Fully Endoscopic Microvascular Decompression for Hemifacial Spasm Using 2-Dimensional/3-Dimensional Endoscopy

Operative Neurosurgery 30:870–879, 2026

This clinical case series reports outcomes of 204 patients who underwent fully endoscopic microvascular decompression (MVD) for hemifacial spasm (HFS), comparing 2D and preliminary 3D endoscopic techniques and analyzing learning-curve effects. Detailed methods, operative technique, intraoperative monitoring (LSR), and complication rates are presented alongside imaging and intraoperative findings.

Results show a 97.1% overall effectiveness with low long-term complication rates and improving outcomes over time; the 3D endoscope afforded improved stereoscopic perception though with higher cost and minor drawbacks, and the authors recommend further study of 3D endoscopy in MVD.

Study scope Retrospective analysis of 204 hemifacial spasm patients treated with fully endoscopic microvascular decompression using 2D (191) or 3D (13) endoscopy (July 2017–Oct 2024); mean follow-up 20.4 months.

Surgical approach Procedures used a retrosigmoid infrafloccular route with LSR monitoring; polytetrafluoroethylene (Teflon) pledgets placed between facial nerve REZ and offending vessels, with further exploration if LSR persisted.

Effectiveness At last follow-up, 198/204 (97.1%) had cessation or significant reduction of spasms (excellent 86.8%, good 10.3%).

Complications Immediate postoperative complications included facial weakness (7), hearing loss (11), tinnitus (1), infection (1), dysphagia (1), and CSF leak (1); 10 patients had persistent complications at last follow-up (6 hearing loss, 3 facial weakness, 1 tinnitus).

Learning curve Outcomes improved over time: effectiveness 95.6% → 97.1% → 98.5% (early/middle/late), while complication rates decreased 5.9% → 5.9% → 2.9%.

Offending vessels Most common offending vessel was AICA (43.1%), with multiple vessels in 33.3% of cases (including combinations with VA and PICA).

3D endoscopy pros/cons 3D endoscope provided subjectively better stereoscopic vision/depth perception aiding surgery, but had drawbacks including slight vertigo and high cost.

Overall conclusion Fully endoscopic MVD offers wide visualization of the neurovascular conflict region and helps minimize brain injury from retraction; favorable outcomes and low complications once technical proficiency is achieved, with more research needed on 3D’s role.

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

J Neurosurg 144:1145–1153, 2026

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

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

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

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

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

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

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

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

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

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

Long-term outcomes of microvascular decompression for trigeminal neuralgia in multiple sclerosis

J Neurosurg 144:1122–1133, 2026

This systematic review and meta-analysis evaluates microvascular decompression (MVD) outcomes for trigeminal neuralgia in patients with multiple sclerosis (TN-MS). The authors pooled 30 studies (265 unique TN-MS patients), finding neurovascular compression in 96.6% and a pooled long-term pain-free (BNI I) success rate of about 30%, with low heterogeneity and primarily transient sensory complications.

The report discusses limited, mostly retrospective evidence, methodological limitations, and potential dual mechanisms of TN in MS. Authors conclude MVD yields lower success than in classic TN but remains a reasonable option for selected TN-MS patients with demonstrable neurovascular compression; they call for prospective studies and refined patient selection.

Objective Evaluate long-term pain relief and complications of microvascular decompression (MVD) for trigeminal neuralgia in patients with multiple sclerosis (TN-MS), a group traditionally considered poor candidates for MVD.

Methods Systematic review/meta-analysis (PRISMA) of PubMed, Embase, Scopus, and Web of Science (search June 2024); primary endpoint was long-term pain-free status BNI I at final follow-up using random-effects meta-analysis of proportions.

Evidence base 30 studies were included, covering 429 TN-MS patients treated with MVD, representing 265 unique patients.

Neurovascular compression Compression was identified in 96.6% of reported TN-MS cases (via MRI and/or intraoperative findings).

Long-term efficacy Pooled long-term pain-free outcome (BNI I) after MVD was 30.2% (95% CI 24.2%–36.9%), with low heterogeneity across analyses.

Complications The most commonly reported complication after MVD was transient facial numbness (with other complications variably reported).

Interpretation MVD is less effective in TN-MS than in classic TN, but can still provide meaningful benefit, particularly when neurovascular compression is present.

