Author: cba

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How I do it: microvascular decompression for vago-glossopharyngeal neuralgia

Acta Neurochirurgica (2026) 168:62

This surgical how-to describes microvascular decompression (MVD) for vago‑glossopharyngeal neuralgia, detailing patient selection, imaging requirements, anesthesia, positioning, and a retrosigmoid infrafloccular approach to expose the IX–X root entry zones. It emphasizes preoperative high-resolution MRI identification of neurovascular conflict—most often PICA or vertebrobasilar compression—and perioperative neurophysiological monitoring.

The technique section outlines stepwise microsurgical maneuvers: arachnoid dissection, vessel mobilization or transposition, cautious Teflon interposition when needed, hemostasis, watertight closure, and targeted postoperative surveillance for dysphagia, hoarseness, CSF leak, and other complications. Practical tips for avoiding complications and key informed‑consent elements are provided.

Vago-Glossopharyngeal Neuralgia (VGN): Rare craniofacial pain syndrome (<1% of facial pain cases), often caused by neurovascular conflict involving the posterior inferior cerebellar artery (PICA) and sometimes the vertebrobasilar artery.

Clinical Features: Characterized by paroxysmal, lancinating pain in the oropharynx, tonsillar fossa, base of tongue, or deep ear canal, typically triggered by swallowing, talking, or coughing.

Diagnosis: High-resolution MRI (T2-weighted CISS/FIESTA/DRIVE, 3D TOF angiography) is mandatory to demonstrate neurovascular conflict and guide surgical planning.

First-line Surgical Treatment: Microvascular decompression (MVD) is the most effective and durable option for drug-refractory VGN, aiming to relieve neurovascular conflict without damaging nerve rootlets.

Surgical Approach: Keyhole retrosigmoid craniectomy with infrafloccular approach exposes the root entry zone of cranial nerves IX and X; careful arachnoid dissection and vessel mobilization or Teflon interposition are performed.

Intraoperative Considerations: Intraoperative neuromonitoring of lower cranial nerves is recommended to minimize risk of postoperative deficits such as dysphagia or hoarseness.

Complications: Main risks include transient dysphagia, hoarseness, or lower cranial nerve palsies, which are usually temporary and resolve within three months.

Outcomes: MVD offers superior and lasting pain relief with functional preservation compared to ablative procedures, making it the preferred surgical option.

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Comprehensive analysis of biomechanical stability and clinical efficacy in oblique lumbar interbody fusion with distinct anterolateral fixation modalities

J Neurosurg Spine 44:436–448, 2026

This study evaluates how different anterolateral screw angles in oblique lumbar interbody fusion with anterolateral fixation (OLIF-AF) affect cage subsidence, biomechanical stability, and clinical outcomes. A retrospective cohort of 80 L4–5 OLIF-AF patients was grouped by coronal and horizontal screw angles, supplemented by finite element models simulating four screw configurations under physiological loads.

Findings show coronal-plane parallel screw placement reduced cage subsidence, cage stress, displacement, and range of motion versus nonparallel placement, while horizontal bifurcation had no significant effect on subsidence; clinical scores and fusion rates were similar across groups. The authors recommend coronal parallelism with bicortical purchase to optimize stability and lower subsidence risk.

Coronal Plane Parallel Screw Placement: Parallel screw placement in the coronal plane during OLIF-AF significantly reduces the risk of cage subsidence (CS) and enhances biomechanical stability compared to nonparallel placement.

Nonparallel Coronal Screw Placement Risks: Nonparallel coronal screw placement (G2 and G3 groups) is independently associated with higher CS rates, greater reduction in disc height (ΔDH), increased cage stress, displacement, and range of motion (ROM), indicating poorer biomechanical outcomes.

Horizontal Screw Bifurcation: Horizontal screw bifurcation (difference in horizontal plane angle) does not have a statistically significant impact on CS risk or clinical outcomes when coronal plane parallelism is maintained.

Bicortical Purchase Importance: Ensuring that screws penetrate the contralateral vertebral cortex (bicortical purchase) may further reduce the risk of CS, while lack of penetration is associated with earlier and more severe subsidence.

Clinical Outcomes: No significant differences in pain relief (VAS-LBP, VAS-LP) or Oswestry Disability Index (ODI) were observed among the four screw configuration groups at any follow-up point; fusion rates were also similar.

Finite Element Analysis Validation: Finite element modeling confirmed that nonparallel screw configurations increase cage stress and spinal ligament tension, especially during flexion, supporting clinical findings.

Risk Factors for Subsidence: Lower bone mineral density (BMD) and nonparallel coronal screw placement are independent risk factors for cage subsidence after OLIF-AF.

Surgical Recommendation: For optimal biomechanical stability and reduced complication risk, OLIF-AF screws should be placed parallel to the coronal plane and close to the endplates, with bicortical purchase, as this configuration provides better load sharing and fusion environment.

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Prevention of Ommaya Reservoir–Associated Bacterial Meningitis With Prophylactic Intraventricular Vancomycin

Neurosurgery 98:643–650, 2026

This clinical cohort study evaluates prophylactic intraventricular vancomycin (10 mg added to each intraventricular chemotherapy cycle) to prevent Ommaya reservoir–associated bacterial meningitis in patients with leptomeningeal disease. Over 501 treatments in 63 patients, infection rate was 0% versus 10.25% in a 5-year historical control, with no observed vancomycin toxicity and substantial cost savings.

The manuscript details methods, statistical analyses, safety monitoring, limitations inherent to a historical-control design, and a meta-analytic context of prior infection rates. Authors conclude prophylactic intraventricular vancomycin eliminated infections in their cohort and recommend consideration of broader adoption and prospective randomized trials.

Prophylactic intraventricular vancomycin: Adding 10 mg of intraventricular vancomycin to each cycle of planned intrathecal chemotherapy through an Ommaya reservoir (OmR) in patients with leptomeningeal disease eliminated OmR-associated bacterial meningitis infections over a 12-month period (0% infection rate in 63 patients, 501 treatments).

