Awake Mapping Research Articles

Functional and oncological outcomes following more than three consecutive surgical resections for multiple relapses of initially grade 2 IDH-mutated gliomas.

Second and third surgeries were demonstrated as safe and efficient in recurrent diffuse low-grade glioma (LGG). Here, the feasibility of more than 3 resections is investigated. Patients who underwent 4 or 5 operations for recurrent initially WHO grade 2 IDH-mutated gliomas were consecutively selected. Twenty-three operations were performed in five patients (all males, mean age 27.2 ± 4 years). Three patients underwent 5 surgeries and two patients underwent 4 surgeries. Twelve procedures (52%) were achieved with awake mapping, including all 4th and 5th operations but one. Repeat electrical mapping detected changes of the cortical maps between at least two awake surgeries in 4 patients. No patients experienced permanent neurological impairment (KPS score ≥ 80 in all cases). The patients returned to work after 22 surgeries among 23 (95.6%). There were 3 oligodendrogliomas and 2 astrocytomas (4 gliomas became malignant at fourth or fifth operation). Although the preoperative tumor volume significantly increased before the fourth (p = 0.026) and fifth operation (p = 0.003) compared with the first operation, there was no significant difference between the residual tumor volume after the fourth or fifth resection versus the first one. The mean delay was 10.6 ± 3.9 years before chemotherapy and 15.4 ± 3.4 years before radiotherapy (one patient never received adjuvant treatment after 21.5 years). The mean follow-up duration was 18.3 ± 3.1 years since the first surgery (2.3 ± 1.8 years since the last surgery). Three patients were still alive at last follow-up. This is the first series showing that to reoperate beyond three times is feasible with a low functional risk and a long survival in multiple LGG recurrences, with the use of awake mapping in 87.5% of 4th and 5th surgeries.

The Safety and Usefulness of Awake Surgery as a Treatment Modality for Glioblastoma: A Retrospective Cohort Study and Literature Review.

Awake surgery contributes to the maximal safe removal of gliomas by localizing brain function. However, the efficacy and safety thereof as a treatment modality for glioblastomas (GBMs) have not yet been established. In this study, we analyzed the outcomes of awake surgery as a treatment modality for GBMs, response to awake mapping, and the factors correlated with mapping failure. Patients with GBMs who had undergone awake surgery at our hospital between March 2010 and February 2023 were included in this study. Those with recurrence were excluded from this study. The clinical characteristics, response to awake mapping, extent of resection (EOR), postoperative complications, progression-free survival (PFS), overall survival (OS), and factors correlated with mapping failure were retrospectively analyzed. Of the 32 participants included in this study, the median age was 57 years old; 17 (53%) were male. Awake mapping was successfully completed in 28 participants (88%). A positive response to mapping and limited resection were observed in 17 (53%) and 13 participants (41%), respectively. The EOR included gross total, subtotal, and partial resections and biopsies in 19 (59%), 8 (25%), 3 (9%), and 2 cases (6%), respectively. Eight (25%) and three participants (9%) presented with neurological deterioration in the acute postoperative period and at 3 months postoperatively, respectively. The median PFS and OS were 15.7 and 36.9 months, respectively. The time from anesthetic induction to extubation was statistically significantly longer in the mapping failure cohort than that in the mapping success cohort. Functional areas could be detected during awake surgery in participants with GBMs. Thus, awake mapping influences intraoperative discernment, contributes to the preservation of brain function, and improves treatment outcomes.

Functional and oncological outcomes after right hemisphere glioma resection in awake versus asleep patients: a systematic review and meta-analysis.