Conclusion/implication MVD should not be categorically excluded for TN-MS; further prospective studies are needed to improve selection and outcomes.

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.

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.

 

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.

Electrophysiological monitoring of trigeminal nerve sensory root using sensory-masseter response for microvascular decompression in trigeminal neuralgia

Acta Neurochirurgica (2026) 168:13

This study presents a novel intraoperative electrophysiological technique—the sensory-masseter response (SMR)—for localizing neurovascular compression (NVC) during microvascular decompression (MVD) for trigeminal neuralgia. In 34 patients, SMR was recorded in 82.4% and showed strong spatial correlation with intraoperatively identified NVC, with significantly lower stimulation thresholds at compression sites (median 0.3 mA).

The authors describe methodology, threshold analyses, mechanistic hypotheses linking focal demyelination and sensory-motor anastomoses to SMR, illustrative cases, safety considerations, and limitations. They conclude SMR offers high spatial specificity as a potential real-time adjunct for MVD, but recommend larger studies to validate clinical utility.

Sensory-Masseter Response (SMR) Technique: SMR is a novel intraoperative electrophysiological monitoring method that applies microcurrent stimulation to the intracranial trigeminal sensory root and records compound muscle action potentials (CMAPs) from the masseter muscle to localize neurovascular compression (NVC) during microvascular decompression (MVD) for trigeminal neuralgia (TN).

High Spatial Specificity and Correlation with NVC: SMR was successfully recorded in 82.4% of cases (28/34), with a strong spatial correlation between SMR-positive sites and intraoperatively identified NVC (p < 0.001).

Lower Stimulation Threshold at NVC Sites: The stimulation threshold required to elicit SMR was significantly lower at NVC sites (median 0.3 mA, IQR 0.2–0.4 mA) compared to distal, central, or non-compressed segments, indicating localized neural hyperexcitability likely due to demyelination.

Mechanistic Basis—Sensory-Motor Root Anastomoses: SMR is likely mediated by abnormal anastomotic pathways between the trigeminal sensory and motor roots at the NVC site, enabling direct excitation of the masseter muscle and bypassing the central reflex arc.

Clinical Utility and Limitations: SMR provides real-time functional feedback for intraoperative localization of NVC, but its clinical value and influence on surgical outcomes require further validation in larger, controlled studies.

Potential Pathogenic Insight: The ability to elicit SMR at NVC sites supports the hypothesis that focal demyelination and abnormal sensory-motor conduction contribute to TN pathogenesis and characteristic symptoms like chewing-triggered pain.

Safety Considerations: SMR stimulation can cause transient blood pressure elevation due to sympathetic activation; precautions include deepening anesthesia and monitoring hemodynamics during stimulation.

Study Limitations: The main limitations include small sample size, absence of SMR testing in non-TN or healthy controls, possible technical constraints in nerve exposure, and restriction of recordings to the masseter muscle only.

Outcome comparison between interposition and “contactless” transposition microvascular decompression approaches for trigeminal neuralgia

J Neurosurg 143:970–981, 2025

This study compared interposition and “contactless” transposition (Teflon and pericranial sling) microvascular decompression techniques for trigeminal neuralgia. Both were effective, but sling transposition showed improved midterm pain control and fewer complications. The only significant predictor of pain freedom was MRI evidence of clear nerve compression.

• Microvascular decompression (MVD) is a main surgical treatment for trigeminal neuralgia (TN), traditionally using Teflon interposition between nerve and artery.

• Recurrence of TN pain after MVD is often due to Teflon complications, prompting the development of “contactless” transposition techniques such as Teflon and pericranial sling transpositions.

• This retrospective study compared outcomes of interposition, Teflon transposition, and pericranial sling transposition in 305 TN patients.

• Sling transposition was mainly used for severe compression by the superior cerebellar artery and involved securing the artery to the tentorium with a pericranial graft.

• All techniques had similar short-term pain relief and complication rates, but sling transposition showed significantly higher pain-free rates at 2 years compared to other methods.

• Clear vascular compression on MRI was the only significant predictor of pain freedom in multivariate analysis.

• Sling transposition uses autologous tissue, avoids foreign body reactions, and may provide more durable pain control, but is technically more complex.