Historical infection rates: Prior to vancomycin prophylaxis, OmR-associated infection rates were 10.25% per patient and 1.71% per treatment in a 5-year historical control group (322 patients, 1932 treatments).

Absolute risk reduction and NNT: The absolute risk reduction for OmR-associated infection was 10.3% (P = .0028), with a number needed to treat (NNT) of 10 to prevent one infection.

No observed toxicity or resistance: No vancomycin-associated toxicity or development of antibiotic-resistant infections was observed during the study period, even with repeated dosing.

Significant cost savings: Prophylactic vancomycin cost $10 per dose, with an estimated annual savings of over $600,000 by preventing infections and associated treatments, not including potential additional savings from avoiding reservoir removal and replacement.

Robust methodology: The intervention was implemented as a global practice change, with prospective data collection for the vancomycin cohort and comparison to a well-matched historical control group, though some differences in tumor type and number of treatments existed.

Clinical and practical implications: The findings support strong consideration of prophylactic intraventricular vancomycin in OmR-based chemotherapy regimens, with the potential to significantly improve patient outcomes and reduce healthcare costs.

Need for further research: Prospective randomized trials are recommended to confirm these results and establish optimal dosing and broader applicability.

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External Ventricular Drain Placement Using Active Augmented Reality Guidance

Operative Neurosurgery 30:414–421, 2026

This technical note presents a proof-of-concept augmented reality (AR) system that guides external ventricular drain (EVD) placement by integrating cloud-based automatic CT segmentation, PACS compatibility, trajectory planning, point-based image-to-patient registration, and real-time 3D AR guidance via an AR head-mounted display. The low-cost, end-to-end workflow and universal tracking tools aim to reduce attention shifts and improve accessibility compared with conventional neuronavigation.

The system was tested in a phantom study with 29 AR-guided EVD insertions by neurosurgical clinicians, yielding 69% optimal placements (Kakarla grade 1), a mean distance-to-target of 9.49 mm, mean angular deviation of 9.20°, an FRE of 4.00 mm, and mean procedural time of 22:45. Authors identify human–computer interaction, tracking fidelity, registration accuracy, and procedural time as primary areas for refinement before clinical adoption.

Augmented Reality (AR) Guidance: A low-cost, end-to-end AR system was developed for external ventricular drain (EVD) placement, integrating real-time 3D guidance, automated CT segmentation, and compatibility with standard hospital PACS infrastructure, all visualized through AR head-mounted displays (AR-HMDs).

Workflow Components: The system includes cloud-based image storage, automatic segmentation, trajectory planning, point-based image-to-patient registration, and real-time EVD tracking, aiming to reduce attention shifts and improve procedural integration.

Proof-of-Concept Results: In simulated procedures on anatomical phantoms with small ventricles, 69% of placements were optimal (Kakarla 1), with a mean distance to target of 9.49 mm and mean angular deviation of 9.20°, but accuracy is not yet at the level of best clinical standards.

Procedural Time: The mean workflow duration was nearly 23 minutes, which is longer than acceptable for emergency EVD placements, with most of the added time attributed to trajectory planning, marker attachment, and image-to-patient registration.

Usability and Interface Challenges: Users experienced difficulties with human-computer interaction, including issues with holographic controls, visual clutter, and marker tracking, which impacted both speed and accuracy.

Affordability and Accessibility: The AR-HMD system (approx. $4950) is significantly less expensive than traditional neuronavigation systems, potentially increasing access to advanced guidance in resource-limited settings

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Incidence of C5 Palsy and Recovery Rate After Cervical Spine Surgery: A Systematic Review and Meta-Analysis

Neurosurgery 98:520–542, 2026

This systematic review and meta-analysis quantifies C5 nerve palsy incidence and recovery following various cervical spine surgeries, comparing anterior and posterior approaches across 155 studies. Pooled rates show higher C5 palsy after posterior procedures (laminectomy 8%, PCDF 7.03%, laminoplasty 5.11%) versus anterior ACDF (2.61%), with overall low permanence rates.

The paper details methods, study selection, heterogeneity, and limitations, and emphasizes the need for standardized diagnostic criteria, prospective cohorts, and treatment algorithms. Findings aim to inform surgical decision-making, patient counseling, and future research priorities to mitigate C5 palsy risk.

C5 palsy incidence: Highest after laminectomy (8%), followed by posterior cervical decompression and fusion (PCDF, 7.03%), laminoplasty (5.11%), corpectomy (4.16%), and lowest after anterior cervical diskectomy and fusion (ACDF, 2.61%).

Permanent C5 palsy rates: Low across all procedures—laminectomy (1.44%), PCDF (1.02%), laminoplasty (0.28%), ACDF (1.06%); no pooled data for corpectomy.

Posterior approaches risk: Posterior decompression procedures (laminectomy, PCDF, laminoplasty) carry a higher risk of C5 palsy than anterior approaches (ACDF, corpectomy).

Resolution and recovery: Most C5 palsy cases are transient and resolve within months; permanent deficits are uncommon with proper follow-up and care.

Surgical decision-making: Choice of approach should consider C5 palsy risk, especially in patients with anatomic risk factors (e.g., narrow foramina, preexisting kyphosis).

Economic impact: C5 palsy increases healthcare costs significantly, with up to $347,000 in the first year and ongoing annual costs of about $42,000 for permanent deficits.

Standardized protocols lacking: There is no consensus on optimal management; most strategies are institution-specific and anecdotal, highlighting the need for standardized treatment protocols.

Research gaps: High study heterogeneity, inconsistent reporting, and lack of long-term data—especially for corpectomy—limit understanding; further prospective studies on risk factors and outcomes are needed.

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A Validation of the Tarlov Cyst Quality-of-Life Survey in Men Surgically Treated for Symptomatic Spinal Tarlov Cysts

Operative Neurosurgery 30:379–384, 2026

This article validates the 11-item Tarlov Cyst Quality-of-Life (TCQoL) scale for male patients undergoing surgical treatment of sacral Tarlov cysts, demonstrating good internal consistency (Cronbach α = 0.85), significant postoperative improvement on nine items, and strong concurrent validity with ODI and SF-36 physical function and pain subscales. The TCQoL showed large responsiveness (SRM = 0.81) and correlated with VAS pain measures.