The right hemisphere has been underestimated by being considered as the non-dominant hemisphere. However, it is involved in many functions, including movement, language, cognition, and emotion. Therefore, because lesions on this side are usually not resected under awake mapping, there is a risk of unfavorable neurological outcomes. The goal of this study is to compare the functional and oncological outcomes of awake surgery (AwS) versus surgery under general anesthesia (GA) in supratentorial right-sided gliomas. A systematic review of the literature according to PRISMA guidelines was performed up to March 2023. Four databases were screened. Primary outcome to assess was return to work (RTW). Secondary outcomes included the rate of postoperative neurological deficit, postoperative Karnofsky Performance Status (KPS) score and the extent of resection (EOR). A total of 32 articles were included with 543 patients who underwent right hemisphere tumor resection under awake surgery and 294 under general anesthesia. There were no significant differences between groups regarding age, gender, handedness, perioperative KPS, tumor location or preoperative seizures. Preoperative and long-term postoperative neurological deficits were statistically lower after AwS (p = 0.03 and p < 0.01, respectively), even though no difference was found regarding early postoperative course (p = 0.32). A subsequent analysis regarding type of postoperative impairment was performed. Severe postoperative language deficits were not different (p = 0.74), but there were fewer long-term mild motor and high-order cognitive deficits (p < 0.05) in AwS group. A higher rate of RTW (p < 0.05) was documented after AwS. The EOR was similar in both groups. Glioma resection of the right hemisphere under awake mapping is a safer procedure with a better preservation of high-order cognitive functions and a higher rate of RTW than resection under general anesthesia, despite similar EOR.

Is intraoperative mapping of music performance mandatory to preserve skills in professional musicians? Awake surgery for lower-grade glioma conducted from a meta-networking perspective.

In surgery for lower-grade glioma (LGG) in professional musicians, for whom preserving music ability is essential, a critical question has emerged, namely, is it mandatory to include music performance during awake mapping, as proposed in several reports? In fact, music ability is subserved by a mosaic of interactive cognitive and emotional processes that rest on several networks. Therefore, from a meta-network perspective, the authors investigated whether an integrated multimodal monitoring of these cognitive and emotional functions during stimulation mapping could be efficient in maintaining musical skill. Indeed, it could be difficult for a patient to play a musical instrument in the surgical setting in addition to performing other tasks, such as movement and language. An awake mapping-guided resection for LGG without intraoperative music performance was performed in 3 professional musicians. Intraoperative tests were tailored to each patient depending on the critical corticosubcortical circuits surrounding the tumor, including not only sensorimotor or language skills but also higher-order functions with a constant multitasking during the resection. Although music skills were not mapped during surgery, all patients resumed their professional activities, preserving the ability to play music and to perform concerts, to teach and to compose music, or to start learning a new instrument. A connectome-based resection without intraoperative music performance seems effective in achieving maximal glioma removal while preserving crucial networks subserving musical skills, creativity, and music learning. Neurosurgery should evolve toward a meta-networking approach to better understand higher-order functions mediating complex behavior, such as being a professional musician.

Awake mapping for resection of cavernous angioma and arteriovenous malformations in the left dominant hemisphere

Awake mapping for resection of cavernous angioma and arteriovenous malformations in the left dominant hemisphere

10115-STMO-4 SURGICAL OUTCOMES OF AWAKE SURGERY FOR GLIOBLASTOMA

Abstract OBJECTIVE Awake surgery contributes to maximal resection of brain tumors and preservation of brain function. In this study, we investigated the surgical outcomes, efficacy and safety of awake surgery for glioblastoma (GBM) at our institution. METHOD All GBM patients who underwent awake surgery at our institution from March 2010 to February 2023 were included. We retrospectively analyzed the clinical characteristics, response to awake mapping, extent of resection, and postoperative complications. RESULTS Seventy-five patients, 92 surgeries were included in the study. Median age at surgery was 47 years, 51 cases (55.4%) were males, and 41 cases (44.6%) were females. Thirty-one cases (33.7%) were primary diseases, 59 cases (64.1%) were recurrent, and 2 cases (2.2%) were residual diseases. Positive responses for awake mapping were observed in 49 cases (53.3%). The resections were discontinued in 38 cases (41.3%) based on the mapping findings. Gross total resection was achieved in 48 cases (52.2%), subtotal resection in 26 cases (28.3%), partial resection in 14 cases (15.2%), and biopsy in 4 cases (4.2%). Twenty-two cases (23.9%) showed neurological deterioration in the acute postoperative period, whereas 5 cases (5.4%) showed deficit 3 months after surgery. Among patients whose excision was discontinued based on mapping findings, one case (1.1%) developed right hemiparesis due to late-onset cerebral infarction, whereas no neurological deficits were observed in the other cases 3 months after surgery. CONCLUSION Complications of awake surgery for glioblastoma were rare. Half of the cases showed positive response to awake mapping. Awake mapping is necessary to resect glioblastoma located in eloquent areas while preserving brain function.

