Is non-awake surgery for supratentorial adult low-grade glioma treatment still feasible?

Mini-strokes after awake surgery for glioma resection: are there anesthesia related factors?

INTRODUCTION

Awake surgery is now a common approach for the resection of glioma. One of the surgical complications is mini-stroke which take the form of periresectional small areas of brain ischemic lesions. The main objective of this study is to evaluate the association between factors related to anesthetic management and the risk of mini-stroke, in awake surgery for glioma resection.

METHODS

In this single-center retrospective study, all patients who were operated on, between 2011 and 2022, in awake conditions for a glioma resection, were retrospectively included. The studied anesthetic parameters included hemodynamic variables, fluid intake and urinary output. The primary endpoint was the presence of mini-stroke on a magnetic resonance imaging performed within the first 48 h postoperatively.

RESULTS

A total of 176 surgeries were included. Mini-stroke was present in 120/171 surgeries (70%), with a median volume of 1.2 interquartile range [0.4-2.2] cubic centimeters (cc). In a multivariable analysis, only the per operative urinary output was significantly associated with the incidence of postoperative mini-strokes (adjusted odd-ratio 0.65, 95% confidence interval 0.45-0.94, p = 0.02). No variables related to the anesthetic management were associated with the volume of postoperative mini-strokes. In particular, the time spent below 90% of the baseline systolic blood pressure was not associated with either the risk or the volume of mini-strokes.

CONCLUSION

During awake surgery for glioma resection, among several anesthesia related factors, only the per operative urinary output was associated with the incidence of postoperative mini-stroke.

Awake surgery for a deaf patient using sign language: A case report

Background

Although awake surgery is the gold standard for resecting brain tumors in eloquent regions, patients with hearing impairment require special consideration during intraoperative tasks.

Case Description

We present a case of awake surgery using sign language in a 45-year-old right-handed native male patient with hearing impairment and a neoplastic lesion in the left frontal lobe, pars triangularis (suspected to be a low-grade glioma). The patient primarily communicated through sign language and writing but was able to speak at a sufficiently audible level through childhood training. Although the patient remained asymptomatic, the tumors gradually grew in size. Awake surgery was performed for tumors resection. After the craniotomy, the patient was awake, and brain function mapping was performed using tasks such as counting, picture naming, and reading. A sign language-proficient nurse facilitated communication using sign language and the patient vocally responded. Intraoperative tasks proceeded smoothly without speech arrest or verbal comprehension difficulties during electrical stimulation of the tumor-adjacent areas. Gross total tumor resection was achieved, and the patient exhibited no apparent complications. Pathological examination revealed a World Health Organization grade II oligodendroglioma with an isocitrate dehydrogenase one mutant and 1p 19q codeletion.

Conclusion

Since the patient in this case had no dysphonia due to training from childhood, the task was presented in sign language, and the patient responded vocally, which enabled a safe operation. Regarding awake surgery in patients with hearing impairment, safe tumor resection can be achieved by performing intraoperative tasks depending on the degree of hearing impairment and dysphonia.

The "state of the art" of intraoperative neurophysiological monitoring: An Italian neurosurgical survey

Introduction

Intraoperative Neurophysiological Monitoring (IOM) is widely used in neurosurgery but specific guidelines are lacking. Therefore, we can assume differences in IOM application between Neurosurgical centers.

Research question

The section of Functional Neurosurgery of the Italian Society of Neurosurgery realized a survey aiming to obtain general data on the current practice of IOM in Italy.

Materials and methods

A 22-item questionnaire was designed focusing on: volume procedures, indications, awake surgery, experience, organization and equipe. The questionnaire has been sent to Italian Neurosurgery centers.

Results

A total of 54 centers completed the survey. The annual volume of surgeries range from 300 to 2000, and IOM is used in 10-20% of the procedures. In 46% of the cases is a neurologist or a neurophysiologist who performs IOM. For supra-tentorial pathology, almost all perform MEPs (94%) SSEPs (89%), direct cortical stimulation (85%). All centers perform IOM in spinal surgery and 95% in posterior fossa surgery. Among the 50% that perform peripheral nerve surgery, all use IOM. Awake surgery is performed by 70% of centers. The neurosurgeon is the only responsible for IOM in 35% of centers. In 83% of cases IOM implementation is adequate to the request.

Discussion and conclusions

The Italian Neurosurgical centers perform IOM with high level of specialization, but differences exist in organization, techniques, and expertise. Our survey provides a snapshot of the state of the art in Italy and it could be a starting point to implement a consensus on the practice of IOM.

Radiological and Not Clinical Variables Guide the Surgical Plan in Patients with Glioblastoma

Background and Purpose: The extent of resection is the most important prognostic factor in patients with glioblastoma. However, the factors influencing the decision to perform a biopsy instead of maximal resection have not been clearly established. The aim of this study was to analyze the factors associated with the intention to achieve maximal resection in glioblastoma patients. Methods: A retrospective single-center case-series analysis of patients with a new diagnosis of glioblastoma was performed. Patients were distributed into two groups: the biopsy (B) and complete resection (CR) groups. To identify factors associated with the decision to perform a B or CR, uni- and multivariate binary logistic regression analyses were performed. Cox regression analysis was also performed in the B and CR groups. Results: Ninety-nine patients with a new diagnosis of glioblastoma were included. Sixty-eight patients (68.7%) were treated with CR. Ring-enhancement and edema volume on presurgical magnetic resonance imaging were both associated with CR. Corpus callosum involvement and proximity to the internal capsule were identified as factors associated with the decision to perform a biopsy. In the multivariate analysis, edema volume (OR = 1.031; p = 0.002) and proximity to the internal capsule (OR = 0.104; p = 0.001) maintained significance and were considered independent factors. In the survival analysis, only corpus callosum involvement (HR = 2.055; p = 0.035) and MGMT status (HR = 0.484; p = 0.027) presented statistical significance in the CR group. Conclusions: The volume of edema and proximity to the internal capsule were identified as independent factors associated with the surgical decision. The radiological evaluation and not the clinical situation of the patient influences the decision to perform a biopsy or CR.

Recovery of major cognitive deficits following awake surgery for insular glioma: a case report

Background: Resection of insular tumours utilising modern neurosurgical techniques has become commonplace since its safety and reduced morbidity was first established. Interest has grown in the cognitive consequences of insula neurosurgery and studies have largely shown postoperative stability or minor decline. Major or widespread improvements in cognitive functioning following resection of insular tumours have not previously been reported.Case description: A 34-year-old, left-handed man with a right insular low-grade glioma (LGG) presented with seizures, nausea, altered sensation, poor balance and extensive cognitive decline. Comprehensive neuropsychological assessment highlighted a striking left hemispatial neglect and impairments in attention, working memory, verbal learning and fluency. During an awake craniotomy with functional cortical mapping, he reported intraoperative improvements in hand function and processing speed. Resolution of the neglect and significant improvements in cognition, mood and functioning were observed at follow-up and sustained over several years.Conclusions: This case highlights that right insular LGGs can cause significant cognitive and functional deficits and that neurosurgery has the potential to alleviate these difficulties to an extent beyond those documented in the extant literature.

Performance of intraoperative neurocognitive tests during awake surgery for patients with diffuse low-grade glioma

Despite great advancements and the diffusion of awake surgery for brain tumors, the literature shows that the tests applied during the procedure are heterogeneous and non-standardized. This prospective, observational, descriptive study collected data on intraoperative brain mapping and the performance of multiple neurocognitive tests in 51 awake surgeries for diffuse low-grade glioma. Frequency of use and rate of intraoperative findings of different neurocognitive tests were analyzed. Patients mean age at the time of surgery was 35.1 (20-57) years. We performed 26 (51.0%) surgeries on the left hemisphere (LH) and 25 (49.0%) on the right hemisphere (RH). Significant differences were observed between the total number of functional findings (cortical and subcortical) identified in the LH and RH (p = 0.004). In subcortical findings alone, the differences remained significant (p = 0.0004). The RH subcortical region showed the lowest number of intraoperative findings, and this was correlated with functional outcome: Karnofsky performance scale at five days (p = 0.022), three months (p = 0.002) and one year (p = 0.002) post-surgery. On average, more tests were used to map the RH, with a lower frequency of both cortical and subcortical functional findings. Even though subcortical findings were less frequent than cortical findings, they were crucial to defining the resection margins. Based on the intraoperative findings, frequency of use, and rate of findings per use of the tests analyzed, the most relevant tests for each hemisphere for awake brain mapping were identified.