Methods include prospective preoperative and 3-month postoperative administration of TCQoL, ODI, SF-36, and VAS in 46 male patients treated surgically between 2016–2023, with detailed psychometric analyses assessing discriminative validity, construct validity, and responsiveness; limitations noted include small sample size, single-surgeon single-center design, and 20% attrition.

TCQoL Validation in Men: The Tarlov Cyst Quality-of-Life (TCQoL) scale, previously validated in women, was successfully validated for male patients undergoing surgical treatment for symptomatic sacral Tarlov cysts, demonstrating good internal consistency (Cronbach α = 0.85) and discriminative validity.

Study Population: The study included 46 male patients (final sample) with an average age of 48.4 years, mostly presenting with multiple sacral cysts and a median symptom duration of nearly 35 months.

Surgical Technique: Surgery involved a posterior approach with laminectomy, cyst drainage, and wrapping of the nerve root with a bovine pericardium sleeve to prevent refilling, followed by closure with a resorbable plate.

Symptom Improvement: Significant improvement was observed in 9 of 11 TCQoL items postoperatively, especially for discomfort while sitting, sacral pain, lower extremity pain, and weakness; sexual function items showed no significant change.

Correlation with Established Measures: The TCQoL showed strong positive correlation with the Oswestry Disability Index (ODI) (r = 0.63, P < .001) and moderate to strong negative correlations with key SF-36 subscales (physical function, bodily pain, vitality, and social functioning), indicating good concurrent validity.

Scale Responsiveness: The standardized response mean (SRM) for TCQoL was 0.81, indicating a large effect size and sensitivity to clinical change after surgery.

Limitations: The study is limited by a small sample size (reflecting the rarity of Tarlov cysts in men), single-center and single-surgeon design, and a 20% attrition rate; findings may not generalize to non-sacral or non-Tarlov cysts.

Clinical Utility: The TCQoL can now be used as a disease-specific HRQoL tool for both male and female patients with symptomatic sacral Tarlov cysts, supporting standardized outcome measurement in future research and clinical practice.

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Partial sensory rhizotomy in therapy‑refractory and recurrent trigeminal neuralgia

Acta Neurochirurgica (2026) 168:42

This single-center retrospective analysis reports outcomes of partial sensory rhizotomy (PSR) for therapy-refractory or recurrent trigeminal neuralgia (TN) in 48 patients treated between 2004 and 2023. The study details patient selection, surgical technique, and perioperative findings, noting immediate pain relief in most patients, variable hypesthesia, and acceptable complication rates without permanent deficits.

Long-term follow-up (mean 38 months) found 65% pain-free without medication and 95% overall satisfaction (BNI 1–3), including a substantive subset with multiple sclerosis; recurrence occurred in 27% with some successfully re-operated. The authors conclude PSR is a viable option for selected refractory or recurrent TN patients, emphasizing informed consent about unpredictable sensory deficits

Partial Sensory Rhizotomy (PSR) Role: PSR is a surgical option for therapy-refractory or recurrent trigeminal neuralgia (TN), especially in patients without neurovascular conflict or those who failed previous microvascular decompression (MVD) or other interventions.

Efficacy: PSR provided immediate total pain relief in 87.5% (42/48) of patients; long-term, 72.1% (31/43) had complete or partial pain relief without medication, and 23.3% were satisfied with ongoing medication.

Indications: PSR is particularly relevant for patients with multiple sclerosis (MS)-related TN and those without a clear neurovascular conflict, as well as for those not responding to or preferring to avoid repeated percutaneous or radiosurgical procedures.

Complications: Postoperative hypesthesia is expected and occurred in 77.1% of patients, but was generally well tolerated; no cases of anesthesia dolorosa or corneal anesthesia were observed. Other complications (e.g., CSF fistula, transient hearing impairment) were rare and resolved with treatment.

Recurrence: The observed recurrence rate after PSR was 27.1%, consistent with previously reported rates (10–49% over five years), and repeat PSR was effective in patients with recurrent pain.

Comparison with Other Treatments: While MVD is preferred when neurovascular conflict is present, PSR offers comparable long-term pain relief in selected patients, but with a higher risk of sensory deficits. Combined MVD+PSR does not improve long-term outcomes if no vascular conflict exists.

Patient Satisfaction: Overall, 95% of patients reported meaningful improvement and satisfaction with PSR, despite sensory deficits, when adequately counseled preoperatively.

Recommendation: PSR should be considered and discussed as a viable surgical alternative for therapy-refractory or recurrent TN, particularly in MS patients and those not suitable for or preferring to avoid other invasive procedures.

 

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Cage migration in multilevel stand-alone lateral lumbar interbody fusion: incidence and clinical correlations

J Neurosurg Spine 44:426–435, 2026

This clinical case series compares the incidence and outcomes of lateral interbody cage migration (LCM) following multilevel stand-alone lateral lumbar interbody fusion (LLIF) versus LLIF with posterior pedicle screw instrumentation in 87 age-matched patients. The retrospective analysis reports similar LCM rates (7% vs 5%), no significant differences in complications, and comparable improvements in Oswestry Disability Index and pain scores at ≥1 year follow-up.

The report details patient selection, radiographic assessment methods, operative characteristics, and risk-factor analysis, emphasizing meticulous selection for multilevel stand-alone LLIF. Authors conclude multilevel stand-alone LLIF can be safe in selected patients but call for prospective studies to validate findings and clarify factors contributing to cage migration.

Lateral Cage Migration (LCM) Incidence: LCM occurred in 7% of multilevel stand-alone LLIF cases and 5% of LLIF cases with posterior instrumentation; this difference was not statistically significant.

Patient Selection Criteria: Optimal candidates for multilevel stand-alone LLIF have neutral sagittal and coronal balance, mild to moderate facet arthropathy, stable grade 1 spondylolisthesis, absence of severe central canal stenosis, normal or mildly reduced bone mineral density, and comorbidities or age that increase surgical risk with posterior fixation.

Clinical Outcomes: Both cohorts (stand-alone and posterior instrumentation) showed significant postoperative improvement in Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, with no significant differences between groups.

