Author: cba

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Nighttime surgery increases complication risk in chronic subdural hematoma: a population‑based cohort study

Acta Neurochirurgica (2025) 167:311

This population-based retrospective cohort study of 2,860 adults undergoing chronic subdural hematoma (CSDH) evacuation at a tertiary neurosurgical center (2006–2023) examines whether nighttime procedures increase postoperative risk. Nighttime surgery—defined by local shift boundaries—was independently associated with higher moderate-to-severe complications (OR 1.58), with risk peaking during final night-shift hours, while adjusted recurrence differences were not statistically significant.

The paper details standardized surgical protocols, staffing patterns, sensitivity analyses using alternative nighttime definitions, and multivariable models adjusting for comorbidity and neurological status. Authors conclude that when clinical stability permits, deferring CSDH evacuation to daytime hours may reduce significant complications, while acknowledging retrospective limitations and potential residual confounding.

Nighttime surgery: Undergoing chronic subdural hematoma (CSDH) surgery at night is independently associated with a higher risk of moderate-to-severe postoperative complications compared to daytime surgery (OR 1.58; 95% CI 1.04–2.37; p = 0.028).

Complication risk timing: The risk of complications increases gradually overnight and peaks during the final hours of the night shift, suggesting a circadian or fatigue-related effect.

Absolute risk increase: Nighttime surgery results in a 1.6% absolute increase in moderate-to-severe complications, with a number needed to harm (NNH) of 63, indicating a modest but clinically meaningful risk.

CSDH recurrence: Although recurrence rates were higher after nighttime surgery in unadjusted analysis, this difference was not statistically significant after adjusting for confounders (adjusted OR 1.28; 95% CI 0.98–1.65; p = 0.067).

Complication types: The most common moderate-to-severe complications include subdural empyema (1.4%), surgical site infection requiring revision (0.3%), and cerebral herniation (0.3%).

Clinical recommendation: When feasible and the patient is stable, deferring CSDH surgery to daytime hours is advised to minimize complication risk.

Prior research limitations: Previous studies were often underpowered, used inconsistent nighttime definitions, and found mixed results regarding the safety of nighttime CSDH surgery.

Study limitations: Retrospective design, possible unmeasured confounding, small differences in baseline severity, and limited generalizability to other healthcare settings with different resources or scheduling practices.

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Lumbar Puncture or External Ventricular Drainage as Initial Treatment for Acute Hydrocephalus in Aneurysmal Subarachnoid Hemorrhage

Neurosurgery 97:1308–1315, 2025

This two-center cohort study compares lumbar puncture (LP) versus external ventricular drainage (EVD) as initial treatments for acute hydrocephalus after aneurysmal subarachnoid hemorrhage, analyzing rates of permanent ventriculoperitoneal shunts (VPS), procedure-related complications, and 3-month functional outcomes. Patients eligible for LP had similar admission severity, and outcomes were adjusted for baseline predictors to compare strategies across centers.

Results show markedly fewer permanent VPS implantations (10% vs 68%) and lower short-term complication rates with LP, while unfavorable functional outcomes at 3 months did not differ significantly. The authors conclude LP is a viable initial option for selected patients, recommending future studies on cognitive and quality-of-life effects.

Initial Treatment: Lumbar puncture (LP) as initial treatment for acute hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH) resulted in significantly fewer patients requiring permanent ventriculoperitoneal shunt (VPS) implantation compared to external ventricular drainage (EVD) (10% vs 68%).

Complication Rates: LP was associated with lower short-term complication rates than EVD (21% vs 38%), including lower rates of intracerebral hemorrhage and infection, especially when LP alone was sufficient.

Functional Outcomes: No statistically significant difference was observed in unfavorable functional outcomes (Glasgow Outcome Scale 1-3 at 3 months) between LP and EVD groups, though the trend favored LP (40% vs 49%).

Patient Selection: LP is suitable as first-line treatment only for selected patients (e.g., GCS ≥7, no space-occupying hematoma, no intraventricular obstruction), while EVD remains necessary for those with contraindications to LP or requiring intracranial pressure monitoring.

Volume of CSF Drainage: Lower cerebrospinal fluid (CSF) volumes drained with LP (typically 25-30 mL per procedure) compared to EVD (hundreds of mL over days) may contribute to reduced VPS dependency.

Study Limitations: Differences in overall management strategies, patient selection, and treatment protocols between centers limit the ability to attribute outcomes solely to the initial hydrocephalus treatment modality; results should not be interpreted as definitive evidence that LP is superior to EVD.

