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Digest

The Weekly Signal

Published March 15, 2026

Executive Summary

This week's digest highlights: In endovascular treatment for large core ischemic stroke, minimizing thrombectomy attempts and using local sedative anesthesia may reduce the risk of parenchymal hemorrhage. Molecular testing for the PTPRZ-MET fusion gene in recurrent high-grade glioma patients can help identify candidates for targeted therapy trials. In spinal cord injury clinical trials, incorporating...

Owen briefs you on what matters in this week's digest.

Think chief-resident chalk talk: what matters, what changes practice, and where to spend your reading time.

Endovascular / Vascular

In large core stroke thrombectomy, minimize thrombectomy attempts and consider local sedative anesthesia to potentially reduce parenchymal hemorrhage risk.

OIn large core stroke thrombectomy, limiting the number of attempts and opting for local sedative anesthesia may significantly reduce the risk of parenchymal hemorrhage, though further studies are needed to confirm these findings.

High evidencePractice changing

Study snapshot

Design

Post-hoc analysis of multicenter randomized controlled trial

Population

Patients with large infarcts who underwent thrombectomy in the ANGEL-ASPECT trial

Intervention

Mechanical thrombectomy

Comparator

None (single-arm analysis of thrombectomy patients)

Primary outcome

Predictive factors for post-thrombectomy parenchymal hemorrhage

Why it matters

Before this study, we knew that parenchymal hemorrhage (PH) was a feared complication after thrombectomy for large core strokes, but specific modifiable risk factors were not well characterized. This post-hoc analysis of the ANGEL-ASPECT trial identifies alcohol use and increased thrombectomy attempts as independent predictors of PH, while local sedative anesthesia appears protective. For clinicians, this suggests that minimizing thrombectomy passes and considering local sedative anesthesia could potentially reduce PH risk in these high-risk patients.

Practice change

Confirms current practice of minimizing thrombectomy attempts, but may support consideration of local sedative anesthesia in appropriate patients.

More context

Key details

  • Post-hoc analysis of the ANGEL-ASPECT randomized trial (NCT04551664)
  • 35 patients (16.1%) experienced parenchymal hemorrhage 24-48 hours after thrombectomy
  • PH associated with worse functional outcome (mRS score 5 vs 3, acOR 0.31, 95% CI 0.16-0.61, P<0.01)
  • Alcohol use independently increased PH risk (acOR 3.22, 95% CI 1.29-8.03, P=0.01)
  • Increased thrombectomy attempts independently increased PH risk (acOR 1.43, 95% CI 1.02-2.00, P=0.04)
  • Local sedative anesthesia independently reduced PH risk (acOR 0.10, 95% CI 0.01-0.84, P=0.03)

High-yield

In patients with large infarcts undergoing thrombectomy, parenchymal hemorrhage occurred in and was associated with significantly worse functional outcomes (adjusted common OR 0.31, P<0.01).

Clinical context

The efficacy of mechanical thrombectomy for treating large infarcts has been established through multiple recent randomized controlled trials. Nevertheless, hemorrhagic transformation remains one of the significant challenges following thrombectomy in these patients.

Limitations

Post-hoc analysis of a larger trial, not pre-specified for this specific questionRelatively small number of PH events (n=35) limits multivariate model stability

Methodological critique

As a post-hoc analysis, findings should be considered hypothesis-generating rather than definitive.

Teaching pearl

When doing thrombectomy for large core strokes, count your passes carefully—each additional attempt increases parenchymal hemorrhage risk by about 40%, and consider local sedative anesthesia which showed a 90% reduction in hemorrhage risk in this analysis.

Funding and COI

Not stated

Tumor / Skull Base

Consider molecular testing for PTPRZ-MET fusion in recurrent high-grade glioma patients to identify candidates for targeted therapy trials.

OMolecular testing for the PTPRZ1-MET fusion in recurrent high-grade gliomas is essential, as it may identify patients who could benefit from targeted therapies like vebreltinib, despite the need for further efficacy validation.