Complication Rates: Postoperative complication rates were similar between groups (23% stand-alone vs. 20% posterior instrumentation), and no intraoperative complications were reported in either group.

Biomechanical Considerations: Supplemental posterior instrumentation increases construct stability, but clinical significance in preventing LCM in well-selected patients remains unclear; stand-alone LLIF can be safe with meticulous patient selection.

Role of Lateral Plates: Adding lateral plates to stand-alone LLIF does not significantly improve stability or reduce cage migration/subsidence in multilevel constructs and may increase cost and risk.

Risk Factors for LCM: No significant demographic, radiographic, or procedural risk factors for LCM were identified in this study; all patients with LCM had normal bone density, and meticulous surgical technique and patient selection are emphasized.

Study Limitations: Retrospective design, single institution, and small sample size may limit generalizability; prospective studies are needed for further validation.

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Contrast-Enhanced Ultrasound Perfusion Imaging of the Spinal Cord Before and After Surgical Decompression for Cervical Spondylotic Myelopathy

Neurosurgery 98:688–697, 2026

Contrast-enhanced ultrasound (CEUS) was applied intraoperatively to acquire spinal cord perfusion metrics before and after posterior decompression in 16 patients with cervical spondylotic myelopathy (CSM). The study details a reproducible surgical ultrasound window, CEUS acquisition parameters, time–intensity curve analysis, and statistical correlation of wash-in-time (WIT) with modified Japanese Orthopedic Association (mJOA) scores.

The technique proved feasible and safe, yielding pre- and postdecompression perfusion data without complications. Predecompression and postdecompression WIT correlated significantly with preoperative, 1-month, and 6-month mJOA scores, suggesting CEUS WIT may have prognostic utility for postoperative neurologic recovery.

Contrast-Enhanced Ultrasound (CEUS) Feasibility: CEUS can safely and effectively acquire spinal cord perfusion data both before and after surgical decompression in patients with cervical spondylotic myelopathy (CSM).

Wash-In Time (WIT) as Key Perfusion Parameter: WIT, defined as the time between initial appearance and peak concentration of contrast microbubbles, is the most relevant CEUS-derived perfusion metric and inversely correlates with neurologic status measured by modified Japanese Orthopedic Association (mJOA) scores.

Correlation with Neurologic Outcomes: Lower WIT values (indicating faster perfusion) are significantly associated with better preoperative and postoperative neurologic function at 1 and 6 months, suggesting potential as a prognostic biomarker.

No Significant Correlation with MRI Signal Change: Preoperative spinal cord signal changes on MRI, previously considered prognostic, did not correlate with WIT or other perfusion indices in this cohort.

Technical Approach: A small bony trough is created at the lateral lamina border to allow direct insonation of the compressed spinal cord, enabling both pre- and post-decompression CEUS imaging without interfering with standard surgical workflow.

No Major Complications: The technique was free of adverse events related to ultrasound contrast administration or the imaging process itself.

Small Sample and Pilot Nature: The study’s findings are limited by its small sample size (16 patients), and further multicenter, prospective studies are needed to validate CEUS as a predictive tool for surgical outcomes in CSM.

Clinical Implication: CEUS, and specifically preoperative WIT, shows promise for intraoperative prognostication and may help identify patients at risk for poor recovery or reperfusion injury after cervical decompression surgery.

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Mapping the Functional Boundaries of the Speech Articulation Network Using Positive and Negative Direct Electrical Stimulation With Resting-State Functional MRI

Neurosurgery 98:577–587, 2026

This clinical research integrates positive and negative direct electrical stimulation (DES) with presurgical resting-state fMRI to refine the speech articulation network (SAN) atlas in glioma patients. Analyzing 25 patients, the study maps DES-positive and DES-negative seed-based connectivity, compares anticorrelated networks, and evaluates sensitivity and specificity across group-frequency thresholds.

Key findings show DES-positive sites robustly identify bilateral SAN regions (rolandic operculum, inferior frontal and superior temporal gyri), while DES-negative points delineate functional borders and improve atlas specificity; a 41% SAN-positive threshold yields approximately 80% sensitivity and specificity for clinical use.

Resting-state fMRI and DES: Resting-state functional MRI (rs-fMRI) is a noninvasive tool for mapping brain networks, while direct electrical stimulation (DES) during awake surgery (AwS) is the gold standard for causally identifying functional brain regions, especially for speech articulation mapping in glioma patients.

Inclusion of DES-negative points: Incorporating both DES-positive (eliciting function) and DES-negative (no function elicited) points enables more precise mapping of the speech articulation network (SAN) and its functional borders, improving specificity and sensitivity compared to using only positive points.

Comprehensive SAN atlas: A new SAN atlas was created from 25 glioma patients using 32 DES-positive and 42 DES-negative points, with presurgical rs-fMRI seed-based connectivity analysis, providing a more accurate and clinically relevant definition of the SAN.

Distinct connectivity patterns: DES-positive points consistently mapped the SAN to bilateral rolandic operculum, inferior frontal gyrus, and superior temporal gyrus, while DES-negative points revealed distinct, only partially overlapping connectivity patterns, helping delineate the SAN’s functional borders.

Threshold for clinical use: A 41% frequency threshold for the SAN-positive network achieves approximately 80% sensitivity and specificity, offering a practical balance for clinical application in presurgical planning.

Functional borders and overlap: Minimal overlap between SAN-positive and SAN-negative networks identifies functional borders, especially in the precentral sulcus and inferior frontal gyrus, aiding neurosurgeons in distinguishing critical from non-critical areas during mapping.

Clinical implications: Defining precise SAN borders improves intraoperative decision-making, reduces irrelevant stimulation, shortens mapping time, and enhances safety in both awake and asleep brain surgeries.

Limitations and future directions: The study’s limitations include sample size, heterogeneity, and MRI field strength; future research should use larger, more homogeneous cohorts and higher-resolution imaging to further refine SAN mapping.