Implications for Practice: LP can be considered as an initial treatment for acute hydrocephalus after SAH in eligible patients, but there is currently no evidence that it improves long-term functional outcomes; further research is needed to assess effects on cognition and quality of life.

Research Needs: More robust, prospective studies are required to clarify optimal patient selection, CSF drainage strategies, and comparative benefits of LP versus EVD in post-SAH hydrocephalus management.

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A Multicenter Study of Noninvasive Wireless Assessment of Cerebrospinal Fluid Shunt Function in Hydrocephalus Patients

Neurosurgery 97:1397–1405, 2025

This multicenter prospective study evaluates a wearable, wireless thermal anisotropy sensor for noninvasive detection of cerebrospinal fluid (CSF) shunt flow in symptomatic hydrocephalus patients. Using a random forest algorithm on data from 112 validated subjects, the device showed high sensitivity (88.9%) and a very high negative predictive value (96.8%), though specificity was modest (49.2%) and a 37.5% no-result rate occurred.

Methods, usability, and comparative analyses are detailed: device design, algorithm development, blinded validation, and 7-day surgical follow-up with intraoperative confirmation as ground truth. Ease-of-use was rated highly, adverse events were minor skin reactions, and combined use with CT/MRI improved specificity and overall accuracy, supporting adjunctive clinical application.

Device Purpose: A novel, noninvasive, wireless wearable device was developed to assess cerebrospinal fluid (CSF) shunt flow in hydrocephalus patients presenting with possible shunt failure, using thermal anisotropy measurements to detect flow through the shunt tubing.

Study Design: The prospective, blinded, multicenter study included both pediatric and adult patients with existing ventriculoperitoneal shunts and symptoms suggestive of shunt failure; subjects underwent device evaluation alongside standard-of-care assessments.

Algorithm Performance: The device’s random forest algorithm demonstrated high sensitivity (88.9%) and negative predictive value (NPV, 96.8%) but moderate specificity (49.2%) for detecting complete shunt failure, indicating strong ability to rule out failure when flow is confirmed.

Clinical Utility: The high NPV suggests the device could help identify patients whose shunts are functioning, potentially reducing unnecessary surgical interventions or additional invasive tests.

Comparison with Standard Tests: Standard imaging tests (CT/MRI) showed moderate-to-high sensitivity and specificity but require radiation or sedation, whereas the device is noninvasive, wireless, and does not require such resources.

Combined Diagnostic Approach: When device results were combined with CT or MRI findings, specificity increased to 93.3% and NPV to 96.6%, supporting a potential workflow where the device is used to complement imaging for risk stratification.

Safety and Usability: The device was rated as easy to use by clinicians, with a low rate of mild, self-resolving skin redness and no serious adverse events reported.

Limitations: The device is not suitable as a stand-alone diagnostic tool due to moderate specificity and a substantial rate of incomplete measurements; further studies are ongoing to optimize performance and generalizability.

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Update and Evaluation of a Preoperative Scoring System to Predict Long-Term Outcomes After Microvascular Decompression in Trigeminal Neuralgia

Operative Neurosurgery 29:824–831, 2025

This clinical research article evaluates and compares two preoperative scoring systems predicting long-term pain freedom after microvascular decompression (MVD) for trigeminal neuralgia (TN). Using a retrospective cohort of 410 patients with mean 63-month follow-up, the study tests the Panczykowski score (system A) and proposes a new four-variable Preoperative TN Scoring System (system B) incorporating age, TN type, neurovascular compression, and response to carbamazepine.

Results show both systems reliably stratify likelihood of pain freedom without medication, with higher scores predicting better outcomes; immediate and late complication rates are reported and limitations—including selection bias and evolving diagnostic criteria—are discussed, emphasizing need for broader external validation before widespread adoption.

Scoring Systems for Trigeminal Neuralgia (TN): Two preoperative scoring systems, the Panczykowski Score (A) and a new 4-variable Preoperative Trigeminal Neuralgia Scoring System (B), were evaluated for predicting long-term pain freedom after microvascular decompression (MVD) in TN patients.

Key Predictive Variables: Age over 45 years, classical TN type, positive response to carbamazepine, and presence/severity of neurovascular compression (NVC) significantly predict postoperative pain freedom without medication.

Scoring System A (Panczykowski): Utilizes three variables—TN type (classical/nonclassical), response to carbamazepine, and graded NVC—to assign a score from 1 to 5; higher scores correlate with greater likelihood of long-term pain freedom.

Scoring System B (Updated): Incorporates four variables—age (>45), TN type, response to carbamazepine, and NVC grade (with updated definitions)—assigning one point for each, for a total score of 0 to 4; higher scores predict increased chance of pain freedom.

