Exploring the Diagnostic Test Accuracy of MicroRNAs as Potential Biomarkers for Glioblastoma

Neurosurgery 98:1221–1230, 2026

This systematic review and meta-analysis evaluates microRNA (miRNA)–based liquid biopsies for diagnosing glioblastoma (GBM), synthesizing data from 15 studies and 28 biomarker evaluations across 868 samples. Key diagnostic metrics—pooled sensitivity 0.84 and specificity 0.89—indicate strong potential, with miR-21 showing the highest accuracy among single-miRNA assays.

The report details search strategy, inclusion criteria, statistical methods, subgroup analyses (miRNA type, biofluid source, control type), and study quality assessment. Limitations include methodological heterogeneity, high risk of bias in patient selection, inconsistent reporting (CSF source, IDH status), and small cohort sizes, underscoring need for standardized clinical validation.

Aim Evaluate the diagnostic accuracy of microRNA (miRNA) liquid biopsies (blood/serum/plasma/CSF) for diagnosing glioblastoma (GBM) via systematic review and meta-analysis.

Methods PRISMA-guided searches of Ovid Medline and Embase (updated through Oct 16, 2024); included studies had histologic GBM confirmation and extractable 2×2 diagnostic data; pooled estimates generated using a random-effects bivariate model.

Evidence base 15 included articles (published 2011–2022) provided 28 miRNA evaluations, totaling 868 samples from 551 GBM patients and 811 samples from 578 controls.

Overall accuracy Pooled sensitivity 0.84 and specificity 0.89, with heterogeneity of 66% (sensitivity) and 39% (specificity); pooled AUC 0.89.

Likelihood ratios Pooled PLR 7.26, NLR 0.19, and DOR 40.17, indicating strong overall discriminatory performance.

Key biomarker miR-21 showed the highest pooled performance among assessed groupings (sensitivity 0.90, specificity 0.95).

Subgroups Single miRNAs had higher specificity than multi-miRNA panels, while diagnostic capability did not differ clearly by biofluid source (CSF vs blood) in this dataset.

Limitations All included studies had high risk of bias in patient selection, and many had bias in index test interpretation/flow-timing; limited CSF comparisons and inconsistent qPCR thresholds/normalization contributed to heterogeneity and constrain clinical translation without standardization and validation.

Morphometric assessment of the posterior cranial fossa and its contents in patients with chiari malformation type I and type 0

Acta Neurochirurgica (2026) 168:117

This study presents a retrospective, landmark-based morphometric analysis of the clivus, tentorium, and posterior cranial fossa on midsagittal MRI in 326 subjects, comparing Chiari malformation Type I (CM-I), Chiari Type 0 (CM-0), and matched controls. Key measured parameters include clivus length and angle, tentorial angle, foramen magnum diameter, and area-based ratios relating cerebellum, posterior fossa, and intracranial cavity.

Findings indicate that CM-I patients exhibit clival shortening, reduced posterior cranial fossa area, altered tentorial orientation, and increased cerebellar occupancy relative to posterior fossa and brain, whereas CM-0 patients show morphometry comparable to controls. The authors conclude CM-I has distinct morphoanatomical remodeling, while CM-0 may represent a functional clinical entity without consistent structural substrate.

Definitions: CM-I is defined by ≥5 mm cerebellar tonsillar descent below the foramen magnum on MRI, while CM-0 is defined by <3 mm descent despite Chiari-like symptoms.

Design: Retrospective mid-sagittal MRI morphometry of 326 adults (CM-I n=111, CM-0 n=27, controls n=188) using multiple cranial base, posterior fossa, cerebellar, and intracranial measurements plus area-based ratios.

Key CM-I anatomy: Compared with CM-0 and controls, CM-I showed shorter clivus length, smaller posterior cranial fossa area, and larger cerebellar area; foramen magnum diameter and total brain area were similar across groups.

Crowding ratios: CM-I had higher cerebellum/posterior fossa and cerebellum/brain area ratios, indicating increased relative cerebellar occupancy despite preserved global cranial proportions.

CM-0 vs controls: CM-0 morphometric measurements were largely comparable to healthy controls, with no consistent structural differences in the main posterior fossa metrics highlighted.

Interpretation: CM-I aligns with a pattern of cranial base remodeling and posterior fossa insufficiency, whereas CM-0 may be better viewed as a functionally defined condition rather than one with a consistent structural substrate.

Reliability/statistics: Analyses used nonparametric tests (Kruskal–Wallis with Bonferroni-corrected Mann–Whitney post hoc), and interobserver measurement reliability was good–excellent (ICC 0.82–0.94).

Limitations: Morphometry was 2D mid-sagittal (not full 3D volumetry) and CSF flow dynamics (e.g., phase-contrast MRI) were not uniformly available, limiting functional assessment—especially relevant to CM-0.

The role of salvage stereotactic radiosurgery for tumor progression following incomplete microsurgical resection of vestibular schwannoma

J Neurosurg 144:1403–1409, 2026

This clinical study evaluates salvage stereotactic radiosurgery (SRS) for vestibular schwannoma (VS) that progresses after incomplete microsurgical resection, reporting long-term tumor control, freedom from additional treatment (FFAT), and complication rates in a 64-patient cohort. Key outcomes include 10- and 15-year tumor control of 87.5% and 84.4%, and FFAT of 95.3% and 92.2%, respectively.

The methods describe retrospective selection, radiosurgical dosimetry (median margin 12.5 Gy), imaging and follow-up protocols, and statistical analyses using Kaplan–Meier and Cox models; no factors significantly predicted control or FFAT, and common complications included trigeminal neuropathy and hearing worsening.