Awake craniotomy for eloquent pial arteriovenous fistula: anesthetic and surgical consideration of a rare case

Intracranial pial Arteriovenous Fistulas (AVFs) are rare cerebral vascular lesions composed of one or more arterial connections to a single venous channel. We report a 50-year-old patient with a ruptured pial AVF located in an eloquent area. Microsurgery for pial AVF occlusion was proposed with awake craniotomy for motor function and neurological evaluation. Awake craniotomy is a technique that is especially useful for cerebral vascular lesions in eloquent areas, where an occlusion often compromises or suppresses the blood supply, culminating in ischemia with consequent transient or definitive deficits in neurological function.

Cognition, Emotional States and Health-Related Quality of Life in Awake Craniotomy for Glioma: A Case Series

BACKGROUND

Awake craniotomy is an effective procedure for optimizing the onco-functional balance of resections in glioma. However, limited data exists on the cognition, emotional states, and health-related quality of life (HRQoL) of patients with glioma who undergo awake craniotomy. This study aims to describe 1) perioperative cognitive function and emotional states in a multilingual Asian population, 2) associations between perioperative cognitive function and follow-up HRQoL, and 3) associations between preoperative emotional states and follow-up HRQoL.

METHODS

This is a case series of 14 adult glioma patients who underwent awake craniotomy in Singapore. Cognition was assessed with the Montreal Cognitive Assessment and the Repeatable Battery for the Assessment of Neuropsychological Status, emotional states with the Depression, Anxiety and Stress Scale-21 Items, and HRQoL using the EuroQol-5D-5L, the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30, and the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-BN20.

RESULTS

Patients with better preoperative cognitive scores on all domains reported better HRQoL. Better postoperative immediate memory and language scores were associated with better HRQoL. Moderate preoperative depression scores and mild and moderate preoperative stress scores were associated with poorer HRQoL compared to scores within the normal range. Mild preoperative anxiety scores were associated with better HRQoL compared to scores within the normal range.

CONCLUSION

This descriptive case series showed that patients with higher preoperative cognitive scores reported better follow-up HRQoL, while patients who reported more preoperative depressive and stress symptomatology reported worse follow-up HRQoL. Future analytical studies may help to draw conclusions about whether perioperative cognition and emotional states predict HRQoL on follow-up.

Can we improve electrocorticography using a circular grid array in brain tumor surgery?

Intraoperative electrocorticography (iECoG) is used as an adjunct to localize the epileptogenic zone during surgical resection of brain tumors in patients with focal epilepsies. It also enables monitoring of after-discharges and seizures with EEG during functional brain mapping with electrical stimulation. When seizures or after-discharges are present, they complicate accurate interpretation of the mapping strategy to outline the brain's eloquent function and can affect the surgical procedure. Recurrent seizures during surgery requires urgent treatment and, when occurring during awake craniotomy, often leads to premature termination of brain mapping due to post-ictal confusion or sedation from acute rescue therapy. There are mixed results in studies on efficacy with iECoG in patients with epilepsy and brain tumors influencing survival and functional outcomes following surgery. Commercially available electrode arrays have inherent limitations. These could be improved with customization potentially leading to greater precision in safe and maximal resection of brain tumors. Few studies have assessed customized electrode grid designs as an alternative to commercially available products. Higher density electrode grids with intercontact distances less than 1 cm improve spatial delineation of electrophysiologic sources, including epileptiform activity, electrographic seizures, and afterdischarges on iECoG during functional brain mapping. In response to the shortcomings of current iECoG grid technologies, we designed and developed a novel higher-density hollow circular electrode grid array. The 360-degree iECoG monitoring capability allows continuous EEG recording during surgical intervention through the aperture with and without electrical stimulation mapping. Compared with linear strip electrodes that are commonly used for iECoG during surgery, the circular grid demonstrates significant benefits in brain tumor surgery. This includes quicker recovery of post-operative motor deficits (2.4 days versus 9 days, p = 0.05), more extensive tumor resection (92.0% versus 77.6%, p = 0.003), lesser reduction in Karnofsky Performance scale postoperatively (-2 versus -11.6, p = 0.007), and more sensitivity to recording afterdischarges. In this narrative review, we discuss the advantages and disadvantages of commercially available recording devices in the operating room and focus on the usefulness of the higher-density circular grid.

The state of art of awake craniotomy in Latin American countries: a scoping review

BACKGROUND AND OBJECTIVE

Awake craniotomy (AC) is a valuable technique for surgical interventions in eloquent areas, but its adoption in low- and middle-income countries faces challenges like limited infrastructure, trained personnel shortage, and inadequate funding. This scoping review explores AC techniques in Latin American countries, focusing on patient characteristics, tumor location, symptomatology, and outcomes.

METHODS

A scoping review followed PRISMA guidelines, searching five databases in English, Spanish, and Portuguese. We included 28 studies with 258 patients (mean age: 43, range: 11-92). Patterns in AC use in Latin America were analyzed.

RESULTS

Most studies were from Brazil and Mexico (53.6%) and public institutions (70%). Low-grade gliomas were the most common lesions (55%), most of them located in the left hemisphere (52.3%) and frontal lobe (52.3%). Gross-total resection was achieved in 34.3% of cases. 62.9% used an Asleep-Awake-Asleep protocol, and 14.8% used Awake-Awake-Awake. The main complication was seizures (14.6%). Mean post-surgery discharge time was 68 h. Challenges included limited training, infrastructure, and instrumentation availability. Strategies discussed involve training in specialized centers, seeking sponsorships, applying for awards, and multidisciplinary collaborations with neuropsychology.

CONCLUSION

Improved accessibility to resources, infrastructure, and adequate instrumentation is crucial for wider AC availability in Latin America. Despite disparities, AC implementation with proper training and teamwork yields favorable outcomes in resource-limited centers. Efforts should focus on addressing challenges and promoting equitable access to this valuable surgical technique in the region.

Neurocognitive Outcome and Seizure Freedom After Awake Surgery of Gliomas

Objectives

Gliomas are often diagnosed due to epileptic seizures as well as neurocognitive deficits. First treatment choice for patients with gliomas in speech-related areas is awake surgery, which aims at maximizing tumor resection while preserving or improving patient’s neurological status. The present study aimed at evaluating neurocognitive functioning and occurrence of epileptic seizures in patients suffering from gliomas located in language-related areas before and after awake surgery as well as during their follow up course of disease.

Materials and Methods

In this prospective study we included patients who underwent awake surgery for glioma in the inferior frontal gyrus, superior temporal gyrus, or anterior temporal lobe. Preoperatively, as well as in the short-term (median 4.1 months, IQR 2.1-6.0) and long-term (median 18.3 months, IQR 12.3-36.6) postoperative course, neurocognitive functioning, neurologic status, the occurrence of epileptic seizures and number of antiepileptic drugs were recorded.