Predictive Value: Both scoring systems reliably predict long-term pain freedom after MVD, with patients scoring higher on either system significantly more likely to be pain free without medication at long-term follow-up (up to 82% for highest scores).

Complication Rates: Immediate postoperative complication rate was 3.7% and late complication rate was 8.1%, with facial numbness, infection, and hearing loss among the most common complications.

Clinical Application and Limitations: These scoring systems can guide preoperative counseling and surgical candidate selection but may be limited by selection bias, changing TN diagnostic criteria, and potential oversimplification of complex patient profiles; external validation is needed before universal adoption.

Conclusion: Incorporating individual patient factors into preoperative scoring helps identify TN patients most likely to benefit from MVD, but further research and validation in broader populations are necessary for widespread clinical use.

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Surgery of peritorcular meningiomas: the structural basis for preservation of torcular venous flow

J Neurosurg 143:1449–1457, 2025

This clinical and anatomical study defines the structural composition of the torcular Herophili and its implications for resection of peritorcular meningiomas, presenting histological evidence of a delaminable collagenous plane between venous endothelium and dural fibrous layers. The authors propose a four-type classification of tumor invasion based on endothelial integrity to guide operative strategy and preserve venous flow.

Clinical outcomes from 14 patients treated between 1997 and 2018 are reported, demonstrating feasibility of gross-total resection for type I–II tumors via layer-by-layer dissection with venous wall reinforcement, while types III–IV require preservation of collateral drainage and tailored reconstructive or adjunctive approaches.

• Torcular Anatomy: The torcular wall consists of two main compartments—an inner venous structure lined by endothelium and supported by elastic and smooth muscle fibers, and an outer fibrous dural layer, separated by a collagenous cleavage plane that enables surgical delamination.

• Meningioma Classification: Peritorcular meningiomas are classified into four types based on anatomical invasion: Type I (dural involvement only), Type II (dural involvement with sinus compression/displacement), Type III (endothelial layer disrupted, tumor penetrates lumen), and Type IV (complete sinus occlusion).

• Surgical Technique: For Type I and II tumors, gross-total resection is feasible by dissecting the tumor away from the inner venous wall at the cleavage plane, preserving venous integrity and flow; in Types III and IV, focus shifts to preserving venous collaterals due to disrupted or occluded flow.

• Preoperative Planning: Detailed imaging and identification of venous collaterals are critical for operative planning, especially when sinus flow is compromised or occluded.

• Outcomes: Gross-total resection was achieved in all patients with Type I and II tumors, with lower recurrence rates; subtotal resection and higher recurrence were associated with Types III and IV and higher-grade meningiomas.

• Complications and Mortality: No surgical mortality was reported; complications included wound infections and, rarely, recurrence or death related to aggressive tumor biology rather than surgery itself.

• Role of Radiotherapy: Radiation therapy was reserved for high-grade, residual, or recurrent tumors, particularly when total resection was not possible or in cases of sinus wall involvement.

• Clinical Significance: Preservation of the torcular venous wall and flow is paramount for favorable outcomes; anatomical understanding of the torcula enables safer, more effective resections and reduces recurrence in benign cases.

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Masseter Sarcopenia and Mortality After Type II Odontoid Fractures in the Elderly: A 5-Year Follow-Up Study

Neurosurgery 97:1297–1307, 2025

This clinical retrospective study evaluates whether masseter sarcopenia, measured on routine head CT scans, predicts mortality after Type II odontoid fractures in elderly patients. Using masseter cross-sectional area (MCSA) thresholds, the authors found that lower MCSA is independently associated with increased 1-year mortality, while frailty indices and age drive longer-term risk.

The paper details methods, cohort characteristics (n=72, mean age 80.9), imaging measurement technique, multivariate Cox models, and Kaplan-Meier analyses. Results support MCSA as a practical prognostic marker to inform postinjury management and targeted interventions in high-risk geriatric trauma patients.

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Minimally invasive surgical evacuation confers a mortality benefit in patients with moderate-sized putaminal hemorrhages

J Neurosurg 143:1514–1521, 2025

Minimally invasive surgical (MIS) evacuation of moderate-sized putaminal intracerebral hemorrhages (pICH, 10–50 mL) was retrospectively compared with matched maximal medical management in a single-center cohort. The study found similar utility-weighted functional outcomes but a marked reduction in 1-year mortality (3% surgical vs 24% medical) and shorter ICU length of stay for surgically treated patients, with an incremental cost-effectiveness ratio of ~$68,463 per QALY.