Objective Assess safety/efficacy of salvage stereotactic radiosurgery (SRS) for vestibular schwannoma (VS) that progresses after incomplete microsurgical resection, including factors affecting tumor control and freedom from additional treatment (FFAT).

Cohort Retrospective series of 64 adults treated with salvage SRS for post-resection tumor progression; median age 51.5 years and 46.9% male.

Treatment parameters Median marginal dose 12.5 Gy (median isodose 50%); median tumor volume 1.6 cm³; median time from surgery to salvage SRS 38.8 months.

Long-term control Tumor control rates after salvage SRS were 87.5% at 10 years and 84.4% at 15 years.

Durability (FFAT) FFAT rates were 95.3% at 10 years and 92.2% at 15 years, indicating most patients avoided further intervention long term.

Predictors No evaluated factors (e.g., Koos grade, age/sex, cranial nerve neuropathies, marginal dose, extent of resection, tumor volume) were significantly associated with tumor control or FFAT in Cox modeling.

Complications Most common post-SRS issue was worsening/new trigeminal neuropathy (15.6% total); hearing worsened in 14.1% (Gardner-Robertson class), and facial nerve function worsened in 4.7% (House-Brackmann).

Conclusion Salvage SRS is a safe and effective long-term strategy for VS tumor progression after incomplete resection, supporting continued monitoring and consideration of SRS once progression is documented.

History and evolution of the far‑lateral approach in neurosurgery

Acta Neurochirurgica (2026) 168:122

This review chronicles the development and technical refinement of the far‑lateral approach (FLA) for accessing the foramen magnum, lower clivus, and craniovertebral junction, tracing its origins from lateral suboccipital exposures to contemporary transcondylar, supracondylar, paracondylar, and extreme lateral transodontoid variants. It summarizes modifications in skin incisions, bony resection strategies, VA management, positioning, and closure techniques that improved exposure while minimizing brain retraction and craniovertebral morbidity.

The article evaluates clinical outcomes, biomechanical data, and technological integrations—endoscopic assistance, neuronavigation, and neuromonitoring—emphasizing a tailored, pathology-driven philosophy: remove only the bone necessary, mobilize the vertebral artery judiciously, and consider occipitocervical fusion when stability thresholds are exceeded to balance maximal resection with minimal long‑term instability and CSF complications.

Purpose: Provides a more anterior, tangential corridor to the foramen magnum/lower clivus/CVJ for ventrolateral or anterior brainstem pathology, reducing the need for brainstem/cerebellar retraction compared with older midline posterior and transoral routes.

Origins: Evolved from posterolateral aneurysm surgery—early unilateral suboccipital routes in the 1970s, with the first detailed “lateral suboccipital” (far-lateral) description by Heros in 1986 to reach distal vertebral and basilar trunk aneurysms by extending bone removal to the lateral foramen magnum rim.

Key bone-work concept: The major exposure-expanding step is selective occipital condyle drilling (transcondylar variant), typically about one-third to one-half to improve the angle of attack while aiming to preserve craniocervical stability; complete condyle removal is rare and generally prompts fusion.

Modular variants: The approach is used as adjustable “modules,” most notably transcondylar, supracondylar (jugular tubercle drilling), and paracondylar extensions, chosen based on lesion location and direction of extension.

Soft-tissue refinements: Incisions shifted from simple linear cuts to more tailored curvilinear/hockey-stick/C-shaped designs with larger musculocutaneous flaps to improve exposure, enable layered closure, and reduce wound/CSF-leak complications.

Positioning evolution: Use moved away from sitting (air embolism risk) toward lateral/modified park-bench positioning to leverage gravity-assisted relaxation and minimize fixed retraction.

Neurovascular strategy: Standardization of extradural vertebral artery (V3/V4) exposure and mobilization (when needed) improved proximal control and widened the corridor, turning the artery from an obstacle into a structure that can be safely managed to expand working space.

Modern extensions & technology: Continued refinement includes endoscope-assisted visualization, neuronavigation, and neuromonitoring; an extreme extension (ELTO) adds aggressive bony removal (including odontoid/C1 elements) for midline-crossing lesions but carries high instability risk, so occipitocervical fusion is typically performed.

Using the Quality Outcomes Database to Identify Minimum Clinically Important Differences for Patients With Cervical Spondylotic Myelopathy

Neurosurgery 98:1347–1358, 2026

This multicenter retrospective analysis of 1,141 surgical cases from the Quality Outcomes Database defines optimal minimum clinically important differences (MCIDs) for commonly used patient-reported outcome measures (PROMs) in cervical spondylotic myelopathy (CSM). The study compares several MCID calculation methods using AUCs anchored to patient satisfaction at 3- and 24-month follow-ups to identify the most predictive thresholds.

Key findings report a ≥30% improvement from baseline as the preferred MCID for NDI and neck/arm NRS, severity-adjusted point increases for mJOA, and absolute numeric cutoffs for EQ-5D (0.065 at 3 months; 0.149 at 24 months). Achievement rates and implications for clinical decision-making and benchmarking across centers are provided.

Aim Identify the most appropriate MCID thresholds for common PROMs in surgical cervical spondylotic myelopathy (CSM) using the Quality Outcomes Database (QOD) cohort.

Cohort Analyze 1141 CSM surgical cases across 14 sites (enrolled 2016–2018) with a 24-month follow-up rate of 87.6% (excluding 2.5% deaths).

