Prognostic utility and characteristics of MIB-1 labeling index as a proliferative activity marker in childhood low-grade glioma: a retrospective observational study.

PURPOSE: The prognostic utility of MIB-1 labeling index (LI) in pediatric low-grade glioma (PLGG) has not yet conclusively been described. We assess the correlation of MIB-1 LI and tumor growth velocity (TGV), aiming to contribute to the understanding of clinical implications and the predictive value of MIB-1 LI as an indicator of proliferative activity and progression-free survival (PFS) in PLGG. METHODS: MIB-1 LI of a cohort of 172 nonependymal PLGGs were comprehensively characterized. Correlation to TGV, assessed by sequential MRI-based three-dimensional volumetry, and PFS was analyzed. RESULTS: Mean MIB-1 LI accounted for 2.7% (range: < 1-10) and showed a significant decrease to 1.5% at secondary surgery (p = .0013). A significant difference of MIB-1 LI in different histopathological types and a correlation to tumor volume at diagnosis could be shown. Linear regression analysis showed a correlation between MIB-1 LI and preoperative TGV (R2 = .55, p < .0001), while correlation to TGV remarkably decreased after incomplete resection (R2 = .08, p = .013). Log-rank test showed no association of MIB-1 LI and 5-year PFS after incomplete (MIB-1 LI > 1 vs ≤ 1%: 48 vs 46%, p = .73) and gross-total resection (MIB-1 LI > 1 vs ≤ 1%: 89 vs 95%, p = .75). CONCLUSION: These data confirm a correlation of MIB-1 LI and radiologically detectable TGV in PLGG for the first time. Compared with preoperative TGV, a crucially decreasing correlation of MIB-1 LI and TGV after surgery may result in limited prognostic capability of MIB-1 LI in PLGG.

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.

Surgical treatment of small recurrent gliomas based on MR imaging examination.

Microrecurrent glioma is a common neurological tumor, and the key to its surgical treatment is to accurately evaluate the size, location and degree of recurrence of the lesion. The purpose of this study was to explore the surgical treatment of microrecurrent glioma based on MR Imaging, and to provide accurate and reliable basis for clinical decision-making. Before surgery, detailed MR Imaging tests were performed for each patient to accurately locate and evaluate the characteristics of the lesions. Multimodal imaging examination were arranged to accurate the pre-operation diagnosis. Neuro-navigation is necessary for the operation design and tumor confirmation. Function monitor and intraoperation MR were prepared when necessary.Mini was defined by the size, location and symptoms. In all 5 cases requiring reoperation, total resection was achieved. No systemic and local complications occurred. No permeant neurological dysfunction remained. The average stay time after the operation is days. All patients survived in the recent follow-up. Reoperation of mini recurrent glioma is a good treatment choice. We made little injury to patients, which wouldn't affect their conditions and next therapies. Through MR Imaging, the diagnosis and location of microrecurrent glioma, as well as the relationship with surrounding tissues and the degree of infiltration, provide important information for surgeons to evaluate the resectable lesion. By combining MR And functional imaging results, the blood supply and functional area of the lesion can be monitored in real time during surgery, thereby reducing surgical risk and maximizing the protection of surrounding healthy tissue.

Ependimomas de fosa posterior de tipo lateral en la edad pediátrica / Lateral-type posterior fossa ependymomas in pediatric population

