS:CSF-Hb showed a delayed peak pattern: concentrations were low after aSAH, rose to a maximum on day 10 (EVD-derived CSF-Hb median 11.3 µM, IQR 2.64 to 25.90) and then declined. Larger haematoma volume (p<0.001) and intraventricular haemorrhage (p<0.001) were associated with higher EVD-derived CSF-Hb. SAH-SBI occurred in 209/366 patients (57%). Daily EVD-derived CSF-Hb showed no association with SAH-SBI (p=0.25) and only poor prognostic potential for same-day SAH-SBI (area under the curve 0.59, 95% CI 0.56 to 0.63), with substantial between-centre heterogeneity. In a post-hoc exploratory analysis, higher CSF methaemoglobin showed a positive point-estimate of association with SAH-SBI (OR 1.18 per log(µM), 95% CI 1.02 to 1.36). Higher acute-phase EVD-derived CSF-Hb was associated with chronic hydrocephalus and a poor 3 month functional outcome. Catheter-related infection rates were low (2.2%). CONCLUSIONS:In this preregistered multicentre validation study, EVD-derived CSF-Hb did not perform as a robust real-time monitoring biomarker for SAH-SBI, showing limited same-day discrimination and substantial between-centre heterogeneity. These findings argue against clinical implementation of CSF-Hb point-measurement as a single-parameter biomarker. Higher CSF methaemoglobin was associated with SAH-SBI; this hypothesis-generating observation requires prospective confirmation and motivates continued investigation of haemolysis-related pathways. Future work using the HeMoVal biobank will apply multi-marker, pathway-level analyses to define haemolysis-related biomarker signatures and provide a platform for robust external validation of future candidates. TRIAL REGISTRATION NUMBER:NCT04998370.

Introduction Adult tethered cord syndrome (TCS) represents a heterogeneous group of congenital and acquired conditions. While primary untethering is an established treatment, re-untethering remains controversial because of concerns regarding limited neurological benefit and increased complication rates. Research question This study evaluates neurological outcomes after adults re-untethering surgery and identifies perioperative factors associated with clinical improvement. Methods We performed a retrospective single-center cohort analysis of all patients surgically treated for TCS between 2008 and 2024. Patients were dichotomized into primary untethering and secondary re-untethering groups. Neurological status was assessed using the McCormick grade. Neurological improvement was defined as improvement of ≥1 McCormick grade. Postoperative complications and revision surgeries were recorded. Age and affected spinal level were analyzed as potential modifiers of outcome. Results Seventy-one patients were included (median age 51.5 years); 42 underwent primary untethering and 29 re-untethering. Patients undergoing re-untethering presented with significantly worse baseline neurological status. Neurological improvement at discharge was more frequent after primary untethering (52.4% vs. 31.0%), but this difference reversed at follow-up, with higher improvement rates after secondary re-untethering (68.4% vs. 61.5%). Neither age nor affected spinal level significantly influenced neurological outcome or revision rates. Re-untethering was associated with more complex surgeries, and higher wound-healing complication rates. Discussion and Conclusion Despite worse baseline neurological status, re-untethering is not associated with inferior neurological outcomes compared with primary untethering. Neurological improvement appears to be a time-dependent process, and baseline impairment alone should not preclude surgical intervention. Re-untethering in adult patients should therefore be considered on an individual basis.

