Prevalence and prognostic significance of epilepsy in patients with gliomas

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.

Clinical and Genomic Predictors of Adverse Events in Newly Diagnosed Glioblastoma

PURPOSE

Adverse clinical events cause significant morbidity in patients with GBM (GBM). We examined whether genomic alterations were associated with AE (AE) in patients with GBM.

EXPERIMENTAL DESIGN

We identified adults with histologically confirmed IDH-wild-type GBM with targeted next-generation sequencing (OncoPanel) at Dana Farber Cancer Institute from 2013 to 2019. Seizure at presentation, lymphopenia, thromboembolic events, pseudoprogression, and early progression (within 6 months of diagnosis) were identified as AE. The biologic function of genetic variants was categorized as loss-of-function (LoF), no change in function, or gain-of-function (GoF) using a somatic tumor mutation knowledge base (OncoKB) and consensus protein function predictions. Associations between functional genomic alterations and AE were examined using univariate logistic regressions and multivariable regressions adjusted for additional clinical predictors.

RESULTS

Our study included 470 patients diagnosed with GBM who met the study criteria. We focused on 105 genes that had sequencing data available for ≥ 90% of the patients and were altered in ≥10% of the cohort. Following false-discovery rate (FDR) correction and multivariable adjustment, the TP53, RB1, IGF1R, and DIS3 LoF alterations were associated with lower odds of seizures, while EGFR, SMARCA4, GNA11, BRD4, and TCF3 GoF and SETD2 LoF alterations were associated with higher odds of seizures. For all other AE of interest, no significant associations were found with genomic alterations following FDR correction.

CONCLUSIONS

Genomic biomarkers based on functional variant analysis of a routine clinical panel may help identify AE in GBM, particularly seizures. Identifying these risk factors could improve the management of patients through better supportive care and consideration of prophylactic therapies.

Glioma genetic profiles associated with electrophysiologic hyperexcitability

BACKGROUND

Distinct genetic alterations determine glioma aggressiveness, however, the diversity of somatic mutations contributing to peritumoral hyperexcitability and seizures over the course of the disease is uncertain. This study aimed to identify tumor somatic mutation profiles associated with clinically significant hyperexcitability.

METHODS

A single center cohort of adults with WHO grades 1-4 glioma and targeted exome sequencing (n = 1716) was analyzed and cross-referenced with a validated EEG database to identify the subset of individuals who underwent continuous EEG monitoring (n = 206). Hyperexcitability was defined by the presence of lateralized periodic discharges and/or electrographic seizures. Cross-validated discriminant analysis models trained exclusively on recurrent somatic mutations were used to identify variants associated with hyperexcitability.

RESULTS

The distribution of WHO grades and tumor mutational burdens were similar between patients with and without hyperexcitability. Discriminant analysis models classified the presence or absence of EEG hyperexcitability with an overall accuracy of 70.9%, regardless of IDH1 R132H inclusion. Predictive variants included nonsense mutations in ATRX and TP53, indel mutations in RBBP8 and CREBBP, and nonsynonymous missense mutations with predicted damaging consequences in EGFR, KRAS, PIK3CA, TP53, and USP28. This profile improved estimates of hyperexcitability in a multivariate analysis controlling for age, sex, tumor location, integrated pathologic diagnosis, recurrence status, and preoperative epilepsy. Predicted somatic mutation variants were over-represented in patients with hyperexcitability compared to individuals without hyperexcitability and those who did not undergo continuous EEG.

CONCLUSION

These findings implicate diverse glioma somatic mutations in cancer genes associated with peritumoral hyperexcitability. Tumor genetic profiling may facilitate glioma-related epilepsy prognostication and management.

Characteristics and Prognosis of Tumor-Related Epilepsy During Tumor Evolution in Patients With IDH Wild-Type Glioblastoma

BACKGROUND AND OBJECTIVES

Tumor-related epilepsy is a well-known symptom of glioblastoma. However, the particular characteristics of epileptic seizures related to glioblastoma, isocitrate dehydrogenase (IDH)-wild-type is almost unexplored longitudinally during the whole course of the disease. We assessed tumor-related epilepsy and seizure control during tumor evolution and the prognostic significance of tumor-related epilepsy.

