Category: Awake craniotomy

Posted on

Resectability of White Matter Tracts in Patients With Language-Critical Gliomas

Neurosurgery 99:140–148, 2026

This study evaluates how resections of language-associated white matter tracts (WMTs) predict persistent postoperative language deficits (PLDs) in 68 glioma patients using tractography, intraoperative mapping, and outcome assessments. Results show WMT resection strongly predicts PLDs with high negative predictive value but modest positive predictive value, and temporal/parietal segments carry the greatest risk.

Anatomic clustering localized high-risk resections to the temporoparietal junction and middle temporal lobe, while frontal operculum and orbitofrontal tracts were often resectable without lasting deficits. Anatomically stratifying tracts (parietal/temporal) improved positive predictive value, supporting tractography-informed surgical planning alongside intraoperative mapping.

Goal Identify predictors of permanent postoperative language deficits (PLDs) in language-eloquent glioma surgery by analyzing which language-associated white matter tract (WMT) segments are resected.

Cohort & approach Retrospective analysis of consecutive adults undergoing awake craniotomy with intraoperative language mapping; WMT tractography reconstructed 6 language-related tracts and parcellated by anatomic location; outcomes based on formal language testing pre-op vs 1–3 months post-op (with clinical follow-up to 6 months for persistence).

Overall predictive signal Any WMT resection strongly increased odds of PLDs (odds ratio 16.0, P = .0115) with high NPV 97.4% but low PPV 29.6%.

Anatomic vulnerability Resections associated with PLDs clustered in the temporoparietal junction (TPJ) and middle temporal lobe (MTL), while resections without PLDs were more diffuse and concentrated in frontal/anterior regions.

Resectability by region Frontal tract segments showed near-complete resectability (PPV = 0 across reported frontal segments), whereas parietal/temporal segments had higher PPVs (eg, parietal AF 0.4, temporal AF 1, temporal IFOF 0.5, temporal ILF 0.5).

Stratified model Focusing only on parietal and temporal tract segment resections improved prediction of PLDs (odds ratio 29.4, P < .001) and increased PPV to 50% (NPV 96.7%).

Resection volume The volume of tract resected did not differ by functional outcome (U = 84.0, P = .70), suggesting location/segment matters more than amount.

Clinical implication WMT resections in orbitofrontal, anterior temporal, and frontal operculum regions were often tolerated, while parietal/temporal WMT injuries substantially increased PLD risk.

Posted on

Speech mapping in awake high-grade glioma resection: subcortical tract proximity as a predictor of language outcomes

J Neurosurg 145:179–189, 2026

This clinical study evaluates intraoperative predictors of postoperative language decline in awake resections of language-eloquent high-grade gliomas using diffusion tractography, 5-ALA, and subcortical stimulation with standardized language testing. It reports rates of transient and permanent deficits, correlates specific white matter tracts (IFOF, ILF, AF/SLF) with domain-specific impairments, and presents stimulation thresholds predictive of decline.

The paper emphasizes that preoperative deficits and positive stimulation of multiple tracts increase risk of lasting language impairment, while most single-tract-related declines tend to recover by three months; proposed SCS amplitude cutoffs are offered as practical guidance to balance maximal resection and language preservation.

Objective Identify intraoperative predictors of postoperative language decline and predictors of temporal language recovery after awake resection of language-eloquent high-grade glioma (HGG).

Methods Single-center cohort (Jan 2017–Nov 2024) undergoing awake craniotomy with diffusion tractography, 5-ALA, subcortical stimulation (SCS), and intraoperative language testing; language outcomes assessed at 48 hours, 2 weeks, and 3 months.

Outcomes New or worsened postoperative language deficit occurred in 53.1% (69/130) and was permanent (>3 months) in 9.2% (12/130).

Key intraoperative predictor (domain-specific) Clinical deterioration during awake testing predicted short-term decline in semantic processing (IFOF) (RR 3.47), reading (ILF) (RR 21.4), and auditory naming/repetition (AF/SLF) (RR 6.98).

Permanent-deficit risk factors Higher risk of persistent language decline was associated with preoperative speech deficit (RR 2.65), intraoperative ILF-related reading deterioration (RR 8.92), and positive SCS of multiple language tracts.

Tract sensitivity & recovery Posterior ILF–related reading function showed the greatest sensitivity to decline and the lowest propensity for recovery; all observed reading deficits were linked to tumors near the posterior ILF.