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Postoperative loss in segmental lumbar lordosis following L5–S1 anterior lumbar interbody fusion

J Neurosurg Spine 44:420–425, 2026

This clinical study evaluates predictors and thresholds for postoperative loss of L5–S1 segmental lordosis following anterior lumbar interbody fusion (ALIF) in 94 adults treated for degenerative disc disease. Multivariate analyses identified baseline obesity, absence of posterior fixation, and larger immediate lordotic correction as independent predictors of 6-week to 1-year segmental lordosis loss, which related to higher rates of cage subsidence and revision.

The authors derived 6-week postoperative L5–S1 lordosis thresholds (overall range 21.6°–26.8°, PI-specific: low 19.0°–24.8°, average 21.0°–26.4°, high 24.1°–28.7°) that minimized subsequent loss and need for revision. Findings support targeted preoperative planning to achieve sustainable correction while balancing risks of overcorrection and subsidence.

Segmental Lordosis Restoration: L5–S1 anterior lumbar interbody fusion (ALIF) provides strong and durable correction of segmental lumbar lordosis and disc height, with most correction maintained at 1 year postoperatively.

Predictors of Lordosis Loss: Baseline obesity, lack of posterior fixation, and larger initial correction in L5–S1 lordosis are independent predictors of postoperative segmental lordosis loss within 1 year.

Complications: Loss of segmental lordosis increases the risk of cage subsidence and revision surgery, particularly due to pseudarthrosis.

Optimal Correction Thresholds: Achieving 6-week postoperative L5–S1 segmental lordosis between 21.6° and 26.8° minimizes the risk of lordotic loss and need for revision; PI-specific thresholds are 19.0°–24.8° (low PI), 21.0°–26.4° (average PI), and 24.1°–28.7° (high PI).

Risks of Overcorrection/Undercorrection: Overcorrection (>26.8°) increases risk of cage subsidence and mechanical complications, while undercorrection (<21.6°) may predispose to implant failure and adjacent segment disease.

Surgical Planning Importance: Preoperative planning should target lordosis correction within these thresholds and consider modifiable risk factors to optimize outcomes and reduce complications.

Comparison to Other Techniques: ALIF offers greater segmental correction than other lumbar interbody fusion techniques such as TLIF or XLIF.

Clinical Implications: Nearly half of patients experience some degree of lordosis loss post-ALIF, highlighting the need for careful patient selection, surgical technique, and postoperative monitoring.

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Microvascular Decompression for Patients With Type 1 Trigeminal Neuralgia Using Vein Sacrifice and a Teflon Transposition Technique: A 23-Year Cohort

Neurosurgery 98:588–596, 2026

This study reports outcomes from a 23-year, prospectively maintained cohort of 523 patients with unilateral Type 1 trigeminal neuralgia treated by microvascular decompression using vein sacrifice and a Teflon transposition technique. Primary outcome was long-term pain-free survival without medications, with median follow-up 8.2 years and 5-, 10-, 15-year pain-free rates of 77.6%, 72.5%, and 69.7%, respectively.

Operative details, complications, and reoperation rates are presented: arterial transposition was performed when possible, veins contacting the nerve were sacrificed, and Teflon pledgets used to maintain separation. Complications were uncommon and generally non-disabling (most frequent: facial numbness, diplopia); true Teflon granulomas were rare but noted in isolated reoperations.

Microvascular decompression (MVD) is the most effective surgical treatment for medically unresponsive Type 1 trigeminal neuralgia (TN), aiming to eliminate neurovascular contact with the trigeminal nerve using arterial transposition, vein sacrifice, and polytetrafluoroethylene (PTFE, “Teflon”) implantation when appropriate.

Study outcomes show that 92.7% of patients were initially pain-free without medications after MVD, with pain-free survival rates of 77.6% at 5 years, 72.5% at 10 years, and 69.7% at 15 years.

Operative technique selection depends on intraoperative findings: arteries are transposed and secured with PTFE whenever possible, veins in contact with the nerve are sacrificed, and partial sensory rhizotomy is reserved for cases without significant vascular compression.

Complication rates are low; the most common was new or worsened facial numbness (7.1%), with higher rates when veins were sacrificed (6.9%) versus arterial decompression alone (1.6%). Venous infarction occurred in 0.6% of patients, and Teflon granuloma in 0.4%.

Pain-free survival was lower in women (hazard ratio 1.48, P = .03), but not associated with pain duration, previous ablative surgery, or new facial numbness.

Vein sacrifice is generally safe and facilitates surgical exposure, though it carries a low but real risk of venous complications; evidence is mixed regarding whether preserving or sacrificing the superior petrosal vein impacts complication rates.

PTFE (“Teflon”) material is widely used for vessel transposition; however, true Teflon granulomas—characterized by mass effect, edema, and inflammatory response—are rare and should not be used to describe all cases of recurrent pain with adherent PTFE.

Terminology precision is important: “Teflon” is a trademark for Chemours’ PTFE products, and not all PTFE felt used in surgery is identical. Variability in material properties may affect surgical outcomes and study reproducibility.

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Intraoperative Evaluation of Dural Arteriovenous Fistula Obliteration Using FLOW 800 Hemodynamic Analysis

Operative Neurosurgery 30:250–259, 2026

This clinical study evaluates intraoperative indocyanine green videoangiography with FLOW 800 software to quantify hemodynamic changes during cranial and spinal dural arteriovenous fistula (dAVF) microsurgical obliteration. Using four FLOW 800 metrics across venous regions of interest, the authors compare pre- and post-obliteration measurements confirmed by intraoperative digital subtraction angiography.

Key findings identify increased Delay Time and decreased Speed as consistent, significant markers of successful dAVF obliteration, supported by nonparametric tests, logistic and Bayesian regression, and PCA visualization. The study suggests FLOW 800 as a practical adjunct to intraoperative imaging, while acknowledging limitations from small sample size and ROI selection variability.

Key Hemodynamic Parameters: Intraoperative FLOW 800 analysis of indocyanine green videoangiography quantifies four hemodynamic parameters—Delay Time, Speed, Time to Peak, and Rise Time—across venous drainage regions before and after dAVF (dural arteriovenous fistula) obliteration.