• Further long-term studies are needed to confirm the durability of sling transposition for TN pain control.

Enhanced Recovery After Surgery Protocol for Microvascular Decompression in Trigeminal Neuralgia: A Retrospective Matched Cohort Study

Neurosurgery 97:936–944, 2025

Implementation of an enhanced recovery after surgery (ERAS) protocol for microvascular decompression in trigeminal neuralgia significantly reduced hospital length of stay, improved postoperative pain scores, and decreased transient hearing alterations compared to conventional care, without increasing complications, according to a retrospective matched cohort study.

• Enhanced Recovery After Surgery (ERAS) protocol was implemented for microvascular decompression (MVD) in trigeminal neuralgia (TN) patients and compared to conventional care in a retrospective matched cohort study.

• ERAS protocol included preoperative counseling, scalp block, small incisions, minimal muscle dissection, total intravenous anesthesia without narcotics, early enteral feeding, and early mobilization.

• 130 patients (65 ERAS, 65 non-ERAS) were analyzed after propensity score matching for key demographics and comorbidities.

• ERAS group had significantly shorter hospital length of stay (1.46 vs 2.95 days, P < .001) and lower postoperative verbal pain scores (1.63 vs 2.48, P = .03) than controls.

• ERAS patients experienced fewer transient postoperative subjective hearing alterations (0 vs 6 cases, P = .03).

• No significant difference in postoperative Barrow Neurological Institute (BNI) pain scores or major complications between groups.

• Subgroup analysis showed ERAS patients discharged at 24 hours had even lower pain scores than controls.

• Study limitations include retrospective design, small sample size, and use of subjective pain scores; larger randomized trials are needed.

How to deal with the superior petrosal vein in microvascular decompression for trigeminal neuralgia?

Neurosurg Focus 59(3):E12, 2025

Sectioning the superior petrosal vein at its main trunk while maintaining venous crossflow is a safe and effective strategy during microvascular decompression for trigeminal neuralgia, improving surgical access without significantly increasing venous-related complications, according to a large retrospective study.

• Management of the superior petrosal vein (SPV) during microvascular decompression (MVD) for trigeminal neuralgia (TN) is controversial, with concerns about operative field access and potential complications.

• A retrospective study evaluated a technique of SPV division at its main trunk near the superior petrosal sinus, maintaining venous crossflow through contributories, in 171 out of 217 patients (79%).

• No statistically significant increase in venous-related complications was observed in the SPV division group compared to the preservation group.

• Only 3 possibly venous-related complications occurred in the SPV division group, all of which were mild and transient.

• Anatomical variations of the SPV require careful intraoperative assessment and preservation of collateral venous drainage for safety.

• Preoperative imaging and intraoperative techniques (e.g., indocyanine green angiography) are recommended to assess collateral flow before SPV division.

• The study concludes that SPV division at the main trunk with preservation of crossflow is a safe strategy that improves surgical exposure during MVD for TN.

Neuroapraxia of Trigeminal Nerve Controlled by Neuromonitoring During Microvascular Decompression in Multiple Sclerosis Patients Affected by Drug-Resistant Trigeminal Neuralgia Recurrent After Previous Operations

Operative Neurosurgery 29:295–300, 2025

This case series reports the first use of intraoperative neuromonitoring-controlled neuroapraxia of the trigeminal nerve with a temporary aneurysm clip during microvascular decompression for drug-resistant, recurrent trigeminal neuralgia in multiple sclerosis patients, showing immediate pain relief and no complications at up to 10 months’ follow-up.

• Trigeminal neuralgia (TN) in multiple sclerosis (MS) patients is difficult to treat and often recurs after surgery.

• This report describes the first 3 cases of recurrent, drug-resistant MS-related TN treated with intraoperative neuromonitoring (IONM)-controlled neuroapraxia during microvascular decompression (MVD).

• Neuroapraxia was induced by applying a temporary titanium aneurysm clip to the trigeminal nerve for up to 30 seconds, with real-time IONM to avoid nerve damage.

• All patients achieved immediate pain relief and maintained Barrow Neurological Institute pain score I at 9–10 months follow-up, with no major complications.

• Compared to previous techniques, this approach minimized complications by reducing clip time and using neuromonitoring.