PROMs Use baseline, 3-month, and 24-month outcomes for NDI, EQ-5D (QALYs), mJOA, and neck/arm pain NRS, with patient satisfaction as the anchor.

Anchor/AUC method Define “satisfied” using the NASS satisfaction scale (responses 1–2) vs “not satisfied” (3–4), then compare MCID methods by AUC for predicting satisfaction.

NDI & pain MCID A ≥30% improvement from baseline is the preferred/optimal MCID benchmark for NDI and neck/arm pain NRS (close to the best-performing ROC-derived percentage cutoffs).

EQ-5D MCID Absolute numeric cutoffs outperform other methods for EQ-5D: +0.065 QALYs (3 months) and +0.149 QALYs (24 months).

mJOA MCID A severity-adjusted approach performs best for mJOA: improvement of ≥1 (mild), ≥2 (moderate), or ≥3 (severe) points.

MCID achievement (24 months) MCIDs are achieved by 63% (NDI), 59% (neck pain NRS), 61% (arm pain NRS), 52% (EQ-5D), and 59% (mJOA) of patients.

Basilar artery perforator rupture as the cause of perimesencephalic subarachnoid hemorrhage

J Neurosurg 144:1271–1277, 2026

This clinical study evaluates the etiology of perimesencephalic subarachnoid hemorrhage (pmSAH) by applying high-resolution cone-beam CT (CBCT) during catheter angiography to detect basilar artery perforator outpouchings. The retrospective analysis of 22 pmSAH patients found that CBCT identified basilar perforator pseudoaneurysms in a substantial subset, with conservative management yielding excellent outcomes.

The authors argue that many pmSAHs may be arterial rather than venous in origin when imaged with modern high-resolution CBCT protocols. They recommend heightened suspicion for an arterial source and detailed angiographic CBCT acquisition, while acknowledging limits of retrospective design, variable imaging quality, and unresolved management questions.

Objective High-resolution CBCT performed during catheter angiography was used to better identify the etiology of perimesencephalic SAH (pmSAH), challenging the historical assumption of a venous source.

Methods Retrospective review of pmSAH cases (Jan 2023–Dec 2024) requiring catheter angiography with available, diagnostic-quality CBCT; images were interpreted by two experienced neuroangiographers to consensus.

Cohort Of 152 spontaneous SAH presentations, 22 met Rinkel criteria for pmSAH; after exclusions (alternative causes found, missing/low-quality CBCT), 13 patients remained for CBCT-based imaging analysis.

Key finding In 8/13 (61.5%) analyzed pmSAH cases, CBCT showed a basilar artery perforator focal outpouching consistent with a rupture site (submillimeter, 0.4–0.8 mm).

Anatomy distribution Among the 8 identified perforator lesions, 6 were rostral basilar perforators, with 1 midbasilar and 1 caudal perforator involvement.

Outcomes All pmSAH patients—including those with identified basilar perforator outpouchings—had excellent recovery, with no re-rupture events and no clinically significant vasospasm reported in the series.

Follow-up imaging In patients who underwent follow-up DSA with CBCT, the basilar perforator finding resolved on follow-up imaging.

Conclusion/implication pmSAH should be approached with high suspicion for an arterial etiology (basilar perforator pseudoaneurysm frequently detectable with high-resolution CBCT), and conservative management was associated with excellent outcomes in this cohort.

A 7-Year Experience in Microsurgical Treatment of Unruptured Intracranial Aneurysms in Older Patients

Neurosurgery 98:1325–1338, 2026

This article reports a 7-year single-center retrospective analysis comparing one-year neurological outcomes after microsurgical clipping of unruptured intracranial aneurysms in patients >65 years versus younger adults. It details patient selection, aneurysm characteristics, statistical methods, and primary endpoint assessment using the modified Rankin Scale.

Findings indicate similar favorable 1-year outcomes between older and younger cohorts, with diabetes and de novo aneurysm formation/growth identified as independent predictors of poor outcome in the older group. The discussion contextualizes results against endovascular options, comorbidity considerations, and limitations of retrospective single-center data.

Question addressed Whether to treat unruptured intracranial aneurysms (UIAs) in patients >65 remains controversial because of frailty/comorbidities and procedural risk vs rupture risk under conservative management.

Study design Retrospective review of UIA patients treated with microsurgical clipping (single quaternary center, 2014–2020), including only those with admission mRS ≤2; primary endpoint was 1-year mRS, with poor outcome defined as mRS >2.

Cohort 390 total surgically treated patients; 132 (34%) were >65 with mean age 71±4 years.

Main outcome No significant difference in poor neurological outcome at 1 year between older vs younger patients (11% vs 9.3%, P=.82), indicating comparable functional outcomes after microsurgery in selected older adults.

Aneurysm differences with age Older patients had larger aneurysm dimensions and more calcification (e.g., calcification 15% vs 2.8%) and higher PHASES/ELAPSS scores than younger patients.

Univariate risk factors (older group) Factors associated with poor 1-year outcome included diabetes, higher Charlson Comorbidity Index, calcification, treating multiple aneurysms, de novo formation/growth, and higher aspect ratio.

Independent predictors On multivariable analysis in older patients, only diabetes (OR 19.1, P=.02) and de novo formation or growth (OR 12.7, P=.02) predicted poor neurological outcome.

Clinical implication Chronological age alone is not a stand-alone contraindication to microsurgical treatment; individualized selection and comorbidity/risk stratification (notably diabetes and aneurysm growth patterns) are key.

