Month: March 2026

Posted on

Neuropsychological profile and risk factors for poor cognitive outcomes in survivors of aneurysmal subarachnoid hemorrhage

J Neurosurg 144:517–525, 2026

This clinical study characterizes long-term neuropsychological outcomes in 156 survivors of aneurysmal subarachnoid hemorrhage (aSAH), using MoCA-22, digit span, and verbal fluency tests. Findings show that 34% scored below the 25th percentile despite largely favorable functional recovery, with deficits concentrated in executive function, working memory, and language.

Multivariable analysis identified modified Fisher grade 4 on admission and new radiological infarction during hospitalization as independent predictors of poor cognitive outcomes. Secondary assessments revealed frequent depressive symptoms and acquired personality disturbances, implicating impacts on work productivity and social relationships.

Objective Characterize neuropsychological deficits in aneurysmal subarachnoid hemorrhage (aSAH) survivors and identify clinical variables linked to poor cognitive outcomes.

Design/assessments Retrospective cohort (2009–2024) with cognitive testing ≥6 months post-aSAH using MoCA-22, Digit Span Forward/Backward, and Verbal Fluency; poor outcome defined as MoCA-22 <25th percentile (norm-adjusted).

Prevalence 34% (53/156) had MoCA-22 <25th percentile despite most having good functional recovery at discharge (mRS ≤2 in 79% of those with poor MoCA-22).

Cognitive profile Moderate/severe deficits (z-score >1 SD below norms) occurred in 11% on DST-F, 27% on DST-B, and 9% on VFT, highlighting prominent working-memory/executive-function vulnerability.

Key risk factors Modified Fisher grade 4 on admission and new radiological infarction during hospitalization were independently associated with poor MoCA-22 outcomes (aOR 2.43 and 2.71, respectively).

Quality of life impact Radiological infarction was associated with worse work productivity (OR 0.69) and social relationships (OR 0.72).

Behavioral sequelae Among those assessed, 27% reported at least mild depressive symptoms and 64% showed acquired personality disturbance.

Bottom line Cognitive/behavioral deficits can persist long after aSAH even with favorable mRS; higher hemorrhage burden (modified Fisher 4) and in-hospital infarction signal higher risk.

Posted on

Historical evolution of microvascular decompression after Jannetta’s establishment: Anatomical maps and physiological compasses—a narrative review

Acta Neurochirurgica (2026) 168:74

This narrative review chronicles five decades of refinement in microvascular decompression (MVD) for trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia, tracing developments from Jannetta’s microsurgical breakthrough to contemporary practice. It emphasizes evolving microsurgical anatomy, tailored craniotomies, endoscopic/exoscopic visualization, and nuanced decompression techniques such as noncompressive transposition versus prosthetic interposition.

The article also highlights operative support advances—high-resolution MRI/MRA, virtual simulation, and intraoperative neuromonitoring (BAEP, LSR)—as physiological “compasses” that improve safety and outcome durability. Together, anatomical “maps” and physiological feedback frame current standards and ongoing challenges in achieving long-term, biologically harmonious decompression.

Microvascular Decompression (MVD) Evolution: MVD has developed from Jannetta’s original microsurgical demonstration of vascular compression into a safe, durable, and standardized surgical treatment for neurovascular compression syndromes, especially trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GPN).

Anatomical Foundations: Detailed microsurgical anatomy, including the “Rule of Three” for the cerebellopontine angle (CPA), enables tailored, minimally invasive approaches and underpins the understanding of neurovascular conflicts and surgical route selection.

Tailored Surgical Approaches: Three individualized approaches—lateral supracerebellar-infratentorial for TN, infrafloccular for HFS, and transcondylar fossa for GPN—minimize cerebellar retraction and optimize decompression, improving safety and efficacy.

Decompression Strategies: Techniques have shifted from prosthetic interposition (placing a material between vessel and nerve) to noncompressive transposition (mobilizing and securing the vessel away from the nerve), with evidence supporting better long-term outcomes for transposition.