• This technique may offer a safe, promising option for MS patients with recurrent TN, but larger studies with longer follow-up are needed.

• The study’s main limitation is the small patient number and short follow-up period.

Stratifying trigeminal neuralgia and characterizing an abnormal property of brain functional organization: a resting-state fMRI and machine learning study

J Neurosurg 143:74–82, 2025

Resting-state fMRI and machine learning revealed distinct brain connectivity and activity differences between classical and idiopathic trigeminal neuralgia (TN) and controls. These findings identify potential neuroimaging biomarkers for TN subtypes, aiding diagnosis and understanding of TN pathophysiology.

Primary trigeminal neuralgia (TN) includes classical (CTN) and idiopathic (ITN) types, sharing clinical features but differing in neurovascular compression (NVC) presence.

• Resting-state fMRI and machine learning were used to analyze brain functional connectivity and spontaneous activity in 50 TN patients (28 CTN, 22 ITN) and 43 controls.

• TN patients showed increased connectivity between the medial prefrontal cortex (mPFC) and left planum temporale, and decreased connectivity between mPFC and left superior frontal gyrus.

• CTN patients had further reduced connectivity between the left insula and left occipital pole, and decreased activity in the right temporal pole compared to ITN.

• TN patients exhibited heightened neural activity in frontal regions compared to controls.

• Machine learning (support vector machine) distinguished TN patients from controls with moderate accuracy (AUC 0.80).

• Findings suggest potential fMRI biomarkers for TN subtypes, aiding understanding of pathophysiology and improving diagnosis.

• Study limitations include small sample size and exclusion of bilateral/secondary TN, warranting further research.

Effects of the length of preoperative conservative management on postoperative outcomes after primary microvascular decompression for trigeminal neuralgia

J Neurosurg 143:92–99, 2025

Prolonged preoperative conservative management with anticonvulsants in trigeminal neuralgia is associated with worse pain outcomes and higher pain recurrence after microvascular decompression. Early surgical intervention may improve postoperative results and reduce pain recurrence risk in these patients.

• Longer duration of preoperative conservative management (anticonvulsant use) before microvascular decompression (MVD) for trigeminal neuralgia (TN) is linked to worse postoperative pain outcomes and higher risk of pain recurrence.

• Median duration of conservative management before surgery was 1.74 years.

• Patients with longer conservative management had higher final BNI pain scores and greater rates of pain recurrence than those with shorter management.

• Longer conservative management predicted shorter pain-free survival after MVD.

• Younger age and longer conservative management duration were independent predictors of worse postoperative pain and recurrence.

• No significant difference in preoperative pain scores between groups; both had high pain levels pre-surgery.

• Findings suggest early surgical intervention may benefit TN patients who are candidates for MVD.

• Study was retrospective and single-institution, limiting generalizability; further research is needed.

Deep learning–based segmentation of the trigeminal nerve and surrounding vasculature in trigeminal neuralgia

J Neurosurg 143:83–91, 2025

This study developed and validated deep learning U-Net models for automated 3D segmentation of the trigeminal nerve and surrounding vasculature in MRI of trigeminal neuralgia patients, enabling objective quantification of neurovascular conflict features and potentially improving preoperative evaluation and treatment planning.

• Deep learning (U-Net) models were used to segment the trigeminal nerve and surrounding vasculature in patients with trigeminal neuralgia using high-resolution CISS MRI.

• Six U-Net variants with different encoder backbones were tested; SE-ResNet50 performed best overall (Dice score = 0.775, IoU = 0.681).

• The models quantified anatomical features such as the surface area of neurovascular contact and distance to the contact point, showing no significant difference from manual segmentations.

• The best model achieved 100% sensitivity and specificity in detecting neurovascular conflict in the testing set.

• Automated 3D segmentation allows for objective, quantitative evaluation, improving on subjective and time-intensive manual methods.

• Limitations include inability to distinguish vessel type (artery vs. vein) and data from a single institution; future work should address these.

• The method may help standardize neurovascular conflict assessment and improve treatment selection for trigeminal neuralgia.