Detailed stereotactic volumetric mapping revealed that hemorrhage spatial distribution predicts outcome differently by treatment: anteromedial extension (caudate/anterior limb internal capsule) associated with worse surgical outcomes, while posterior/superior extension (corona radiata/frontal lobe) predicted worse medical outcomes. The authors propose imaging-based selection criteria for MIS candidacy and recommend validation in larger, multicenter studies.

• Mortality Benefit: Minimally invasive surgical (MIS) evacuation of moderate-sized putaminal intracerebral hemorrhages (pICHs, 10–50 mL) significantly reduced 1-year mortality compared to medical management (3% vs 24%, p = 0.010).

• Functional Outcome: Functional outcomes (utility-weighted modified Rankin Scale) were statistically similar between surgical and medical cohorts, with no significant difference detected (mean uw-mRS 0.44 vs 0.33, p = 0.174), possibly due to limited sample size.

• ICU Stay: MIS evacuation resulted in a shorter median ICU length of stay by 3 days compared to medical management (4 vs 7 days, p = 0.045).

• Cost-Effectiveness: Surgical evacuation was cost-effective with an incremental cost-effectiveness ratio of $68,462.55 per quality-adjusted life year (QALY), under the commonly accepted $100,000/QALY threshold.

• Anatomical Predictors: Poor functional outcomes after MIS were associated with anteromedial hemorrhage extension (anterior limb of internal capsule/caudate), while poor outcomes after medical management were linked to posterior/superior extension (frontal lobe/corona radiata).

• Patient Selection: Imaging-based spatial distribution of pICH can help predict which patients may benefit most from surgical versus medical management, suggesting a role for CT-based anatomical biomarkers in clinical decision-making.

• Study Limitations: Retrospective, single-center design, small sample size, and potential selection bias limit generalizability and statistical power, especially regarding functional outcome differences.

• Guideline Context: Current evidence and guidelines do not define optimal selection criteria for surgery in basal ganglia ICH, highlighting the need for further prospective, multicenter research to refine indications for MIS evacuation

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Cognitive-Affective Improvement on Cerebellar Neuropsychiatric Rating Scale Scores in Adults and Children After Decompression of Chiari Malformation Type I

Neurosurgery 97:1450–1458, 2025

This clinical study assesses the Cerebellar Neuropsychiatric Rating Scale (CNRS) applied to adults and children with symptomatic Chiari Malformation Type I undergoing posterior fossa decompression. Preoperative and 8–24 month postoperative CNRS scores in 87 patients (56 follow-up) showed significant reductions in total, attentional, emotional, and autism-spectrum symptoms, with feasible administration under 15 minutes.

Correlations linked higher preoperative CNRS scores to worse neuropsychological test performance and poorer Chicago Chiari Outcome Scale subscores for attention and autism domains. Exploratory factor analysis supported five interpretable CNRS factors, suggesting CNRS as a practical perioperative patient-reported tool to capture cognitive-affective outcome domains complementary to standard functional metrics.

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Detailed Analysis of Late Adverse Effects of Stereotactic Radiosurgery for Dural Arteriovenous Fistulas

Neurosurgery 97:1368–1376, 2025

This single-center retrospective study evaluates long-term late radiation-induced complications (LRICs) after stereotactic radiosurgery (SRS) for dural arteriovenous fistulas (DAVFs) in 30 patients over a median 99-month follow-up, reporting obliteration rates, post-SRS T2 signal changes, and incidence of chronic encapsulated hematoma (CEH). Findings show high DAVF obliteration (79.6% at 5 years) with rare but notable LRICs (11.1% at 10 years), and an association between post-SRS signal changes and CEH occurrence.

The report details radiosurgical techniques, diagnostic criteria, case courses of two asymptomatic CEHs managed conservatively, and discusses pathophysiology linking radiation, VEGF-mediated permeability, and lesion expansion. The authors recommend prolonged imaging surveillance, heightened monitoring for patients with post-SRS T2 changes, and call for larger multicenter studies to refine predictive models and management strategies.

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Factors Affecting Long-Term Pain Control After Gamma Knife Radiosurgery in Secondary Tumor-Related Trigeminal Neuralgia

Neurosurgery 97:1003–1011, 2025

This clinical study evaluates long-term pain outcomes after Gamma Knife radiosurgery (GKRS) for secondary tumor-related trigeminal neuralgia in 156 patients, reporting complete pain relief (BNI 1) in 38.8% and adequate relief (BNI 2–3) in 47.4% over a median 48.5-month follow-up. The cohort—predominantly schwannomas and meningiomas—received tumor-targeted single-session GKRS with a median dose of 12 Gy and facial hypesthesia noted in 8.3%.