Results

Between 09/2012 and 09/2019, a total of 27 glioma patients, aged 36.1 ± 11.8 years, were included. Tumor resection was complete in 15, subtotal in 6 and partial in 6 patients, respectively. While preoperatively impairment in at least one neurocognitive domain was found in 37.0% of patients, postoperatively, in the short-term, 36.4% of patients presented a significant deterioration in word fluency (p=0.009) and 34.8% of patients in executive functions (p=0.049). Over the long-term, scores improved to preoperative baseline levels. The number of patients with mood disturbances significantly declined from 66.7% to 34.8% after surgery (p=0.03). Regarding seizures, these were present in 18 (66.7%) patients prior to surgery. Postoperatively, 22 (81.5%) patients were treated with antiepileptic drugs with all patients presenting seizure-freedom.

Conclusions

In patients suffering from gliomas in eloquent areas, the combination of awake surgery, regular neurocognitive assessment - considering individual patients´ functional outcome and rehabilitation needs – and the individual adjustment of antiepileptic therapy results in excellent patient outcome in the long-term course.

Comparison of Clinical Effects of Temozolomide Single Agent and Combined Doxorubicin in the Treatment of Glioma

In this article, we have compared and analyzed the clinical effects of temozolomide single agent and combined doxorubicin in the treatment of glioma. To evaluate this, a total of 70 patients diagnosed with glioma in our hospital from July 2019 to July 2020 were randomly divided into two groups, the observation group and the control group, with 35 patients in each group. The control group received temozolomide capsules orally. The observation group was treated with temozolomide single agent and doxorubicin. After treatment, the clinical efficacy, adverse reactions, and KPS score of the two groups were observed. After treatment, the total response rate of the control group was 31.43%, and the total response rate of the observation group was 62.86%. The difference between the two groups was statistically significant ( $P<0.05$ ). Before treatment, there was no significant difference in KPS scores between the two groups ( $P>0.05$ ). After treatment, the KPS scores of both groups were improved, and the KPS scores of the observation group and the control group were significantly better, with statistical significance ( $P<0.05$ ). In the observation group, 17 cases had adverse reactions, including 10 cases of nausea and vomiting, 2 cases of leucopenia, and 5 cases of thrombocytopenia, with a total incidence of 48.57%. In the control group, there were 31 cases of adverse reactions, including 22 cases of nausea and vomiting, 6 cases of leucopenia, and 4 cases of thrombocytopenia, with a total incidence of 91.43%. The difference between the two groups was statistically significant ( $P<0.05$ ). The efficacy of temozolomide single agent and combined doxorubicin in the treatment of glioma was significant. Moreover, it can significantly improve clinical efficacy, reduce the incidence of adverse reactions, and improve the health status of patients, which is worthy of further clinical application.

Large tumour volume reduction of IDH-mutated anaplastic glioma involving the insular region following radiotherapy

Background

The impact of near-total resection of IDH-mutated anaplastic glioma (IDHmutAG) is well-established but there remains uncertainty of benefit in tumours of the insular cortex where the extent of safe resection may be limited. This study aimed to assess tumour volume reduction in patients following IMRT and impact of residual post-surgical volume.

Methods and materials

Patients with IDHmutAG involving insular cortex managed with IMRT from 2008 to 2019 had baseline patient, tumour and treatment factors recorded. Volumetric assessment of residual disease on MRI was performed at baseline, month+ 3 and month+ 12 post-IMRT. Potential prognostic factors were analysed for tumour reduction and relapse-free survival, and assessed by log-rank and Cox regression analyses.

Results

Thirty two patients with IDHmutAG of the insular cortex were managed with median follow-up post-IMRT of 67.2 months. Pathology was anaplastic astrocytoma (AAmut) in 20, and anaplastic oligodendroglioma (AOD) in 12 patients. Median pre-IMRT volume on T1 and T2Flair was 24.3cm³ and 52.2cm³. Twenty-seven patients were alive with 5-year relapse-free survival of 80%. There was a median 67 and 64% reduction from baseline occurring at 3 months post-IMRT for T1 and T2Flair respectively; and subsequent median 78 and 73% at 12 months. At 12 months AOD patients had median 83% T1 volume reduction compared to 63% in AAmut (p < 0.01). There was no difference on T2Flair volume (p = 0.64). No other pathological factors influenced volume reduction at 12 months. No factors were associated with relapse-free survival including baseline T1 (p = 0.52) and T2Flair (p = 0.93) volume.

Conclusion

IMRT provides large tumour volume reduction in IDHmutAG of the insular cortex. While maximal safe debulking remains standard of care when feasible, this patient cohort reported no significant negative impact of residual disease volume on relapse-free survival.

Intraoperative hand strength as an indicator of consciousness during awake craniotomy: a prospective, observational study

Awake craniotomy enables mapping and monitoring of brain functions. For successful procedures, rapid awakening and the precise evaluation of consciousness are required. A prospective, observational study conducted to test whether intraoperative hand strength could be a sensitive indicator of consciousness during the awake phase of awake craniotomy. Twenty-three patients who underwent awake craniotomy were included. Subtle changes of the level of consciousness were assessed by the Japan Coma Scale (JCS). The associations of hand strength on the unaffected side with the predicted plasma concentration (Cp) of propofol, the bispectral index (BIS), and the JCS were analyzed. Hand strength relative to the preoperative maximum hand strength on the unaffected side showed significant correlations with the Cp of propofol (ρ =  − 0.219, p = 0.007), the BIS (ρ = 0.259, p = 0.002), and the JCS (τ =  − 0.508, p = 0.001). Receiver operating characteristic curve analysis for discriminating JCS 0–1 and JCS ≥ 2 demonstrated that the area under the curve was 0.76 for hand strength, 0.78 for Cp of propofol, and 0.66 for BIS. With a cutoff value of 75% for hand strength, the sensitivity was 0.76, and the specificity was 0.67. These data demonstrated that hand strength is a useful indicator for assessing the intraoperative level of consciousness during awake craniotomy.

The Effect of Right Temporal Lobe Gliomas on Left and Right Hemisphere Neural Processing During Speech Perception and Production Tasks

Using fMRI, we investigated how right temporal lobe gliomas affecting the posterior superior temporal sulcus alter neural processing observed during speech perception and production tasks. Behavioural language testing showed that three pre-operative neurosurgical patients with grade 2, grade 3 or grade 4 tumours had the same pattern of mild language impairment in the domains of object naming and written word comprehension. When matching heard words for semantic relatedness (a speech perception task), these patients showed under-activation in the tumour infiltrated right superior temporal lobe compared to 61 neurotypical participants and 16 patients with tumours that preserved the right postero-superior temporal lobe, with enhanced activation within the (tumour-free) contralateral left superior temporal lobe. In contrast, when correctly naming objects (a speech production task), the patients with right postero-superior temporal lobe tumours showed higher activation than both control groups in the same right postero-superior temporal lobe region that was under-activated during auditory semantic matching. The task dependent pattern of under-activation during the auditory speech task and over-activation during object naming was also observed in eight stroke patients with right hemisphere infarcts that affected the right postero-superior temporal lobe compared to eight stroke patients with right hemisphere infarcts that spared it. These task-specific and site-specific cross-pathology effects highlight the importance of the right temporal lobe for language processing and motivate further study of how right temporal lobe tumours affect language performance and neural reorganisation. These findings may have important implications for surgical management of these patients, as knowledge of the regions showing functional reorganisation may help to avoid their inadvertent damage during neurosurgery.

Perioperative Factors Affecting Readmission After Awake Craniotomy: Analysis of 609 Consecutive Cases

BACKGROUND

Awake craniotomy is being used widely for tumors near eloquent areas of the brain and also to facilitate early discharge from the hospital. Although most of the complications occur early in the postoperative period, there is a certain risk of delayed postoperative adverse events after discharge. This study investigated the incidence and the risk factors for postdischarge readmission after awake surgeries.

METHODS

This was a single-institution cohort study of 609 awake craniotomies by one surgeon at Toronto Western Hospital, 2006-2018.

