This Week in Neurosurgery — Sep 23, 2026

This AudioScholar briefing is generated by artificial intelligence for healthcare professionals and trainees. It is not medical advice.

Welcome to This Week in Neurosurgery. This week we're covering 10 notable papers spanning neuro-oncology imaging and prognostication, surgical technique and efficiency across skull base and brainstem work, and the evolving technology and antithrombotic questions at the edges of our practice. Let's dive in.

Let's start with a cluster of papers asking how much we can learn about a glioma before we ever make the incision. In Neurosurgery, Fares and colleagues looked at 29 patients with IDH-wildtype frontal glioblastoma who had complete resection of all contrast-enhancing tumour, and asked whether preoperative diffusion tensor imaging could predict which direction the tumour would come back. Diffusion anisotropy, what they call DTI-q, predicted the direction of progression with a median accuracy of about 0.83, clearly outperforming conventional FLAIR and the isotropic diffusion component, which sat near 0.69. Medial and posterior progression were the commonest patterns, inferior progression carried the worst survival, and the authors judged that lobectomy-style supramaximal resection would have been anatomically feasible in about half of the cohort. This is a small, retrospective series from a prospectively recruited multicentre pool, so it is a proof of concept for directionally tailored planning rather than a mandate, but it is the kind of biomarker that could plausibly slot into existing navigation workflows. Alongside that, in the Journal of Neuro-Oncology, Atli and colleagues tackled malignant transformation in 155 patients with radiologically low-grade WHO grade 2 to 3 glioma, using interval-censored models because transformation is only ever detectable somewhere between two scans. Contrast enhancement at diagnosis was by far the strongest predictor of transformation, dwarfing tumour volume and an entire 99-feature radiomic panel, none of which survived shrinkage. Strikingly, that enhancement signal remained predictive even after gross total resection had physically removed the enhancing tissue, suggesting it marks intrinsic biology rather than just tissue burden. Gross total resection was the only modifiable determinant, associated with roughly a two-thirds lower hazard of transformation. And the methodological point matters: conventional dating of transformation overstated the hazard about fourfold, which should make all of us more sceptical of published transformation timelines.

Staying with glioblastoma prognostication, also in the Journal of Neuro-Oncology, Lavrador and colleagues report on 77 patients with motor-eloquent IDH-wildtype grade 4 glioblastoma who had preoperative navigated transcranial magnetic stimulation mapping. Two derived cortical excitability metrics independently predicted overall survival after adjustment for age, sex, deficit, MGMT methylation and extent of resection, with lower intra-motor-cortex excitability and higher global cortical excitability both tracking with worse survival. Bilateral mapping outperformed unilateral mapping for 12-month prediction. This is single-centre and retrospective, and the authors' claim that excitability profiling is clinically actionable is ahead of the evidence, but it does suggest that mapping studies we already perform for safety may carry prognostic information we are currently discarding.

The second theme is how aggressive we can be, and what it costs. In the Journal of Neuro-Oncology, Jankovic and colleagues reviewed 74 patients undergoing resection of gliomas involving or approached through the supplementary motor area. Exactly half of the patients developed postoperative SMA syndrome, and more extensive RANO class 2 resections raised the odds of it roughly fivefold compared with class 1. But here is the reassuring part: SMA syndrome was not associated with delayed adjuvant therapy, nor with progression-free or overall survival. What did matter was genuine functional decline, a drop of 20 points or more in Karnofsky score, which was strongly associated with receiving modified or reduced-intensity adjuvant treatment. The authors read this as support for maximal safe resection in the SMA region on the grounds that the classic transient syndrome does not appear to cost patients downstream therapy, though this is a single-centre retrospective cohort. Two other surgical papers round this out. In World Neurosurgery, Vergeer and colleagues externally validated the modified Knosp grade in 482 endoscopic transsphenoidal pituitary cases. Gross total resection was achieved in roughly seven in ten patients overall, but the gradient across grades was stark, from near-universal at grade 0 down to well under half at grade 3A, around a third at 3B, and under one in ten at grade 4. The modified grade remained the strongest independent predictor of complete resection, and the split of grade 3 into 3A and 3B carried real prognostic weight, which matters most for honest preoperative counselling. And in Acta Neurochirurgica, Al-Afif and colleagues describe the retrosigmoid trans-middle cerebellar peduncle approach for intrinsic pontine cavernous malformations across three academic centres. This is five patients only, so treat it as a technical feasibility report rather than evidence of comparative safety. Gross total resection was achieved in every case, all five patients had some new postoperative neurological morbidity, but it was predominantly transient, and median modified Rankin score improved from 4 before surgery to 1 at follow-up, with residual symptoms limited to mild ataxia, facial hypesthesia, dysarthria or vertigo. The main contribution is that a technique previously reported almost exclusively from its originating centre appears reproducible elsewhere in experienced hands.