Multivariable analysis identified age ≥50 years and decreased or stable tumor volume at follow-up as strong predictors of favorable pain outcomes, while tumor progression and younger age predicted failure. The authors conclude tumor control contributes to pain relief but is not the sole mechanism, and targeting tumor alone achieved similar BNI 1–3 rates as reports that also targeted the nerve.

• Gamma Knife Radiosurgery (GKRS) Efficacy: GKRS provides complete pain relief (BNI 1) in 38.8% and adequate pain relief (BNI 2-3) in 47.4% of patients with secondary tumor-related trigeminal neuralgia, with a median follow-up of about 48.5 months.

• Predictors of Pain Relief: Age ≥50 years (odds ratio: 6.95) and decreased or stable tumor volume at follow-up (odds ratio: 40.38) significantly predict successful pain relief (BNI 1-3) after GKRS.

• Tumor Control and Pain Relief Relationship: While tumor control (stable or reduced volume) strongly correlates with pain relief, pain relief can still occur without significant tumor shrinkage, indicating other contributing mechanisms.

• Most Common Tumor Types: Schwannomas (67.9%) and meningiomas (29.6%) are the most frequent causes of secondary tumor-related trigeminal neuralgia treated with GKRS.

• Complications: Facial hypesthesia is the most common complication post-GKRS, affecting 8.3% of patients; no cases of anesthesia dolorosa or worsening pain were reported.

• Tumor Volume Impact: Larger pre-treatment tumor volume is associated with higher rates of pain relief failure; patients with pain relief failure had a median tumor volume of 5.9 cc versus 3.1–4 cc in those with successful outcomes.

• Prior Procedures: Previous interventions (such as radiofrequency ablation, rhizotomy, or tumor resection) do not significantly affect pain relief outcomes after GKRS.

• Alternative Approaches: Targeting the tumor alone with GKRS is effective; nerve targeting may be reserved for cases where tumor-targeted GKRS fails.

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Outcomes After Repeat-Percutaneous Balloon Compression for Recurrent Trigeminal Facial Pain

Neurosurgery 97:1012–1020, 2025

This clinical case series evaluates the safety and efficacy of repeat percutaneous balloon compression (PBC) for recurrent trigeminal neuralgia in 36 patients treated from 2019–2023, reporting 55 procedures. Outcomes include pain-free duration, BNI pain scores, facial numbness, medication reduction, operative metrics, and complications, with midterm follow-up averaging 33 months.

Key findings indicate repeat PBC yields durable pain relief for most patients (72% sustained complete relief), enables medication reduction in 71%, and incurs low complication rates without observed deafferentation pain; multiple sclerosis patients required more repeats but benefited similarly. The study calls for larger comparative trials to confirm these single-center results.

• Repeat Percutaneous Balloon Compression (PBC) Efficacy: Repeat PBC procedures are effective in managing recurrent trigeminal neuralgia, with 72% of patients maintaining complete pain relief at midterm follow-up (mean: 33 months), and 71% able to permanently decrease or eliminate facial pain medications.

• Safety of Repeat PBC: Repeat PBCs do not increase the risk of complications, regardless of the number of procedures or balloon inflation time, and no patients experienced deafferentation pain in this cohort.

• Complication Profile: Minor transient complications occurred in 10.9% of procedures, with only one major complication (carotid artery puncture); most adverse effects were temporary and non-severe, such as transient numbness, chewing difficulties, or partial corneal anesthesia.

• Pain-Free Interval: The mean pain-free interval after the first PBC was 18 months, with longer intervals observed after subsequent procedures (second: 20 months, third: 41 months in one case), and a decreasing proportion of patients requiring further interventions with each repeat procedure.

• Patient Selection and Outcomes: PBC was performed in patients with predominantly neuralgic facial pain who were not candidates for microvascular decompression; patients with multiple sclerosis (MS) required more repeat procedures but still achieved high rates of pain relief.

• Comparison to Other Techniques: Compared to other percutaneous procedures like radiofrequency thermocoagulation (RFT) and glycerol rhizotomy, repeat PBC appears to have fewer severe complications such as deafferentation pain, dysesthesia, or persistent sensory deficits.

• Balloon Compression Time: Longer balloon inflation times (up to 10 minutes for repeat procedures) did not correlate with increased complications and may contribute to longer pain-free intervals, though no statistical significance was found in this study.

• Clinical Recommendation: Given the likelihood of recurrence after percutaneous procedures, PBC is a safe and effective option for recurrent trigeminal neuralgia, especially for patients unsuitable for more invasive surgery, but larger multi-institutional studies are needed for broader validation.