RESULTS

Of 609 cases, 562 cases were available for analyses on postoperative readmission. In total, 6.0% (34 cases) were readmitted for medical reasons within 30 days after surgery, including neurologic decline (n = 9, 1.6%), infection at the surgical site (n = 8, 1.4%), followed by seizure (n = 5, 0.9%). Preoperative history of seizure (generalized or complex) was associated with readmission (P = 0.02). Eight of these plus 6 other cases experienced reoperation, and all the cases were due to infection but one (intraventricular hemorrhage). Investigations on correlations between perioperative factors and the reoperation found that redo surgery and findings of hemorrhage on postoperative imaging were significantly associated with reoperation (P = 0.0032, 0.0104 on multivariate analyses, respectively).

CONCLUSIONS

Although age, malignancy, or preoperative performance status were not related to readmission or reoperation, redo surgery cases and cases with postoperative hematoma were found to be at an increased risk for reoperation. Special attention and care need to be paid to these cases for potential complications after discharge, especially in situations in which patients tend to be discharged early after awake surgeries.

Presence of a translator in the operating theater for awake mapping in foreign patients with low-grade glioma: a surgical experience based on 18 different native languages

OBJECTIVE

Intraoperative brain mapping with neurocognitive monitoring during awake surgery is currently the standard pattern of care for patients with diffuse low-grade glioma (DLGG), allowing a maximization of the extent of resection (EOR) while preserving quality of life. This study evaluated the feasibility of DLGG resections performed with intraoperative cognitive monitoring via the assistance of a translator for patients speaking foreign languages, and compared the surgical functional and oncological outcomes according to the possibility of direct communication with the surgical team.

METHODS

Foreign patients who underwent awake surgery with intraoperative electrical mapping with the assistance of a translator for the resection of a DLGG in the authors' institution between January 2010 and December 2020 were included. Patients whose native language included one of the three languages spoken by the surgical team (i.e., French, English, or Spanish) were excluded. The patients were classified into two groups. Group 1 was composed of patients able to communicate in at least one of these three languages in addition to their own native language. Group 2 was composed of patients who spoke none of these languages, and therefore were unable to communicate directly with the operating staff. The primary outcome was the patients' ability to return to work 3 months after surgery.

RESULTS

Eighty-four patients were included, of whom 63 were classified in group 1 and 21 in group 2. Eighteen different native languages were tested in the operating theater. Awake mapping was successful, with elicitation of transitory disturbances in all patients. There was no significant difference in the 3-month return-to-work status between the two groups (95% in group 1 [n = 58/61] vs 88% in group 2 [n = 15/17]; p = 0.298). Similarly, no significant difference between the two groups was found regarding the intraoperative tasks performed, the mean duration of the surgery, and the rate of permanent postoperative deficit. A significantly greater EOR was observed in group 1 patients in comparison to group 2 patients (90.4% ± 10.6% vs 87.7% ± 6.1%; p = 0.029).

CONCLUSIONS

Real-time translation by an interpreter during awake resection of glioma is feasible and safe in foreign patients. Nonetheless, when no direct verbal communication is possible between the surgical team and the patient, the EOR is less.

Multimodal integrated approaches in low grade glioma surgery

Surgical management of Diffuse Low-Grade Gliomas (DLGGs) has radically changed in the last 20 years. Awake surgery (AS) in combination with Direct Electrical Stimulation (DES) and real-time neuropsychological testing (RTNT) permits continuous intraoperative feedback, thus allowing to increase the extent of resection (EOR). The aim of this study was to evaluate the impact of the technological advancements and integration of multidisciplinary techniques on EOR. Two hundred and eighty-eight patients affected by DLGG were enrolled. Cases were stratified according to the surgical protocol that changed over time: 1. DES; 2. DES plus functional MRI/DTI images fused on a NeuroNavigation system; 3. Protocol 2 plus RTNT. Patients belonging to Protocol 1 had a median EOR of 83% (28–100), while those belonging to Protocol 2 and 3 had a median EOR of 88% (34–100) and 98% (50–100) respectively (p = 0.0001). New transient deficits with Protocol 1, 2 and 3 were noted in 38.96%, 34.31% and 31,08% of cases, and permanent deficits in 6.49%, 3.65% and 2.7% respectively. The average follow-up period was 6.8 years. OS was influenced by molecular class (p = 0.028), EOR (p = 0.018) and preoperative tumor growing pattern (p = 0.004). Multimodal surgical approach can provide a safer and wider removal of DLGG with potential subsequent benefits on OS. Further studies are necessary to corroborate our findings.

Awake Epilepsy Surgery in Patients with Focal Cortical Dysplasia

BACKGROUND

Awake craniotomy (AC) and direct electric stimulation emerged together with epilepsy surgery >80 years ago. The goal of our study was to evaluate the benefits of awake surgery in patients with drug-resistant epilepsy caused by focal cortical dysplasia (FCD) affecting eloquent areas.

METHODS

Our material included 95 patients with drug-resistant epilepsy and FCD, who were operated on between January 2009 and December 2018. These 95 patients were assigned into 3 groups: AC; general anesthesia (GA) with intraoperative neuromonitoring; and GA without intraoperative neuromonitoring. We investigated the following variables: age at surgery, lesion side, eloquent cortex involvement, brain mapping success rate, epilepsy surgery success rate, intraoperative complications, postoperative complications, and intraoperative changes of the preoperative resection plan according to results of the brain mapping by direct electric stimulation.

RESULTS

We found statistically significant differences between the AC and GA groups in the mean age at operation, lesion side, eloquent localization, and postoperative transient neurologic deficit. Seizure outcome in the AC was satisfactory (71% complete seizure control) and comparable to the seizure outcome in the GA groups. Our preoperative plan was changed because of functional constraints in 6 patients (43%) operated on during AC.

CONCLUSIONS

AC during epilepsy surgery for FCD in eloquent areas may change the preoperative plan. The good rate of postoperative seizure control and the absence of permanent postoperative neurologic deficit in our series is the main proof that AC is a useful tool in patients with FCD involving the eloquent cortex.

Role of Preoperative Assessment in Predicting Tumor-Induced Plasticity in Patients with Diffuse Gliomas

When diffuse gliomas (DG) affect the brain’s potential to reorganize functional networks, patients can exhibit seizures and/or language/cognitive impairment. The tumor–brain interaction and the individual connectomic organization cannot be predicted preoperatively. We aimed to, first, investigate the relationship between preoperative assessment and intraoperative findings of eloquent tumors in 36 DG operated with awake surgery. Second, we also studied possible mechanisms of tumor-induced brain reorganization in these patients. FLAIR-MRI sequences were used for tumor volume segmentation and the Brain-Grid system (BG) was used as an overlay for infiltration analysis. Neuropsychological (NPS) and/or language assessments were performed in all patients. The distance between eloquent spots and tumor margins was measured. All variables were used for correlation and logistic regression analyses. Eloquent tumors were detected in 75% of the patients with no single variable able to predict this finding. Impaired NPS functions correlated with invasive tumors, crucial location (A4C2S2/A3C2S2-voxels, left opercular-insular/sub-insular region) and higher risk of eloquent tumors. Epilepsy was correlated with larger tumor volumes and infiltrated A4C2S2/A3C2S2 voxels. Language impairment was correlated with infiltrated A3C2S2 voxel. Peritumoral cortical eloquent spots reflected an early compensative mechanism with age as possible influencing factor. Preoperative NPS impairment is linked with high risk of eloquent tumors. A systematic integration of extensive cognitive assessment and advanced neuroimaging can improve our comprehension of the connectomic brain organization at the individual scale and lead to a better oncological/functional balance.