Awake Mapping of Supplementary Motor Area Networks for Maximal Safe Resection of Left Superior Frontal Gyrus Low-Grade Glioma.

Awake Mapping of Supplementary Motor Area Networks for Maximal Safe Resection of Left Superior Frontal Gyrus Low-Grade Glioma.

Localization and symptoms associated with removal of negative motor area during awake surgery

Background In awake surgery, cortical mapping may identify the negative motor area (NMA). However, since speech arrest occurs regardless of whether the NMA or the frontal language area (FLA) is stimulated, the presence of speech arrest alone does not distinguish the NMA from the FLA. Furthermore, the exact location and function of the NMA is not well understood. The purpose of this study was to more accurately locate the NMA in a group of cases in which the NMA and FLA could be identified in different brain gyri, and to describe symptoms in cases in which the NMA was removed. Methods There were 18 cases of awake surgery at our institution between 2000 and 2013 in which cortical stimulation allowed identification of FLA and NMA in separate brain gyri. In these cases, the pre- and post-removal mapping results were projected onto a 3D model postoperatively. We investigated the symptoms and social rehabilitation in a case in which the tumour invaded the same brain gyrus as the NMA and the NMA had to be resected in combination with the tumour. Results In cases where the NMA and FLA could be identified in different brain gyri, NMA was localized inferior to the precentral gyrus in all cases. In four cases where NMA was removed with the tumour, apraxia of speech was observed during the surgery; the same symptoms persisted after it, but it improved within a few months, and the patients were able to return to work. Conclusion In cases where NMA and FLA could be identified separately by awake mapping, the NMA was commonly localized inferior to the precentral gyrus. When NMAs were resected in combination with tumour invasion, they did not lead to serious, long-term complications.

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

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. 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. 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. 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).

Development of an educational method to rethink and learn oncological brain surgery in an "a la carte" connectome-based perspective.

Understanding the structural connectivity of white matter tracts (WMT) and their related functions is a prerequisite to implementing an "a la carte" "connectomic approach" to glioma surgery. However, accessible resources facilitating such an approach are lacking. Here we present an educational method that is readily accessible, simple, and reproducible that enables the visualization of WMTs on individual patient images via an atlas-based approach. Our method uses the patient's own magnetic resonance imaging (MRI) images and consists of three main steps: data conversion, normalization, and visualization; these are accomplished using accessible software packages and WMT atlases. We implement our method on three common cases encountered in glioma surgery: a right supplementary motor area tumor, a left insular tumor, and a left temporal tumor. Using patient-specific perioperative MRIs with open-sourced and co-registered atlas-derived WMTs, we highlight the critical subnetworks requiring specific surgical monitoring identified intraoperatively using direct electrostimulation mapping with cognitive monitoring. The aim of this didactic method is to provide the neurosurgical oncology community with an accessible and ready-to-use educational tool, enabling neurosurgeons to improve their knowledge of WMTs and to better learn their oncologic cases, especially in glioma surgery using awake mapping. Taking no more than 3-5min per patient and irrespective of their resource settings, we believe that this method will enable junior surgeons to develop an intuition, and a robust 3-dimensional imagery of WMT by regularly applying it to their cases both before and after surgery to develop an "a la carte" connectome-based perspective to glioma surgery.

Subcortical language localization using sign language and awake craniotomy for dominant posterior temporal glioma resection in a hearing-impaired patient

Intraoperative direct cortical stimulation (DCS) is the gold standard technique to maximize the extent of resection of tumors located in eloquent areas. To date, there are three cases reported of awake mapping for language centers in deaf patients who could communicate only with sign language. We present the case of DCS in a deaf patient who could communicate vocally, native to American Sign Language and English, that underwent intraoperative awake mapping. DCS showed similar disruption of expressive phonology to both pictorial and gestural stimuli, confirming that sign language follows the same pattern as oral language.