Antecedentes y objetivos: Los ependimomas de fosa posterior de tipo lateral son un subtipo clínico e histológico característico, con un pronóstico poco favorable. Su incidencia es baja y su manejo quirúrgico es particularmente complejo. El objetivo del presente trabajo es revisar nuestra serie de ependimomas de fosa posterior de tipo lateral y contrastar nuestros resultados con la literatura disponible. Materiales y métodos: Sobre una muestra de 30 ependimomas intervenidos en neurocirugía pediátrica en los últimos 10 años, se identifican 7 casos de ependimomas de tipo lateral de la fosa posterior. Sobre esta serie de casos se realiza un estudio descriptivo retrospectivo. Resultados: La edad media de nuestros pacientes al diagnóstico fue de 3,75 años. Seis se presentaron con hidrocefalia. El volumen tumoral medio al diagnóstico fue de 61cm3. En 6 casos se llevó a cabo una resección completa y en un caso una resección casi completa. Cinco pacientes precisaron de forma transitoria una traqueostomía y una gastrostomía. La media de seguimiento fue de 58 meses. Durante este tiempo se produjo un caso de recidiva que posteriormente evolucionó a muerte. Cuatro casos de hidrocefalia posquirúrgica precisaron una derivación ventriculoperitoneal de LCR y 2 casos fueron manejados con ventriculostomía endoscópica. En la última revisión en consulta 4 pacientes llevaban una vida normal y 2 mostraban una restricción leve de la actividad de acuerdo con la escala de Lansky. Conclusiones: El objetivo del tratamiento quirúrgico de los ependimomas de tipo lateral de fosa posterior es la resección completa. Los déficits asociados a la disfunción de los pares bajos en nuestra serie fueron muy frecuentes pero transitorios. La progresiva caracterización molecular de estos tumores puede identificar diferentes grupos de riesgo sobre los que dirigir de forma adecuada la intensidad de los tratamientos adyuvantes.(AU)

Background and aims: Lateral-type posterior fossa ependymomas are a well-defined subtype of tumors both clinically and pathologically, with a poor prognosis. Their incidence is low and surgical management is challenging. The objective of the present work is to review our series of lateral-tye posterior fossa ependymomas and compare our results with those of previous series. Materials and methods: Among 30 cases of ependymoma operated in our pediatric department in the last 10 years, we identified seven cases of lateral-type posterior fossa ependymomas. We then performed a retrospective, descriptive study. Results: Mean age of our patients was 3.75 years. Six cases presented with hydrocephalus. Mean tumor volume at diagnosis was 61cc. A complete resection was achieved in six cases and a near-total resection in one patient. Five patients transiently required a gastrostomy and a tracheostomy. Mean follow-up was 58 months. One case progressed along this period and eventually died. Four cases of hydrocephalus required a ventriculoperitoneal CSF shunt and two were managed with a third ventriculostomy. At last follow-up four patients carried a normal life and two displayed a mild restriction according to Lansky's scale. Conclusions: The aim of surgical treatment in lateral-type posterior fossa ependymomas is complete resection. Neurological deficits associated to lower cranial nerve dysfunction are common but transient. Deeper genetic characterization of these tumors may identify risk factors that guide stratification of adjuvant therapies.(AU)

Impaired creative cognition after surgery for an IDH-mutated glioma: A proof-of-concept study.

Assessment of high cognitive functions, such as creativity, is often overlooked in medical practice. However, it is crucial to understand the impact of brain tumors, specifically low-grade gliomas, on creative cognition, as these tumors predominantly affect brain regions associated with cognitive creativity. In this study, we investigated creative cognition using the Alternative Uses Task (AUT) and the Combination of Associates Task (CAT) in a cohort of 29 patients who underwent brain surgery for a low-grade glioma, along with 27 control participants. While the group of patients did not exhibit deficits in clinical neuropsychological assessments, our results revealed significant impairment in generating original and creative ideas compared to the control group. Furthermore, when analyzing the specific brain regions affected by the tumors, patients with lesions overlapping the left rostro-lateral prefrontal cortex, a critical region for creativity, displayed more pronounced impairments in the CAT compared to patients with lesions outside this region. These findings provide proof of concept that patients can experience impaired creative cognition following surgery for low-grade glioma, highlighting the importance of assessing higher-order cognitive functions, including creativity, in neurosurgical patients. Moreover, beyond its clinical relevance, our study contributes to advancing our understanding of the neuroscience of creativity.

Survival Analysis of Patients Undergoing Intraoperative Contrast-enhanced Ultrasound in the Surgical Treatment of Malignant Glioma.