SCS threshold cutoffs ROC/Youden-derived SCS amplitudes predictive of postoperative deficits were reported per tract: IFOF 5.5 mA (48h/2w), 4.5 mA (3m); ILF (reading) 7.0 mA (48h/2w), 4.5 mA (3m); AF/SLF 5.5 mA (48h/2w), 2.5 mA (3m).

Multiple-tract involvement At 3 months, deficits occurred in 7.4% (5/68) with single-tract positive SCS versus 75.0% (9/12) with two tracts; both patients with all three tracts stimulated had persistent deficits beyond 3 months.

Posted on

Awake Versus Asleep Craniotomy for Glioma: A Comparison of Survival and Costs Using Time-Driven Activity-Based Costing

Operative Neurosurgery 30:653–667, 2026

Awake versus asleep (general anesthesia) craniotomy are two approaches for glioma resection, and this work compares their intraoperative costs and survival outcomes.

Key Insights and Themes

Clinical question centers on whether awake craniotomy (AC) differs from asleep craniotomy under general anesthesia (GA) in intraoperative cost and in survival for glioma patients.

Cohort identification included all glioma resections at one institution from 2017–2022: 298 GA cases and 67 AC cases.

Awake-craniotomy indication primarily involved tumors in eloquent brain regions to allow intraoperative monitoring of neural function, while noneloquent tumors typically started under GA.

Costing method (TDABC) used process maps plus automated time-stamped extraction from the electronic medical record to capture intraoperative resources and time.

Cost components were dominated by supplies and personnel, with other elements (turnover and overhead) described as relatively minor contributors.

Baseline overall intraoperative cost had a median total of $6600 (IQR $2875), largely driven by supply cost (median $3178) and personnel cost (median $3141).

Operating-room time was longer for AC (median 5.2 hours) than GA (median 4.5 hours), and AC had about 30 additional minutes of incision-to-closure time.

Patient/tumor comparability showed GA patients were older, but there were no differences in WHO grade distribution or extent of resection between groups.

Unadjusted total cost difference showed higher median intraoperative cost for AC ($8506) versus GA ($6033).

Unadjusted subcomponent differences showed AC had higher median supply cost ($4238 vs $2928) and higher median personnel cost ($4111 vs $2962) than GA.

Adjusted total cost effect found AC associated with $2175 additional intraoperative cost versus GA after accounting for confounders.

Adjusted cost drivers attributed the added AC cost to higher supply cost (+$1272) and higher personnel cost (+$970).

Supply subcomponents were higher for AC than GA across consumables, implants, sterilization, and medications in unadjusted comparisons.

Personnel mix differed in that neurology attendings/fellows were included in AC but not GA at this institution, contributing to personnel-cost differences.

Unadjusted survival showed higher overall survival for AC on Kaplan–Meier analysis (log-rank P = .011), while progression-free survival did not significantly differ (log-rank P = .106).

Adjusted survival showed no significant differences between AC and GA in overall survival (HR 0.84, P = .48) or progression-free survival (HR 0.9, P = .66) after multivariable adjustment.

Key limitation (missing GA neuromonitoring costs) is that electrophysiological neuromonitoring personnel costs for GA were not captured due to EMR documentation limits.

Scope limitation (episode-of-care costs) is that the analysis focuses on intraoperative costs, and commenters note postoperative/inpatient costs could change conclusions about overall expense.

Conclusion

Awake craniotomy for glioma resection had higher intraoperative costs than asleep craniotomy, but after adjustment it showed no significant survival advantage in overall or progression-free survival.

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.

Posted on

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

Neurosurgery 98:365–375, 2026

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

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

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

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

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

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

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

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

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

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

Posted on

Functional status in long-term survivors after mapping-guided surgery for diffuse low-grade glioma

J Neurosurg 144:139–150, 2026

This clinical study reports long-term functional outcomes in 103 consecutive patients with diffuse low-grade glioma who underwent mapping-guided resections and were followed for at least 15 years. Key findings include high overall survival (83.5%), mean postoperative KPS of 94.8, and 90% return-to-work rate, with low permanent neurological morbidity across 205 resections.

Comparative analysis shows patients who sustained employment had smaller pre/postoperative tumor volumes, greater extent of resection (including more supratotal resections), and less exposure to radiotherapy. The data support early maximal safe resection and postponement of radiotherapy to preserve long-term functional status and professional activity.