Introduction:Spondylodiscitis poses diagnostic challenges due to nonspecific symptoms and limitations of conventional imaging modalities. Moreover, causative infection foci often remain unidentified. Early and accurate diagnosis and treatment of the infectious focus are essential to prevent severe complications. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) has emerged as complementary tool to MRI, enabling detection of metabolically active infectious processes. Research question:This study evaluates the diagnostic accuracy of FDG-PET/CT in patients with suspected spondylodiscitis and its ability to identify additional infectious foci. Material and methods:A retrospective analysis included 191 patients who underwent FDG-PET/CT for suspected spondylodiscitis between 01.01.2016 and 31.12.2023. PET findings were compared with MRI, pathological, and microbiological and clinical data. Results:Spinal infection was confirmed in 160 of 191 patients. In patients with inconclusive MRI findings (n = 46), FDG-PET/CT led to diagnostic reclassification in 21 cases (45.7%). In the subgroup analyzed for diagnostic accuracy (n = 56), sensitivity was 56% for FDG-PET/CT and 62% for MRI, increasing to 74% when both modalities were combined (p = 0.002). Specificity was 96% for FDG-PET/CT and 86% for MRI. FDG-PET/CT identified 23 previously unknown extraspinal infectious foci and confirmed 23 suspected foci, resulting in detection of infectious sources in 73% of patients. Infectious foci were detected more frequently in cervical infections (33.3% vs. 9.5%, p = 0.001). Patients undergoing FDG-PET/CT showed higher clinical resolution rates at follow-up (p = 0.045). Discussion and conclusion:FDG-PET/CT provides complementary value in suspected spondylodiscitis, particularly in cases with inconclusive MRI and for detecting additional infectious foci, supporting its role in multimodal diagnostic strategies.

Introduction:Device-assisted endovascular treatment of ruptured aneurysms may require antiplatelet therapy, but bleeding risk is a concern. This retrospective propensity score-matched cohort study investigated whether tirofiban, including prolonged administration for ≥7 days, was associated with secondary bleeding complications. Methods:We analyzed 99 patients treated endovascularly aSAB between 2006 and 2024, including 51 patients receiving tirofiban and 48 controls selected using propensity score matching. Tirofiban patients were categorized into short-term treatment (<7 days) and prolonged treatment (≥7 days). Bleeding complications were classified using an adapted Heidelberg bleeding classification and categorized as spontaneous or surgery-associated. Results:For the main bleeding endpoints, evaluable data were available for 42 controls, 29 patients with short-term tirofiban, and 18 patients with prolonged tirofiban. Any spontaneous secondary bleeding occurred in 6/42 controls (14%), 2/29 short-term tirofiban patients (7%; p = 0.46), and 1/18 prolonged tirofiban patients (6%; p = 0.66). Surgery-associated bleeding occurred in 13/42 controls (31%), 11/29 short-term tirofiban patients (38%; p = 0.72), and 7/18 prolonged tirofiban patients (39%; p = 0.77). Clinically relevant bleeding occurred in 2/42 controls (5%), 0/29 short-term tirofiban patients (0%; p = 0.51), and 1/18 prolonged tirofiban patients (6%; p = 1.00). Median hospital duration was 21 days in controls, 18 days in short-term, and 31 days in prolonged tirofiban patients. Conclusion:In this small retrospective cohort, tirofiban, including prolonged administration for ≥7 days, was not associated with a statistically significant increase in spontaneous, surgery-associated, or clinically relevant secondary bleeding. These exploratory findings require confirmation in larger prospective studies.

To evaluate the accuracy of opportunistic measurements of volumetric bone mineral density (vBMD) in intraoperative multi-detector CT (MDCT) scans, using preoperative MDCT as the reference. This retrospective, single-center study included 105 patients (mean age: 73 ± 12.6 years, 53 women) who underwent spine surgery for various indications. All patients had preoperative MDCT with/without intravenous contrast and unenhanced intraoperative scans. VBMD of thoracolumbar vertebrae was automatically extracted using a convolutional neural network (CNN)-based framework with asynchronous calibration and contrast-phase correction. Vertebrae affected by artifacts, fractures, or severe degenerations were excluded. Root-mean-square errors (RMSEs) for associations between pair-wise vertebrae from preoperative and intraoperative vBMD values were calculated in linear regression models. Mean bias and 95