OBJECTIVE: Complete resection of malignant gliomas is often challenging. Our previous study indicated that intraoperative contrast-enhanced ultrasound (ICEUS) could aid in the detection of residual tumor remnants and the total removal of brain lesions. This study aimed to investigate the survival rates of patients undergoing resection with or without the use of ICEUS and to assess the impact of ICEUS on the prognosis of patients with malignant glioma. METHODS: A total of 64 patients diagnosed with malignant glioma (WHO grade HI and IV) who underwent surgery between 2012 and 2018 were included. Among them, 29 patients received ICEUS. The effects of ICEUS on overall survival (OS) and progression-free survival (PFS) of patients were evaluated. A quantitative analysis was performed to compare ICEUS parameters between gliomas and the surrounding tissues. RESULTS: The ICEUS group showed better survival rates both in OS and PFS than the control group. The univariate analysis revealed that age, pathology and ICEUS were significant prognostic factors for PFS, with only age being a significant prognostic factor for OS. In multivariate analysis, age and ICEUS were significant prognostic factors for both OS and PFS. The quantitative analysis showed that the intensity and transit time of microbubbles reaching the tumors were significantly different from those of microbubbles reaching the surrounding tissue. CONCLUSION: ICEUS facilitates the identification of residual tumors. Age and ICEUS are prognostic factors for malignant glioma surgery, and use of ICEUS offers a better prognosis for patients with malignant glioma.

Minimally invasive keyhole approach for supramaximal frontal glioma resections: technical note.

OBJECTIVE: The authors aimed to review the frontal lobe's surgical anatomy, describe their keyhole frontal lobectomy technique, and analyze the surgical results. METHODS: Patients with newly diagnosed frontal gliomas treated using a keyhole approach with supramaximal resection (SMR) from 2016 to 2022 were retrospectively reviewed. Surgeries were performed on patients asleep and awake. A human donor head was dissected to demonstrate the surgical anatomy. Kaplan-Meier curves were used for survival analysis. RESULTS: Of the 790 craniotomies performed during the study period, those in 47 patients met our inclusion criteria. The minimally invasive approach involved four steps: 1) debulking the frontal pole; 2) subpial dissection identifying the sphenoid ridge, olfactory nerve, and optic nerve; 3) medial dissection to expose the falx cerebri and interhemispheric structures; and 4) posterior dissection guided by motor mapping, avoiding crossing the inferior plane defined by the corpus callosum. A fifth step could be added for nondominant lesions by resecting the inferior frontal gyrus. Perioperative complications were recorded in 5 cases (10.6%). The average hospital length of stay was 3.3 days. High-grade gliomas had a median progression-free survival of 14.8 months and overall survival of 23.9 months. CONCLUSIONS: Keyhole approaches enabled successful SMR of frontal gliomas without added risks. Robust anatomical knowledge and meticulous surgical technique are paramount for obtaining successful resections.

Prevalence and risk factors of early postoperative seizures in patients with glioma: A protocol for meta-analysis and systematic review.

INTRODUCTION: Early postoperative seizures has been the most common clinical expression in gliomas; however, the incidence and risk factors for early postoperative seizures in gliomas are more controversial. This protocol describes a systematic review and meta-analysis to clarify the prevalence and risk factors of early postoperative seizures in patients with glioma. METHODS AND ANALYSIS: Searches will be conducted on CNKI, WanFang, VIP, PubMed, Embase, Cochrane Library databases and Web of Science for the period from database inception to December 31st, 2023. Case-control and cohort studies of the incidence and risk factors for early postoperative seizures in all gliomas will be included. The primary outcome will be incidence, risk factors. Newcastle-Ottawa Scale was used for quality evaluation. Review of article screening, extracting data and risk of bias assessment will be repeated by two independent reviewers. RESULT: This study will provide evidence for the risk factors and incidence of early postoperative seizures in patients with glioma. CONCLUSION: Our study will provide evidence for the prevention of early postoperative seizures in glioma patients. TRAIL REGISTRATION: This protocol was registered in PROSPERO and registration number is CRD42023415658.

Intraoperative ultrasound for surgical resection of high-grade glioma and glioblastoma: a meta-analysis of 732 patients.