Evaluation of 2 Surgical Techniques—Transposition Versus Interposition Microvascular Decompression for Hemifacial Spasm: A Systematic Review of 19 437 Patients

Neurosurgery 97:16–27, 2025

This systematic review of 19,437 patients compares transposition and interposition microvascular decompression techniques for hemifacial spasm. Both methods show similar efficacy and safety, with no conclusive evidence favoring one. Slightly higher facial nerve weakness was noted with transposition. Prospective trials are needed for definitive comparison.

Hemifacial spasm (HFS) is a rare disorder caused by compression of the facial nerve, leading to involuntary facial muscle contractions.

Microvascular decompression (MVD) is an effective surgical treatment for HFS, with two main techniques: interposition (placing a prosthesis between nerve and vessel) and transposition (moving the vessel away without direct prosthesis contact).

• A systematic review of 62 studies (19,437 patients) compared outcomes of interposition (18,627 cases) and transposition (810 cases) in MVD for HFS.

Spasm freedom rates were similar: 90.4% for transposition and 89.6% for interposition.

Complication rates were similar, though temporary facial nerve weakness/palsy was higher with transposition (9.52% vs 6.03%).

No conclusive evidence was found that one technique is superior in safety or efficacy; interposition may be preferred in certain clinical situations.

A prospective trial is needed to determine true differences and optimal indications for each technique.

• The review highlights the need for future studies to stratify outcomes by technique and report prognostic factors.

Gamma Knife radiosurgery for relapsing trigeminal neuralgia following microvascular decompression

J Neurosurg 142:1247–1255, 2025

Salvage Gamma Knife radiosurgery (GKRS) offers effective, noninvasive treatment for relapsing trigeminal neuralgia after microvascular decompression, with a favorable complications profile. Patients with facial numbness and better initial pain responses may experience more durable pain relief following salvage GKRS.

Gamma Knife radiosurgery (GKRS) is explored as a treatment for relapsing trigeminal neuralgia (TN) following microvascular decompression (MVD).

• The study aimed to assess the response rate, complications, and predictors of pain relapse for salvage GKRS after MVD.

83.1% of patients experienced initial pain relief after salvage GKRS, with a median time to relapse of 1.75 years.

Facial numbness post-GKRS decreased pain relapse risk, while a worse initial pain response increased it.

Radiofrequency ablation (RFA) prior to MVD reduced the likelihood of an initial response to GKRS.

Salvage GKRS is presented as an effective, noninvasive option for recurring TN after MVD, with a favorable complications profile compared to salvage MVD.

• The study acknowledges limitations, including potential selection bias and small sample size, and suggests further research with larger cohorts

Tobacco Use and Trigeminal Neuralgia: Clinical Features and Outcome After Microvascular Decompression

Neurosurgery 96:667–672, 2025

Tobacco use affects trigeminal neuralgia (TN) outcomes: Smokers with TN tend to develop symptoms at a younger age and have worse long-term outcomes after microvascular decompression (MVD) surgery compared to nonsmokers.

Smokers show more widespread facial pain: TN in smokers is associated with a more widespread distribution of facial pain, suggesting a more severe form of the disease.

Immediate postoperative outcomes similar: There is no significant difference in immediate postoperative outcomes between smokers and nonsmokers, although smokers are less likely to be pain-free in the long term.

Potential benefits of smoking cessation: Patients with a remote history of smoking have outcomes similar to those who never smoked, indicating potential benefits of quitting smoking before surgery.

Study limitations: The study is a single-center retrospective analysis and may not be generalizable to all TN patients or those undergoing different treatments.

Implications for treatment: Findings suggest the need for presurgical counseling and support for smoking cessation to improve outcomes for TN patients undergoing MVD.

Microvascular Decompression Using the Gelatin Sponge Insertion Technique for Trigeminal Neuralgia

Operative Neurosurgery 28:52–58, 2025

Microvascular decompression (MVD) is the primary surgical intervention for trigeminal neuralgia (TN), with Teflon being the most conventional decompressing material. However, Teflon has been associated with adhesion and granulomas after MVD, which closely correlated with the recurrence of TN. Therefore, we developed a new technique to prevent direct contact between Teflon and nerve. The purpose of this study is to compare the efficacy of MVD using the gelatin sponge (GS) insertion technique with that of Teflon inserted alone in treating primary TN.