Brain Mapping-Aided SupraTotal Resection (SpTR) of Brain Tumors: The Role of Brain Connectivity

Brain gliomas require a deep knowledge of their effects on brain connectivity. Understanding the complex relationship between tumor and functional brain is the preliminary and fundamental step for the subsequent surgery. The extent of resection (EOR) is an independent variable of surgical effectiveness and it correlates with the overall survival. Until now, great efforts have been made to achieve gross total resection (GTR) as the standard of care of brain tumor patients. However, high and low-grade gliomas have an infiltrative behavior and peritumoral white matter is often infiltrated by tumoral cells. According to these evidences, many efforts have been made to push the boundary of the resection beyond the contrast-enhanced lesion core on T1w MRI, in the so called supratotal resection (SpTR). SpTR is aimed to maximize the extent of resection and thus the overall survival. SpTR of primary brain tumors is a feasible technique and its safety is improved by intraoperative neuromonitoring and advanced neuroimaging. Only transient cognitive impairments have been reported in SpTR patients compared to GTR patients. Moreover, SpTR is related to a longer overall and progression-free survival along with preserving neuro-cognitive functions and quality of life.

What effects does awake craniotomy have on functional and survival outcomes for glioblastoma patients?

PURPOSE

Neurosurgeons adopt several different surgical approaches to deal with glioblastomas (GB) located in or near eloquent areas. Some attempt maximal safe resection by awake craniotomy (AC), but doubts persist concerning the real benefits of this type of surgery in this situation. We performed a retrospective study to evaluate the extent of resection (EOR), functional and survival outcomes after AC of patients with GB in critical locations.

METHODS

Forty-six patients with primary GB treated with the Stupp regimen between 2004 and 2019, for whom brain mapping was feasible, were included. We assessed EOR, postoperative language and/or motor deficits three months after AC, progression-free survival (PFS) and overall survival (OS).

RESULTS

Complete resection was achieved in 61% of the 46 GB patients. The median PFS was 6.8 months (CI 6.1; 9.7) and the median OS was 17.6 months (CI 14.8; 34.1). Three months after AC, more than half the patients asymptomatic before surgery remained asymptomatic, and one third of patients with symptoms before surgery experienced improvements in language, but not motor functions. The risk of postoperative deficits was higher in patients with preoperative deficits or incomplete resection. Furthermore, the presence of postoperative deficits was an independent predictive factor for shorter PFS.

CONCLUSION

AC is an option for the resection of GB in critical locations. The observed survival outcomes are typical for GB patients in the Stupp era. However, the success of AC in terms of the recovery or preservation of language and/or motor functions cannot be guaranteed, given the aggressiveness of the tumor.

Intraoperative brain mapping of language, cognitive functions, and social cognition in awake surgery of low-grade gliomas located in the right non-dominant hemisphere

OBJECTIVE

The aim of our study was to evaluate the usefulness of cortical-subcortical intraoperative brain mapping (ioBM) in resective awake surgery of low-grade gliomas (LGG) of the right non-dominant hemisphere (RndH). It was estimated how ioBM may affect both the extent of resection and postoperative outcome of language, spatial cognition, social cognition, and executive functions including attention and working memory.

PATIENTS AND METHODS

Fifteen patients that underwent ioBM in resective awake surgery of LGG located on the RndH, were included. A cohort of 15 patients with the same tumour location operated under general anaesthesia without brain mapping was used as control. Specific intraoperative tasks for each location were carried out and results registered. Neuropsychological assessment was performed preoperatively and at 6 months after surgery.

RESULTS

In the group of patients operated by using ioBM in awake surgery, an 86.66 % mean of resection was obtained compared to 60.33 % in the control group. Speech arrest and incorrect naming responses were elicited in higher proportion in frontal and insular locations. Parietal stimulation associated higher number of incorrect responses in social cognition task. Parietal and temporal stimulation were more frequently associated with incorrect performance of spatial cognition task. Parietal stimulation associated with higher frequency incorrect execution of attention and working memory tasks. After comparing clinical and neuropsychological results in both cohorts, worst outcome at 6 months was observed in the group of patients operated under general anaesthesia without brain mapping, especially in parietal and insular locations.

CONCLUSIONS

Intraoperative identification of language, cognitive functions, and social cognition of RndH by means of ioBM, can be of paramount importance in improving the extent of resection of low-grade gliomas and positively affects clinical and neuropsychological outcome at six months.

Clinical Management of Diffuse Low-Grade Gliomas

Diffuse low-grade gliomas (LGG) represent a heterogeneous group of primary brain tumors arising from supporting glial cells and usually affecting young adults. Advances in the knowledge of molecular profile of these tumors, including mutations in the isocitrate dehydrogenase genes, or 1p/19q codeletion, and in neuroradiological techniques have contributed to the diagnosis, prognostic stratification, and follow-up of these tumors. Optimal post-operative management of LGG is still controversial, though radiation therapy and chemotherapy remain the optimal treatments after surgical resection in selected patients. In this review, we report the most important and recent research on clinical and molecular features, new neuroradiological techniques, the different therapeutic modalities, and new opportunities for personalized targeted therapy and supportive care.

Diffuse low grade glioma and pregnancy: Practical considerations and clinical tips

OBJECTIVE

The interaction between pregnancy and diffuse low-grade glioma (DLGG) is poorly investigated. The goal of this study was to provide further insights into the relationship between pregnancy and DLGG.

METHODS

A total of 12 patients were selected from a shared database of DLGGs, according to the following inclusion criteria: DLGG diagnosis in post-partum, DLGG recurrence after pregnancy in patients previously operated for DLGG. The extent of surgical resection (EOR) at first surgery were evaluated. All cases were assessed based on the 2016 WHO classification. The tumor growing patter, expresses by preoperative ΔT2T1 MRI index was evaluated.

RESULTS

In four cases newly diagnosed DLGG were detected patients in post-partum. Seven women, previously operated for DLGG, experienced pregnancy during the natural history of glioma, and were affected by tumor recurrence after pregnancy. One singular had an incidental LGG not surgically treated, who presented an important tumor growth after pregnancy. Radiological and surgical data were discussed according to literature.

CONCLUSIONS

Pregnancy does not seem to have an impact on the survival of women with DLGG. The potential role of pregnancy as risk factor in tumor recurrence is described, however, not proven. In this regard, the association between pregnancy and Tumor recurrence is extremely doubtful, and currently attributable to the simple coincidence. Further multicenter molecular investigations are required to better understand the mechanisms by which the pregnancy, in patients with a pervious surgery for DLGG, may influence tumor regrowth in comparison with the natural history of the disease.

Anesthetic considerations for awake craniotomy

Awake craniotomy is a gold standard of care for resection of brain tumors located within or close to the eloquent areas. Both asleep-awake-asleep technique and monitored anesthesia care have been used effectively for awake craniotomy and the choice of optimal anesthetic approach is primarily based on the preferences of the anesthesiologist and surgical team. Propofol, remifentanil, dexmedetomidine, and scalp nerve block provide the reliable conditions for intraoperative brain mapping. Appropriate patient selection, adequate perioperative psychological support, and proper anesthetic management for individual patients in each stage of surgery are crucial for procedural safety, success, and patient satisfaction.

The Ethical Dilemma in the Surgical Management of Low Grade Gliomas According to the Variable Availability of Resources and Surgeon Experience

Low grade gliomas (LGGs) affect young individuals in the prime of life. Management may alternatively include biopsy and observation or surgical resection. Recent evidence strongly favors maximal and supramaximal resection of LGGs in optimizing survival metrics. Awake craniotomy with cortical mapping and electrical stimulation along with other preoperative and intraoperative surgical adjuncts, including intraoperative magnetic resonance and diffusion tensor imaging, facilitates maximization of resection and eschews precipitating neurological deficits. Intraoperative imaging permits additional resection of identified residual to be completed within the same surgical session, improving extent of resection and consequently progression free and overall survival. These resources are available in only a few centers throughout the United States, raising an ethical dilemma as to where patients harboring LGGs should most appropriately be treated.

Anesthesia management for low-grade glioma awake surgery: a European Low-Grade Glioma Network survey

BACKGROUND

Awake surgery has become a key treatment of diffuse low-grade gliomas (DLGG) and is divided in three main phases: opening, tumor resection - during which the patient needs to be fully awake - and closure. The anesthetic management of awake neurosurgery is a challenge, and there are currently no guidelines.