Background Multicenter clinical datasets are increasingly available but are often analyzed using models that ignore center-specific variability or fail to capture complex dependencies among variables. This is particularly limiting in the context of intracranial aneurysms (IAs), where existing risk scores lack precision and interpretability. Objective We apply mixed-effects additive Bayesian networks (ABNs) to a large multicenter dataset to model interdependencies among demographic, clinical, and aneurysm-specific features in solitary ruptured IAs, while accounting for heterogeneity across study centers. Methods Data from seven European centers were subsequently harmonized into an observational, cross-sectional cohort of patients with solitary ruptured IAs to mitigate selection bias inherent in cohorts with incidentally discovered unruptured IAs. Mixed-effects ABNs modeled probabilistic dependencies using generalized linear models with random intercepts for study centers. Structure learning was performed via structural Markov chain Monte Carlo sampling with Bayesian information criterion scoring. Model performance was assessed using graphical comparison, intraclass correlation coefficients (ICCs), and predictive metrics. Results The mixed-effects ABN produced a more parsimonious network than the pooled model and better captured center-specific variation, particularly for variables with high ICCs (e.g., family history: ICC = 0.369). It also outperformed the pooled ABN in predicting family history (Area Under the Curve = 0.694 vs. 0.585) while yielding clinically interpretable associations, such as the influence of sex, smoking, and IA location on IA size. Conclusion This application of mixed-effects ABNs reveals that accounting for inter-center heterogeneity is critical for accurately modeling risk factor dependencies in multicenter IA cohorts. This approach yields a more parsimonious network structure by reducing spurious associations found in pooled models. By disentangling patient-level effects from center-specific variations, the model enhances predictive power for heterogeneous variables and provides more reliable, clinically interpretable insights into IA pathophysiology, advancing the potential for personalized risk assessment.

Aneurysmal subarachnoid hemorrhage (aSAH) caused by mycotic intracranial aneurysms (MIAs) is a rare cerebrovascular condition resulting from bacterial infiltration and arterial wall damage due to systemic or local infections. Due to limited data - often restricted to case reports or small series - no standardized diagnostic or therapeutic strategies exist. Therefore, this study aimed to characterize clinical, radiological, microbiological, and histopathological features of aSAH due to MIAs and to analyze treatment approaches in a larger cohort. We conducted a retrospective analysis of consecutive patients with aSAH from MIAs treated at two neurovascular centers between 2007 and 2024. Inclusion required both suggestive aneurysm morphology (e.g., distal, dysplastic) and evidence of systemic or local infection. Twenty-five patients (64% male, median age 44.7 years) were included. Mean Glasgow Coma Scale on admission was 8 ± 5, with most patients presenting with Hunt and Hess (HH) grades 5 (40%) or 4 (28%). MIAs were most often located at the middle cerebral artery (44%), with a median aneurysm size of 5.9 mm. More than one-third of patients had multiple aneurysms, and 16% developed new MIAs during hospitalization. Infections were associated with prior intracranial surgery (16%) or secondary foci, particularly infective endocarditis (44%). Hospital mortality was 36%, and the mean GOS at discharge was 2, highlighting the severity of the condition.

BACKGROUND:Odontoid fractures of the second cervical vertebra commonly affect elderly patients due to osteoporosis and low-energy trauma. Treatment is controversial, with prolonged cervical collar immobilization risking non-union and complications, and surgical C1-C2 stabilization involving higher upfront surgical risks. High-level evidence from randomized controlled trials to guide optimal treatment decisions is lacking. The SCORE study aims to determine whether surgical stabilization is non-inferior to conservative collar management in maintaining functional independence for elderly patients with unstable odontoid fractures. METHODS:SCORE is a multicenter, parallel-group, randomized controlled non-inferiority trial enrolling 322 patients aged ≥70 years with acute (≤2 weeks) unstable odontoid Type II, III, or atypical fractures. Participants will be randomized 1:1, stratified by center, to receive surgical stabilization via posterior C1-C2 fixation or conservative management with a rigid cervical collar. The primary outcome measure is the change in Barthel Index (BI) from baseline to 12 weeks. Secondary outcomes include quality of life (EQ-5D), neck pain (Visual Analog Scale, VAS), neck disability (Neck Disability Index, NDI), radiographic fusion, treatment compliance, cross-over rates to surgery, and incidence of adverse and serious adverse events up to 6 months. Follow-ups will take place at 12 weeks and 6 months post-injury, with an additional visit at approximately 2 weeks post-surgery for surgical patients. Analysis will use mixed models for repeated measures, targeting 90% power to detect non-inferiority within a 5-point margin on the BI (one-sided α = 0.025), accounting for 15% attrition. DISCUSSION:This trial addresses a critical evidence gap by directly comparing surgical and conservative treatments, aiming to guide clinical decision-making and improve functional outcomes and quality of life in elderly patients. TRIAL REGISTRATION:ClinicalTrials.gov, ID: NCT06961578.