Same-day spine surgery at an ambulatory surgical center versus hospital outpatient department

J Neurosurg Spine 44:835–846, 2026

This clinical study compares safety, complications, and patient-reported outcomes for same-day anterior cervical arthrodesis/arthroplasty and lumbar decompression performed in ambulatory surgical centers (ASC) versus hospital outpatient departments (HOPD) using a propensity-matched statewide registry. Primary outcomes included complication rates, return to OR, ED visits, and readmissions; secondary outcomes assessed PROMs and return-to-work at 90 days and 1 year.

Matched analysis of 3,351 lumbar decompressions and 806 anterior cervical procedures found no differences in PROs between ASC and HOPD, comparable safety for anterior cervical surgery, but a slightly higher rate of return to OR—driven by reherniation—for lumbar decompression performed in ASCs. Authors recommend future cost-effectiveness and patient-selection research.

Objective Compare safety and outcomes of same-day discharge anterior cervical arthrodesis/arthroplasty (1–2 levels) and lumbar decompression performed in an ambulatory surgical center (ASC) versus a hospital outpatient department (HOPD).

Design/Data source Retrospective, propensity-matched comparative cohort analysis using the statewide Michigan Spine Surgery Improvement Collaborative (MSSIC) registry for cases from Jan 1, 2021 to Jun 30, 2023.

Matching approach HOPD:ASC cohorts matched 4:1 using BMI, ASA class, and number of operative levels to improve comparability and power.

Primary outcomes Assessed any complication, return to operating room (OR) within 90 days, and ED visit or readmission within 30 and 90 days; secondary outcomes included PROs at 90 days/1 year and return to work.

Sample size (matched) Included 3351 lumbar decompressions (2679 HOPD, 672 ASC) and 806 anterior cervical cases (644 HOPD, 162 ASC).

Cervical results No significant ASC vs HOPD differences for complications, PROs at 90 days or 1 year, or return to work at 90 days or 1 year (p > 0.05).

Lumbar results (safety) ASC had higher rates of any complication (8% vs 5.5%) and return to OR (4.9% vs 2.1%) than HOPD in univariate analysis, and this persisted in multivariate analysis (IRR 1.5 for any complication; IRR 2.3 for return to OR).

Lumbar results (driver & outcomes) Elevated return-to-OR risk in ASC was driven primarily by lumbar reherniation requiring reoperation (3.2% ASC vs 1.0% HOPD), while PROs at 90 days and 1 year were otherwise similar between settings.

Diagnosing Cerebrospinal Fluid Shunt Failure: Systematic Review and Meta-Analysis of Noninvasive and Minimally Invasive Tests in Children and Adults

Neurosurgery 98:1206–1220, 2026

This systematic review and meta-analysis evaluates diagnostic performance of noninvasive and minimally invasive tests (X-ray shunt series, CT, MRI, nuclear scintigraphy, thermal flow) for cerebrospinal fluid shunt failure in pediatric and adult patients, synthesizing 33 studies and 8,077 patients. Pooled accuracy was 82%, sensitivity 67%, and specificity 88%, with X-ray series showing lower sensitivity but higher specificity compared with CT.

The analysis highlights substantial study bias—especially in patient selection and reference standards—and concludes no existing test is adequate as a standalone diagnostic for shunt failure, underscoring the need to optimize diagnostic pathways, reduce harm, and develop improved point-of-care functional tests.

Objective Assess diagnostic performance of noninvasive/minimally invasive tests (X-ray shunt series, CT, MRI, nuclear scintigraphy, thermal flow evaluation) for suspected CSF shunt failure in pediatric and adult patients.

Methods Systematic review/meta-analysis (PROSPERO CRD42024596142) including patients with permanent CSF shunts who underwent the above index tests; performance (accuracy, sensitivity, specificity) modeled via meta-regression incorporating test type, age group, follow-up timeframe, and shunt type.

Evidence base PubMed search (Oct 22, 2024) screened 465 articles; 33 studies included, totaling 8077 patients.

Pooled performance Overall pooled accuracy 82%, sensitivity 67%, specificity 88% across included tests.

Key comparative finding (sensitivity) X-ray shunt series had significantly lower sensitivity than CT (OR 0.106, 95% CI 0.056–0.201; overall effect of test type on sensitivity P = .013).

Key comparative finding (specificity) No overall effect of test type on specificity (P = .192), but X-ray shunt series showed higher specificity than CT in subgroup analysis (OR 4.04, 95% CI 1.938–8.424).

Covariates No significant effects of age group, follow-up timeframe, or shunt type on accuracy, sensitivity, or specificity.

Conclusion/limitations No test performed well enough to serve as a standalone diagnostic for shunt failure; evidence limited by high risk of bias, especially in the reference standard domain for most studies.

Hybrid fluoroscopy–neuronavigation technique for percutaneous balloon compression in trigeminal neuralgia

Acta Neurochirurgica (2026) 168:110

This article presents a hybrid fluoroscopy–electromagnetic neuronavigation technique for percutaneous balloon compression in trigeminal neuralgia, detailing preoperative CT trajectory planning, intraoperative dual guidance, and practical steps to optimize foramen ovale cannulation. Emphasis is placed on safety measures, anesthesia considerations, and procedural specifics such as entry point, stylet use, and balloon inflation parameters.

The manuscript discusses candidate selection, advantages for elderly or comorbid patients, limitations including equipment needs and limited evidence, and practical tips to minimize complications. Key points summarize indications, procedural timing, anatomical landmarks, and the hybrid approach’s potential to shorten the learning curve for junior surgeons.