Technical Aspects of Motor and Language Mapping in Glioma Patients.

Gliomas are infiltrative primary brain tumors that often invade functional cortical and subcortical regions, and they mandate individualized brain mapping strategies to avoid postoperative neurological deficits. It is well known that maximal safe resection significantly improves survival, while postoperative deficits minimize the benefits associated with aggressive resections and diminish patients' quality of life. Although non-invasive imaging tools serve as useful adjuncts, intraoperative stimulation mapping (ISM) is the gold standard for identifying functional cortical and subcortical regions and minimizing morbidity during these challenging resections. Current mapping methods rely on the use of low-frequency and high-frequency stimulation, delivered with monopolar or bipolar probes either directly to the cortical surface or to the subcortical white matter structures. Stimulation effects can be monitored through patient responses during awake mapping procedures and/or with motor-evoked and somatosensory-evoked potentials in patients who are asleep. Depending on the patient's preoperative status and tumor location and size, neurosurgeons may choose to employ these mapping methods during awake or asleep craniotomies, both of which have their own benefits and challenges. Regardless of which method is used, the goal of intraoperative stimulation is to identify areas of non-functional tissue that can be safely removed to facilitate an approach trajectory to the equator, or center, of the tumor. Recent technological advances have improved ISM's utility in identifying subcortical structures and minimized the seizure risk associated with cortical stimulation. In this review, we summarize the salient technical aspects of which neurosurgeons should be aware in order to implement intraoperative stimulation mapping effectively and safely during glioma surgery.

883 Impact of Awake Craniotomy within Eloquent Glioblastoma Subgroups (GLIOMAP): A Propensity-Score Matched Analysis of an International, Multicenter, Cohort Study

INTRODUCTION: Awake mapping has been associated with decreased neurological deficits and increased extent of resection in eloquent glioma resections. However, its impact within clinically relevant glioblastoma subgroups remains poorly understood. METHODS: Propensity-score matching with a 1:3 ratio was used to match awake with asleep patients for the overall cohort and subgroups stratified by age, NIHSS score and KPS. Cox proportional-hazard regressions and multiple multivarible logistic regressions were performed to analyze the independent impact of awake mapping. RESULTS: 1047 patients with resection for primary eloquent glioblastoma between 2010 and 2020 were included. Overall, awake craniotomy resulted in fewer neurological deficits at 3 months and 6 months postoperatively; a lower residual tumor volume, a higher extent of resection, longer overall survival and progression-free survival. Regression analyses independently associated awake craniotomy with gross-total resection and overall survival. Awake craniotomy led in all subgroups to a higher extent of resection and in the subgroups age &lt;70, NIHSS 0-1, NIHSS ≥ 2 and KPS 90-100 to less postoperative neurological deficits at 3 months and 6 months. For patients in the ≥70 years subgroup and KPS ≤ 80 subgroup, awake craniotomy led to less postoperative neurological deficits at 3 months (≥70 years) or 6 months (KPS ≤ 80). Median overall survival and progression-free survival were longer for the awake group in the subgroups aged &lt;70, NIHSS 0-1 and KPS 90-100. CONCLUSIONS: Awake craniotomy was especially suitable in patients aged &lt;70, with NIHSS score 0-1 or KPS 90-100, leading to decreased neurological morbidity, increased amount of tumor resection and improved OS and PFS. In patients aged ≥ 70, with NIHSS score ≥2 or KPS ≤ 80, awake craniotomy could be useful to prevent late deficits or to help patients maintain their performance status to undergo adjuvant therapy.