METHODS

We performed an observational, retrospective single-center study at one tertiary referral neuro-oncology surgical center (2000-2020). We included adult patients treated for a newly diagnosed supratentorial glioblastoma, IDH-wild-type with available preoperative and postoperative MRI and with available epileptic seizure status at diagnosis. To determine factors associated with tumor-related epilepsy or seizure control, univariate analyses were performed using the χ2 or Fisher exact tests for categorical variables and the unpaired t test or Mann-Whitney rank-sum test for continuous variables. Predictors associated with tumor-related epilepsy and seizure control in unadjusted analysis were entered into backward stepwise logistic regression models.

RESULTS

One thousand six patients were enrolled. The cumulative incidence of tumor-related epilepsy increased during tumor evolution (33.1% at diagnosis, 44.7% after oncologic treatment, 52.4% at progression, and 51.8% at the end-of-life phase) and is related to tumor features (cortex involvement, no necrosis, and small volume). Uncontrolled epileptic seizures increased during tumor evolution (20.1% at diagnosis, 32.0% after oncologic treatment, 46.7% at progression, and 41.1% at the end-of-life phase). Epileptic seizure control after oncologic treatment was related to seizure features (uncontrolled before oncologic treatment and focal-to-bilateral tonic-clonic seizures) and to the extent of resection. Epileptic seizure control at tumor progression was related to seizure features (presence at diagnosis and uncontrolled after oncologic treatment) and to the time to progression. Tumor-related epilepsy at diagnosis was a predictor of a longer overall survival (adjusted hazard ratio, 0.78; 95% CI 0.67-0.90; p < 0.001) independent of age, Karnofsky Performance Status score, tumor location and volume, extent of resection, standard combined chemoradiotherapy, levetiracetam use, and MGMT promoter methylation.

DISCUSSION

The progression of tumor-related epilepsy with the evolution of glioblastoma, IDH-wild-type and the effects of surgery on seizure control argue for proper antiseizure medication and maximal safe resection. Tumor-related epilepsy is an independent predictor of a longer survival.

Brain tumor-related epilepsy management: A Society for Neuro-oncology (SNO) consensus review on current management

Tumor-related epilepsy (TRE) is a frequent and major consequence of brain tumors. Management of TRE is required throughout the course of disease and a deep understanding of diagnosis and treatment is key to improving quality of life. Gross total resection is favored from both an oncologic and epilepsy perspective. Shared mechanisms of tumor growth and epilepsy exist, and emerging data will provide better targeted therapy options. Initial treatment with antiseizure medications (ASM) in conjunction with surgery and/or chemoradiotherapy is typical. The first choice of ASM is critical to optimize seizure control and tolerability considering the effects of the tumor itself. These agents carry a potential for drug-drug interactions and therefore knowledge of mechanisms of action and interactions is needed. A review of adverse effects is necessary to guide ASM adjustments and decision-making. This review highlights the essential aspects of diagnosis and treatment of TRE with ASMs, surgery, chemotherapy, and radiotherapy while indicating areas of uncertainty. Future studies should consider the use of a standardized method of seizure tracking and incorporating seizure outcomes as a primary endpoint of tumor treatment trials.