Visualization and Simulation Advances: The integration of endoscopic/exoscopic systems, neuronavigation, and virtual simulation has enhanced visualization, surgical precision, and education, extending the original ethos of microscopic surgery.

Intraoperative Monitoring: Real-time monitoring using brainstem auditory evoked potentials (BAEPs) and lateral spread response (LSR) on facial EMG helps avoid complications and assess decompression adequacy, significantly reducing postoperative morbidity.

Role of Imaging: High-resolution MRI and MRA now routinely identify neurovascular compression preoperatively, though imaging findings are considered supportive rather than diagnostic due to limited specificity in low-grade conflicts.

Sustained First-Line Role: Despite advances in radiosurgery and pharmacotherapy, MVD remains the first-line surgical option for appropriately selected patients, due to its proven long-term efficacy and safety.

Posted on

Complications associated with anterior cervical spine surgery: A systematic review of literature

Brain and Spine 6 (2026) 105897

This systematic review examines complications following anterior cervical spine surgery, quantifying incidence rates across studies and identifying major risks such as dysphagia, adjacent segment disease, recurrent laryngeal nerve palsy, infection, pseudarthrosis, esophageal perforation, hematoma, and vertebral artery injury. It synthesizes data from 116 studies (1989–2024) and assesses study quality using the Newcastle–Ottawa Scale.

The review highlights key risk factors—multilevel procedures, revision surgery, OPLL, smoking, older age, and surgeon experience—and emphasizes the importance of preoperative planning, patient selection, standardized prospective monitoring, and timely management to minimize morbidity and guide informed consent and long-term surveillance.

Aim Quantify frequency, causes, and outcomes of complications associated with anterior cervical spine surgery.

Methods Systematic review following PRISMA; searched CINAHL Plus, MEDLINE, PubMed, Scopus, and EMBASE for English-language studies (1989–2024) in adults; quality assessed with the Newcastle Ottawa Scale.

Evidence base 326 records screened; 116 studies included; study quality ranged from 3/9 to 9/9 on NOS, with frequent weaknesses in external control selection and cohort comparability.

Most common complication (dysphagia) Reported incidence varied widely (2.3%–87.5%); overall rate across all included dysphagia studies was 13%, with higher pooled incidence in prospective vs retrospective cohorts (53.7% vs 12.7%).

Other key complications (ranges) Adjacent segment disease 0.4%–32%; recurrent laryngeal nerve palsy 0.1%–9%; infection 0.39%–8.5%; pseudarthrosis 0.25%–31%; esophageal perforation 0.1%–0.45%; vertebral artery injury 0.3%–7.7%; Horner’s syndrome 0.06%–0.45%; graft failure 2.7%–35.5%; CSF leak 0%–1%; postoperative hematoma 0.21%–7%; new/worsening neurological deficits 0.37%–3.3.

Risk factors (higher complication rates) Multilevel disease, revision surgery, and ossification of the posterior longitudinal ligament (OPLL) were associated with increased complications.

Volume–outcome effect Greater surgeon experience and higher case volume were consistently associated with lower complication rates.

Prevention emphasis Reducing complications depends on thorough preoperative planning, careful patient selection, and proper surgical technique.

Posted on

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

Acta Neurochirurgica (2026) 168:80

This retrospective cohort study from Tel-Aviv Medical Center evaluates predictors of clinical benefit following shunt placement in idiopathic normal pressure hydrocephalus (iNPH). Among 167 patients undergoing high-volume lumbar puncture, 62 (37%) were LP responders and 38 proceeded to shunting; 21 of 38 (55%) experienced favorable outcomes at one year, with gait disturbance the commonest presenting symptom.

Key associations with LP responsiveness and positive one‑year shunt outcome included lower CSF total tau, lower CSF protein, younger age at symptom onset, pronounced immediate gait improvement after CSF drainage, and the presence of a disproportionately enlarged subarachnoid-space hydrocephalus (DESH) imaging pattern. The authors recommend a multimodal approach combining clinical response, imaging, and fluid biomarkers to refine patient selection for shunting.