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Central thalamic deep brain stimulation for disorders of consciousness: an individual participant data meta-analysis

J Neurosurg 143:1217–1226, 2025

This individual participant data meta-analysis evaluates central thalamic deep brain stimulation (DBS) for chronic disorders of consciousness, pooling 49 patients from seven centers to assess neurological outcomes via the JFK Coma Recovery Scale–Revised. Results show modest mean CRS-R improvement, with age and shorter delay to implantation predicting better gains, but insufficient evidence that DBS alters the natural recovery trajectory.

The report details heterogeneity in targets, stimulation schedules, and methodological limitations—no randomized controls, selection bias, and variable reporting—highlighting the need for matched comparative studies, standardized outcome metrics, and refined targeting (CL vs CM-Pf/DTTm) to determine DBS efficacy and optimize patient selection.

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Multi-institutional recommendations on the use of 7T MRI in deep brain stimulation

J Neurosurg 143:1165–1175, 2025

This multi-institutional review presents consensus recommendations for integrating 7T ultrahigh-field MRI into deep brain stimulation (DBS) workflows, drawing on experience from over 1,000 procedures. It summarizes technical challenges—B1+ heterogeneity, susceptibility and gradient nonlinear distortions—and practical solutions for acquisition, distortion correction, and coregistration to ensure stereotactic accuracy.

The document details optimized sequences and target-specific imaging strategies (STN, GPi, thalamic nuclei, ANT, CM), advanced modalities (DTI/DiMANI, QSM, tractography), and multidisciplinary workflow considerations to improve patient-specific anatomical and connectivity-based DBS targeting and programming.

• 7T MRI Advantages: Ultrahigh-field 7T MRI provides superior spatial resolution, signal-to-noise ratio, and tissue contrast, enabling clearer visualization of deep brain structures critical for deep brain stimulation (DBS) targeting compared to 1.5T and 3T MRI.

• Improved DBS Targeting: 7T MRI enhances direct anatomical and connectivity-based targeting for DBS, supporting more precise, patient-specific electrode placement for Parkinson’s disease, essential tremor, and epilepsy.

• Key Technical Challenges: 7T MRI introduces unique challenges including B1+ transmit field inhomogeneity, increased image distortions (gradient nonlinearity and susceptibility), and chemical shift artifacts, all of which require specialized correction and protocol optimization.

• Distortion Correction and Coregistration: Accurate DBS planning with 7T MRI demands robust correction for gradient and susceptibility distortions, careful coregistration with stereotactic CT, and often manual or nonlinear registration adjustments for optimal anatomical alignment.

• Recommended Imaging Sequences: Specific 7T MRI sequences, such as T2-weighted, FGATIR, MP2RAGE, SWI, QSM, and advanced diffusion imaging (DTI/DiMANI), are recommended for visualizing common DBS targets (STN, GPi, thalamic nuclei), each offering distinct advantages for different structures.

• Connectivity and Tractography: Advanced diffusion MRI at 7T allows submillimetric tractography, enabling functional parcellation of DBS targets (e.g., STN, GPi, DRTT), which can improve patient outcomes by supporting symptom- and network-specific targeting.

• Clinical Impact: Implementation of 7T MRI in over 1000 DBS procedures across multiple centers has demonstrated that, with appropriate workflow and expertise, technical challenges can be managed and targeting accuracy and patient outcomes can be improved.

• Multidisciplinary Collaboration: Effective use of 7T MRI for DBS requires close collaboration between neurosurgeons, MR technicians, physicists, and neuroradiologists to optimize protocols and address the complexity of ultrahigh-field imaging

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Fusion Sequence and Risk Factors for Pseudarthrosis in Multilevel Anterior Cervical Discectomy and Fusion

Neurosurgery 97:1153–1161, 2025

This clinical study evaluates fusion rates, fusion timing, and pseudarthrosis risk factors in 119 patients undergoing 2-level versus 3-level anterior cervical discectomy and fusion (ACDF) with minimum two-year follow-up. Fusion was assessed via angular and linear interspinous motion on dynamic radiographs, with Kaplan-Meier and Cox regression analyses.

Key findings show higher and faster fusion in 2-level ACDF; middle levels fuse earliest while caudal levels have lowest rates. Polyetheretherketone (PEEK) cages and multilevel constructs associate with increased pseudarthrosis risk, highlighting material choice and level-specific biomechanics as critical for surgical planning and future research.

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Indirect cognitive mapping in glioma surgery in patients not eligible for awake craniotomy

Acta Neurochirurgica (2025) 167:289

This article presents a neurosurgical technique for indirectly mapping cognitive subcortical white matter pathways during glioma resection in patients who cannot undergo awake craniotomy. Using preoperative DTI and fMRI to create a 3D functional map, the team employs intraoperative monopolar subcortical motor stimulation as a live landmark to infer and protect nearby cognitive tracts like the arcuate fasciculus and IFOF.