PURPOSE: Here, we conducted a meta-analysis to explore the use of intraoperative ultrasound (iUS)-guided resection in patients diagnosed with high-grade glioma (HGG) or glioblastoma (GBM). Our aim was to determine whether iUS improves clinical outcomes compared to conventional neuronavigation (CNN). METHODS: Databases were searched until April 21, 2023 for randomized controlled trials (RCTs) and observational cohort studies that compared surgical outcomes for patients with HGG or GBM with the use of either iUS in addition to standard approach or CNN. The primary outcome was overall survival (OS). Secondary outcomes include volumetric extent of resection (EOR), gross total resection (GTR), and progression-free survival (PFS). Outcomes were analyzed by determining pooled relative risk ratios (RR), mean difference (MD), and standardized mean difference (SMD) using random-effects model. RESULTS: Of the initial 867 articles, only 7 articles specifically met the inclusion criteria (1 RCT and 6 retrospective cohorts). The analysis included 732 patients. Compared to CNN, the use of iUS was associated with higher OS (SMD = 0.26,95%CI=[0.12,0.39]) and GTR (RR = 2.02; 95% CI=[1.31,3.1]) for both HGG and GBM. There was no significant difference in PFS or EOR. CONCLUSION: The use of iUS in surgical resections for HGG and GBM can improve OS and GTR compared to CNN, but it did not affect PFS. These results suggest that iUS reduces mortality associated with HGG and GBM but not the risk of recurrence. These results can provide valuable cost-effective interventions for neurosurgeons in HGG and GBM surgery.

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.

Verbal fluency predicts work resumption after awake surgery in low-grade glioma patients.

BACKGROUND: Resuming professional activity after awake surgery for diffuse low-grade glioma (DLGG) is an important goal, which is not reached in every patient. Cognitive deficits can occur and persist after surgery. In this study, we analyzed the impact of mild cognitive impairments on the work resumption. METHODS: Fifty-four surgeries (including five redo surgeries) performed between 2012 and 2020 for grade 2 (45) and 3 (nine) DLGG in 49 professionally active patients (mean age 40 [range 23-58.) were included. We retrospectively extracted the results of semantic and phonemic verbal fluency tests from preoperative and 4-month postoperative cognitive assessments. Patients were interviewed about their working life after surgery, between April and June 2021. RESULTS: Patients (85%) returned to work, most within 3 to 6 months. Patients (76%) reported subjective complaints (primarily fatigue). Self-reported symptoms and individual and clinical variables had no impact on the work resumption. Late-postoperative average Z-scores in verbal fluency tasks were significantly lower than preoperative for the entire cohort (Wilcoxon test, p < 0.001 for semantic and p = 0.008 for phonemic fluency). The decrease in Z-scores was significantly greater (Mann Whitney U-test, semantic, p = 0.018; phonemic, p = 0.004) in the group of patients who did not return to work than in the group of patients who did. CONCLUSION: The proportion of patients returning to work was comparable to similar studies. A decrease in verbal fluency tasks could predict the inability to return to work.

Distant recurrence in the cerebellar dentate nucleus through the dentato-rubro-thalamo-cortical pathway in supratentorial glioma cases.

BACKGROUND: Distant recurrence can occur by infiltration along white matter tracts or dissemination through the cerebrospinal fluid (CSF). This study aimed to clarify the clinical features and mechanisms of recurrence in the dentate nucleus (DN) in patients with supratentorial gliomas. Based on the review of our patients, we verified the hypothesis that distant DN recurrence from a supratentorial lesion occurs through the dentato-rubro-thalamo-cortical (DRTC) pathway. METHODS: A total of 380 patients with supratentorial astrocytoma, isocitrate dehydrogenase (IDH)-mutant (astrocytoma), oligodendroglioma, IDH mutant and 1p/19q-codeleted (oligodendroglioma), glioblastoma, IDH-wild type (GB), and thalamic diffuse midline glioma, H3 K27-altered (DMG), who underwent tumor resection at our department from 2009 to 2022 were included in this study. Recurrence patterns were reviewed. Additionally, clinical features and magnetic resonance imaging findings before treatment, at the appearance of an abnormal signal, and at further progression due to delayed diagnosis or after salvage treatment of cases with recurrence in the DN were reviewed. RESULTS: Of the 380 patients, 8 (2.1%) had first recurrence in the DN, 3 were asymptomatic when abnormal signals appeared, and 5 were diagnosed within one month after the onset of symptoms. Recurrence in the DN developed in 8 (7.4%) of 108 cases of astrocytoma, GB, or DMG at the frontal lobe or thalamus, whereas no other histological types or sites showed recurrence in the DN. At the time of the appearance of abnormal signals, a diffuse lesion developed at the hilus of the DN. The patterns of further progression showed that the lesions extended to the superior cerebellar peduncle, tectum, tegmentum, red nucleus, thalamus, and internal capsule along the DRTC pathway. CONCLUSION: Distant recurrence along the DRTC pathway is not rare in astrocytomas, GB, or DMG at the frontal lobe or thalamus. Recurrence in the DN developed as a result of the infiltration of tumor cells through the DRTC pathway, not dissemination through the CSF.