Management of Brain Metastases: A Review of Novel Therapies

Brain metastases (BMs) represent the most common intracranial tumors in adults, and most commonly originate from lung, followed by breast, melanoma, kidney, and colorectal cancer. Management of BM is individualized based on the size and number of brain metastases, the extent of extracranial disease, the primary tumor subtype, neurological symptoms, and prior lines of therapy. Until recently, treatment strategies were limited to local therapies, like surgical resection and radiotherapy, the latter in the form of whole-brain radiotherapy or stereotactic radiosurgery. The next generation of local strategies includes laser interstitial thermal therapy, magnetic hyperthermic therapy, post-resection brachytherapy, and focused ultrasound. New targeted therapies and immunotherapies with documented intracranial activity have transformed clinical outcomes. Novel systemic therapies with intracranial utility include new anaplastic lymphoma kinase inhibitors like brigatinib and ensartinib; selective "rearranged during transfection" inhibitors like selpercatinib and pralsetinib; B-raf proto-oncogene inhibitors like encorafenib and vemurafenib; Kirsten rat sarcoma viral oncogene inhibitors like sotorasib and adagrasib; ROS1 gene rearrangement (ROS1) inhibitors, anti-neurotrophic tyrosine receptor kinase agents like larotrectinib and entrectinib; anti-human epidermal growth factor receptor 2/epidermal growth factor receptor exon 20 agent like poziotinib; and antibody-drug conjugates like trastuzumab-emtansine and trastuzumab-deruxtecan. This review highlights the modern multidisciplinary management of BM, emphasizing the integration of systemic and local therapies.

Management of Complications in Neuro-oncology Patients

OBJECTIVE

The purpose of this article is to familiarize the reader with the spectrum of neurologic and medical complications relevant to the care of patients with neurologic cancer while highlighting best practices to prevent morbidity and mortality. Topics include tumor-related epilepsy, vasogenic edema, complications of corticosteroid use, disruption of the hypothalamic-pituitary axis, venous thromboembolism, and opportunistic infection.

LATEST DEVELOPMENTS

In 2021, a joint guideline from the Society for Neuro-Oncology and the European Association of Neuro-Oncology reaffirmed recommendations first established in 2000 that patients with newly diagnosed brain tumors should not be prescribed an antiseizure medication prophylactically. For those with tumor-related epilepsy, monotherapy with a non-enzyme-inducing anticonvulsant is the preferred initial treatment, and levetiracetam remains the preferred first choice. Surveys of physician practice continue to demonstrate excessive use of glucocorticoids in the management of patients with both primary and metastatic central nervous system malignancy. This is particularly concerning among patients who require checkpoint inhibitors as the efficacy of these agents is blunted by concomitant glucocorticoid use, resulting in a reduction in overall survival. Finally, direct oral anticoagulants have been shown to be safe in patients with brain tumors and are now favored as first-line treatment among those who require treatment for venous thromboembolism.

ESSENTIAL POINTS

Medical care for patients impacted by primary and secondary central nervous system malignancy is complex and requires a committed team-based approach that routinely calls upon the expertise of physicians across multiple fields. Neurologists have an important role to play and should be familiar with the spectrum of complications impacting these patients as well as the latest recommendations for management.

High-Frequency Oscillations in Tumor-Related Epilepsy

INTRODUCTION

To define the patient characteristics, tumor characteristics, and clinical course of patients with primary brain tumors with high-frequency oscillations (HFOs) recorded on electrocorticography. Furthermore, we evaluated whether the presence of HFOs portends a greater risk of postoperative tumor-related epilepsy and whether the resection of HFO-generating tissue reduces likelihood of postoperative tumor-related epilepsy.

METHODS

This was a retrospective study of 35 patients undergoing awake craniotomy for tumor resection, all of whom underwent intraoperative electrocorticography. Electrocorticography data were reviewed to assess the presence of HFOs and determine their contact locations. The data were analyzed to determine whether HFO-generating tissue was included in the resection and relationship to postoperative seizure outcome.

RESULTS

Seventeen patients (48.5%) were found to have HFOs. Very few patients (4 of 35, 11.4%) had sharp waves. Patients with and without HFOs did not significantly differ in demographics, presentation, tumor characteristics, or tumor molecular genetics. A history of seizures prior to resection was not associated with the presence of HFOs ( P = 0.62), although when patients had seizures during the same hospitalization as the resection, HFOs were more likely to be present ( P = 0.045). Extent of HFO resection was not associated with the likelihood of postoperative seizure freedom.

CONCLUSIONS

Approximately half (48.5%) of patients undergoing resection for a primary brain tumor had HFOs. Although HFO resection was not shown to lead to improved seizure freedom, this study was limited by a small sample size, and further investigation into HFO resection and patient outcomes in this population is warranted.