OBJECTIVE

The objective of the survey was to explore differences and commonalities regarding the anesthetic management of awake DLGG surgery within the European Low-Grade Glioma Network (ELGGN) centers.

METHODS

A form that contained 14 questions about the anesthetic management was sent to 28 centers in May 2015.

RESULTS

Twenty centers responded. During the opening and closing non-awake periods, 56% of teams chose general anesthesia with mechanical ventilation for at least one period (asleep-awake-asleep, SAS protocol), and 44% monitored anesthesia care including sedation without mechanical ventilation (MAC protocol). In case of SAS, all the teams chose intravenous anesthesia, 82% used laryngeal mask instead of endotracheal intubation during the opening sequence, and 71% during closure. Local and regional anesthesia was practiced by all the teams. The most frequently reported cause of pain was dural and cerebral vessels manipulation (77%). Pain management was mostly based on paracetamol (70%) and remifentanil (55%).

CONCLUSION

Our survey showed that there was an equivalent proportion of centers using SAS or MAC protocols in the anesthetic management of awake surgery in ELGGN centers. The advantages and disadvantages of each anesthesia protocol were reviewed.

Neurocognitive and functional outcomes in patients with diffuse frontal lower-grade gliomas undergoing intraoperative awake brain mapping

OBJECTIVE

Lower-grade gliomas (LGGs) are often observed within eloquent regions, which indicates that tumor resection in these areas carries a potential risk for neurological disturbances, such as motor deficit, language disorder, and/or neurocognitive impairments. Some patients with frontal tumors exhibit severe impairments of neurocognitive function, including working memory and spatial awareness, after tumor removal. The aim of this study was to investigate neurocognitive and functional outcomes of frontal LGGs in both the dominant and nondominant hemispheres after awake brain mapping.

METHODS

Data from 50 consecutive patients with diffuse frontal LGGs in the dominant and nondominant hemispheres who underwent awake brain surgery between December 2012 and September 2018 were retrospectively analyzed. The goal was to map neurocognitive functions such as working memory by using working memory tasks, including digit span testing and N-back tasks.

RESULTS

Due to awake language mapping, the frontal aslant tract was frequently identified as a functional boundary in patients with left superior frontal gyrus tumors (76.5%). Furthermore, functional boundaries were identified while evaluating verbal and spatial working memory function by stimulating the dorsolateral prefrontal cortex using the digit span and visual N-back tasks in patients with right superior frontal gyrus tumors (7.1%). Comparing the preoperative and postoperative neuropsychological assessments from the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) and Wechsler Memory Scale-Revised (WMS-R), significant improvement following awake surgery was observed in mean Perceptual Organization (Z = -2.09, p = 0.04) in WAIS-III scores. Postoperative mean WMS-R scores for Visual Memory (Z = -2.12, p = 0.03) and Delayed Recall (Z = -1.98, p = 0.04) were significantly improved compared with preoperative values for every test after awake surgery. No significant deterioration was noted with regard to neurocognitive functions in a comprehensive neuropsychological test battery. In the postoperative course, early transient speech and motor disturbances were observed in 30.0% and 28.0% of patients, respectively. In contrast, late permanent speech and motor disturbances were observed in 0% and 4.0%, respectively.

CONCLUSIONS

It is noteworthy that no significant postoperative deterioration was identified compared with preoperative status in a comprehensive neuropsychological assessment. The results demonstrated that awake functional mapping enabled favorable neurocognitive and functional outcomes after surgery in patients with diffuse frontal LGGs.

Awake brain surgery in children-a single-center experience

INTRODUCTION

Awake brain surgery (ABS) represents a rare surgical procedure in children as age and psychological aspects, which are considered to interfere with its feasibility and psychological outcome and limit its application. Only few pediatric case series have been reported so far, indicating a more complex translation of this surgical approach to children. However, the advances in neuropsychological testing and monitoring may have a substantial impact on ameliorating the eligibility of children undergoing awake procedures. This study addresses the condition of ABS in a pediatric cohort, focusing on its practicability and diversified outcome aspects.

METHODS

We performed a retrospective review and prospective outcome analysis of pediatric patients with CNS lesions undergoing ABS between 2005 and 2018, completed at the University of Lyon, France.

RESULTS

Eighteen children were considered for ABS with respect to the eloquent location of their CNS lesions documented in their pre-operative MRI. Seventeen of them underwent asleep-awake-asleep brain surgery. The cohort included 5 males and 12 females. The median age at surgery was 14.8 years, (range 9.4 to 17.6 years). Intraoperative testing included electrocortical stimulation while pursuing speech or motor activity. Most of the lesions were intrinsic tumors of glial origin. A complete tumor removal was achieved in 11 patients (65%). Post-operative neurological deficits were transiently observed in 2 patients, whereas severe psychological reactions occurred in 1 child. Persistent attention deficits were found in 2 patients. One patient experienced an infectious complication requiring antibiotic treatment. Two patients died during follow-up due to tumor progression. The mean duration of follow up was 22.2 months (range 3.4 to 46.8 months).

CONCLUSIONS

ABS was shown to be beneficial in terms of efficient tumor resection besides simultaneous preservation of neurological functions. Psychological preparation of the families and the children is essential to increase the number and age range of patients, who can benefit from this technique. Neuropsychological testing before and after surgery is essential to determine cognitive outcome, which can be altered in a minority of patients.

Italian consensus and recommendations on diagnosis and treatment of low-grade gliomas. An intersociety (SINch/AINO/SIN) document

In 2018, the SINch (Italian Society of Neurosurgery) Neuro-Oncology Section, AINO (Italian Association of Neuro-Oncology) and SIN (Italian Association of Neurology) Neuro-Oncology Section formed a collaborative Task Force to look at the diagnosis and treatment of low-grade gliomas (LGGs). The Task Force included neurologists, neurosurgeons, neuro-oncologists, pathologists, radiologists, radiation oncologists, medical oncologists, a neuropsychologist and a methodologist. For operational purposes, the Task Force was divided into five Working Groups: diagnosis, surgical treatment, adjuvant treatments, supportive therapies, and follow-up. The resulting guidance document is based on the available evidence and provides recommendations on diagnosis and treatment of LGG patients, considering all aspects of patient care along their disease trajectory.

Receptor tyrosine kinase gene amplification is predictive of intraoperative seizures during glioma resection with functional mapping

OBJECTIVE

Intraoperative seizures during craniotomy with functional mapping is a common complication that impedes optimal tumor resection and results in significant morbidity. The relationship between genetic mutations in gliomas and the incidence of intraoperative seizures has not been well characterized. Here, the authors performed a retrospective study of patients treated at their institution over the last 12 years to determine whether molecular data can be used to predict the incidence of this complication.

METHODS

The authors queried their institutional database for patients with brain tumors who underwent resection with intraoperative functional mapping between 2005 and 2017. Basic clinicopathological characteristics, including the status of the following genes, were recorded: IDH1/2, PIK3CA, BRAF, KRAS, AKT1, EGFR, PDGFRA, MET, MGMT, and 1p/19q. Relationships between gene alterations and intraoperative seizures were evaluated using chi-square and two-sample t-test univariate analysis. When considering multiple predictive factors, a logistic multivariate approach was taken.

RESULTS

Overall, 416 patients met criteria for inclusion; of these patients, 98 (24%) experienced an intraoperative seizure. Patients with a history of preoperative seizure and those treated with antiepileptic drugs prior to surgery were less likely to have intraoperative seizures (history: OR 0.61 [95% CI 0.38-0.96], chi-square = 4.65, p = 0.03; AED load: OR 0.46 [95% CI 0.26-0.80], chi-square = 7.64, p = 0.01). In a univariate analysis of genetic markers, amplification of genes encoding receptor tyrosine kinases (RTKs) was specifically identified as a positive predictor of seizures (OR 5.47 [95% CI 1.22-24.47], chi-square = 5.98, p = 0.01). In multivariate analyses considering RTK status, AED use, and either 2007 WHO tumor grade or modern 2016 WHO tumor groups, the authors found that amplification of the RTK proto-oncogene, MET, was most predictive of intraoperative seizure (p < 0.05).