Awake intraoperative mapping for the prevention of amusia.

The authors describe the awake surgical mapping of music skills for patients who require resection in brain areas that may support musical abilities. A 65-year-old man was diagnosed with an anterolateral right temporal nonenhancing lesion, likely a diffusely infiltrating glioma, after presenting with several episodes of altered taste and smell and one episode of loss of consciousness. The patient specializes in music and music technology and has composed scores for films. An awake surgery was planned in a semiseated position. Prerecorded melodies were designed preoperatively as a surrogate for a composition skill task. These consisted of 10- to 15-second musical clips played during bipolar electrical stimulation of the overlying cortex and were divided into three segments: listen, play, and accuracy check. During the "listen" phase, the patient listened to a musical prompt. During the "play" phase, he played a musical response on a keyboard. Stimulation at multiple temporal neocortical sites was negative for any alteration in task performance. The patient did well postoperatively with excellent clinical and radiographic results and returned to composing music without functional compromise. Musical composition tasks can be performed safely intraoperatively for patients with musical expertise. Whether stimulating more posterior nondominant temporal neocortex or other cortical or white matter locations can disrupt this task remains undetermined.

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.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

From molecular signatures to radiomics: tailoring neurooncological strategies through forecasting of glioma growth.

OBJECTIVE: Contemporary oncological paradigms for adjuvant treatment of low- and intermediate-grade gliomas are often guided by a limited array of parameters, overlooking the dynamic nature of the disease. The authors' aim was to develop a comprehensive multivariate glioma growth model based on multicentric data, to facilitate more individualized therapeutic strategies. METHODS: Random slope models with subject-specific random intercepts were fitted to a retrospective cohort of grade II and III gliomas from the database at Kepler University Hospital (n = 191) to predict future mean tumor diameters. Deep learning-based radiomics was used together with a comprehensive clinical dataset and evaluated on an external prospectively collected validation cohort from University Hospital Zurich (n = 9). Prediction quality was assessed via mean squared prediction error. RESULTS: A mean squared prediction error of 0.58 cm for the external validation cohort was achieved, indicating very good prognostic value. The mean ± SD time to adjuvant therapy was 28.7 ± 43.3 months and 16.1 ± 14.6 months for the training and validation cohort, respectively, with a mean of 6.2 ± 5 and 3.6 ± 0.7, respectively, for number of observations. The observed mean tumor diameter per year was 0.38 cm (95% CI 0.25-0.51) for the training cohort, and 1.02 cm (95% CI 0.78-2.82) for the validation cohort. Glioma of the superior frontal gyrus showed a higher rate of tumor growth than insular glioma. Oligodendroglioma showed less pronounced growth, anaplastic astrocytoma-unlike anaplastic oligodendroglioma-was associated with faster tumor growth. Unlike the impact of extent of resection, isocitrate dehydrogenase (IDH) had negligible influence on tumor growth. Inclusion of radiomics variables significantly enhanced the prediction performance of the random slope model used. CONCLUSIONS: The authors developed an advanced statistical model to predict tumor volumes both pre- and postoperatively, using comprehensive data prior to the initiation of adjuvant therapy. Using radiomics enhanced the precision of the prediction models. Whereas tumor extent of resection and topology emerged as influential factors in tumor growth, the IDH status did not. This study emphasizes the imperative of advanced computational methods in refining personalized low-grade glioma treatment, advocating a move beyond traditional paradigms.

Awake brain mapping paradigms for nondominant hemisphere gliomas.

