Acta Neurochirurgica最新文献

Purpose

Trigeminal neuralgia (TN), a debilitating condition, is commonly treated with microvascular decompression (MVD). However, effective intraoperative neurophysiological monitoring remains challenging. This study introduces a novel electrophysiological technique using sensory-masseter response (SMR) to monitor trigeminal nerve compression during MVD.

Methods

A total of 34 patients with TN underwent MVD. A concentric neurostimulator was employed to systematically deliver microcurrent stimulation to various intracranial segments of the trigeminal sensory root. We specifically probed the segment distal to the suspected neurovascular conflict (NVC) site, the actual compression point itself, and the segment central to the NVC site. Stimulation was performed at equivalent anatomical levels on both the compressed and non-compressed sides for comparison. Simultaneously, compound muscle action potentials (CMAPs) were recorded from the masseter muscle. These recorded potentials were defined as the SMR. The spatial correlation between SMR positivity and NVC was analyzed to assess its clinical utility.

Results

SMR was successfully recorded in 28 out of 34 patients (82.4%). Among these 28 SMR-positive cases, NVC was identified at the stimulation site in 24 cases, with 19 showing visible vascular indentation. The mean SMR latency was 3.30 ± 0.36 ms. The stimulation threshold required to elicit SMR was significantly lower at the NVC site (median 0.3 mA, IQR 0.2–0.4 mA) compared to the distal segment of the NVC side (p < 0.001), the non-compressed side (p < 0.001), and the central segment of the NVC side (p = 0.012). A strong association was observed between NVC and SMR positivity (p < 0.001). These findings suggest that SMR positivity correlates with NVC sites.

Conclusion

This study introduces a novel electrophysiological technique SMR for localizing NVC during microvascular decompression for trigeminal neuralgia. SMR is likely mediated by focal demyelination and sensory-motor anastomoses. Although SMR demonstrates potential in assisting intraoperative localization during MVD, its clinical value requires further validation.

Purpose

Glioblastoma (GBM) inevitably recurs despite maximal safe resection and standard chemoradiotherapy. The factors influencing survival after first recurrence and re-resection remain controversial.

Research question

What are the prognostic factors influencing survival following re-resection of glioblastoma?

Methods

A systematic search of major databases was conducted for original studies reporting on survival outcomes. Data on hazard ratios (HR) for overall survival and key prognostic factors were extracted, followed by meta-analyses of univariate and multivariate Cox models. Study quality and risk of bias were assessed.

Results

A total of 30 studies were included. Gross total resection and methylated MGMT promoter status were significantly associated with improved survival, with pooled HRs of 0.52 (95% CI: 0.36–0.76, p < 0.001) and 0.58 (95% CI: 0.45–0.75, p < 0.001), respectively. In contrast, age was modestly associated with worse survival (HR: 1.02, 95% CI: 1.01–1.03, p < 0.001). Preoperative Karnofsky Performance Status (KPS) < 70 was associated with worse survival (HR: 2.25, 95% CI: 1.59–3.19, p < 0.001). Adjuvant chemotherapy (HR: 0.69, 95% CI: 0.33–1.45, p = 0.33) and time to re-resection (HR: 0.69, 95% CI: 0.41–1.16, p = 0.16) failed to show consistent survival benefits.

Conclusion

Our findings suggest gross total resection of contrast-enhancing tumour and MGMT promoter methylation are strongly associated with improved survival following first recurrence of glioblastoma. Conversely, age, preoperative KPS, adjuvant chemotherapy, and timing of re-resection showed inconsistent or non-significant associations, emphasizing the need for prospective studies to refine prognostic assessments and guide individualized treatment strategies in recurrent glioblastoma.

Background

Fusiform posterior inferior cerebellar artery (PICA) aneurysms are technically challenging for both microsurgical and endovascular approaches, particularly when PICA is at high risk for occlusion. Optimal outcomes may be achieved through a collaborative hybrid strategy.

Methods

We present a single-stage hybrid minimally invasive technique for fusiform PICA aneurysm management, involving microsurgical PICA-PICA revascularization and endovascular coil embolization for definitive aneurysm occlusion in the hybrid operating suite.

Conclusion

Combining microsurgical and endovascular modalities allows durable aneurysm exclusion while preserving PICA flow. This hybrid approach leverages the strengths of both techniques, offering a safe and effective option for complex PICA aneurysms.

Background

Endovascular therapy (EVT) is the standard of care for acute ischemic stroke due to large vessel occlusion. While predictors of 90-day functional outcome are well-established, the determinants of functional recovery remain less clearly defined in the post-discharge period for patients with initial disability. We aimed to identify the predictors of functional outcome at 3 months in patients who underwent EVT and were discharged with an unmet need for recovery (modified Rankin scale (mRS) score > 2).