The third theme is efficiency, antithrombotics, and technology. Also in the Journal of Neuro-Oncology, Yogeswaran and colleagues examined a post-operative day one discharge pathway across 263 consecutive craniotomies for tumour resection. Discharge on day one was achieved in just over half of the patients, and crucially it was not associated with any increase in 30-day unplanned readmission, which ran at around 8 percent overall and a very similar rate in the early-discharge group. Mean cumulative hospital days over 30 days were one day in the early-discharge group versus seven in those needing prolonged admission. Diabetes, postoperative adverse events and new neurological deficits all reduced the likelihood of day one discharge, while eloquent tumour location roughly tripled the odds of readmission. It is retrospective and single-centre with obvious selection effects, but it supports structured early discharge pathways in carefully selected patients. In Neurosurgery, Pekyi-Boateng and colleagues used the TriNetX network to compare a direct oral anticoagulant plus single antiplatelet therapy against a direct oral anticoagulant plus dual antiplatelet therapy after carotid artery stenting, with 293 propensity-matched patients per arm. Intracranial haemorrhage rates were essentially identical at around 4 percent in each group, and gastrointestinal bleeding, mortality, venous thromboembolism, readmission and new ischaemic stroke were all comparable. The authors are appropriately cautious: this is a retrospective registry analysis, the event numbers are modest, and comparable outcomes in matched observational data is not the same as demonstrated non-inferiority. They frame it as justification for the randomised trial that this question still needs. And finally, in the Journal of Clinical Neuroscience, Sivakumar offers a narrative review of machine learning in adaptive deep brain stimulation, framed around the February 2025 FDA approval of adaptive DBS with beta-band sensing. The argument is that single-biomarker threshold control with hand-set parameters captures only part of the symptom landscape, and that multimodal, learned control policies are the next step, but that translation hinges on distinctly neurosurgical factors: lead placement precision, signal quality and patient selection, alongside unresolved problems of generalisability, safety validation, explainability and equity. Rounding out the neuro-oncology coverage, Koutsouras and colleagues provide a comprehensive review of posterior fossa ependymoma in the Journal of Neuro-Oncology, reinforcing that group A and group B tumours are biologically distinct entities, that 1q gain and 6q loss define a very high-risk group enriched at relapse, and that gross total resection followed by focal radiotherapy remains the backbone of treatment.

If you only have time for one paper this week, make it the malignant transformation study from the Journal of Neuro-Oncology. It reopens a question many of us thought settled, showing that enhancement at diagnosis keeps predicting transformation even after the enhancing tissue has been resected, and it demonstrates that our conventional estimates of when transformation happens have been substantially off.

Here is what this week's evidence adds up to in neurosurgery. First, preoperative imaging and mapping are carrying more prognostic signal than we currently extract, whether that is diffusion anisotropy predicting the direction of glioblastoma recurrence, contrast enhancement predicting transformation in lower-grade glioma, or navigated transcranial magnetic stimulation excitability tracking with survival, but all three are retrospective and none is ready to independently drive a surgical decision. Second, radiomic panels underperformed a single well-understood imaging feature, which is a useful corrective to the current enthusiasm. Third, the evidence on aggressive resection in eloquent territory is mildly reassuring, with SMA syndrome not appearing to cost patients adjuvant therapy or survival, and functional status rather than the syndrome itself driving treatment intensity. Fourth, both the day one discharge pathway and the simplified antithrombotic regimen after carotid stenting show comparable safety in observational data, which is a signal to test formally rather than a licence to change practice. And fifth, the modified Knosp grade continues to validate externally as the dominant predictor of complete pituitary resection, with the 3A versus 3B split earning its place in preoperative counselling.

That's your roundup for This Week in Neurosurgery. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.

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This is an automated summary generated by artificial intelligence, which can make mistakes. Always review the original source materials.