Aim Identify clinical, imaging, and CSF biomarkers linked to LP responsiveness and 1-year shunt outcomes in suspected idiopathic normal pressure hydrocephalus (iNPH).

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

LP response rate 62/167 (37%) improved after CSF drainage and were referred; 38/62 (61%) ultimately received a shunt (others mainly declined surgery).

Clinical predictors (LP response) Gait disturbance was the most common initial symptom (68%) and was more frequent in LP responders, while cognitive symptoms were more common as the first symptom among non-responders.

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

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

Shunt effectiveness Among shunted patients, 21/38 (55%) had a favorable clinical outcome at 1 year.

Outcome predictors (post-shunt) Favorable 1-year outcomes were associated with more frequent DESH and a trend toward lower t-tau.

Posted on

Perimesencephalic hemorrhage: a proposed explanation of its cause and clinical manifestations

J Neurosurg 144:740–746, 2026

This neurosurgical forum article analyzes perimesencephalic hemorrhage (PMH), proposing that small dural arterial variants—particularly the artery of Wollschlaeger and Wollschlaeger (AWW) arising from the superior cerebellar artery—can undergo distraction-avulsion and explain PMH’s characteristic cisternal distribution and benign clinical course. The authors present a surgical case with intraoperative identification of an SCA-derived dural branch and perform detailed anatomical correlation.

The paper contrasts venous and arterial hypotheses, reviews perimesencephalic cisternal anatomy and tentorial blood supply, and argues that spontaneous tearing of a tethered intradural dural branch best accounts for imaging, pathophysiology, and low recurrence of PMH, while acknowledging limits of confirmatory testing.

PMH profile Nonaneurysmal perimesencephalic hemorrhage (PMH) is ~10%–15% of spontaneous cisternal SAH, with CT blood confined around the midbrain and typically a benign course with complete recovery and rare recurrence.

Unknown etiology Despite decades of imaging/anatomical work, the cause often remains unidentified on initial and follow-up angiography, leading to the concept of “SAH of unknown cause,” especially when bleeding is perimesencephalic-only.

Index case A 54-year-old woman with SAH had angiography showing a dural arteriovenous fistula (DAVF) fed by the meningohypophyseal trunk and draining via the superior petrosal vein; surgery disconnected the fistula with good outcome.

Unexpected anatomy Intraoperatively, a dural branch from the superior cerebellar artery (SCA) was found bridging the ambient cistern to the undersurface of the tentorium (the artery of Wollschlaeger and Wollschlaeger, AWW) and was sacrificed; it had not been seen on preop angiography and was not the hemorrhage source in that case.

Key anatomical concept The perimesencephalic cistern system (interpeduncular, ambient, quadrigeminal) surrounds the midbrain at the tentorial incisura; vessels can traverse cisternal spaces and arachnoid septations, influencing where blood can collect.

Tentorial dural supply variants The medial tentorium can be supplied by the marginal tentorial artery from the meningohypophyseal trunk, plus intradural-origin dural branches from the PCA (artery of Davidoff and Schechter, ADS) and from the SCA (AWW) that course within the ambient cistern before entering tentorium.

Competing sources considered Two structures fit many PMH constraints: the basal vein of Rosenthal (BVR) (venous, tethered to vein of Galen) and the ADS/AWW (arterial dural branches tethered to the medial tentorial edge).

Proposed mechanism for PMH Spontaneous distraction-avulsion of the AWW from its fragile tentorial attachment during everyday Valsalva/exertion could cause focal cisternal bleeding that self-limits as pressure equalizes in the confined cistern; this is proposed to explain PMH distribution, negative angiography, generally mild course, low hydrocephalus/vasospasm, and rare rebleed.

Posted on

The Helsinki Unruptured Intracranial Aneurysm Quality of Care study: a prospective observational study

J Neurosurg 144:507–516, 2026

This prospective single-center study evaluates the safety of unruptured intracranial aneurysm (UIA) treatments by prospectively measuring postprocedural diffusion-weighted MRI (DWI) lesions and correlating them with clinical outcomes at 3 months. Among 169 consecutive patients, 63% developed new DWI lesions, with endovascular cases showing more multiple lesions and surgical cases showing larger lesions.