Purpose: Hybrid fluoroscopy + electromagnetic neuronavigation improves accuracy and safety of foramen ovale cannulation for percutaneous balloon compression in trigeminal neuralgia, reducing multiple passes in anatomically variable cases

Planning: Preoperative thin-slice CT is used to design an individualized needle trajectory to the foramen ovale, sometimes modifying the classical Hartel entry point to avoid bony collision

Anesthesia: Performed under general anesthesia because trigeminal ganglion manipulation can trigger a vagal reflex causing severe bradycardia/asystole; atropine readiness is required

Setup & entry: Patient supine with slight head extension; entry point is typically ~2.5 cm lateral to the oral commissure, with neuronavigation confirming the skin site/trajectory and C-arm fluoroscopy providing real-time position checks

Needle guidance: Needle advanced under fluoroscopy toward the petrous ridge–clivus junction (lateral view alignment), then an electromagnetic sensor/stylet is inserted to confirm and fine-tune alignment with the preplanned path before FO passage

Balloon step: After cannulation, a 4F Fogarty balloon is inflated with ~0.75 ml iopamidol to achieve the characteristic pear-shaped configuration under fluoroscopy

Compression time: Balloon compression is maintained for ~1–3 minutes to balance pain relief with risks such as hypoesthesia and masticatory weakness; limit to a maximum of 3 minutes

Clinical role & limits: Useful for medication-refractory TN, especially elderly/comorbid patients or when MRI shows no neurovascular conflict; limitations include added cost/skill needs and low evidence base (lack of randomized trials)

Guidelines for the Treatment of Adults With WHO Grade II Diffuse Glioma: Update

Neurosurgery 98:984–991, 2026

These updated CNS evidence-based guidelines consolidate current literature on the management of WHO grade II diffuse gliomas, covering imaging, surgical strategies, neuropathology, radiotherapy, chemotherapy, and recurrence. They summarize evidence levels, provide topic-specific recommendations, and identify areas needing higher-quality research to inform clinical decisions.

The document details unchanged, updated, and new recommendations—ranging from MRI protocols and intraoperative mapping to molecular testing and adjuvant therapy—while describing methodology, conflict-of-interest procedures, and plans for periodic revision to ensure clinical relevance.

Scope: Updated evidence-based recommendations for adult WHO grade II diffuse glioma across imaging, surgery, neuropathology/molecular markers, radiotherapy, chemotherapy, and recurrence management.

Methods: Systematic search of MEDLINE/Embase/Cochrane covering Jan 1, 2013–Jan 31, 2020, with recommendations based on evidence rather than consensus.

Imaging (minimum MRI): Minimum evaluation includes T2-weighted and pre- and post-gadolinium T1-weighted MRI; serial imaging is used to detect new enhancement or significant growth suggesting higher-grade transformation.

Imaging (advanced/PET): Diffusion plus perfusion techniques (e.g., DSC/DCE/ASL) are suggested when standard MRI cannot distinguish grade II from higher-grade gliomas; amino-acid PET (FET or FDOPA) may be added when not evident on MRI to help with grading, prognosis (FET), or progression detection (FDOPA).

Surgery: When safe/feasible, resection (gross total or subtotal) is recommended over biopsy alone to reduce progression; extent of resection should be maximized when safely possible (including for IDH-mutant and IDH–wild-type tumors).

Pathology/molecular testing: Diagnosis relies on histopathology from representative tissue; IDH mutation testing is recommended for classification/prognosis, and 1p/19q loss-of-heterozygosity testing is recommended in oligodendroglial cases for prognosis/treatment planning.

Adjuvant therapy (high-risk): For high-risk grade II diffuse glioma (age >40 or <40 without gross total resection), adding chemotherapy to radiotherapy is recommended to improve overall survival (including procarbazine/PCV-based approaches) and is also recommended without decline in neurocognitive function.

Recurrence: At suspected recurrence, advanced imaging (MRS/perfusion/diffusion/PET) is suggested; temozolomide is suggested (often initial choice) and procarbazine may help (strongest evidence in oligodendroglioma); radiation is suggested if not previously given and reirradiation may be considered.

How much do patients benefit in quality of life after surgery for cervical spondylotic myelopathy? A Spine CORe™ analysis of QOD data

Neurosurg Focus 60(5):E2, 2026

This multicenter Quality Outcomes Database analysis evaluates long-term quality of life after surgery for cervical spondylotic myelopathy (CSM), using EQ-5D scores at baseline and 3, 12, 24, and 60 months. The study reports significant, durable postoperative EQ-5D improvements and a mean gain of 0.72 QALYs at five years across a large surgical cohort.

The analysis identifies predictors of clinically meaningful improvement: worse baseline EQ-5D increased odds of improvement, while greater baseline neck pain severity and undergoing anterior cervical corpectomy and fusion (ACCF) decreased those odds. Complication and mortality rates were low, supporting sustained quality-of-life benefits of CSM surgery.

Objective Assess long-term postoperative quality-of-life benefit after surgery for cervical spondylotic myelopathy (CSM) and identify factors linked to meaningful improvement.

Methods Post hoc analysis of a prospectively collected, 14-site QOD CSM cohort using EQ-5D at baseline and 3, 12, 24, and 60 months; MCID for EQ-5D defined as 0.11; multivariable logistic regression used to find predictors of 60-month MCID achievement.

Cohort At 60 months, follow-up status was available for 895/1085 patients (82.4%); 788 patients had 60-month EQ-5D data for the main EQ-5D analysis.

Quality-of-life gains Mean EQ-5D improved from 0.58 ± 0.22 preop to 0.76 ± 0.22 at 60 months (p < 0.001), with improvements evident by 3 months and sustained through 5 years.