METHODS: We retrospectively analyzed the medical records and the follow-up data of 734 patients with unilateral primary TN who underwent MVD at our center from January 2014 to December 2019. After exclusions, we identified 313 cases of GS-inserted MVD and 347 cases of traditional MVD. The follow-up exceeded 3 years.

RESULTS: The operating time of the GS-inserted group was longer than that of the Teflon group (109.38 ± 14.77 vs 103.53 ± 16.02 minutes, P < .001). There was no difference between 2 groups in immediate surgical outcomes and postoperative complications. The yearly recurrence rate for GS-inserted MVD was lower at first (1.0%), second (1.2%), and third (1.2%) years after surgery, compared with its counterpart of Teflon group (3.7%, 2.9%, and 1.7% respectively). The first-year recurrence rate (P = .031) and total recurrence rate in 3 years (P = .013) was significantly lower in the GS-inserted group than Teflon group. Kaplan–Meier survival analysis demonstrated better outcomes in GS-inserted Microdescompresión vascular groups (P = .020).

CONCLUSION: The application of the GS insertion technique in MVD reduced first-year postoperative recurrence of TN, with similar complications rates compared with traditional MVD.

External assessment of preoperative scores for predicting outcome after microvascular decompression for trigeminal neuralgia

J Neurosurg 141:1056–1062, 2024

Recently, two scoring systems have been developed for predicting pain-free outcomes after microvascular decompression (MVD). Evaluation of these scores on large external datasets has been limited. In this study, the authors aimed to evaluate the performance of published MVD scoring systems in predicting pain-free outcome.

METHODS A total of 458 patients who underwent MVD for trigeminal neuralgia (TN) between 2007 and 2020 and had at least 6 months of follow-up were included in this study. Hardaway and Panczykowski scores were retrospectively computed for each patient and compared with postoperative pain recurrence and pain-free duration.

RESULTS The mean ± SD area under the receiver operating characteristic curve for predicting any pain recurrence after MVD was 0.567 ± 0.081 using the Hardaway score and 0.546 ± 0.085 using the Panczykowski score. On log-rank tests and Kaplan-Meier analysis, the patients with Hardaway scores of 0–2 had significantly shorter pain-free survival times after MVD than did those with a score of 3. Patients with a Panczykowski score of 1 had a significantly shorter pain-free duration after surgery compared with both patients with scores of 2–3 and patients with scores of 4–5. Patients with Panczykowski scores of 2–3 also had significantly shorter pain-free duration compared with patients with scores of 4–5.

CONCLUSIONS Both the Hardaway and Panczykowski scores may be useful for predicting postoperative pain-free duration in TN patients, and their utility may be greatest when scores are clustered. Continued refinement of both scoring systems will help to improve our ability to predict patient outcomes after MVD.

Visualization of the nervus intermedius during microvascular decompression in hemifacial spasm: anatomical study

J Neurosurg 141:1049–1055, 2024

The surgical anatomy of the nervus intermedius (NI) is highly variable. The aim of this study was to describe the anatomy of the NI during endoscope-assisted microvascular decompression (MVD) in hemifacial spasm (HFS), and the involvement of the nerve in the vascular conflict.

METHODS The authors reviewed a prospectively maintained database for MVDs performed between 2002 and 2022 and extracted clinical data including patient demographics, symptoms, and offending vessel(s). Operative videos and photographs were analyzed retrospectively in an attempt to identify the NI.

RESULTS Endoscopic identification of the NI was possible in 139 of 435 MVDs. The anatomy is very variable. In 79 (56.8%) patients, a single-bundle pattern was detected, whereas a multiple-bundle pattern was identified in 60 (43.2%) patients. Overall the most common pattern was a single-bundle type A (49.7%). In 20.1%, a multiple-bundles type A was identified. In 4.3%, a single-bundle type B was detected. In 2.9% a single-bundle type C was found, and in just 0.7% a multiple-bundles type C was detected. A multiple-origin pattern (type D) was found in 31 patients (22.3%). The NI was frequently involved in the neurovascular conflict (approximately 85%). The type of NI or vascular compression pattern did not affect the results regarding the outcome or recurrence of HFS.

CONCLUSIONS The anatomy of the NI is for the first time evaluated endoscopically in MVD for HFS. The nerve had various anatomical patterns that were clearly identified. Further studies to evaluate the compression patterns in relation to NI neuralgia are warranted.