Despite excellent functional outcomes by modified Rankin Scale (98% mRS 0–1) and high return-to-work rates, DWI lesions were associated with increased neurological symptoms, longer hospital stays, and worse outcomes when ≥10 mm. The authors argue that routine DWI should complement mRS to better capture ischemic burden and guide quality assessment and follow-up.

Objective Evaluate safety of unruptured intracranial aneurysm (UIA) treatment by measuring postprocedural ischemic lesions on MRI diffusion-weighted imaging (DWI) and correlating them with clinical outcomes.

Design Prospective, investigator-initiated, single-center observational cohort of consecutive UIA patients treated at Helsinki University Hospital (Dec 2022–Aug 2024) with brain MRI within 3 days and 3-month follow-up (mRS, neurological symptoms, return to work).

Cohort 169 patients: 120 (71%) endovascular and 49 (29%) surgical; aneurysm location distribution differed (most surgical cases were MCA aneurysms).

DWI incidence New DWI lesions occurred in 63% overall, with no difference between endovascular and surgical treatment (63% vs 63%).

Lesion patterns by modality Endovascular treatment more often produced high lesion counts (≥6 lesions: 14% vs 0%), while surgery more often produced larger lesions (≥10 mm: 20% vs 8%).

Symptoms association Most DWI lesions were asymptomatic (85%), but having any DWI lesion increased risk of new neurological symptoms (15% vs 2%), with 59% of symptoms transient.

mRS association Any DWI lesion was not associated with mRS outcomes, but lesions ≥10 mm were linked to poorer mRS status (mRS 0–1: 84% vs 99%) and higher risk of mRS worsening (21% vs 1%).

Return to work & conclusion 97% of previously working patients returned to work within 3 months; DWI lesions are common despite excellent mRS outcomes, and DWI may add information that mRS alone misses when assessing quality of care.

Posted on

Machine learning models for predicting patient satisfaction after adult spinal deformity surgery

J Neurosurg Spine 44:457–468, 2026

This clinical study develops and internally validates machine learning–guided logistic regression models to predict patient satisfaction 24 months after adult spinal deformity (ASD) surgery, using 213 patients and three feature-selection methods. Nine routinely measurable predictors—including postoperative WOMAC function, frailty, pelvic compensation, imaging MCID achievement, rFCSA, and SVA—were identified and ranked by SHAP for their influence on satisfaction.

The model showed strong discrimination (AUROC 0.846) and calibration, yielded a nomogram for individualized prognostication, and emphasizes modifiable targets for perioperative care and rehabilitation. Limitations include single-center retrospective design, modest sample size, and inclusion of postoperative variables limiting preoperative decision use.

Goal Develop and internally validate models to predict patient satisfaction 24 months after adult spinal deformity (ASD) surgery, using SRS-22r satisfaction (high satisfaction defined as score ≥ 4.5).

Cohort 213 ASD patients met criteria; 128 (60%) used for training and 85 (40%) for internal test validation.

Pipeline Used three ML feature-selection methods—LASSO, recursive feature elimination (RFE), and Boruta—and retained variables consistently selected by all three.

Final predictors Nine key indicators were retained: rFCSA, fatty infiltration, frailty, pelvic compensation, postoperative SVA, imaging MCID achievement, postoperative subtotal score, postoperative WOMAC function, and change in WOMAC function.

Model Built an interpretable logistic regression model from these predictors; binary cutoff optimized via ROC/Youden index, with SHAP used to rank feature importance.

Performance In the test set, the model achieved AUROC 0.846 and accuracy 0.812 (also reported AUPRC 0.894 and Brier score 0.153).

Top drivers (SHAP order) Higher postoperative WOMAC function, absence of frailty, imaging MCID achieved, larger WOMAC function improvement, higher rFCSA, higher postoperative subtotal, lower postoperative SVA, successful pelvic compensation, and lower fatty infiltration increased satisfaction likelihood.

Implication/limitation Intended mainly to identify modifiable factors to guide postoperative rehabilitation; practical preoperative counseling is limited because key inputs include postoperative variables, and external multicenter validation is still needed.