Functional Preservation: Long-term survivors of diffuse low-grade glioma (LGG) surgery had high rates of preserved functional status, with 90.7% of surviving patients maintaining a Karnofsky Performance Scale (KPS) score ≥ 80 after an average of 18.2 years follow-up.

Return to Work: 90% of patients were able to return to work after mapping-guided resection, and maintaining professional activity was strongly associated with higher preoperative KPS and greater extent of resection (EOR).

Extent of Resection (EOR): Greater EOR, particularly supratotal or total resections, correlated with better long-term functional outcomes and higher rates of continued employment.

Radiation Therapy Impact: Early or any radiotherapy (RT) was linked to lower rates of return to work and a reduced proportion of patients with KPS ≥ 80 at last follow-up, while chemotherapy did not show this negative association.

Timing of Surgery: Early surgery at diagnosis, especially in patients with higher KPS and smaller tumor volume, increased the chance for maximal resection and long-term preservation of functional status.

Low Neurological Morbidity: Permanent postoperative neurological deficits were rare (1.5% after 205 resections), supporting the safety of maximal resection with intraoperative mapping.

Malignant Transformation: The risk of malignant transformation was lower in patients with greater EOR and those who continued to work, suggesting oncological benefit from radical resection.

Adjuvant Therapy Strategy: A wait-and-watch strategy after maximal safe resection, postponing adjuvant treatments unless necessary, helped preserve long-term quality of life and autonomy.

Posted on

Awake surgery for IDH-mutant grade 2 glioma involving the corpus callosum: long-term onco-functional results after callosectomy in 157 consecutive patients

J Neurosurg 143:1280–1289, 2025

This clinical study reports outcomes from 157 consecutive patients with IDH‑mutant grade 2 gliomas infiltrating the corpus callosum who underwent connectome-guided awake surgery with callosectomy. It summarizes surgical technique, extent of resection, complication rates, return-to-work statistics, histology, adjuvant treatments, reoperations, and long-term overall survival.

Comparative analysis contrasts complete (total/supratotal) versus incomplete resections, showing higher extent of resection, greater reoperation potential, and longer median overall survival when callosal tumor was fully removed, while preserved function and a 96.8% return-to-work rate underline favorable onco-functional balance.

Posted on

Resectability of White Matter Tracts in Patients With Language-Critical Gliomas

Neurosurgery 00:1–9, 2025 (Published Online, October 15, 2025)

Resection of white matter tracts (WMTs) in language-critical glioma surgery robustly predicts permanent postoperative language deficits, particularly when parietal and temporal segments are involved. Frontal lobe WMTs are often safely resectable. Anatomical stratification enhances prediction, supporting data-driven, segment-specific surgical planning.

Resecting language-associated white matter tracts (WMTs) in glioma surgery robustly predicts permanent postoperative language deficits (PLDs).

• Frontal lobe WMT segments (e.g., arcuate fasciculus, IFOF, UF, SLF, FAT) are often resectable without causing PLDs.

• Resections in the temporoparietal junction (TPJ) and middle temporal lobe (MTL) significantly increase the risk of PLDs.

• Anatomically stratifying resections to parietal and temporal tracts improves prediction accuracy for PLDs (PPV increases to 50%).

• Volume of tract resected does not correlate with risk of PLDs; specific tract location is more important.

• Broca area and underlying white matter can often be resected safely, challenging traditional localizationist models.

• Combining imaging data with intraoperative mapping remains essential due to some nonfunctional tract segments leading to low PPV.

• Study limitations include small sample size, operator variability in tractography, and need for multicenter validation.

Posted on

Awake surgery with direct electrical stimulation mapping and real‑time cognitive monitoring for functionally guided tumor resection

Acta Neurochirurgica (2025) 167:239

Awake surgery with direct electrical stimulation and real-time cognitive monitoring enables maximal safe brain tumor resection by mapping individual functional networks, preserving quality of life and cognitive abilities. This multidisciplinary, patient-centered approach is gold standard for low-grade gliomas and is increasingly applied to other brain tumors.

• Awake surgery with direct electrical stimulation (DES) mapping is the gold standard for low-grade glioma resection and can also be applied to other brain tumors.

• This approach uses real-time cognitive monitoring to guide tumor removal based on the patient’s individual brain connectome, preserving neurocognitive functions and quality of life.

• A multidisciplinary team—including neurosurgeons, anesthesiologists, and neuropsychologists or speech therapists—is essential for patient selection, preparation, and intraoperative mapping.