Most Sensitive Indicators: Delay Time (time for dye to reach ROI) and Speed (rate of dye flow) are the most sensitive and consistent hemodynamic indicators of successful dAVF obliteration, with Delay Time increasing and Speed decreasing significantly post-obliteration.

Statistical Significance: Delay Time increased from a median of 2.07s to 7.86s (P = .020), and Speed decreased from 13.5 s⁻¹ to 5.5 s⁻¹ (P = .029), both changes being statistically significant; Time to Peak and Rise Time showed no significant association.

Predictive Value: A 50% increase in Delay Time is associated with 2.16 times higher odds of achieving obliteration (OR = 4.59), while a 50% decrease in Speed is associated with 1.28 times higher odds; Delay Time and Speed are the strongest predictors in regression analyses.

Clinical Utility: FLOW 800 provides real-time, semiquantitative intraoperative feedback, supporting its use as a noninvasive adjunct to traditional imaging (like intraoperative DSA) for confirming dAVF obliteration, especially where DSA is unavailable.

Study Limitations: The study is limited by small sample size (8 patients, 14 ROIs), single-center design, and possible variability in ROI selection; findings require validation in larger, multicenter studies.

Practical Considerations: Complete visualization of venous outflow is necessary for FLOW 800 utility; current evidence supports its use as a complementary tool rather than a replacement for DSA.

Clinical Outcome: All patients in the study had successful dAVF obliteration confirmed by intraoperative DSA, no complications or recurrences at median 19.4 months follow-up, and FLOW 800 changes were consistent with successful surgical outcomes.

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Predicting chronic subdural hematoma risk in elderly patients with mild traumatic brain injury

Acta Neurochirurgica (2026) 168:40

This study develops and validates a concise bedside risk score to predict chronic subdural hematoma (CSDH) within 2–12 weeks after mild traumatic brain injury in patients aged 65+. Using a large retrospective cohort (7,246 events) and multivariable modeling, pathological CT at presentation, male sex, older age, and renal failure emerged as key predictors.

The score-based model (including anticoagulant use by expert choice) achieved AUROC 0.76 and 86% sensitivity at the chosen threshold, classifying ~61% as high-risk. Authors propose this tool to guide targeted surveillance and earlier intervention, while noting limitations from retrospective data and need for external validation.

Pathological CT Findings: Pathological findings on initial head CT after mild traumatic brain injury (TBI) are the strongest predictor for developing chronic subdural hematoma (CSDH) within 2–12 weeks in elderly patients.

Key Risk Factors: Older age, male sex, and renal failure are also significant independent predictors for CSDH following mild TBI.

Anticoagulant Use: Chronic use of anticoagulant medications showed a trend toward increased risk but was not statistically significant in this cohort; antiplatelet use was not associated with increased risk.

Prediction Model: A simple score-based risk model was developed, incorporating pathological CT (14 points), male sex (4), renal failure (4), anticoagulant use (4), and age (1 point per 5 years over 65), with a threshold of 5 points or higher identifying high-risk patients.

Model Performance: The risk model achieved an area under the ROC curve (AUROC) of 0.76 and a sensitivity of 86% for detecting CSDH, but the positive predictive value was low (1.6%) due to the rare occurrence of the outcome.

Clinical Implications: Early identification of high-risk patients may enable targeted surveillance, timely CT scanning, and consideration of non-surgical management options such as corticosteroids or middle meningeal artery embolization.

Population Impact: The incidence of CSDH is rising globally due to population aging and increased use of antithrombotic agents, with elderly adults being particularly at risk.

Study Scope: The findings support the use of bedside risk stratification in the emergency department for elderly patients with mild TBI, but further research is needed before widespread clinical implementation.

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Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Surgical Resection for the Treatment of Patients With Vestibular Schwannomas: Update

Neurosurgery 98:272–277, 2026

These updated Congress of Neurological Surgeons guidelines review surgical management of sporadic vestibular schwannomas using literature from 2015–2022, reaffirming many prior recommendations and highlighting persistent evidence gaps. Key recommendations address approach selection (middle fossa, retrosigmoid, translabyrinthine), hearing-preservation surgery options, and counseling patients about outcomes after prior stereotactic radiosurgery.

The document details systematic review methods, inclusion criteria, and evidence grading, noting most data are class III and insufficient to prove superiority of specific surgical approaches for many questions. It emphasizes individualized treatment decisions, need for multicenter registries or trials, and future research priorities to resolve unanswered clinical issues.

Surgical Approach Selection: No surgical approach (middle fossa, retrosigmoid, or translabyrinthine) has proven superiority for facial nerve preservation or gross total resection in sporadic vestibular schwannoma; choice depends on individual patient factors and tumor characteristics.

Hearing Preservation: Hearing preservation surgery via middle fossa or retrosigmoid approach may be considered for patients with good preoperative hearing as an alternative to observation, but evidence for long-term superiority is limited.

Subtotal Resection and Radiosurgery: Subtotal resection followed by stereotactic radiosurgery does not have sufficient evidence to support better facial nerve or hearing outcomes compared to complete resection.

Microsurgery After SRS: Patients undergoing microsurgical resection after prior stereotactic radiosurgery should be counseled about increased risk of subtotal resection and worse facial nerve function.

Trigeminal Neuralgia: Surgical resection may provide better relief of trigeminal neuralgia symptoms compared to stereotactic radiosurgery in patients with sporadic vestibular schwannoma.

Balance and Observation: There is insufficient evidence to support surgery or radiosurgery for improving preoperative balance problems, and no clear evidence that surgery should be primary treatment for small tumors eligible for observation.

Evidence Quality: All reviewed evidence is class III (retrospective series, flawed controls), with significant potential for bias and limitations in drawing strong conclusions.

Future Directions: Improved data from multicenter registries or randomized trials are needed to clarify optimal management, as current recommendations reflect standard practice but lack high-level evidence for many questions.