Posted on

Three-dimensional microsurgical anatomy of the basal aspect of the cerebrum: a fiber dissection study

J Neurosurg 144:690–702, 2026

This study presents a three-dimensional microsurgical fiber-dissection analysis of the basal aspect of the human cerebrum, detailing the spatial organization of commissural, projection, and association fibers and their relationships with subcortical nuclei, ventricles, and cortical landmarks. Using 10 formalin-fixed brains with layer-by-layer dissection and stereoscopic photography, the authors map tracts such as the ILF, UF, SS, cingulum, fornix, and connections around the amygdala and nucleus accumbens.

The findings emphasize surgical implications by clarifying trajectories and landmarks relevant to approaches like STIO and SCTT, illustrating a clinical case of hippocampal glioma resection with optic-radiation preservation, and proposing that 3D anatomical insight enhances safe, precise planning for medial temporal and basal lesions.

Objective Limited surgical exposure of the cerebral base makes basal fiber-tract injury a key risk; detailed 3D tract anatomy is needed to plan safer resections and support brain-function research.

Aim Mapped the topography of basal white-matter tracts and subcortical gray matter (including hippocampus, amygdala, and nucleus accumbens) and their relationships to cortex, ventricles, and nuclei.

Methods Performed Klingler-style layer-by-layer fiber dissection on 10 formalin-fixed human brains under ×6–×40 magnification, documenting each stage with stereoscopic 3D photography.

Key anatomy (basal tracts) Sequential basal dissection exposed U fibers, inferior cingulum (lower part), Li-Am fasciculus, SRF, and ILF; removing Li-Am/ILF revealed the temporal horn with the hippocampus medially.

Sagittal stratum layering The lateral wall of the atrium is layered (medial→lateral): ependyma, tapetum, IC-SL, optic radiations, posterior AC extension, IFOF, MdLF, posterior SLF/AF, U fibers, cortex—together forming the sagittal stratum.

ILF clarification The ILF was identified as a long association tract connecting the base of the temporal pole to the occipital base, located above the fusiform gyrus and beneath the sagittal stratum; “merging fibers” in lateral occipital base were distinguished from the temporal portion of the AF.

Amygdala connectivity The amygdala links to septal nuclei/hypothalamus/thalamus via the stria terminalis, projects to cortical regions via the uncinate fasciculus, and connects via additional pathways including amygdalofugal routes and the anterior commissure.

Surgical application (STIO case) A right hippocampal WHO grade 2 glioma was resected via a supratentorial-infraoccipital (STIO) approach; the fusiform gyrus was incised anterior to the basal turning point of the optic radiation to reach the lateral ventricle, and postoperative DTI confirmed optic-radiation preservation.

Posted on

Suprasellar Versus Third Ventricular Cysts: Anatomic and Surgical Considerations

Operative Neurosurgery 30:468–471, 2026

This surgical case instruction contrasts suprasellar arachnoid cysts (SACs) and third ventricular cysts (3VCs), emphasizing their distinct imaging features, clinical presentations, and risks of obstructive hydrocephalus. It summarizes patient examples, MRI findings, and outcomes after endoscopic cyst fenestration, demonstrating restoration of cerebrospinal fluid flow and symptom resolution.

The article details stepwise endoscopic techniques—cyst plane development, wall reduction, excision, and membrane management—highlighting anatomical cues that guide whether endoscopic third ventriculostomy is necessary. Practical tips on preserving hypothalamic structures, restoring aqueduct patency, and minimizing reaccumulation are provided for neurosurgical practice.

Prevalence Intracranial arachnoid cysts occur in ~2.6% of children and ~1.4% of adults; suprasellar arachnoid cysts (SACs) comprise ~9%–21% of pediatric arachnoid cysts and can be confused with rarer third ventricular cysts (3VCs).

Presentation SACs and 3VCs often enlarge and cause obstructive hydrocephalus with symptoms of increased intracranial pressure, prompting urgent treatment to restore CSF circulation.