High evidencePractice changing

Study snapshot

Design

Multicenter, randomized, open-label phase III trial

Population

Patients aged 18-65 years with previously treated astrocytoma, IDH-mutant, grade 4, or glioblastoma, IDH wild-type, with PTPRZ1-MET fusion gene

Intervention

Vebreltinib 300 mg orally twice daily

Comparator

Standard therapy (temozolomide or cisplatin/etoposide combination)

Primary outcome

Overall survival

Why it matters

Previously, patients with recurrent high-grade gliomas harboring the PTPRZ1-MET fusion had limited therapeutic options beyond standard chemotherapy regimens. This phase III trial demonstrates that vebreltinib, a brain-penetrant MET inhibitor, shows promising activity in this molecularly defined subgroup. While definitive efficacy data are pending, clinicians should consider molecular testing for ZM fusion in appropriate glioma patients to identify candidates for targeted therapy trials.

Practice change

Could consider molecular testing for PTPRZ1-MET fusion in appropriate glioma patients to identify candidates for targeted therapy trials.

More context

Key details

  • Multicenter, randomized, open-label phase III trial (FUGEN trial)
  • Patients with previously treated astrocytoma, IDH-mutant, grade 4, or glioblastoma, IDH wild-type, with PTPRZ1-MET fusion gene
  • ZM fusion present in approximately 15% of secondary glioblastomas

High-yield

Vebreltinib, a next-generation MET inhibitor with enhanced brain penetration, demonstrated encouraging preliminary efficacy in a phase I study with partial responses in of patients with secondary glioblastoma harboring the PTPRZ-MET fusion.

Clinical context

Gliomas represent the most common and lethal malignant primary tumors of the central nervous system. The discovery of the PTPRZ1-MET fusion gene in approximately 15% of secondary glioblastomas has provided important insights into glioma progression and therapeutic vulnerabilities.

Limitations

Open-label design introduces potential bias in outcome assessmentSpecific efficacy results and statistical significance not yet reported in available text

Methodological critique

Open-label design may introduce bias in outcome assessment, particularly for subjective endpoints.

Teaching pearl

When seeing recurrent high-grade glioma patients, remember that approximately 15% of secondary glioblastomas harbor the PTPRZ1-MET fusion—molecular testing could open doors to targeted therapies like vebreltinib that show early promise.

Funding and COI

Not stated

Spine

Enhanced clinical trial stratification in spinal cord injury: the value of electrophysiology.

Research • Spine • Brain : a journal of neurology • 2026-03-05

Consider incorporating somatosensory evoked potential testing in spinal cord injury trial design to improve patient stratification and reduce required sample sizes.

OIncorporating somatosensory evoked potential testing in spinal cord injury trials can significantly enhance patient stratification and reduce sample size, though reliance on electrophysiology should be balanced with clinical assessments to ensure comprehensive evaluation.

High evidencePractice changing

Study snapshot

Design

Retrospective stratification analysis of a randomized, placebo-controlled phase 2b trial

Population

Patients aged 18-70 years with acute (4-28 days) cervical spinal cord injury

Intervention

NG101 (anti-Nogo-A antibody)

Comparator

Placebo

Primary outcome

Comparison of treatment effect sizes for recovery of upper extremity motor scores and spinal cord independence measure between stratification methods

Why it matters

Previous spinal cord injury trials have relied primarily on clinical measures for patient stratification, which may not optimally identify those most likely to benefit from plasticity-inducing interventions. This analysis demonstrates that electrophysiological stratification using preserved somatosensory evoked potentials identifies treatment responders more effectively than clinical criteria alone. For trial design, incorporating electrophysiology could substantially reduce required sample sizes while increasing effect sizes.

Practice change

May support incorporating electrophysiological measures in future spinal cord injury trial design to improve patient enrichment.

More context

Key details

  • Retrospective stratification analysis of the NISCI randomized, placebo-controlled phase 2b trial (NCT03935321)
  • 116 participants with acute cervical spinal cord injury (74 NG101, 41 placebo)

High-yield

Electrophysiological stratification using preserved somatosensory evoked potentials reduced required sample size from to 32 patients and increased effect size from Cohen's d=0.46 to compared to clinical stratification in a spinal cord injury trial.