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Shifts in epilepsy treatment: a 12-year review of surgical approaches and outcomes in lesional and nonlesional epilepsy

J Neurosurg 144:259–272, 2026

This study analyzes national inpatient trends from 2009–2020 comparing lesional and nonlesional epilepsy patients who underwent surgical or neuromodulation treatments. Using NIS data with propensity score matching, it reports demographic differences, socioeconomic disparities, and shifting utilization patterns across VNS, RNS, DBS, resection, radiosurgery, and LITT.

The findings reveal increasing adoption of RNS and LITT, declining VNS and radiosurgery, higher costs for most interventions, and shorter length of stay with LITT. Persistent racial and income-based inequities in access and differing outcomes by lesion status prompt calls for tailored care and further cost-effectiveness and long-term outcome studies.

Distinct Patient Profiles: Lesional epilepsy patients are older, more likely male, have higher comorbidity burdens, and higher income/Medicare coverage compared to nonlesional epilepsy patients, who are more prevalent in lower income quartiles and rely more on Medicaid or private insurance.

Surgical Treatment Trends: Use of responsive neurostimulation (RNS) and laser interstitial thermal therapy (LITT) increased significantly for both lesional and nonlesional epilepsy from 2009–2020, while vagus nerve stimulation (VNS) declined for nonlesional epilepsy; deep brain stimulation (DBS) and radiosurgery declined for both groups.

Resective Surgery Patterns: Resective surgery utilization increased significantly for nonlesional epilepsy, but not for lesional epilepsy, indicating a growing acceptance of surgery in nonlesional cases despite the absence of overt lesions.

Healthcare Disparities: White patients, and those in higher income quartiles, have higher probabilities of receiving advanced treatments (VNS, RNS, DBS, resective surgery, radiosurgery); Black patients have persistently lower access regardless of income, and Hispanic patients show variable, income-dependent access.

Outcomes by Modality: RNS and LITT are associated with shorter or unchanged length of stay (LOS) and higher likelihood of routine discharge, while DBS and resective surgery increase LOS and costs; all surgical interventions increase hospital charges.

LITT Advantages: LITT is linked to decreased LOS and improved routine discharge rates, especially for lesional epilepsy, but incurs higher total charges compared to other modalities.

Mortality Impact: None of the interventions (VNS, RNS, DBS, resective surgery, radiosurgery, LITT) significantly affected mortality in either lesional or nonlesional epilepsy groups.

Need for Tailored Approaches: Persistent demographic, socioeconomic, and clinical differences between lesional and nonlesional epilepsy patients highlight the importance of individualized treatment strategies and further research on long-term and cost-effectiveness outcomes.

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Unraveling the cause of microspurs in spontaneous intracranial hypotension type 1: discogenic origin or calcified Hofmann’s ligament?

J Neurosurg Spine 44:315–319, 2026

This clinical study investigates the origin of ventral spinal microspurs causing spontaneous intracranial hypotension (SIH) type 1, comparing discogenic lesions with fibrotic tissue consistent with Hofmann’s ligament. Retrospective histopathological reanalysis of 27 surgically resected microspurs showed both discogenic and fibrotic origins, with 13 discogenic, 9 fibrotic, and 5 unclassifiable cases, and no significant differences in spur length, location, or CT density.

The authors conclude that ventral CSF leaks can arise from calcified intervertebral discs as well as calcified or fibrotic Hofmann’s ligaments, expanding the pathophysiological understanding of SIH and highlighting limitations from retrospective design, small sample size, and histological classification challenges.

Etiology of Microspurs: Microspurs causing ventral CSF leaks in spontaneous intracranial hypotension (SIH) type 1 can originate from both calcified intervertebral discs (discogenic) and calcified fibrous tissue associated with Hofmann’s ligament, not exclusively from disc material.

Histopathological Classification: Microspurs were histopathologically classified as either discogenic (cartilage/fibrocartilaginous tissue, often with secondary calcification) or fibrotic (hypercellular fibrous tissue with or without calcification, suggestive of Hofmann’s ligament).

Distribution: Most microspurs were located in the thoracic spine, with about one-third found at the cervicothoracic or thoracolumbar junctions, and the rest in the midthoracic region.

Imaging Findings: There was no statistically significant difference in microspur length or CT density (Hounsfield units) between discogenic and fibrotic (Hofmann’s ligament) origins, limiting the ability of imaging to distinguish between them preoperatively.

Clinical Implications: Both discogenic and fibrotic origins should be considered in the diagnosis and surgical planning for SIH with ventral CSF leaks, as relying solely on the discogenic theory may overlook alternative etiologies.

Pathophysiological Mechanism: Calcified microspurs, whether from discs or Hofmann’s ligament, may cause dural tears due to mechanical stress at spinal junctions or in regions with a narrow spinal canal.

Limitations: The study’s retrospective design, small sample size, and challenges in histopathological classification (lack of specific markers, possible sampling errors) limit the generalizability and precision of findings

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Are there distinct patterns of clinical deficits in cervical deformity? A discriminant analysis of health-related quality of life measures

J Neurosurg Spine 44:242–252, 2026

This clinical study analyzes preoperative health-related quality of life (HRQOL) measures in 134 adults with cervical deformity (CD) to identify distinct clinical deficit patterns and their association with radiographic morphotypes. Using factor and cluster analyses on NDI, mJOA, and SWAL-QOL items, four patient clusters emerged: sleep/fatigue, low neck disability, dysphagia with severe neck disability, and myelopathy.

These HRQOL-derived clusters correlated with specific radiographic types among severe deformities: cervicothoracic, focal, and flat-neck morphotypes. The findings support integrating patient-reported clinical dimensions into CD classification systems to guide tailored surgical planning and outcome assessment.

Distinct HRQOL Patterns: Four distinct patterns of health-related quality of life (HRQOL) deficits were identified in patients with cervical deformity: sleep/fatigue impairment, low neck disability, severe dysphagia and neck disability, and predominant myelopathy.

Cluster Analysis: Principal component and cluster analyses using NDI, mJOA, and SWAL-QOL questionnaires grouped patients into four homogeneous outcome clusters, each reflecting a unique constellation of clinical deficits.

Radiographic Associations: Each HRQOL deficit pattern was significantly associated with specific cervical deformity morphotypes: severe dysphagia/neck disability with cervicothoracic deformity, myelopathy with focal deformity, and sleep/fatigue or low disability with flat neck deformity.