Clinically meaningful benefit 58.7% of patients achieved the EQ-5D MCID at 60 months.

Negative predictors Greater baseline neck pain severity and undergoing ACCF (anterior cervical corpectomy and fusion) were independently associated with lower odds of achieving the 60-month EQ-5D MCID.

Positive predictor Worse baseline quality of life (lower baseline EQ-5D) was associated with increased odds of achieving long-term (60-month) MCID improvement.

QALYs Mean gain after surgery was 0.72 ± 1.11 QALYs over 60 months (calculated via area-under-the-curve with baseline-projected QALYs subtracted).

Transforming Neurosurgery With Spatial Computing: Enhancing Intraoperative Visualization and Precision Through Augmented Reality

Operative Neurosurgery 30:760–764, 2026

This technical note reports three neurosurgical cases using the Medivis surgical augmented reality platform with the Microsoft HoloLens 2 to overlay real-time 3D imaging, exoscopic, and endoscopic outputs intraoperatively. The workflow, registration method, hardware and software integration, and case-specific operative details are described, with all patients recovering without complications.

The report evaluates benefits and limitations of wearable XR in the operating room, highlighting improved visualization, surgical precision, and ergonomics, while addressing challenges such as registration accuracy, latency, cognitive overload, and avenues for future hardware and software improvements.

Goal Integrate wearable XR/AR and spatial computing into neurosurgical operating rooms to enhance intraoperative visualization, precision, and ergonomics.

System setup Three neurosurgical cases used the Medivis SurgicalAR platform paired with a Microsoft HoloLens 2 worn by the primary surgeon, enabling overlay of 3D volumes and intraoperative video in the surgeon’s field of view.

Imaging workflow Preoperative CT/MRI (including tractography/connectomic imaging when available) were uploaded from PACS, processed quickly (windowing/coloring/cropping/brightening), and stored for OR use, then linked to the HoloLens.

Registration approach Intraoperative holographic point-matching registration matched physical landmarks on the patient to virtual fiducials via an optical localizer recognized by HoloLens 2, with an FDA-approved navigation system also used in all cases for confirmation.

Video integration Exoscopic/endoscopic outputs were captured and streamed to the AR computer and transmitted to the HoloLens for real-time manipulation and interaction by the surgeon.

Observed benefits Combined overlays improved visualization and supported ergonomic operating posture, optimized sight lines, and reduced OR footprint while maintaining standard team visualization via the exoscope monitor.

Case outcomes All three patients recovered well postoperatively without complications; no critical intraoperative issues from latency/dropped frames prevented procedure completion.

Limitations & next steps Key challenges include potential cognitive overload/inattentional blindness, hologram registration accuracy, and technical issues like latency/dropped frames; future work targets improved/universal registration and broader overlayable data streams (e.g., conferencing, checklists).

Incidence and risk factors of adjacent segment degeneration in lumbosacral or lumbo-iliac fusion with L2 as the uppermost instrumented vertebra

J Neurosurg Spine 44:693–703, 2026

This clinical retrospective study evaluates the incidence and risk factors for symptomatic adjacent segment degeneration (ASD) after instrumented fusion from L2 to the sacrum or ilium in 89 adults treated for diffuse lumbar degeneration or mild–moderate deformity. Over a mean 38.6-month follow-up, 40% developed symptomatic L1–2 ASD and 23.6% required revision, with Kaplan-Meier ASD-free rates of 79% at 1 year and 59% at 3 years.

Multivariate analysis identified L2–3 decompression, preexisting advanced L1–2 disc degeneration, greater postoperative PI–LL mismatch, and higher lordosis distribution index as independent ASD risk factors; distal failures (13.5%) were linked to male sex, younger age, and absence of iliac screws. The authors recommend careful selection of L2 as UIV, balanced lordosis restoration, and consideration of pelvic fixation to mitigate proximal and distal complications.

Aim Quantify incidence of symptomatic adjacent segment degeneration (ASD) after instrumented fusion from L2 (UIV) to sacrum or ilium and identify associated risk factors.

Design/definition Retrospective review (Jan 2016–Dec 2023) of adults undergoing first-time L2–S1/ilium fusion; symptomatic ASD defined by new/worsening pain or neurologic symptoms with L1–2 degenerative/junctional changes (e.g., disc degeneration/stenosis progression, listhesis, junctional kyphosis, fracture, or UIV fixation failure).

Cohort 89 patients (mean age 68.5 years) with mean follow-up 38.6 months.

ASD incidence 36/89 (40%) developed symptomatic ASD at L1–2; mean time to ASD 21 months; 21/89 (23.6%) required reoperation.

ASD-free survival Kaplan-Meier ASD-free rates: 79% at 1 year, 68% at 2 years, 59% at 3 years (mean ASD-free period 52.8 months).

ASD risk factors Higher ASD risk associated with simultaneous decompression at L2–3, preexisting advanced L1–2 disc degeneration, greater postoperative PI-LL mismatch, and higher lordosis distribution index (LDI).

Distal failure incidence 12/89 (13.5%) developed distal failure (including 9 L5–S1 pseudarthroses, 2 sacral fractures, 1 rod fracture); mean time 19 months.

Distal failure risk factors Male sex, younger age, and lack of iliac screws increased risk of distal failure.