Clinical context

There are no approved interventional therapies, aside from neurorehabilitation, that enhance neurological recovery after acute traumatic spinal cord injury. A key challenge is the lack of biomarkers surpassing clinical standards for optimal stratification.

Limitations

Retrospective analysis of a single trial limits generalizabilitySmall sample size for the electrophysiological stratification group (n=32)

Methodological critique

Retrospective nature limits causal inferences about the superiority of electrophysiological stratification.

Teaching pearl

In spinal cord injury trial design, don't overlook electrophysiology—preserved SSEPs can identify treatment responders so effectively that you might need only a quarter of the patients compared to clinical stratification alone.

Funding and COI

Not stated

Functional

In DBS candidates with ventriculomegaly or brain atrophy, employ meticulous image-guided trajectory planning to avoid ventricular wall transgression while recognizing these patients may still benefit from intervention.

OIn patients with ventriculomegaly or brain atrophy undergoing deep brain stimulation, careful image-guided trajectory planning is essential to prevent ventricular wall transgression and mitigate the risk of postoperative confusion, despite the potential for meaningful clinical benefits.

Low evidencePractice changing

Study snapshot

Design

Narrative literature review

Population

Patients with medication-refractory movement disorders undergoing DBS

Intervention

Deep brain stimulation

Comparator

None

Primary outcome

Impact of ventriculomegaly and brain atrophy on motor outcomes, safety, and surgical complications

Why it matters

Before this review, ventriculomegaly and brain atrophy were recognized as common findings in DBS candidates, but their precise impact on outcomes and risks was debated. This review synthesizes evidence showing these morphometric changes correlate with poorer motor improvement and identifies ventricular wall transgression as a specific risk factor for postoperative confusion. Clinicians should not consider ventriculomegaly and atrophy as absolute contraindications but should employ meticulous image-guided planning to mitigate risks while recognizing patients may still derive quality-of-life benefits.

Practice change

Confirms current practice of meticulous surgical planning in patients with ventriculomegaly or brain atrophy while providing evidence-based risk quantification.

More context

Key details

  • Review of literature on ventriculomegaly and brain atrophy in DBS for movement disorders
  • Ventriculomegaly and atrophy serve as markers of underlying neurodegenerative burden
  • Factors contributing to adverse outcomes include patient comorbidities, surgical technique, and postoperative electrode displacement
  • Excellent outcomes are achievable in patients with marked ventriculomegaly and atrophy with meticulous surgical planning
  • Modern image-guided software and careful trajectory planning can mitigate risks
  • Patients may derive significant quality of life benefits even with modest motor improvements
  • Provides evidence-based framework to guide clinical judgment and surgical strategy

High-yield

Transgressing the ventricular wall during STN DBS surgery increases the risk of postoperative confusion by a relative risk of , highlighting the critical importance of trajectory planning in patients with ventriculomegaly.

Clinical context

Deep brain stimulation is a cornerstone treatment for medication-refractory movement disorders. Ventriculomegaly and brain atrophy, common findings in DBS candidates, present technical challenges and potential safety concerns.

Limitations

Narrative review design limits quantitative synthesis and may be subject to selection bias in article inclusionRelies on existing cohort studies with potential heterogeneity in patient populations and outcome measures

Methodological critique

As a narrative review, this study lacks systematic methodology for article selection and quantitative synthesis of evidence.

Teaching pearl

When planning DBS trajectories in patients with ventriculomegaly, use modern image-guided software to meticulously avoid ventricular wall transgression—this single technical detail can dramatically reduce the risk of postoperative confusion.

Funding and COI

Not stated

General Neurosurgery

Do not add topical vancomycin to standard systemic antibiotic prophylaxis for SSI prevention in craniotomies and noninstrumented spinal procedures, as it provides no significant benefit.