Study Design Retrospective multicenter study. Objective To examine the epidemiology and clinical outcomes of spondylodiscitis in patients with intravenous drug abuse (IVDU) and compare them with non-IVDU patients. Methods Data from 575 patients diagnosed with spondylodiscitis between 1 January 2018 and 31 December 2023 from three high-volume spine centers was analyzed. Of these, 33 (5.74%) were patients with IVDU, and 542 (94.26%) were non-IVDU patients. Clinical characteristics, bacterial spectrum, and treatment outcomes, including revision surgery rates and cure rates, were compared. Results Patients with IVDU were significantly younger (mean age 43.9 ± 9.1 years) compared to non-IVDU patients (mean age 70.5 ± 11.9 years) ( P < .0001). The median Charlson Comorbidity Index (CCI) was significantly lower in IVDU patients (1, IQR: 0-3) compared to non-IVDU patients (4, IQR: 3-6) ( P < .0001). The bacterial spectrum was similar between both groups, with Staphylococcus aureus as the most frequent pathogen. Revision surgery rates were comparable; however, among patients requiring revision, recurrent or progressive discitis was more frequently the cause in IVDU patients (55.6%) compared to non-IVDU patients (17.9%). At 10-week follow-up, 87.9% of non-IVDU patients were cured, while only 57.9% of IVDU patients achieved a cure ( P = .0018). Conclusions IVDU patients with spondylodiscitis are younger and have fewer comorbidities than non-IVDU patients. Contrary to common assumptions, they do not present with more severe infections. However, they experience higher relapse and progression rates, highlighting the need for tailored treatment strategies in this high-risk group.

BACKGROUND:Spinal hemangioblastomas (sHBs) are rare vascular tumors with significant neurological implications. Their management, particularly in von Hippel-Lindau (VHL) disease, remains challenging due to recurrence and functional decline. Timely identification and intervention are critical for optimal outcomes. METHODS:This international, multicenter retrospective cohort study included 357 patients (199 VHL-associated, 158 sporadic) from 13 neuro-oncological centers. Clinical and imaging data were analyzed to assess progression-free survival (PFS) and functional outcomes using the modified McCormick Scale (mMCS) at 12 months. Secondary analyses identified factors associated with VHL disease in sHBs. RESULTS:Complete resection was achieved in 87.7% of cases, leading to significantly improved PFS at 72 months (sporadic: 95.1%, VHL-associated: 91.1%; hazard ratio: 0.18, 95% CI: 0.08-0.4). Multivariable analysis identified predictors of unfavorable outcomes at 12 months: preoperative mMCS ≥2 (odds ratio [OR]: 5.17, P = .008), intramedullary tumor location (OR: 9.48, P = .01), and preoperative bleeding (OR: 31.12, P = .02). Factors independently associated with VHL disease in sHBs included non-cervical tumor location (OR: 2.08, P = .004), intramedullary growth (OR: 2.39, P < .001), and age <43 years (OR: 3.24, P < .001). Functional improvements were observed in most patients, particularly those with sporadic sHBs. CONCLUSIONS:Complete surgical resection is essential for long-term tumor control and favorable functional outcomes in both sporadic and VHL-associated sHBs. Early intervention, particularly in mild symptomatic and progressive cases, before neurological deterioration or hemorrhage, optimizes recovery. This study, the largest of its kind in a multicentric international setting, provides robust evidence to guide the management of both sporadic and VHL-associated sHBs.