• The asleep–awake–asleep protocol with continuous cognitive testing and tailored tasks optimizes functional mapping and minimizes permanent deficits.

• Subpial dissection and limited coagulation reduce vascular injury and promote better cognitive outcomes.

• Early postoperative rehabilitation is crucial for neuroplasticity and functional recovery.

• Careful patient selection and preparation are vital; conditions impairing intraoperative testing are relative contraindications.

• This personalized surgical philosophy has led to high cognitive preservation, low permanent deficit rates, and high return-to-work rates.

Posted on

Feasibility, Safety, and Impact of Awake Resection for Recurrent Insular Diffuse Gliomas in Adults

Neurosurgery 97:399–409, 2025

Function-based transopercular awake resection for recurrent insular diffuse gliomas in adults is feasible and safe, with similar resection rates, complications, and outcomes as first-time surgery, though prior combined treatments may increase intraoperative cooperation difficulties and sick leave, especially in high-grade gliomas.

• Transopercular awake resection for recurrent insular diffuse gliomas is feasible and safe, showing similar resection rates and outcomes to first-time surgery.

• No significant increase in intraoperative adverse events or surgery-related complications was observed for recurrent cases compared to first-line surgeries.

• Patients with previous combined oncological treatments had a higher risk of insufficient intraoperative cooperation, but this did not lead to mapping failure.

• Extent of resection and 6-month postoperative outcomes (Karnofsky Performance Status, seizure control, sick leave) were similar between recurrent and first-line groups.

• Longer sick leave was associated with high-grade gliomas and adjuvant treatments, not with surgery type.

• Shorter awake phase duration was observed in recurrent cases, likely due to easier access from prior surgeries and smaller tumor volumes.

• Study supports careful preoperative counseling and patient selection, especially for those with previous combined treatments.

• Results are specific to adult insular glioma patients treated with transopercular awake surgery and may not generalize to other populations or techniques.

 

Posted on

Electrocorticography and navigated transcranial magnetic stimulation–tailored supratotal resection for epileptogenic low-grade gliomas

J Neurosurg 142:918–926, 2025

The study evaluates ECoG-nTMS–tailored supratotal resection (ETT-SpTR) for low-grade gliomas with epilepsy, demonstrating improved seizure control and preserved neurological function compared to gross-total resection. ETT-SpTR effectively identifies high-risk epilepsy areas, enhancing epileptic and functional outcomes without permanent deficits.

• Objective: Evaluate the effectiveness of ECoG-nTMS–tailored supratotal resection (ETT-SpTR) for low-grade gliomas (LGGs) in controlling seizures and preserving neurological function.

• Methods: Retrospective analysis of patients with LGG and epileptic seizures undergoing resective surgery, comparing gross-total resection (GTR) with ETT-SpTR.

• Results: ETT-SpTR significantly improved seizure control (85.7% Engel class IA) compared to GTR (25% Engel class IA) with no permanent neurological deficits.

• Conclusion: ETT-SpTR is effective in improving epileptic outcomes and preserving functions without causing permanent neurological worsening.

• Preoperative Techniques: Functional cortical areas were identified using TMS, and ECoG guided the removal of high-risk epilepsy areas (HREAs).

• Statistical Analysis: Significant differences in seizure control between groups, with ETT-SpTR showing better outcomes.

• Limitations: Small patient cohort and limited follow-up period; future studies required for confirmation.

Posted on

Awake surgery with mapping-based resection to treat focal epilepsy in eloquent brain areas

Acta Neurochirurgica (2024) 166:430

Resective surgery is a potential therapeutic option for select patients with intractable focal epilepsy. However, the presence of ictal onset zones within or surrounding highly functional brain areas presents a surgical challenge, leading to poor seizure and functional outcomes. This report describes our experiences with awake mapping-tailored resection of epileptogenic areas involving eloquent cortices and evaluates their feasibility, tolerance, limitations, and significance.

Methods The study included patients who underwent surgery for drug-resistant focal epilepsy at our center under awake conditions. The surgical approach aimed to achieve maximum resection of preoperatively defined epileptogenic zones, considering the boundaries defined by surrounding functional areas. We collected data on preoperative evaluations, intraoperative tests and seizures, postoperative status epilepticus, and neurological functional outcomes.