OTopical vancomycin should not be used as an adjunct to standard systemic antibiotic prophylaxis in craniotomies and noninstrumented spinal procedures, as recent high-quality evidence demonstrates it does not significantly reduce surgical site infection rates.

High evidencePractice changing

Study snapshot

Design

Randomized controlled trial

Population

Patients undergoing craniotomy or noninstrumented spinal procedures

Intervention

Topical vancomycin application at surgical site plus standard systemic antibiotic prophylaxis

Comparator

Standard systemic antibiotic prophylaxis alone

Primary outcome

Surgical site infection rate at postoperative day 30

Why it matters

Previous studies had suggested potential benefits of topical vancomycin for SSI prophylaxis in neurosurgery, but evidence was limited. This RCT provides high-quality evidence showing no significant reduction in SSI rates with topical vancomycin compared to standard systemic prophylaxis alone. Clinicians should not adopt topical vancomycin as standard practice for craniotomies and noninstrumented spinal procedures based on current evidence.

Practice change

May support discontinuing routine use of topical vancomycin for SSI prophylaxis in craniotomies and noninstrumented spinal procedures given no demonstrated benefit.

More context

Key details

  • Randomized controlled trial of topical vancomycin for SSI prophylaxis
  • 1103 patients randomly assigned to topical vancomycin plus standard systemic antibiotics (n=552) or standard antibiotics alone (n=551)
  • SSI symptoms assessed via standardized patient surveys at postoperative day 30
  • No significant reduction in SSI rates with topical vancomycin in overall analysis or when stratified by procedure type
  • Sensitivity analysis using various SSI classification schemes showed no significant reduction
  • Topical vancomycin use not associated with significant systemic absorption or adverse events
  • Authors conclude topical vancomycin should not be established as standard of care without clear evidence of superiority

High-yield

Topical vancomycin added to standard systemic antibiotic prophylaxis did not reduce surgical site infection rates in craniotomies and noninstrumented spinal procedures (3.94% vs 4.10%, p=0.90).

Clinical context

Surgical site infections remain a significant concern in neurosurgical procedures. The role of topical vancomycin as adjunctive prophylaxis has been debated.

Limitations

SSI assessment relied on patient surveys rather than direct clinical evaluation, potentially introducing recall biasStudy may not have been powered to detect small differences in SSI rates between groups

Methodological critique

Reliance on patient self-reported symptoms for SSI assessment rather than direct clinical evaluation represents a potential limitation in outcome measurement.

Teaching pearl

When considering adjunctive measures for SSI prophylaxis, remember that this RCT shows topical vancomycin provides no additional benefit over standard systemic antibiotics alone for craniotomies and noninstrumented spinal procedures—stick with evidence-based practices.

Funding and COI

Not stated

Basic Science

Cognitive loss after brain trauma results from sex-specific activation of synaptic pruning processes.

Research • Basic Science • Brain : a journal of neurology • 2026-03-05

While not yet ready for clinical application, this study identifies a novel, potentially reversible mechanism of synaptic damage after brain trauma that may inform future therapeutic development for cognitive protection.

OThis study highlights a potentially reversible mechanism of cognitive dysfunction post-TBI involving glial D-serine and synaptic pruning, warranting attention for future therapeutic strategies despite its current low evidence quality.

Low evidencePractice changing

Study snapshot

Design

Preclinical basic science study

Population

Wild-type mice, genetically modified mice, and human TBI patients (n=41 for tissue analysis)

Intervention

Evaluation of D-serine influence on synaptic damage mechanisms

Comparator

Genetic modifications and control conditions

Primary outcome

Mechanistic understanding of synaptic damage after brain injury

Why it matters

Previous understanding of cognitive loss after brain trauma focused on focal tissue damage with limited therapeutic options. This preclinical study identifies a novel mechanism where prolonged glial D-serine release reactivates developmental synaptic pruning processes, leading to widespread synaptic damage. While not immediately changing clinical practice, this work suggests potential new therapeutic targets for protecting cognitive function after TBI.

Practice change

Could consider this mechanistic understanding when evaluating future therapeutic trials targeting glial D-serine release or synaptic pruning pathways in TBI patients.