Imaging differences (SAC) SACs elevate the third ventricular floor, displace mammillary bodies superiorly/posteriorly, and elongate/stretch the midbrain and aqueduct, with aqueduct occlusion from distortion and the posterior cyst wall.

Imaging differences (3VC) 3VCs displace the third ventricular floor and mammillary bodies inferiorly with midbrain compaction; the aqueduct is obstructed by midbrain distortion and the inferoposterior cyst wall.

Treatment rationale A shunt without cyst fenestration can lead to asymmetric hydrocephalus and/or continued cyst enlargement due to cyst-related occlusion of the foramina of Monro; neuroendoscopy enables cyst fenestration with low morbidity risk at experienced centers.

Endoscopic steps A stepwise intraventricular endoscopic approach includes: developing the cyst/ventricle plane; reducing cyst wall size (coagulation); excising roof/lateral/medial walls (with caution laterally in SACs due to hypothalamic fusion); removing/reducing floating membranes (especially posteriorly) to open access to the aqueduct.

Inferior wall strategy In SACs, inferior membrane fenestration may be unnecessary because the prepontine cistern is already exposed/communicates with the third ventricle; in 3VCs, the inferior aspect is the third ventricular floor, and endoscopic third ventriculostomy (ETV) is an option.

ETV decision point If posterior membrane resection fully restores aqueduct patency, ETV may not be necessary; reducing expansile membranes is pursued to lower risk of reaccumulation from scarring.

Posted on

Utilization of robotic pars repair for early return to activity in adolescents with symptomatic spondylolysis

J Neurosurg Spine 44:349–354, 2026

This case series from a tertiary academic spine center reports outcomes of robot-assisted percutaneous pars repair in nine adolescents with symptomatic lumbar spondylolysis who failed conservative management. The authors describe a single–midline incision technique using CT-based robotic guidance and a single lagged transdefect screw, detailing operative workflow, implant sizes, and a standardized postoperative rehabilitation protocol.

Results show most patients returned to preinjury or higher activity within months, with low complication rates and radiographic evidence of union in those who obtained CT follow-up. The authors conclude that minimally invasive robotic pars repair is a viable option after failed nonoperative care and advocate timely surgical consultation to potentially accelerate return to sport and avoid progressive spondylolisthesis.

Clinical problem Symptomatic lumbar pars interarticularis fractures (spondylolysis) are a common cause of adolescent low-back pain; nonoperative care with activity modification is standard first-line treatment.

Nonunion risk Despite conservative management, about 20% of patients may progress to symptomatic nonunion, and some can later develop spondylolisthesis that may require fusion.

Study aim Robotic surgical guidance was used to enable percutaneous pars screw placement; the series reports the largest cohort of adolescents treated with robot-assisted pars repair to date.

Design & cohort Retrospective review of a prospectively collected database identified 9 adolescents/young adults (13–25 years) treated with a single-screw pars repair technique.

Technique Using Excelsius robotic planning/registration and intraoperative 3D imaging, bilateral screw trajectories were planned to converge so bilateral pars screws could be placed through a single 1–2 cm midline incision; compression was achieved via a “lag-by-technique” preparation without direct pars visualization/grafting.

Postop protocol Patients walked only for 2 weeks, then added stationary biking for 2 weeks, followed by 4 weeks of sport-directed physical therapy; if tolerated symptom-free, they were cleared for activity (cleared to begin return-to-sport training at 4 weeks).

Outcomes Mean preop activity cessation at consultation was 8.6 ± 10.6 months; at mean follow-up 11.4 ± 9.1 months, 78% had returned to baseline activity or were cleared to return to sport.

Safety/efficacy conclusion Robot-assisted pars repair was reported as a safe, effective option after failed nonoperative care, enabling return to activity in as little as 8 weeks; a single lag-style screw may be clinically effective compared with prior open debridement/bone-grafting approaches.

Posted on

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.

Posted on

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.

Posted on

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.

Posted on

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

Posted on

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.

Posted on

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.

Posted on

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.

 

Posted on

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.

Posted on

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.

Posted on

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.

Proudly powered by WordPress