Results We included 22 patients, 10 of whom had non-lesional epilepsy. Language, motor function, and sensory function were at risk in 19, 9, and 4 patients, respectively. Resection was performed as planned in 14 (63.6%) patients, while modifications were necessary in 8 (36.4%) patients due to functional constraints. The mean follow-up duration was 29.8 months. Sixteen (72.7%) patients achieved Engel class Ia outcomes, indicating seizure freedom, while none of the patients experienced clinically significant permanent postoperative neurological deficits.

Significance Resective surgery with intraoperative brain mapping under awake conditions was a valid treatment option for achieving a cure in cases of drug-resistant focal epilepsy, even in situations in which the condition is considered inoperable due to the risk of significant postoperative neurological deficits.

Posted on

Asleep triple-modality motor mapping for perirolandic gliomas: an update on outcomes

J Neurosurg 140:1029–1037, 2024

Maximal safe resection of gliomas near motor pathways is facilitated by intraoperative mapping. Here, the authors review their results with triple-modality asleep motor mapping with motor evoked potentials and bipolar and monopolar stimulation for cortical and subcortical mapping during glioma surgery in an expanded cohort.

METHODS This was a retrospective analysis of patients who underwent resection of a perirolandic glioma near motor pathways. Clinical and neuromonitoring data were extracted from the electronic medical records for review. All patients with new or worsened postoperative motor deficits were followed for at least 6 months. Regression analyses were performed to assess factors associated with a persistent motor deficit.

RESULTS Between January 2018 and December 2021, 160 operations were performed in 151 patients with perirolandic glioma. Sixty-four patients (40%) had preoperative motor deficits, and the median extent of resection was 98%. Overall, patients in 38 cases (23.8%) had new or worse immediate postoperative deficits by discharge, and persistent deficits by 6 months were seen in 6 cases (3.8%), all in patients with high-grade gliomas. There were no new persistent deficits in low-grade glioma patients (0%). The risk factors for a persistent deficit included an insular tumor component (OR 8.6, p = 0.01), preoperative motor weakness (OR 8.1, p = 0.03), intraoperative motor evoked potential (MEP) changes (OR 36.5, p < 0.0001), and peri–resection cavity ischemia (OR 7.5, p = 0.04). Most persistent deficits were attributable to ischemic injury despite structural preservation of the descending motor tracts. For patients with persistent motor deficits, there were 3 cases (50%) in which a change in MEP was noted but subsequent subcortical monopolar stimulation still elicited a response in the corresponding muscle groups, suggesting axonal activation distal to a point of injury.

CONCLUSIONS Asleep triple motor mapping results in a low rate of permanent deficits, especially for low-grade gliomas. Peri–resection cavity ischemia continues to be a significant risk factor for permanent deficit despite maintaining appropriate distance for subcortical tracts based on monopolar feedback.

Posted on

Awake Versus Asleep Craniotomy for Patients With Eloquent Glioma: A Systematic Review and Meta-Analysis

Neurosurgery 94:38–52, 2024

Awake vs asleep craniotomy for patients with eloquent glioma is debatable. This systematic review and meta-analysis sought to compare awake vs asleep craniotomy for the resection of gliomas in the eloquent regions. METHODS: MEDLINE and PubMed were searched from inception to December 13, 2022. Primary outcomes were the extent of resection (EOR), overall survival (month), progression-free survival (month), and rates of neurological deficit, Karnofsky performance score, and seizure freedom at the 3-month follow-up. Secondary outcomes were duration of operation (minute) and length of hospital stay (LOS) (day).

RESULTS: Fifteen studies yielded 2032 patients, from which 800 (39.4%) and 1232 (60.6%) underwent awake and asleep craniotomy, respectively. The meta-analysis concluded that the awake group had greater EOR (mean difference [MD]= MD= 8.52 [4.28, 12.76], P < .00001), overall survival (MD = 2.86 months [1.35, 4.37], P = .0002), progression-free survival (MD = 5.69 months [0.75, 10.64], P = .02), 3-month postoperative Karnofsky performance score (MD = 13.59 [11.08, 16.09], P < .00001), and 3-month postoperative seizure freedom (odds ratio = 8.72 [3.39, 22.39], P < .00001). Furthermore, the awake group had lower 3-month postoperative neurological deficit (odds ratio = 0.47 [0.28, 0.78], P = .004) and shorter LOS (MD = -2.99 days [-5.09, -0.88], P = .005). In addition, the duration of operation was similar between the groups (MD = 37.88 minutes [-34.09, 109.86], P = .30).

CONCLUSION: Awake craniotomy for gliomas in the eloquent regions benefits EOR, survival, postoperative neurofunctional outcomes, and LOS. When feasible, the authors recommend awake craniotomy for surgical resection of gliomas in the eloquent regions.