Methods

A multi-center, observational cohort study was conducted using data from the Big Data Observatory Platform for Stroke in China. We included 836 patients from eight comprehensive stroke centers (August 2018 – December 2024) who received EVT, had a pre-stroke mRS of 0–2, and had an mRS > 2 at discharge. The primary outcome was functional outcome at 3 months post-EVT, defined as an mRS score of 0–2. Univariate and multivariate logistic regression analyses were performed to identify independent predictors.

Results

Of the 836 patients, 151 (18.1%) achieved a favorable functional outcome (mRS 0–2) at 3 months. In univariate analysis, the favorable outcome group was significantly younger, had a lower pre-EVT NIHSS, a lower rate of atrial fibrillation, a higher rate of intravenous thrombolysis, a higher rate of complete recanalization (mTICI 3), and a lower rate of parenchymal hematoma (PH) (all p < 0.05). Multivariate regression confirmed four independent predictors: younger age (aOR: 0.973; 95% CI: 0.958–0.989; p = 0.001), lower pre-EVT NIHSS (aOR: 0.940; 95% CI: 0.912–0.968; p < 0.001), complete recanalization (aOR: 1.921; 95% CI: 1.305–2.826; p = 0.001), and absence of PH (aOR: 0.424; 95% CI: 0.235–0.768; p = 0.005).

Conclusion

A significant proportion of patients discharged with disability experiences meaningful functional recovery by 3 months post-EVT. The key predictors of this subsequent recovery are younger age, milder initial stroke severity, complete reperfusion, and the avoidance of hemorrhagic complications.

Purpose

Neurosurgical biopsies require high accuracy and precision and are executed with image-guided surgical navigation. The current state-of-the-art techniques require markers, are displayed on a 2D screen, and have a time-consuming setup. We propose an AR-driven surgical navigation method that automatically projects a 3D virtual overlay onto a patient in real-time, without the use of any markers.

Method

Baseline accuracy of the proposed system and the StealthStation S8 was measured on a 3D printed human head phantom in a lab-based setting. For the measurements in the operating room, seventeen participants who underwent a neurosurgical biopsy with the StealthStation S8 were included. Prior to the clinical procedure, our proposed markerless AR system provided an automated three-dimensional virtual overlay onto the patient to the surgeon. By measuring the difference in the planned biopsy trajectory between the state-of-the-art StealthStation S8 and our experimental system, a comparison was made between the two systems.

Results

The average clinical error for the entry point of the proposed system was 4.5 ± 2.2 mm, which is lower than the total error of the current clinical gold standard found in literature.

Conclusion

The total error of the system proposed in this study reaches the gold standard for image-guided neuronavigation, in both lab-controlled and clinical settings. These initial results highlight the potential and advantages of AR over other methods, offering promising AR opportunities for future clinical applications.

Background

The impact of acute subdural hematoma (aSDH) on measures of glymphatic–meningeal lymphatic function has not previously been reported. We present a descriptive observational study including a small case series—one patient following unilateral aSDH, three following unilateral subarachnoid hemorrhage (SAH), and three control subjects—providing new insights into the differential effects of surface intracranial bleeds.

Methods

The magnetic resonance imaging (MRI) contrast agent gadobutrol (0.5 mmol), administered intrathecally, was used as a cerebrospinal fluid (CSF) tracer. Multiphase contrast-enhanced MRI was performed to assess glymphatic tracer enrichment. CSF tracer clearance to blood, serving as a proxy for dural lymphatic function, was estimated using population pharmacokinetic modeling. All hemorrhagic cases involved unilateral bleeds, allowing within-subject comparison between affected and unaffected hemispheres.

Results

The series included one patient with aSDH (2.8 months post-event), three patients with unilateral SAH (mean 5.8 months post-event), and three age-matched, near-healthy reference subjects. Compared with controls, glymphatic tracer enrichment 24 h post-injection was slightly increased on the affected hemisphere in the aSDH case, whereas SAH patients showed markedly reduced enrichment on the affected side. Tracer distribution in controls was symmetrical. CSF clearance to blood was notably reduced in the aSDH case compared with references, suggesting impaired dural lymphatic function.

Conclusion

This small descriptive series suggests that aSDH and SAH may differentially affect glymphatic and dural lymphatic functions. While glymphatic enrichment appeared only modestly altered after aSDH, it was severely impaired following SAH. In contrast, CSF clearance to blood was markedly reduced in the aSDH case, potentially reflecting compromised dural lymphatic drainage. The limited number of cases prevent broad generalization, but these findings offer novel hypothesis-generating observations that may inform future studies on the effects of surface intracranial hemorrhages on brain clearance pathways.