Three illustrative cases demonstrate planning limits based on measured motor stimulation thresholds (approx. 1 mA ≈ 1 mm) and show safe resections with preserved cognitive and motor function. The report discusses indications, limitations versus awake mapping, importance of patient counselling about transient deficits, and integration of neuronavigation, tractography, and intraoperative motor mapping.

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The Far-Lateral Approach and Its Variants

Operative Neurosurgery 29:740–745, 2025

This technical report details the far‑lateral craniotomy and its variants for accessing ventral and ventrolateral craniovertebral pathologies, emphasizing indications, anatomical considerations, and operative steps. It outlines positioning, incision choices, bone work including condylar modifications, dural handling, and strategies to protect the vertebral artery and lower cranial nerves.

The article highlights advantages, limitations, and common pitfalls—such as occipitocervical instability with extensive condylectomy, hypoglossal canal risk, and CSF leak prevention—and supplements the text with high‑quality dissections and a 4K instructional video aimed at trainees and early‑career neurosurgeons.

 

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An Artificial Intelligence Tool for the Diagnosis of Facial Pain

Neurosurgery 97:993–1002, 2025

This study presents development and validation of an AI-based diagnostic decision support tool that distinguishes temporomandibular disorders (TMDs) from trigeminal neuralgia (TN) using a standardized facial pain questionnaire and targeted orofacial examination. Supervised machine learning models (Random Forest, Logistic Regression, SVM) were trained on data from 101 patients, with the Random Forest achieving the best performance (≈90% accuracy; ROC-AUC ~0.95).

The analysis identifies clinically interpretable predictors—TMJ and masticatory muscle tenderness favor TMD, while brief electric-shock–like pain and prior response to trigeminal surgery favor TN—and evaluates class imbalance effects and limitations for clinical deployment. The work emphasizes the need for external validation, cautious integration into workflows, and balanced training to improve generalizability.

• Differentiation Challenge: Temporomandibular disorders (TMDs) and trigeminal neuralgia (TN) both cause orofacial pain but require very different treatments, making accurate diagnosis crucial; TMDs are far more common and often misdiagnosed as TN, leading to inappropriate management.

• AI Diagnostic Tool: A machine learning (ML) model using questionnaire data and physical examination can reliably distinguish TMD from TN with approximately 90% accuracy, with a Random Forest Classifier showing the best performance (F1 score up to 0.953).

• Key Predictive Features: The most important diagnostic indicators are TMJ tenderness and masticatory muscle tenderness (favoring TMD), and brief, unpredictable, electric shock–like pain episodes (favoring TN).

• Data Collection: Comprehensive data—including both patient-reported symptoms and structured physical examination—significantly improves diagnostic accuracy compared to using only a subset of features.

• Prevalence and Misdiagnosis: TMDs affect 5–12% of the population, while TN is much rarer (0.03–0.3%); the high prevalence of TMD means misdiagnosis as TN is a significant concern, with many patients meeting criteria for TN2 possibly having TMD instead.

• Model Robustness: Training ML models on balanced datasets (even when real-world prevalence is imbalanced) improves accuracy and reduces false positives for the minority class (TN).

• Clinical Utility: The AI tool provides transparent, interpretable results that align with clinical reasoning, supporting clinicians in differentiating between TMD and TN, but external validation in diverse populations is needed before routine clinical adoption.

• Limitations: Further research is required for external validation, integration into workflows, and to address potential algorithmic bias; overreliance on algorithmic output should be avoided in favor of combined clinical expertise.

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Modic Change Edema in Chronic Low Back Pain Treated With Infliximab or Placebo

Spine 2025;50:1091–1101

This randomized, double-blind clinical trial evaluated whether infliximab reduces Modic type 1 (MC1) edema on STIR MRI and whether baseline edema or ADC values modify its effect on disability and low back pain (LBP). Patients with chronic LBP and MC1 received four infliximab or placebo infusions; MRI and clinical outcomes (ODI, pain) were assessed at five and six months.

Results showed no clinically relevant edema reduction by infliximab in the primary per-protocol analysis, and baseline STIR edema or MC-related ADC did not modify treatment effects or prognosticate ODI or LBP. Sensitivity analyses yielded a modest edema signal in the full analysis set, but overall findings do not support infliximab for chronic LBP with MC1.

• Infliximab: Did not have a clinically relevant effect in reducing Modic change (MC) edema at six months in patients with chronic low back pain and MC type 1 (MC1) compared to placebo.