159 Neuroplastic Changes Across Multiple Brain Resections in Glioma Patients: Identification of Patterns that Predict Beneficial Repeat Resection

INTRODUCTION: The brain displays degrees of functional reorganization, i.e., neuroplasticity, that enable interventions that were previously thought to be impossible (e.g., resection of “Broca’s area”). Studies have described the static, single-point in time neuroplastic potential in diffuse low-grade gliomas (DLGG) following one surgery. METHODS: We studied n=103 patients with a DLGG that underwent multiple brain resections achieved up to critical neural networks identified under awake mapping by means of direct cortical and subcortical electrostimulation. We used normalized postoperative images to generate probability overlap, atlas-based cortical and subcortical parcellation, and functional compensation maps for both surgeries. We performed statistical analysis correcting for multiple comparisons across all cortical parcels and tracts to determine differences at the cortical and subcortical levels between surgeries. RESULTS: We show for the first time the dynamics of neuroplastic changes occurring in DLGG that undergo multiple awake resections. We created residual and resection cavity overlap probability maps; cortical parcel damage and subcortical tract disconnection maps and the difference between surgeries; and functional compensation maps and subcortical volumes. We discovered the following four main patterns that constrain how and to what degree this dynamic reorganization occurs between surgeries: cortical vs subcortical, superficial vs deep, unimodal vs multimodal, and left vs right. We found greater plasticity at the cortical level, superficial terminations of white matter tracts, multimodal networks, and left ventral and right dorsal networks. CONCLUSIONS: These newly discovered patterns of reorganization provide a unifying model to understand the dynamics of neuroplasticity in DLGG patients undergoing multiple resections. These dynamics with its patterns that constrain mechanisms of neuroplasticity, can help guide neurosurgeons to predict which patients are likely to benefit from a repeat resection.

Magnetic Resonance Tractography and Intraoperative Direct Electrical Stimulation in Eloquent Area Glioma Surgery for 102 Cases: A Tertiary Care Center Experience From Northwest India.

Surgery of eloquent area gliomas is challenging and requires monitoring of the nearby white fiber tracts. In the present study, we analyzed 102 patients with eloquent region gliomas and discussed the concept of intraoperative dynamic white fiber tract navigation and monitoring. A total of 102 patients with an eloquent area glioma (52 insular, 29 motor area, 21 temporoparietal) were evaluated. The position of the white fiber tracts (corticospinal tract [or motor fiber; CST], inferior fronto-occipital fasciculus [ventral language fiber; IFOF], superior longitudinal fasciculus [SLF], and arcuate fasciculus [dorsal language fiber; AF) was recorded. Awake mapping of the cortical and subcortical eloquent structures was performed for all 102 patients. The suction stimulator was coregistered and used as a dynamic stimulator navigator. Of the 102 patients, 60 were men and 42 were women, with an average age of 39.8 years. Most of the white fiber tracts were normal (CST, 31.3%; IFOF, 39.2%; SLF/AF, 40.19%) or displaced (CST, 59.8%; IFOF, 47.05%; AF/SLF, 44.11%). A few were disrupted (CST, 8.8%; IFOF, 13.7%; SLF/AF, 15.7%). The extent of tumor resection was 82.8%, 86.5%, and 94% for those with insular glioma, motor area glioma, and temporoparietal glioma, respectively. Of the 102 patients, 18 had developed transient speech and language disturbances with improvement, and 14 had developed motor deficits, of whom, all except for 2, had shown gradual improvement. When the dynamic suction stimulator navigator was used, the extent of resection was 96.5%, without any added deficits. The use of intraoperative neuronavigation and neurophysiological assessment can help achieve maximal tumor resection of eloquent area gliomas. Use of the integrated suction stimulator navigator provided dynamic navigation and mapping of the peritumoral eloquent fibers.

The current state of the art of primary motor mapping for tumor resection: A focused survey

IntroductionCortical and subcortical motor mapping has advanced the notion of maximal safe resection of intra-axial brain tumours, thereby preserving neurological functions as well as improving survival. Despite being an age-old and established neurosurgical procedure across the world, the strategy and techniques involved in motor mapping have a gamut of variation due to a lack of defined standard protocols. MethodsWe disseminated a structured survey among focused group of neurosurgeons with established practices involving brain mapping. It consisted of 40 questions, split into five sections assessing the practice description, general approach for motor mapping, preference for asleep versus awake mapping, operative techniques and approach to representative tumor cases. Practice-patterns during primary motor mapping for brain tumours were analysed from responses of 51 neurosurgeons. Results60.8 % felt that any lesion even near (without infiltration) was suffice to define “involvement” of the cortical/subcortical motor pathways. 82.4 % felt that motor mapping was necessary for brain tumours involving motor pathways, irrespective of the tumor histology or patient age. 90.2 % opined that tumor location was the predominant factor affecting their choice between awake or asleep mapping. 31.4 % believed that all cases should be performed awake unless patient-related medical, psychological, or anaesthetic contraindications exist, whereas 45.1 % felt that all cases should be performed asleep unless language mapping is required. MRI, DTI-based tractography and intra-operative fluorescence were the most commonly employed surgical adjuncts. ConclusionsThe data from this survey may serve as a preliminary foundation for a more standardized approach to patient selection and the approach to motor mapping for brain tumors.