Defining the target for hemifacial spasm –regarding microvascular decompression

Acta Neurochirurgica (2026) 168:103

This paper argues that the physiologic target for microvascular decompression (MVD) in hemifacial spasm (HFS) is the full extent of the centrally myelinated facial root exit zone (fREZ), from the pontomedullary sulcus (root exit point) to the transitional zone, rather than the shorter REZ segment often emphasized. The authors critique recent anatomical definitions and highlight histological and intraoperative evidence supporting a longer susceptible CMP.

The manuscript details four fREZ segments (RExP, attached segment, root detachment point, TZ), presents frequency data of culprit compressions concentrated on the attached segment, and stresses diagnostic-imaging and surgical implications. Adopting the expanded fREZ map and subfloccular approach is presented as essential to reduce failed MVDs for HFS.

Target definition problem: Equating the cranial nerve REZ with just the short segment between the brainstem surface and the TZ does not accurately represent the physiologically vulnerable central myelin portion (CMP) of the facial nerve in hemifacial spasm surgery.

Facial CMP length: The facial nerve’s exposed centrally myelinated fibers extend proximally along the pontine surface and are considerably longer (about ~1 cm) than the commonly measured brainstem-to-TZ segment.

Expanded fREZ anatomy: A practical surgical definition divides the facial root exit zone (fREZ) into four parts—RExP (root exit point at the pontomedullary sulcus), AS (attached segment adherent to the pons), RDP (root detachment point), and distal TZ (2–3 mm beyond RDP).

Physiologic susceptibility zone: The vulnerable target for MVD in HFS is the entire exposed centrally myelinated facial segment from the pontomedullary sulcus (RExP) to the TZ, not only the short “REZ” segment near the brainstem edge.

Compression distribution: Culprit neurovascular compression in HFS occurs most often along the AS (~80%), less at RExP (~10%) and RDP–TZ (~10%), and only rarely on the distal cisternal portion (typically with severe distortion).

Imaging implication: Diagnostic imaging interpretation for HFS should assess the most proximal fREZ (RExP and AS) rather than focusing only distal to the RDP.

Surgical failure mechanism: Failed MVD can result when decompression is directed at more distal facial nerve portions, missing persistent compression at the true proximal anatomical target.

Approach to access target: A subfloccular approach helps reach the proximal fREZ by tracking glossopharyngeal fibers to the brainstem, supporting effective decompression of the susceptible proximal segment.

Predictors of shunt responsiveness and outcomes in idiopathic normal pressure hydrocephalus: a retrospective cohort study

Acta Neurochirurgica (2026) 168:80

This retrospective cohort study from Tel-Aviv Medical Center evaluates predictors of clinical improvement after shunt placement in patients with idiopathic normal pressure hydrocephalus (iNPH) assessed between 2020–2022. The authors analyze clinical presentation, standardized gait testing, MRI features (including DESH), CSF biomarkers (notably total tau and protein), and PET findings to determine associations with lumbar puncture (LP) responsiveness and one-year post-shunt outcomes.

Key findings show 37% LP responsiveness among 167 patients, 38 underwent shunting, and 55% of shunted patients had favorable one‑year outcomes. Lower CSF total tau and presence of a DESH imaging pattern correlated with LP response and improved one‑year outcomes, while greater immediate post‑LP gait improvement predicted sustained benefit; vascular comorbidities and standard MRI metrics were less predictive.

Objective Identify clinical, imaging, and CSF biomarkers linked to favorable outcomes after shunt placement in suspected idiopathic normal pressure hydrocephalus (iNPH).

Cohort & pathway 183 patients were evaluated (2020–2022); 167 underwent high-volume lumbar puncture (≥30 mL removed); LP responders were referred for shunting and followed for 1 year.

LP responsiveness rate 62/167 (37%) improved after CSF drainage and were referred for shunt surgery; 38/62 (61%) ultimately underwent shunt placement.

Clinical pattern Gait disturbance was the most common presenting symptom (68%) and was more frequent in LP responders, while cognitive symptoms were more common among non-responders (29.5% vs 10%).

CSF biomarkers (LP response) LP responders had lower CSF total tau (t-tau) and protein than non-responders.

Imaging marker (LP response) The DESH pattern was more common in LP responders (73% vs 46%).

Shunt outcomes (1 year) 21/38 (55%) shunted patients had a favorable outcome at one year; favorable outcome was associated with more frequent DESH and lower t-tau (trend).

Overall takeaway Combining post-LP clinical response with DESH imaging and CSF t-tau may help refine selection for shunting and predict better outcomes.

Clinical Outcomes of Subarachnoid Hemorrhage in Patients With Nicotine Dependence

Neurosurgery 98:1095–1102, 2026

This retrospective, population-based study analyzes clinical outcomes after nontraumatic subarachnoid hemorrhage (SAH) among 43,315 patients with documented nicotine dependence versus patients without substance use disorders. Using the TriNetX network with propensity score matching, primary endpoints included mortality, vasospasm, hydrocephalus, and delayed cerebral ischemia (DCI), with nicotine dependence associated with significantly higher hazards for all outcomes.

The manuscript details methods, matching variables, statistical analyses, mechanistic discussion of nicotine’s vascular effects, and limitations inherent to large electronic health record databases. Conclusions emphasize that nicotine dependence predicts worse SAH outcomes and support prioritizing smoking cessation counseling as part of long-term patient management.

Study focus: Clinical outcomes after nontraumatic subarachnoid hemorrhage (SAH) in adults with nicotine dependence versus those with no substance use disorder diagnoses.

Data source & cohort: TriNetX electronic medical record network analysis of adults (≥18) with ICD-10 I60 (nontraumatic SAH) from 2004–2024; 43,315 had nicotine dependence (F17) out of ~210k+ SAH patients.