OBJECTIVE: Traditionally, resection of nondominant hemisphere brain tumors was performed under general anesthesia. An improved understanding of right-lateralized neural networks has led to a paradigm shift in recent decades, where the right or nondominant hemisphere is no longer perceived as "functionally silent." There is an increasing interest in awake brain mapping for nondominant hemisphere resections. The objective of this study was to perform a comprehensive review of the existing brain mapping paradigms for patients with nondominant hemisphere gliomas undergoing awake craniotomies. METHODS: In accordance with PRISMA guidelines, systematic searches of the Medline, Embase, and American Psychological Association PsycInfo databases were undertaken from database inception to July 1, 2023. Studies providing a description of the intraoperative mapping paradigm used to assess cognition during an awake craniotomy for resection of a nondominant hemisphere glioma were included. RESULTS: The search yielded 1084 potentially eligible articles. Thirty-nine unique studies reporting on 788 patients were included in the systematic review. The most frequently tested cognitive domains in patients with nondominant hemisphere tumors were spatial attention/neglect (17/39 studies, 43.6%), speech-motor/language (17/39 studies, 43.6%), and social cognition (9/39 studies, 23.1%). Within the frontal lobe, the highest number of positive mapping sites was identified for speech-motor/language, spatial attention/neglect, dual tasking assessing motor and language function, working memory, and social cognition. Within the parietal lobe, eloquence was most frequently found upon testing spatial attention/neglect, speech-motor/language, and calculation. Within the temporal lobe, the assessment of spatial attention/neglect yielded the highest number of positive mapping sites. CONCLUSIONS: Cognitive testing in the nondominant hemisphere is predominantly focused on evaluating two domains: spatial attention/neglect and the motor aspects of speech/language. Multidisciplinary teams involved in awake brain mapping should consider testing an extended range of functions to minimize the risk of postoperative deficits and provide valuable information about anatomo-functional organization of cognitive networks.

The role of preoperative [11C]methionine PET in defining tumor-related epilepsy and predicting short-term postoperative seizure control in temporal lobe low-grade gliomas.

OBJECTIVE: Surgery is the mainstay of treatment for low-grade glioma (LGG)-related epilepsy. However, the goal of achieving both oncological radical resection and seizure freedom can be challenging. PET with [11C]methionine (MET) has been recently introduced in clinical practice for the management of patients with LGGs, not only to monitor the response to treatments, but also as a preoperative tool to define the metabolic tumor extent and to predict tumor grading, type, and prognosis. Still, its role in defining tumor-related epilepsy and postoperative seizure outcomes is limited. The aim of this preliminary study was to investigate the role of MET PET in defining preoperative seizure characteristics and short-term postoperative seizure control in a cohort of patients with newly diagnosed temporal lobe low-grade gliomas (tLGGs). METHODS: Patients with newly diagnosed and histologically proven temporal lobe grade 2/3 gliomas (2021 WHO CNS tumor classification) who underwent resection at the authors' institution between July 2011 and March 2021 were included in this retrospective study. MET PET images were acquired, fused with MRI scans, and qualitatively and semiquantitatively analyzed. Any eventual PET/MRI involvement of the temporomesial area, seizure characteristics, and 1-year seizure outcomes were reported. RESULTS: A total of 52 patients with tLGGs met the inclusion criteria. MET PET was positive in 41 (79%) patients, with a median metabolic tumor volume of 14.56 cm3 (interquartile range [IQR] 6.5-28.2 cm3). The median maximum and mean tumor-to-background ratio (TBRmax, TBRmean) were 2.24 (IQR 1.58-2.86) and 1.53 (IQR 1.37-1.70), respectively. The metabolic tumor volume was found to be related to the presence of seizures at disease onset, but only in noncodeleted tumors (p = 0.014). Regarding patients with uncontrolled seizures at surgery, only the temporomesial area PET involvement showed a statistical correlation both in the univariate (p = 0.058) and in the multivariate analysis (p = 0.030). At 1-year follow-up, seizure control was correlated with MET PET-derived semiquantitative data. Particularly, higher TBRmax (p = 0.0192) and TBRmean (p = 0.0128) values were statistically related to uncontrolled seizures 1 year after surgery. CONCLUSIONS: This preliminary study suggests that MET PET may be used as a preoperative tool to define seizure characteristics and outcomes in patients with tLGGs. These findings need to be further validated in larger series with longer epileptological follow-ups.