Beyond Avoiding Hemiplegia after Glioma Surgery: The Need to Map Complex Movement in Awake Patient to Preserve Conation

Improving the onco-functional balance has always been a challenge in glioma surgery, especially regarding motor function. Given the importance of conation (i.e., the willingness which leads to action) in patient's quality of life, we propose here to review the evolution of its intraoperative assessment through a reminder of the increasing knowledge of its neural foundations-based upon a meta-networking organization at three levels. Historical preservation of the primary motor cortex and pyramidal pathway (first level), which was mostly dedicated to avoid hemiplegia, has nonetheless shown its limits to prevent the occurrence of long-term deficits regarding complex movement. Then, preservation of the movement control network (second level) has permitted to prevent such more subtle (but possibly disabling) deficits thanks to intraoperative mapping with direct electrostimulations in awake conditions. Finally, integrating movement control in a multitasking evaluation during awake surgery (third level) enabled to preserve movement volition in its highest and finest level according to patients' specific demands (e.g., to play instrument or to perform sports). Understanding these three levels of conation and its underlying cortico-subcortical neural basis is therefore critical to propose an individualized surgical strategy centered on patient's choice: this implies an increasingly use of awake mapping and cognitive monitoring regardless of the involved hemisphere. Moreover, this also pleads for a finer and systematic assessment of conation before, during and after glioma surgery as well as for a stronger integration of fundamental neurosciences into clinical practice.

Should we modify antiepileptic drugs after induced intraoperative seizures during awake mapping? Conclusions after 121 surgeries.

Should we modify antiepileptic drugs after induced intraoperative seizures during awake mapping? Conclusions after 121 surgeries.

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

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. 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. 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 true-eloquent 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. 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.

Impact of maximal extent of resection on postoperative deficits, patient functioning, and survival within clinically important glioblastoma subgroups.

The impact of extent of resection (EOR), residual tumor volume (RTV), and gross-total resection (GTR) in glioblastoma subgroups is currently unknown. This study aimed to analyze their impact on patient subgroups in relation to neurological and functional outcomes. Patients with tumor resection for eloquent glioblastoma between 2010 and 2020 at 4 tertiary centers were recruited from a cohort of 3919 patients. One thousand and forty-seven (1047) patients were included. Higher EOR and lower RTV were significantly associated with improved overall survival (OS) and progression-free survival (PFS) across all subgroups, but RTV was a stronger prognostic factor. GTR based on RTV improved median OS in the overall cohort (19.0months, P<.0001), and in the subgroups with IDH wildtype tumors (18.5months, P=.00055), MGMT methylated tumors (35.0months, P<.0001), aged <70 (20.0months, P<.0001), NIHSS 0-1 (19.0months, P=.0038), KPS 90-100 (19.5months, P=.0012), and KPS ≤80 (17.0months, P=.036). GTR was significantly associated with improved OS in the overall cohort (HR 0.58, P=.0070) and improved PFS in the NIHSS 0-1 subgroup (HR 0.47, P=.012). GTR combined with preservation of neurological function (OFO 1 grade) yielded the longest survival times (median OS 22.0months, P<.0001), which was significantly more frequently achieved in the awake mapping group (50.0%) than in the asleep group (21.8%) (P<.0001). Maximum resection was especially beneficial in the subgroups aged <70, NIHSS 0-1, and KPS 90-100 without increasing the risk of postoperative NIHSS or KPS worsening. These findings may assist surgical decision making in individual glioblastoma patients.