Fibrous dysplasia is a benign bone disease characterized by the replacement of normal bone tissue with fibrous tissue, resulting in irregular bone structure. Cases of craniofacial fibrous dysplasia in children associated with Chiari type I malformation and syringomyelia are extremely rare. This case illustrates the complex clinical manifestations of craniofacial fibrous dysplasia along with Chiari type I malformation and syringomyelia, in which surgical intervention significantly improved the prognosis, and follow-up revealed near-complete resolution of the syringomyelia. It offers valuable insights for managing similar cases in the future.

Background

External ventricular drain (EVD) placement is a common neurosurgical procedure with high rates of misplacement when performed using the freehand technique. With augmented reality (AR), the accuracy of EVD placement could be improved by providing a 3-D overlay, guiding optimal placement using a virtual trajectory superimposed over the patient. In this study, we aimed to assess the efficacy and usability of an AR application for assisting EVD placements which supported trajectory planning, point-based image-to-patient registration and 3-D stereoscopic projection.

Method

We conducted a randomized controlled crossover trial involving 15 neurosurgical residents and one neurosurgeon, who performed 236 EVD procedures (118 AR-assisted and 118 freehand) on biomimetic phantoms. EVD placement accuracy was evaluated using the Kakarla scale, distance-to-target, angular inaccuracy, and depth inaccuracy. The total procedural time was recorded. The user experience was evaluated using the NASA Task Load Index (NASA-TLX) and the Usefulness, Satisfaction, and Ease of Use (USE) questionnaire.

Results

AR-assisted placement achieved significantly higher rates of optimal placement (Kakarla grade 1: 57.6% vs 37.3%; p < .001), lower rates of erroneous placement (Kakarla grade 3: 21.2% vs 40.7%; p < .001), a lower distance-to-target (median, 7.2 mm vs 11.4 mm; p < .001) and lower angular inaccuracy (median, 5.58° vs 7.60°; p < .001). Procedural time was longer for AR (median, 7 min 30 s vs 1 min 11 s; p < .001). Participants rated the AR system favorably on the USE for ease of learning (mean, 6.09/7 [SD, 0.94]) and satisfaction (mean, 6.45/7 [SD, 0.69]), while NASA-TLX scores indicated similar workloads between AR and freehand techniques.

Conclusions

AR improves the accuracy of EVD placement compared to the freehand technique, which is expected to improve the efficacy in clinical settings. It increases total procedural time but remains within clinically acceptable limits and provides favorable usability.

Purpose

Anterior clinoidal meningioma (ACM) remains a challenging lesion to treat surgically due to its intricate neurovascular relationships with surrounding anatomy and often presents with ipsilateral visual loss. Anterior clinoidectomy (AC) by skilled skull base surgeons enables early optic nerve (ON) decompression, tumor devascularization, and radical tumor resection. The authors provide an update on ACM surgery, current views on the role of AC and its impact on outcomes in surgical treatment, as well as a new 2 stage 4 by 4 step concept of ON decompression involving AC.

Methods

A systematic review of PubMed and meta-regression of surgically treated ACMs was performed.

Results

In total, 908 patients were analyzed; 415 (45.7%) underwent routine AC (performed in all cases) and 493 (54.3%) underwent selective AC (planned preoperatively). The routine AC cohort showed higher risk for new cranial-nerve (CN) deficits (12.5% vs. 3.0%; p < 0.001), vascular complications (6.7% vs. 3.3%; p = 0.02), and new focal neurological deficits (5.5% vs. 2.3%; p = 0.04). No differences were found in visual outcomes, gross-total resection, mortality, recurrence, or other major complications. Random-effects meta-regression of routine AC showed increased odds of new CN deficit (odds ratio [OR], 3.34; 95% confidence interval [95% CI], 1.51–7.38; p = 0.005; heterogeneity [I²] = 60.5%) and vascular complication (OR, 2.59; 95% CI, 1.05–6.38; p = 0.04; I² = 47.8%), with moderate and substantial heterogeneity among routine AC studies, respectively.

Conclusions

In experienced hands, AC remains an invaluable tool for ACM treatment as it offers more consistent tumor devascularization, prevention of tumor recurrence, optic nerve decompression, and increased working space, which facilitates optimal tumor resection and better long‐term control and functional outcome. We propose a new didactical structured concept of routine AC via 2-stage, 4 by 4 steps to improve the utility of AC and decrease associated operative risks compared to selective AC.