CONCLUSIONS

This study describes a previously unreported association between genetic alterations in RTKs and the occurrence of intraoperative seizures during glioma resection with functional mapping. Future models estimating intraoperative seizure risk may be enhanced by inclusion of genetic criteria.

Psychological aspects of awake brain surgery in children-interests and risks

Awake brain surgery (ABS) in children remains a subject of controversial debate for the potential psychological limitations that are related to this type of procedure. However, the tolerance and benefits of ABS in adults advocate for increased application of ABS in children. In this study, we report the psychological assessment, evaluation algorithm, and outcome of pediatric patients, who underwent ABS for surgical treatment of lesions in eloquent areas. Psychological selection criteria and the specifications of psychological support are described. A retrospective review and analysis of psychological assessment and psychological outcome of pediatric patients, who underwent ABS between 2005 and 2018 at the Department of pediatric neurosurgery, University of Lyon, France, was performed. Long-term psychological outcomes are reported. ABS was proposed to 18 children aged between 9 and 17 years and their families. After psychological evaluation of the individual patient and their familial surrounding, five boys and 12 girls (n = 17) were accounted eligible for ABS. They underwent asleep-awake-asleep brain surgery with intraoperative testing. In 16 cases, ABS could be performed as planned. Psychological alterations were postoperatively observed in 3 patients, symptoms of a post-traumatic stress disorder in 1 patient. The precise preoperative evaluation of the risk-benefit ratio in children plays a crucial role in anticipating a good psychological outcome. Professional psychological preparation and support of the child and his or her family are the key elements for successful completion of ABS.

T2 Fluid-Attenuated Inversion Recovery Resection for Glioblastoma Involving Eloquent Brain Areas Facilitated Through Awake Craniotomy and Clinical Outcome

BACKGROUND

Despite evidence that a greater extent of resection (EOR) improves survival, the role of extended resection based on magnetic resonance imaging (MRI) fluid-attenuated inversion recovery (FLAIR) in the prognosis of glioblastoma (GBM) remains controversial. This study aims to investigate the role of additional resection of FLAIR-detected abnormalities and its influence on clinical outcomes of patients with GBM.

METHODS

Forty-six patients with newly diagnosed GBM involving eloquent brain areas were included. Surgeries were performed using awake craniotomy (AC) or AC combined with sodium fluorescein (SF) guidance. Following total removal of the contrast-enhancing tumor area, the EOR of FLAIR abnormalities was dichotomized to identify the best separation threshold for progression-free survival (PFS), overall survival (OS), and 30-day postoperative neurologic function of patients with GBM.

RESULTS

The threshold for removal of FLAIR abnormalities affecting survival was determined to be 25%. The median OS and PFS were shorter in the group with FLAIR resection <25% compared with the group with FLAIR resection ≥25% (12 months vs. 26 months; P = 0.001 and 6 months vs. 15 months; P = 0.016, respectively). Univariate and multivariate analyses identified tumor location within or near the eloquent brain areas and the 25% threshold for FLAIR EOR as independent factors affecting OS and PFS.

CONCLUSIONS

Identifying a feasible threshold for the resection of FLAIR abnormalities is valuable in improving the survival of patients with GBM. Extended resection of GBM involving eloquent brain areas was safe when using a combination of AC and SF-guided surgery.

Preoperative predictive factors affecting return to work in patients with gliomas undergoing awake brain mapping

PURPOSE

This study aimed to investigate the preoperative predictive factors affecting return to work in patients with gliomas in the left cerebral hemisphere undergoing awake surgery.

METHODS

We retrospectively reviewed 50 consecutive glioma patients who underwent awake surgery from January 2012 to July 2017. Adult patients older than 18 years, who reported working prior to surgery, were recruited for this study.

RESULTS

Comparing sociodemographic, disease-related and preoperative neurocognitive variables of glioma patients who returned to work and those who did not, binomial logistic regression models for preoperative predictors affecting return to work revealed significant differences in age and sole breadwinner status as sociodemographic variables, tumour volume as a disease-related variable, and Verbal IQ, Performance IQ, general memory, attention/concentration, and working memory as neurocognitive variables. Multivariate logistic regression models demonstrated that the independent factors associated with propriety of returning to work 1 year after surgery was the sociodemographic variable sole breadwinner status (yes vs no; OR = 15.00, 95% CI 2.22-101.35, p = 0.01), the disease-related variable tumour volume (per 1 cm³; OR = 0.98, 95% CI 0.96-0.99, p = 0.04), and the preoperative neurocognitive variable general memory (≥ 100 vs < 100; OR = 21.70, 95% CI 2.60-183.94, p = 0.01).

CONCLUSIONS

Our results suggest that three predictive factors including sole breadwinner status, tumour volume and general memory that can be assessed in the preoperative stage substantially contribute to returning to work in patients with gliomas in the left cerebral hemisphere, 1 year after awake surgery.

Awake Craniotomy for a Left Pan-Hippocampal Diffuse Low-Grade Glioma in a Deaf and Mute Patient Using Sign Language

BACKGROUND

Awake craniotomy is becoming an essential technique, especially for intrinsic brain tumors which have no clear margins and where extent of resection (EOR) matters. However, intraoperative monitoring for awaken patients requires voice feedback in regular settings. Resection of hippocampal glioma is challenging because of its deep-seated location, its extension in an anterior-posterior axis, and being covered with eloquent cortex. We present a native deaf and mute patient, who has been diagnosed of a left pan-hippocampal glioma, who underwent an awake craniotomy using sign language during intraoperative monitoring.

CASE DESCRIPTION

The patient was a 58-year-old, right-handed, native deaf and mute woman who was diagnosed with a left pan-hippocampal glioma. Magnetic resonance imaging (MRI) revealed an intrinsic, nonenhanced, expansile lesion involving the pan-hippocampus. Functional MRI preferred a right hemisphere-dominant pattern. Neuropsychologic testing was normal. An awake craniotomy was successfully performed using sign language to preserve her remaining sole method of communication. A standard sleep-awake-sleep protocol with a transmiddle temporal gyrus (2.5 × 1 cm gyrectomy) approach was performed after a negative mapping result. More than 90% EOR was achieved with only a 0.7 cm³ residual tumor at the hippocampal tail. The pathology was anaplastic ganglioglioma, Ki-67 70%, and World Health Organization grade III. Her postoperative neuropsychologic status was the same as preoperative condition.

CONCLUSIONS

We demonstrated using sign language for intraoperative monitoring is feasible in a native deaf and mute patient. We also showed a navigation-assisted minimal transcortical approach to achieve >90% EOR for a pan-hippocampal glioma in a single-stage operation.