Methods: Used 1:1 propensity score matching to balance demographics, comorbidities, lab/substance testing, and SAH severity (NIS-SAH Severity Score elements), then applied Cox proportional hazards and Kaplan–Meier survival analyses.

Mortality risk: Nicotine dependence associated with higher post-SAH mortality hazard (HR ≈ 1.24–1.25, statistically significant).

Vasospasm risk: Nicotine dependence associated with higher hazard of vasospasm (HR ≈ 1.47–1.49, statistically significant).

DCI risk: Nicotine dependence associated with higher hazard of delayed cerebral ischemia (DCI) (HR reported ≈ 1.30–1.35, statistically significant).

Hydrocephalus risk: Nicotine dependence associated with higher hazard of newly diagnosed hydrocephalus (HR ≈ 1.27, statistically significant).

Clinical implication: Elevated risks linked to nicotine dependence underscore the importance of smoking cessation counseling for long-term management after SAH.

The utility of partial sensory rhizotomy and adjunct procedures in the surgical management of trigeminal neuralgia secondary to multiple sclerosis

J Neurosurg 144:1145–1153, 2026

This clinical study evaluates long-term outcomes of partial sensory rhizotomy (PSR) for trigeminal neuralgia (TN) secondary to multiple sclerosis (MS), comparing PSR alone, redo PSR, and PSR combined with microvascular decompression (MVD) or internal neurolysis (IN). Retrospective analysis of 37 procedures in 30 patients shows high immediate pain relief (89.2%), mean recurrence at 1.64 years, and variable durability across groups.

At final follow-up, combination therapy (PSR+MVD or PSR+IN) trended toward superior sustained pain freedom without increased complications, while first PSR commonly required additional interventions. The authors conclude PSR is an effective salvage option and suggest adjunctive MVD or IN may improve long-term outcomes, recommending prospective validation.

Objective Evaluate long-term outcomes of partial sensory rhizotomy (PSR) alone versus PSR combined with microvascular decompression (MVD) or internal neurolysis (IN) for trigeminal neuralgia secondary to multiple sclerosis.

Methods Retrospective review of PSR cases (2012–2023) grouped as first PSR, redo PSR, PSR+MVD, and PSR+IN; assessed pain outcomes, recurrence, and complications.

Cohort 30 patients underwent 37 procedures; 89.2% of procedures followed at least one prior ipsilateral TN procedure.

Immediate outcomes 89.2% achieved immediate postoperative pain relief (pain free with or without medication), with no significant differences between procedure groups.

Durability Pain recurred on average at 1.64 ± 1.71 years after the procedure, with no significant differences among groups.

Final follow-up pain freedom At mean 3.14 ± 2.58 years follow-up, 75% of PSR+MVD and 100% of PSR+IN cases were pain free; 52.3% of first PSR cases required additional procedures.

Complications Overall complication rate was 29.7% with no significant differences between groups; ipsilateral facial numbness was common (59.5%) and treated as an expected outcome rather than a complication.

Conclusion PSR functions effectively as a salvage option for MS-related TN, and adding MVD or IN may improve long-term pain relief without increasing complication rates.

Disruptive technologies in spine surgery: current trends, outcomes, and ethical implications

J Neurosurg Spine 44:756–768, 2026

Disruptive technologies in spine surgery—AR/VR, robotics, neuronavigation, endoscopy, and patient-specific implants—are examined for their roles in enhancing precision, training, and patient outcomes. The review summarizes evidence for preoperative simulation, AR-assisted planning, and 3D segmentation, highlighting improvements in accuracy, reduced fluoroscopy, and trainee confidence.

Intraoperative advances such as robot-assisted techniques, computer-assisted navigation, and endoscopic approaches offer minimally invasive alternatives with favorable recovery profiles but face challenges of cost, learning curves, and equitable access. The authors emphasize ethical considerations, need for standardized outcomes, and strategies to expand accessibility and training.

Scope Disruptive spine-surgery technologies emphasized include AR/VR (XR), advanced navigation, robotics, patient-specific implants/3D printing, and endoscopic spine surgery.

XR definitions VR provides a fully immersive digital environment, AR overlays digital content onto the real world, and MR blends both; all fall under XR.

Training impact VR simulation in spine training improved trainee comfort and autonomy and reduced fluoroscopy use in lateral lumbar interbody fusion simulations; VR-trained learners also made fewer pedicle-screw placement errors than traditional instruction.

Preop planning VR-based planning can reduce fluoroscopy/localization time and improve puncture accuracy in endoscopic lumbar discectomy; segmented 3D models support rehearsal, trajectory planning, and risk assessment around critical structures.

AR navigation outcomes Wearable AR navigation (e.g., FDA-cleared xvision) has shown high pedicle-screw placement accuracy (reported ~96.7% thoracic and ~99.1% lumbosacral) and may reduce operative time and radiation exposure.

Patient-specific surgery Segmentation + 3D printing/predictive modeling enable personalized approaches and implants (e.g., patient-specific rods, templates, custom cages), with early reports of high accuracy for template-guided instrumentation and promising feasibility for custom interbody devices.

Endoscopic techniques ESS supports minimally invasive treatment across multiple pathologies and can match conventional outcomes for lumbar disc herniation while improving recovery (e.g., shorter stays/earlier return to work), but broader adoption is constrained by learning curve and reimbursement challenges.

Implementation ethics/costs High acquisition/maintenance costs and limited reimbursement risk widening access disparities; recommended mitigations include subsidized training, shared equipment models, and reimbursement policies to support equitable implementation alongside standardized outcomes and training.