• Disability and Pain: Infliximab did not improve disability (Oswestry Disability Index) or low back pain intensity at five or nine months follow-up versus placebo.

• Edema as Modifier: Baseline MC edema and apparent diffusion coefficient (ADC) values did not modify the effect of infliximab on disability or low back pain.

• Prognostic Value: Baseline MC edema and ADC values did not predict disability or low back pain outcomes, regardless of treatment group.

• Statistical Findings: The odds ratio for reduced MC edema at six months with infliximab versus placebo was not statistically significant in the per protocol analysis (OR 2.2, 95% CI: 0.8–5.8; P = 0.12), but reached statistical significance in the full analysis set (OR 2.1, 95% CI: 1.02–4.5; P = 0.04), though the clinical benefit was limited.

• Clinical Relevance: Any observed difference in clinical improvement between patients with and without reduced edema was near or below the threshold for clinical relevance (10 ODI points, 1.5–2.0 pain points).

• Reliability: MRI assessment methods for MC and edema (using STIR imaging and ADC) showed good to very good inter-rater reliability.

• Recommendation: These results do not support the use of infliximab as a treatment for chronic low back pain with MC1.

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Tentorial Dural Arteriovenous Fistulas: A Retrospective Cohort Study

Operative Neurosurgery 29:678–685, 2025

This single-center retrospective cohort study analyzes 275 patients with tentorial dural arteriovenous fistulas (TDAVFs) treated between 2001 and 2022, detailing demographic, angiographic, and treatment data across six Lawton-classified subtypes. Results highlight a predominance of middle-aged male patients, high immediate occlusion rates with endovascular techniques, and subtype-specific differences in venous drainage patterns and complication rates.

The manuscript compares treatment modalities and outcomes, noting superior petrosal sinus TDAVFs more often require microsurgery, while Galenic and torcular subtypes showed lower immediate cure rates and higher complications or new fistula formation. Follow-up angiographic and clinical data emphasize favorable functional recovery for most patients despite treatment-related risks.

• Patient Demographics: Tentorial dural arteriovenous fistulas (TDAVFs) predominantly affect middle-aged men, with 85.8% of cases occurring in males and a mean age of 51.1 years.

• Subtype Distribution: The most common TDAVF subtype is superior petrosal sinus (34.9%), followed by tentorial sinus (31.6%), Galenic (15.6%), torcular (7.3%), incisural (5.5%), and straight sinus (5.1%).

• Aggressiveness and Presentation: TDAVFs are less common than other DAVFs but are the most aggressive, frequently presenting with hemorrhage or progressive neurological deficits; more than half of patients present with intracranial hemorrhage or nonhemorrhagic neurological deficits (NHNDs).

• Treatment Approach: Most TDAVFs (83.0%) can be effectively treated with endovascular embolization, but superior petrosal sinus TDAVFs more often require microsurgical intervention (31.6% in this group).

• Immediate Occlusion and Complications: Immediate complete occlusion was achieved in 92.8% of treated cases, with Galenic TDAVFs showing a lower occlusion rate and both Galenic and superior petrosal sinus TDAVFs exhibiting higher complication rates (12.5% overall).

• Outcomes: Favorable clinical outcomes (mRS <3) were achieved in 82.6% of patients, with torcular and tentorial sinus TDAVFs associated with better outcomes compared to other subtypes.

• Recurrence and New Fistulas: Recurrence after complete occlusion was rare (0.9%), but torcular TDAVFs had a higher tendency to develop new fistulas post-treatment (2.6% of cases).

• Key Technical Considerations: Endovascular treatment is preferred when feasible, but surgical approaches are indicated for lesions with unfavorable arterial access or higher risk of complications, particularly in superior petrosal sinus TDAVFs.

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Avoidance of Major Vascular Injury in Transcranial Brain Tumor Surgery Using Real-Time Doppler Navigation

Operative Neurosurgery 29:633–638, 2025

This clinical technical note and case series evaluates real-time Doppler probe navigation during transcranial craniotomy for brain tumor resection, describing technique, operative workflow, and outcomes from 501 operations where the Doppler was used. The authors report a low rate of major vessel injury (<1%) and discuss how Doppler guidance complements neuronavigation and ultrasound as tumor resection progresses and brain shift reduces image accuracy.

The paper details patient selection, surgical approaches, probe specifications and intraoperative use, illustrates three case examples with video, and analyzes stroke and infarction rates attributable to vasospasm or small-vessel injury. Limitations include retrospective design and variable probe penetrance; the authors recommend routine Doppler adjunctive use for tumors encasing or adherent to major arteries.

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