Setup presentation and clinical outcome analysis of treating highly language-eloquent gliomas via preoperative navigated transcranial magnetic stimulation and tractography

OBJECTIVE Awake surgery combined with intraoperative direct electrical stimulation (DES) and intraoperative neuromonitoring (IONM) is considered the gold standard for the resection of highly language-eloquent brain tumors. Different modalities, such as functional magnetic resonance imaging (fMRI) or magnetoencephalography (MEG), are commonly added as adjuncts for preoperative language mapping but have been shown to have relevant limitations. Thus, this study presents a novel multimodal setup consisting of preoperative navigated transcranial magnetic stimulation (nTMS) and nTMS-based diffusion tensor imaging fiber tracking (DTI FT) as an adjunct to awake surgery. METHODS Sixty consecutive patients (63.3% men, mean age 47.6 ± 13.3 years) suffering from highly language-eloquent left-hemispheric low- or high-grade glioma underwent preoperative nTMS language mapping and nTMS-based DTI FT, followed by awake surgery for tumor resection. Both nTMS language mapping and DTI FT data were available for resection planning and intraoperative guidance. Clinical outcome parameters, including craniotomy size, extent of resection (EOR), language deficits at different time points, Karnofsky Performance Scale (KPS) score, duration of surgery, and inpatient stay, were assessed. RESULTS According to postoperative evaluation, 28.3% of patients showed tumor residuals, whereas new surgery-related permanent language deficits occurred in 8.3% of patients. KPS scores remained unchanged (median preoperative score 90, median follow-up score 90). CONCLUSIONS This is the first study to present a clinical outcome analysis of this very modern approach, which is increasingly applied in neurooncological centers worldwide. Although human language function is a highly complex and dynamic cortico-subcortical network, the presented approach offers excellent functional and oncological outcomes in patients undergoing surgery of lesions affecting this network.

Glioma surgery: From preservation of motor skills to conservation of cognitive functions

The first step of glioma treatment is surgery. Extent of resection (EOR) improves patient survival if surgery does not negatively impair a patient's neurological status. However, how surgery affects the patient's quality of life (QOL) has been less studied, especially as regards cognitive aspects. In our study, we retrospectively analyzed our cases with awake surgery. In all patients, surgical excision was stopped when active functions were intraoperatively identified. A neuropsychological assessment was performed both before and after surgery (5 days and 1 month after). Writing, motor speech, comprehension, expression, reading, pragmatics, attention, memory, problem solving and visuoperceptive functions were evaluated and scored with the NOMS scale. We found no differences in the median values of writing and motor speech, while there was a difference in the following variables: comprehension, expression, reading, pragmatics, attention, memory, problem solving and visuoperceptive functions. Moreover, the Dunn test did not show any difference between preoperative evaluation and evaluation performed 30 days after surgery regarding comprehension, expression, reading, pragmatics, attention, problem solving and visuoperceptive functions. However, there was a difference between preoperative and postoperative evaluation for memory. This retrospective study shows that awake surgery could be a reasonable possibility to preserve a patient's QOL achieving an EOR >82% of the Total Tumor Volume (Fluid-attenuated inversion recovery (FLAIR) hyperintense region in low-grade gliomas and enhancing nodules plus FLAIR hyperintense region in high-grade gliomas). In this series memory was the only aspect that had an impairment after surgery without a complete recovery at one month after surgery.

Electrophysiological Mapping and Monitoring during an Awake Craniotomy for Low-Grade Glioma: Case Report

Awake craniotomy is advocated for the resection of supratentorial low-grade gliomas (LGG). The combination of neurophysiological electrical mapping techniques and performing the craniotomy awake has demonstrated increased total and supratotal resection of LGG, as well as increased overall survival rates. We present an illustrative case where the patient's gross motor function deteriorated during the resection of a LGG and mapping techniques using the phase reversal technique and Taniguchi direct cortical stimulation technique while the patient was awake proved to be valuable in determining continuity of the corticospinal tracts.

Anesthesia for awake craniotomy

PURPOSE OF REVIEW

The current review reports on current trends in the anesthetic management of awake craniotomy, including preoperative preparation, sedation schemes, pain management, and prevention of intraoperative complications.

RECENT FINDINGS

Both approaches for anesthesia for awake craniotomy, asleep-awake-asleep and monitored anesthesia care (MAC), have shown equal efficacy for performing intraoperative brain mapping. Choice of the appropriate scheme is currently based mainly on the preferences of the particular anesthesiologist. Dexmedetomidine has demonstrated high efficacy and safety in MAC for awake craniotomy and has become a rational alternative to propofol. Despite the high efficacy of scalp block and opioids, pain remains a common compliant in awake craniotomy. Appropriate surgical tactics can reduce pain and even prevent postoperative neurological complications. Although the efficacy of prophylaxis of intraoperative seizures with anticonvulsants remains doubtful, levetiracetam can be superior to other drugs for this purpose.

SUMMARY

Following a great deal of progress in anesthetic management, awake craniotomy, which had been a relatively rare approach, is now a commonly performed procedure for neurosurgical intervention. Modern anesthesia techniques can provide for successful brain mapping in almost any patient. Management of awake craniotomy in high-risk patients is a central task for future research.

Tumour volume reduction following PET guided intensity modulated radiation therapy and temozolomide in IDH mutated anaplastic glioma

The role of maximal surgical debulking in isocitrate dehydrogenase (IDH) mutated anaplastic glioma prior to adjuvant radiation therapy remains uncertain. This study assessed the reduction in tumour volume following intensity modulated radiation therapy (IMRT) and temozolomide in this favourable and more responsive tumour pathology. 56 patients were managed from 2011 to 2014 and 53 had residual disease. To assess radiological response, tumour volumes were created on representative T1/T2Flair MRI sequences using identical slice-levels in three planes for pre-IMRT, month + 3 and month + 12 post-IMRT scans. Change in volumes was assessed between time periods. Progression-free survival (PFS) was calculated from start of radiotherapy. Median follow-up for survivors is 48.2 months. Pathology was anaplastic oligodendroglioma (AOD) and anaplastic astrocytoma IDH-mutated (AAmut) in 32 and 21 patients respectively. 93% received sequential chemotherapy. The median residual disease on T1 and T2Flair imaging was 9.7 cm³ and 20.6 cm³. 17 patients relapsed for projected 5 year PFS of 74.9%; with 8 isolated relapses within initial surgical site. On MRI at month + 3, the median volume for T1 and T2Flair reduced by 69.4% and 67.3% respectively; which further decreased to 82.4% and 81.3% at month + 12. By month + 12, 69.2% and 62.2% of patients had >75% volume reduction. Patients with AOD had superior reduction at month + 3 compared with AAmut (p = 0.02); but equivalent reduction at month + 12 (p = 0.14). Thus, in patients with anaplastic glioma harbouring an IDH mutation, where an attempt at near-total resection may be associated with unacceptable morbidity, this data suggests that the radiation therapy may provide effective cytoreduction of residual disease.

Extent of Resection and Residual Tumor Thresholds for Postoperative Total Seizure Freedom in Epileptic Adult Patients Harboring a Supratentorial Diffuse Low-Grade Glioma

BACKGROUND

Epileptic seizures impair quality of life in diffuse low-grade glioma (DLGG) patients. Tumor resection significantly impacts postoperative seizure control, but the precise extent of resection (EOR) required for optimal seizure control is not clear yet.

OBJECTIVE

To identify the EOR and residual tumor volume that correlated to postoperative seizure control, defined as a total seizure freedom (Class 1A in reference to Engel classification system) with and without antiepileptic drugs in patients undergoing surgical resection of supratentorial DLGG.

METHODS

A retrospective review was conducted of all patients who underwent first-line surgical resection of supratentorial DLGG who presented with preoperative seizures without adjuvant oncological treatment. EOR and residual tumor volume were quantified from pre- and post-operative magnetic resonance imagings. Receiver operating characteristic curves were plotted to determine the EOR and residual tumor volume that corresponded to optimal postoperative seizure control.

RESULTS

Of the 346 included patients, 65.5% had controlled seizures postoperatively, with higher age at resection (adjusted OR per unit, 1.03 [95% confidence interval:1.01-1.06], P = .043) and higher percentage of resection (adjusted OR per unit, 1.02 [95% confidence interval:1.00-1.03], P < .001) found as independent predictors of postoperative seizure control. Optimal EOR was ≥91% and optimal residual tumor volume was ≤19 cc to improve postoperative seizure control.

CONCLUSION

Postoperative seizure control is more likely when EOR is ≥91% and/or when residual tumor volume is ≤19 cc in supratentorial DLGG gliomas who present with seizures. Resected peritumoral cortex should, however, be taken into account in future studies.