More context

Key details

  • Preclinical study examining synaptic damage mechanisms after brain trauma
  • Used wild-type mice and mice deficient in microglial serine racemase or neuronal GluN2B
  • Measured biochemical alterations in synaptic proteins, dendritic spine numbers/morphology, electrophysiological responses, and learning/memory behavior
  • Employed single-cell analysis to examine cell-type specific contributions
  • Analyzed perilesional tissues from 41 traumatic brain injury patients for mRNA/protein differences
  • Found synaptic pruning pathway is reversible at several stages within acute injury period
  • Suggests targeting specific molecules in this pathway may represent new therapeutic strategy for TBI

High-yield

Prolonged glial D-serine release after brain injury reactivates developmental synaptic pruning processes through hyperactivation of perisynaptic NMDA receptors, representing a reversible mechanism underlying cognitive dysfunction.

Clinical context

Cognitive losses from severe brain trauma have long been associated with focal tissue damage, with few available pharmacological therapies for patients.

Limitations

Preclinical study using mouse models, limiting direct translation to human clinical practiceMechanistic findings require validation in larger human studies before clinical application

Methodological critique

As a preclinical study primarily using animal models, direct clinical applicability is limited without further human validation.

Teaching pearl

When considering the pathophysiology of cognitive dysfunction after TBI, recognize that this study suggests a potentially reversible mechanism involving glial D-serine release and synaptic pruning—keeping an eye on future therapeutic developments targeting this pathway.

Funding and COI

Not stated

Trials to Know

Why it matters

This recruiting trial may offer eligible patients access to novel interventions.

Why it matters

This recruiting trial may offer eligible patients access to novel interventions.

MMA Embolization for Refractory Chronic Migraine

Trial • Trials to Know • ClinicalTrials.gov • 2026-03-15

Why it matters

This recruiting trial may offer eligible patients access to novel interventions.

From the Preprint Wire

Why it matters

This preprint demonstrates that archival human brain tissue stored for up to 78 years can still yield reliable immunohistochemical detection of key neurodegenerative proteins like α-synuclein, tau, and β-amyloid. For neurosurgeons, this suggests that historical brain bank collections may remain valuable for research into diseases like Parkinson's and Alzheimer's, potentially informing surgical decision-making in deep brain stimulation or other interventions. However, as an unreviewed preprint, these findings require validation before clinical application.

More context

Key details

  • Original paraffin blocks from 41 autopsy brains (1946-1980) showed consistent good staining for α-synuclein, tau, and β-amyloid.
  • Newly prepared blocks from long-term fixated tissue had slightly lower scores for Lewy-related pathology and tau, but amyloid-β plaques showed similar or slightly higher scores.
  • The findings indicate preserved pathological hallmarks of Lewy body and Alzheimer's diseases in archival tissue, supporting the utility of historical collections for neurodegenerative research.

Real-Time Kinematic Adaptive DBS Reduces Gait Impairment in Parkinson's Disease

Preprint • From the Preprint Wire • medrxiv • 2026-03-02

Why it matters

This preprint reports on a novel adaptive deep brain stimulation system that uses wearable sensors to dynamically adjust stimulation based on real-time gait metrics, potentially offering a more personalized approach to treating gait impairment and freezing of gait in Parkinson's disease. For neurosurgeons involved in DBS programming and management, this represents an important step toward closed-loop systems that could improve patient outcomes, though it's crucial to note this is an unreviewed preprint requiring validation.

More context

Key details

  • KaDBS integrates bilateral shank-mounted IMUs with an investigational neurostimulator to enable real-time modulation based on step-detection and probabilistic freezing classification.
  • The system demonstrated safety with no serious adverse events and symptom-free reports of 87.5% for the arrhythmicity model and 71.4% for the P(FOG) model, compared to 50.0% for continuous DBS.
  • Two participants with 100% time freezing during OFF stimulation achieved complete resolution with KaDBS, suggesting particular benefit for baseline freezers while non-freezers maintained stable gait.