Posted on

Surgical, functional, and oncological considerations regarding awake resection for giant diffuse lower-grade glioma of more than 100 cm3

J Neurosurg 139:934–943, 2023

Surgery for giant diffuse lower-grade gliomas (LGGs) is challenging, and very few data have been reported on this topic in the literature. In this article, the authors investigated surgical, functional, and oncological aspects in patients who underwent awake resection for large LGGs with a volume > 100 cm3.

METHODS The authors retrospectively reviewed a consecutive cohort of patients who underwent surgery in an awake condition for an LGG (WHO grade 2 with possible foci of grade 3 transformation) with a volume > 100 cm3.

RESULTS A total of 108 patients were included, with a mean age of 36.1 ± 8.5 years. The mean presurgical LGG volume was 136.7 ± 34.5 cm3. In all but 2 patients a disconnection resective surgery up to functional boundaries was possible thanks to active patient collaboration during the awake period. At 3 months of follow-up, all but 1 patient had a normal neurological examination, with a mean Karnofsky Performance Status (KPS) score of 89.8 ± 10.36. In all patients with preoperative epilepsy, there was postoperative control or significant reduction of seizure events. Moreover, 85.1% of patients returned to work. The mean extent of resection (EOR) was 88.9% ± 7.0%, with a mean residual tumor volume (RTV) of 16.3 ± 12.0 cm3 (median RTV 15 cm3). Pathological examination revealed 73 grade 2 gliomas (67.6%; 26 oligodendrogliomas and 47 astrocytomas) and 35 gliomas with foci of grade 3 (32.4%; 19 oligodendrogliomas and 16 astrocytomas). During the postoperative period, 93.6% of patients underwent adjuvant chemotherapy with a median interval between surgery and first chemotherapy of 14 months (IQR 2–26 months), and 55% of patients had radiotherapy with a median interval of 38.5 months (IQR 18–59.8 months). At the last follow-up, 69.7% of patients were still alive with a median follow-up of 62 months (IQR 36–99 months). Overall survival (OS) rates at 1, 5, and 10 years were 100% (95% CI 0.99–1), 80% (95% CI 0.72–0.9), and 58% (95% CI 0.45–0.73), respectively. The median OS was 138 months. In multivariable Cox regression analysis, RTV was established as the only independent prognostic factor for survival.

CONCLUSIONS With the application of rigorous surgical methodology based on functional-guided resection, resection of giant LGGs (volume > 100 cm3) can be reproducibly achieved during surgery with patients under awake mapping with both favorable functional results (< 1% permanent neurological worsening) and favorable long-term oncological outcomes (median OS > 11 years, with a more significant benefit when the RTV is < 15 cm3).

Posted on

Precuneal gliomas promote behaviorally relevant remodeling of the functional connectome

J Neurosurg 138:1531–1541, 2023

The precuneus hosts one of the most complex patterns of functional connectivity in the human brain. However, due to the extreme rarity of neurological lesions specifically targeting this structure, it remains unknown how focal damage to the precuneus may impact resting-state functional connectivity (rsFC) at the brainwide level. The aim of this study was to investigate glioma-induced rsFC modulations and to identify patterns of rsFC remodeling that accounted for the maintenance of cognitive performance after awake-guided surgical excision.

METHODS In a unique series of patients with IDH1-mutated low-grade gliomas (LGGs) infiltrating the precuneus who were treated at a single neurosurgical center (Montpellier University Medical Center, 2014–2021), the authors gauged the dynamic modulations induced by tumors on rsFC in comparison with healthy participants. All patients received a preoperative resting-state functional MRI and underwent operation guided by awake cognitive mapping. Connectome multivariate pattern analysis (MVPA), seed-network analysis, and graph theoretical analysis were conducted and correlated to executive neurocognitive scores (i.e., phonological and semantic fluencies, Trail-Making Test [TMT] parts A and B) obtained 3 months after surgery.