[Surgical treatment of brain tumors adjacent to corticospinal tract in children]. / Aktual'nye voprosy khirurgicheskogo lecheniya opukholei golovnogo mozga, prilegayushchikh k kortikospinal'nomu traktu u detei.

An urgent problem in modern neurosurgery is resection of brain tumors adjacent to corticospinal tract (CST) due to high risk of its damage and subsequent disability. The main methods for prevention of intraoperative damage to CST are preoperative MR tractography and intraoperative electrophysiological monitoring. Both methods are used in pediatric neurosurgery. We reviewed the PubMed database since 2000 using the following keywords: «tumors of the hemispheres in children¼, «corticospinal tract¼, «MR tractography¼, «intraoperative electrophysiological monitoring¼. We present available literature data on preoperative MR tractography and intraoperative electrophysiological monitoring in children with supratentorial tumors near CST. Algorithm of intraoperative electrophysiological monitoring is often missing or insufficiently described. MR tractography is usually presented in case reports. Researchers do not compare the effectiveness of MR tractography and intraoperative electrophysiological monitoring. In case of MR tractography, a limitation is impossible CST reconstruction in children 2-3 years old. This may be due to unformed pyramidal system in these children. CONCLUSION: Preoperative MR tractography and intraoperative electrophysiological monitoring are valid methods for assessment of CST. Optimal research parameters in children require careful study that will allow objective planning of each stage of preoperative management and increase resection quality for gliomas near CST in children without neurological deterioration.

Exo- and endoscopic lateral orbital wall approach for the medial temporal lobe glioma: how I do it.

BACKGROUND: The endoscopic transorbital approach provides a direct access to the medial temporal lobe (MTL). However, when excising a highly vascular tumour, a wider access route that enables the concurrent use of standard neurosurgical instruments with both hands is preferable. METHOD: We described the concept and technique of the lateral orbital wall approach (LOWA), which comprises orbitotomy and mini-craniotomy to treat MTL lesions using an exoscope and endoscope. CONCLUSION: The LOWA provides a safe and natural surgical corridor to the MTL and enables 2- or 3-hand surgery. Hence, LOWA can potentially improve safety and efficiency to treat MTL lesions.

Pre-operative predictors of post-operative seizure control in low-grade glioma: a systematic review and meta-analysis.

As many as 80% of low-grade gliomas (LGGs) present with seizures, negatively impacting quality of life. While seizures are associated with gliomas regardless of grade, the importance of minimizing impact of seizures for patients with low grade tumors cannot be understated given the prolonged survival period in this population. The objective of this systematic review and meta-analysis was to summarize existing literature and identify factors associated with post-operative seizure control (defined as Engel I classification) in patients with LGGs, with a focus on pre-operative factors. Patient data extracted include tumor location and histology, pre-operative anti-seizure medication use, extent of resection (EOR), adjuvant treatment, pre-operative seizure type, duration, and frequency, and post-operative Engel classification. A random-effects model was used to calculate the effects of EOR, pre-operative seizure duration, adjuvant radiation, and adjuvant chemotherapy on post-operative seizure control. The effect of tumor location and histology on post-operative Engel I classification was determined using contingency analyses. Thirteen studies including 1628 patients with seizures were included in the systematic review. On meta-analyses, Engel I classification was associated with pre-operative seizure type (OR = 0.79 (0.63-0.99), p = 0.0385, focal versus generalized), frontal lobe LGGs (OR = 1.5 (1.1-2.0), p = 0.0195), and EOR (OR (95% CI) = 4.5 (2.3-6.7), p < 0.0001 gross-total versus subtotal). Pre-operative seizure duration less than one year, adjuvant radiation, adjuvant chemotherapy, and tumor histology were not associated with achieving Engel I classification. In addition to the known effects of EOR, Engel I classification is less likely to be achieved in patients with focal pre-operative seizures and more likely to be achieved in patients with frontal lobe LGGs.