Background Remote ischemic preconditioning (RIPC) has shown potential in reducing vasospasm-induced secondary ischemia after aneurysmal subarachnoid hemorrhage (aSAH). Research suggests RIPC may help the brain adapt to periods of reduced blood flow, thereby reducing the risk of cerebral infarction secondary to delayed cerebral ischemia. This study aimed to analyze the possible impact of RIPC in patients with vasospasm following aSAH. Methods We performed a prospective, randomized, controlled, and rater-masked trial at our high-volume neurovascular center. Patients treated for aSAH between November 2019 and September 2023 were randomly allocated to either the control or RIPC intervention group. The RIPC intervention involved three upper arm blood pressure cuff inflations (20 mm Hg above systolic pressure) for 5 min, followed by 5 min of reperfusion, administered for 10 consecutive days within the initial 14 days after aSAH. The primary end point was postinterventional computed tomography to identify new cerebral infarction areas. Results Among 60 patients (29 in the intervention group, 31 in the control group) the entire cohort averaged 62.0 years, with no significant age difference between groups ( p = 0.41). RIPC did not significantly affect the initial occurrence of symptomatic vasospasms or the incidence of cerebral infarctions (RIPC 24.1% vs. control 16.1%, p = 0.44). No significant difference was found between the two groups with respect to incidence of new neurological symptoms ( p = > 0.99) or in-hospital mortality ( p = 0.5). Conclusions Remote ischemic preconditioning does not appear to influence the occurrence of vasospasms or the development of new infarcts on computed tomography. Larger studies are needed to further explore whether RIPC may have a role in specific high-risk subgroups or clinical settings.

Controversy surrounds seasonal variations in aneurysmal subarachnoid hemorrhage (aSAH) incidence and course. Investigating weather effects associated with weather fronts may provide more insights. Meteorological parameters are grouped into classes describing biotropic weather conditions influencing human health. Known as bio-synop classes, they impact human health by influencing biological processes. Our study explores the relationship between these classes and aSAH occurrence and severity using data from our neurovascular center and the German national weather registry. Data from 605 aSAH patients treated between 2006 and 2021 was analyzed. The Kruskal-Wallis Test was used to assess the incidence and severity of aSAH, classified by Hunt Hess (HH) grades across bio-synop classes. Additionally, we explored seasonal clustering of aSAH events. While no significant difference in ASAH incidence across specific bio-synop classes was observed (p = 0.165), class 4 “Low-pressure with cold air advection” was significantly associated with a higher incidence of poorer HH grades (p = 0.022). Further, we observed a decrease in aSAH cases in June in month-to-month comparisons (May vs. June p < 0.001). Although bio-synop classes may not directly affect aSAH incidence, they appear linked to aSAH severity. The reduction in June aSAH cases suggests a potential seasonal influence, indicating a complex interplay of environmental factors warranting further investigation.

BACKGROUND AND OBJECTIVES:Spinal arachnoid cysts (SAC) are benign but space-occupying outpouchings of the arachnoid membrane. Symptoms at presentation in adults often include back pain and spinal cord compression symptoms. MRI is key for diagnosis, complemented by cervicothoracic junction myelography. On MRI, misdiagnosis of ventral myelon herniation (VMH) may be falsely made. To facilitate intraoperative diagnosis, here we suggest the application of ultrasound for surgical planning and real-time confirmation. METHODS:We performed a single-center retrospective analysis on patients treated surgically for suspected VMH, ventral myelon adhesion (VMA), or intradural SAC from 2007 to 2024. Primary diagnosis was made on MRI. Neurological status was assessed pre- and postoperatively by the modified McCormick scale, and surgical approaches were documented. Intraoperative ultrasound imaging was used in 2 illustrative cases. RESULTS:Among 42 patients, initial MR imaging suggested VMH/VMA in 10 patients and SAC in 32 patients. 36 cases were ultimately intraoperatively confirmed to be SAC. In 16 patients, additional inspection of the ventral dura was performed, and surgery was significantly longer (P = .0168; 154 minutes vs 114 minutes). Most pathologies were thoracic (81%), and surgical approaches varied. Neurological improvement was observed in 16.2%% and deterioration in 8.1%; neurological status was unchanged in 75.7%. Intraoperative ultrasound effectively aided diagnosis and surgical guidance in 2 cases, which are illustrated. CONCLUSION:SAC are rare lesions causing spinal cord compression, often misdiagnosed as VMH or VMA. Our study promotes intraoperative ultrasound as a handy tool for precise surgical planning and accurate diagnosis. It enables precise cyst localization and thus improving outcomes by reducing the extent of procedures. As a consequence of surgical manipulation of the myelon, potentially by the ventral dura inspection, some patients may experience neurological decline. These findings highlight the potential of intraoperative ultrasound in enhancing surgical strategy for SAC and suspected VMH/VMA.