RESULTS Seventeen patients with focal precuneal infiltration were selected (mean age 38.1 ± 11.2 years) and matched to 17 healthy participants (mean age 40.5 ± 10.4 years) for rsFC analyses. All patients underwent awake cognitive mapping, allowing total resection (n = 3) or subtotal resection (n = 14), with a mean extent of resection of 90.6% ± 7.3%. Using MVPA (cluster threshold: p–false discovery rate corrected < 0.05, voxel threshold: p-uncorrected < 0.001), remote hotspots with significant rsFC changes were identified, including both insulas, the anterior cingulate cortex, superior sensorimotor cortices, and both frontal eye fields. Further seed-network analyses captured 2 patterns of between-network redistribution especially involving hyperconnectivity between the salience, visual, and dorsal attentional networks. Finally, the global efficiency of the salience-visual-dorsal attentional networks was strongly and positively correlated to 3-month postsurgical scores (n = 15) for phonological fluency (r 15 = 0.74, p = 0.0027); TMT-A (r 15 = 0.65, p = 0.012); TMTB (r 15 = 0.70, p = 0.005); and TMT-B-A (r 15 = 0.62, p = 0.018).

CONCLUSIONS In patients with LGGs infiltrating the precuneus, remote and distributed functional connectivity modulations in the preoperative setting are associated with better maintenance of cognitive performance after surgery. These findings provide a new vision of the mechanistic principles underlying neural plasticity and cognitive compensation in patients with LGGs.

Posted on

Evaluating syntactic comprehension during awake intraoperative cortical stimulation mapping

J Neurosurg 138:1403–1410, 2023

Electrocortical stimulation mapping (ECS) is widely used to identify essential language areas, but sentence-level processing has rarely been investigated.

METHODS While undergoing awake surgery in the dominant left hemisphere, 6 subjects were asked to comprehend sentences varying in their demands on syntactic processing.

RESULTS In all 6 subjects, stimulation of the inferior frontal gyrus disrupted comprehension of passive sentences, which critically depend on syntactic processing to correctly assign grammatical roles, without disrupting comprehension of simpler tasks. In 4 of the 6 subjects, these sites were localized to the pars opercularis. Sentence comprehension was also disrupted by stimulation of other perisylvian sites, but in a more variable manner.

CONCLUSIONS These findings suggest that there may be language regions that differentially contribute to sentence processing and which therefore are best identified using sentence-level tasks. The functional consequences of resecting these sites remain to be investigated.

Posted on

Recurrent insular low-grade gliomas: factors guiding the decision to reoperate

J Neurosurg 138:1216–1226, 2023

Reoperation has been established as an effective therapeutic strategy in recurrent diffuse low-grade gliomas (LGGs). Insular gliomas represent a specific surgical challenge because of the surrounding vascular and functional structures. The aim of this study was to investigate the main clinicoradiological factors guiding the decision to reoperate on recurrent insular LGGs (ILGGs).

METHODS In this retrospective consecutive series, the authors screened all patients operated on for an ILGG in their institution who further presented with a tumor regrowth without the development of contrast enhancement. They compared patients who were subsequently offered a reoperation under awake mapping at recurrence or who underwent reoperation after adjuvant treatment had reduced the volume of the initial tumor recurrence (with a proven pathological diagnosis of LGG after the second surgery) to patients who were not selected for a reoperation. The first group (reoperated group; n = 20) included all recurrent ILGG patients who underwent second resection, and the second group (nonreoperated group; n = 60) included patients who did not undergo reoperation but underwent adjuvant oncological treatment.

RESULTS Factors significantly associated with reoperation were extent of resection (EOR) at first surgery (91.9% vs 89.7%, p = 0.014), residual tumor volume (9.5 ± 7.1 mL [range 0–30 mL] vs 6.3 ± 7.3 mL [range 0–30 mL], p = 0.02) at first surgery and left temporopolar infiltration at the time of tumor recurrence (Liebermeister statistical analysis, 4293 voxels survived false discovery rate correction with p < 0.05; maximal z-statistic = 6.50). Infiltration of the anterior perforated substance at tumor recurrence was significantly anticorrelated to reoperation (179 voxels survived false discovery rate correction with p < 0.05; minimal z-statistic = −4.33). The mean EOR was 83.7% at reoperation with a 90% survival rate at last follow-up (9.3 ± 3.8 years), low postsurgical morbidity (Karnofsky Performance Status score ≥ 80 in 95% of patients), a high rate of postoperative professional resumption (95%), and seizure control in 57.1% of patients.

CONCLUSIONS In selected patients with recurrent ILGG without radiographic evidence of malignant transformation, reoperation with intraoperative awake mapping is associated with favorable oncological outcomes and a low postsurgical morbidity. A greater EOR and a lower residual tumor volume at first surgery were significantly associated with reoperation. Patients who benefited from a second surgery typically had a recurrent pattern within cortical areas (such as the temporopolar region), while other patients typically presented with a deeper infiltrative pattern within the anterior perforated substance and the surrounding white matter pathways. Such original findings may be helpful to select the optimal indications of reoperation in recurrent ILGG.