Clinical Implications: Recognizing these HRQOL patterns may inform tailored management strategies, surgical planning, and prognosis for different cervical deformity subtypes.

Measurement Tools: The study utilized validated patient-reported outcome measures: Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, and Swallowing Quality of Life (SWAL-QOL) questionnaire.

Radiographic Parameters: Comprehensive imaging assessments included cervical and spinopelvic alignment measures, such as cervical SVA, T1 slope, C2–7 lordosis, and T1S-CL mismatch.

Demographic Factors: No significant differences in age, sex, BMI, or most comorbidities were found across clusters, except for higher rates of depression and prior spine surgery in those with the most severe clinical deficits.

Classification Framework: Findings support integrating HRQOL measures with radiographic parameters for a more comprehensive, patient-centered cervical deformity classification system.

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Minimal Clinically Important Difference and Relative Change in Patient-Reported Outcomes After Surgery for Cervical Spondylotic Myelopathy: A Nationwide Study of 1,700 Patients

Neurosurgery 98:358–364, 2026

This nationwide registry study of 1,756 patients evaluates minimal clinically important difference (MCID) versus minimal clinically important relative change (MCIRC) for patient-reported outcomes after surgery for degenerative cervical myelopathy. Using anchor-based ROC analyses, the authors derive MCID and MCIRC thresholds for NRS neck/arm pain, EQ-5D index, EQ VAS, and NDI, and compare predictive accuracy for patient satisfaction at one year.

Key findings show MCIRC outperforms absolute MCID for NRS neck and arm pain and NDI, while MCID is superior for EQ-5D index and EQ VAS; selected thresholds are reported (e.g., NRS neck MCID −3 and MCIRC −47%). The study recommends incorporating MCIRC in future spine outcome guidelines to improve individualized assessment.

Minimal Clinically Important Difference (MCID): MCID represents the smallest absolute change in patient-reported outcome measures (PROMs) that signifies meaningful improvement for the patient after cervical spondylotic myelopathy surgery.

Minimal Clinically Important Relative Change (MCIRC): MCIRC is a proportional measure that reflects the minimum relative change in PROMs from baseline, making it more sensitive to changes in patients with extreme baseline values.

Calculation Methods: MCID and MCIRC values were determined using anchor-based approaches (with patient satisfaction as the anchor), ROC curve analysis with the Youden index, minimal detectable change (MDC), and mean change methods.

Key Thresholds Identified: MCID values were −3 for NRS neck pain, −2 for NRS arm pain, 0.09 for EQ5D index, 7 for EQ VAS, and −12 for NDI; MCIRC values were −47% for NRS neck pain, −40% for NRS arm pain, 386% for EQ5D index, 52% for EQ VAS, and −32% for NDI.

Predictive Accuracy: Relative change (MCIRC) provided greater predictive accuracy for identifying patient satisfaction in NRS neck/arm pain and NDI, while absolute difference (MCID) was superior for EQ5D index and EQ VAS.

Clinical Implication: MCIRC is recommended for PROMs influenced by baseline severity (like pain and disability scores), as it better accounts for individual variability and may enhance individualized patient assessment.

Study Population: The study analyzed 1,756 patients from the Swedish Spine Registry who underwent surgery for degenerative cervical myelopathy, with 59% reporting satisfaction at one year postoperatively.

Practical Recommendation: Incorporating MCIRC thresholds into future spine surgery outcome guidelines could improve evaluation of individualized patient recovery.

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Maximizing Tumor Resection and Managing Cognitive Attentional Outcomes: Measures of Impact of Awake Surgery in Glioma Treatment

Neurosurgery 98:365–375, 2026

This clinical research article compares awake surgery (AwS) and asleep surgery (AsS) in 64 glioma patients, focusing on attentional outcomes, extent of resection, and survival. Using neuropsychological testing at preoperative, 1-week, and 1-month intervals, combined with structural MRI, lesion-symptom mapping, and lesion network mapping, the study quantifies transient attentional decline and its anatomical correlates.

Results show AwS enables greater supramaximal resection of non–contrast-enhanced tumor tissue and improved overall survival for IDH wild-type glioblastoma, but is the sole predictor of transient postoperative attentional worsening at 1 week that recovers by 1 month. Analyses implicate left prefrontal/default mode network regions and large-scale attention networks in postoperative attentional changes, supporting tailored patient selection and development of intraoperative attention monitoring.

Awake Surgery (AwS) vs. Asleep Surgery (AsS): AwS enables a more extensive (supramaximal) resection of non–contrast-enhanced tumor areas in glioma patients compared to AsS, which correlates with improved oncological outcomes but higher transient attentional deficits postoperatively.

Transient Attentional Decline: Patients undergoing AwS experience a significant, temporary decline in attentional performance 1 week after surgery, with recovery to preoperative levels after 1 month; this effect is not observed with AsS.

Predictors of Attention Outcome: The only significant predictor of postoperative attentional deterioration is undergoing AwS; other factors such as age, sex, tumor location, grade, IDH mutation, and MGMT methylation do not significantly influence attentional decline.

Extent of Resection and Attention: Greater extent of resection (EOR) of non–contrast-enhanced tumor (especially >61%) is associated with immediate postoperative attentional worsening, but also with improved survival outcomes.

Oncological Benefit: In patients with IDH wild-type glioblastoma, AwS leads to significantly longer overall survival (mean 887.73 days) compared to AsS (mean 553.71 days), mainly due to lower non-contrast-enhanced residual tumor volume after AwS.

Functional Neuroanatomy: Postoperative attentional deficits are associated with lesions in the left prefrontal region of the default mode network (DMN); attention relies on distributed large-scale networks, including dorsal and ventral attention networks.

Patient Selection: Proper selection for AwS is crucial, especially for tumors involving anterior regions of the left DMN, and preoperative attentional abilities should be considered to balance oncological benefits and cognitive risks.

Monitoring Limitations: There are currently no established intraoperative tools for direct monitoring of attention during AwS; development of standardized, quantitative attention monitoring could further optimize outcomes.

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