Posted on

Personalized surgery of brain tumors in language areas: the role of preoperative brain mapping in patients not eligible for awake surgery

Neurosurg Focus 53 (6):E3, 2022

Awake surgery represents the gold standard for resection of brain tumors close to the language network. However, in some cases patients may be considered not eligible for awake craniotomy. In these cases, a personalized brain mapping of the language network may be achieved by navigated transcranial magnetic stimulation (nTMS), which can guide resection in patients under general anesthesia. Here the authors describe their tailored nTMS-based strategy and analyze its impact on the extent of tumor resection (EOR) and language outcome in a series of patients not eligible for awake surgery.

METHODS The authors reviewed data from all patients harboring a brain tumor in or close to the language network who were considered not eligible for awake surgery and were operated on during asleep surgery between January 2017 and July 2022, under the intraoperative guidance of nTMS data. The authors analyzed the effectiveness of nTMS-based mapping data in relation to 1) the ability of the nTMS-based mapping to stratify patients according to surgical risks, 2) the occurrence of postoperative language deficits, and 3) the EOR.

RESULTS A total of 176 patients underwent preoperative nTMS cortical language mapping and nTMS-based tractography of language fascicles. According to the nTMS-based mapping, tumors in 115 patients (65.3%) were identified as true-eloquent tumors because of a close spatial relationship with the language network. Conversely, tumors in 61 patients (34.7%) for which the nTMS mapping disclosed a location at a safer distance from the network were identified as false-eloquent tumors. At 3 months postsurgery, a permanent language deficit was present in 13 patients (7.3%).

In particular, a permanent deficit was observed in 12 of 115 patients (10.4%) with true-eloquent tumors and in 1 of 61 patients (1.6%) with false-eloquent lesions. With nTMS-based mapping, neurosurgeons were able to distinguish trueeloquent from false-eloquent tumors in a significant number of cases based on the occurrence of deficits at discharge (p < 0.0008) and after 3 months from surgery (OR 6.99, p = 0.03). Gross-total resection was achieved in 80.1% of patients overall and in 69.5% of patients with true-eloquent lesions and 100% of patients with false-eloquent tumors.

CONCLUSIONS nTMS-based mapping allows for reliable preoperative mapping of the language network that may be used to stratify patients according to surgical risks. nTMS-guided asleep surgery should be considered a good alternative for personalized preoperative brain mapping of the language network that may increase the possibility of safe and effective resection of brain tumors in the dominant hemisphere whenever awake mapping is not feasible.

Posted on

Network-level prediction of set-shifting deterioration after lower-grade glioma resection

J Neurosurg 137:1329–1337, 2022

The aim of this study was to predict set-shifting deterioration after resection of low-grade glioma.

METHODS The authors retrospectively analyzed a bicentric series of 102 patients who underwent surgery for low-grade glioma. The difference between the completion times of the Trail Making Test parts B and A (TMT B-A) was evaluated preoperatively and 3–4 months after surgery. High dimensionality of the information related to the surgical cavity topography was reduced to a small set of predictors in four different ways: 1) overlap between surgical cavity and each of the 122 cortical parcels composing Yeo’s 17-network parcellation of the brain; 2) Tractotron: disconnection by the cavity of the major white matter bundles; 3) overlap between the surgical cavity and each of Yeo’s networks; and 4) disconets: signature of structural disconnection by the cavity of each of Yeo’s networks. A random forest algorithm was implemented to predict the postoperative change in the TMT B-A z-score.

RESULTS The last two network-based approaches yielded significant accuracies in left-out subjects (area under the receiver operating characteristic curve [AUC] approximately equal to 0.8, p approximately equal to 0.001) and outperformed the two alternatives. In single tree hierarchical models, the degree of damage to Yeo corticocortical network 12 (CC 12) was a critical node: patients with damage to CC 12 higher than 7.5% (cortical overlap) or 7.2% (disconets) had much higher risk to deteriorate, establishing for the first time a causal link between damage to this network and impaired set-shifting.

CONCLUSIONS The authors’ results give strong support to the idea that network-level approaches are a powerful way to address the lesion-symptom mapping problem, enabling machine learning–powered individual outcome predictions.

Proudly powered by WordPress