Glioblastoma imitating a cavernoma radiologically: A unique image report

Background:

Glioblastoma is the most common primary malignant brain tumor with characteristic radiological features in most cases.

Case Description:

We highlight an unusual case of a 54-year-old woman, neurologically intact, with a diagnostically challenging lesion. The patient’s magnetic resonance imaging revealed a left frontal lesion with surrounding edema and a hemosiderin ring, misleading it to be a cavernoma. Intraoperatively, the lesion was found to be a solid tumor with hematoma and was confirmed to be glioblastoma on histopathology.

Conclusion:

The dilemma associated with our patient’s radiological findings and longstanding history of epilepsy is rare and a diagnostic challenge.

Glioma genetic profiles associated with electrophysiologic hyperexcitability

Distinct genetic alterations determine glioma aggressiveness, however the diversity of somatic mutations contributing to peritumoral hyperexcitability and seizures is uncertain. In a large cohort of patients with sequenced gliomas (n=1716), we used discriminant analysis models to identify somatic mutation variants associated with electrographic hyperexcitability in a subset with continuous EEG recording (n=206). Overall tumor mutational burdens were similar between patients with and without hyperexcitability. A cross-validated model trained exclusively on somatic mutations classified the presence or absence of hyperexcitability with an overall accuracy of 70.9%, and improved estimates of hyperexcitability and anti-seizure medication failure in multivariate analysis incorporating traditional demographic factors and tumor molecular classifications. Somatic mutation variants of interest were also over-represented in patients with hyperexcitability compared to internal and external reference cohorts. These findings implicate diverse mutations in cancer genes associated with the development of hyperexcitability and response to treatment.

Glioblastoma and Other Primary Brain Malignancies in Adults: A Review

Importance

Malignant primary brain tumors cause more than 15 000 deaths per year in the United States. The annual incidence of primary malignant brain tumors is approximately 7 per 100 000 individuals and increases with age. Five-year survival is approximately 36%.

Observations

Approximately 49% of malignant brain tumors are glioblastomas, and 30% are diffusely infiltrating lower-grade gliomas. Other malignant brain tumors include primary central nervous system (CNS) lymphoma (7%) and malignant forms of ependymomas (3%) and meningiomas (2%). Symptoms of malignant brain tumors include headache (50%), seizures (20%-50%), neurocognitive impairment (30%-40%), and focal neurologic deficits (10%-40%). Magnetic resonance imaging before and after a gadolinium-based contrast agent is the preferred imaging modality for evaluating brain tumors. Diagnosis requires tumor biopsy with consideration of histopathological and molecular characteristics. Treatment varies by tumor type and often includes a combination of surgery, chemotherapy, and radiation. For patients with glioblastoma, the combination of temozolomide with radiotherapy improved survival when compared with radiotherapy alone (2-year survival, 27.2% vs 10.9%; 5-year survival, 9.8% vs 1.9%; hazard ratio [HR], 0.6 [95% CI, 0.5-0.7]; P < .001). In patients with anaplastic oligodendroglial tumors with 1p/19q codeletion, probable 20-year overall survival following radiotherapy without vs with the combination of procarbazine, lomustine, and vincristine was 13.6% vs 37.1% (80 patients; HR, 0.60 [95% CI, 0.35-1.03]; P = .06) in the EORTC 26951 trial and 14.9% vs 37% in the RTOG 9402 trial (125 patients; HR, 0.61 [95% CI, 0.40-0.94]; P = .02). Treatment of primary CNS lymphoma includes high-dose methotrexate-containing regimens, followed by consolidation therapy with myeloablative chemotherapy and autologous stem cell rescue, nonmyeloablative chemotherapy regimens, or whole brain radiation.

Conclusions and Relevance

The incidence of primary malignant brain tumors is approximately 7 per 100 000 individuals, and approximately 49% of primary malignant brain tumors are glioblastomas. Most patients die from progressive disease. First-line therapy for glioblastoma is surgery followed by radiation and the alkylating chemotherapeutic agent temozolomide.

Effects of gross total resection and subtotal resection on survival outcomes of glioma patients: a meta-analysis

This study was to conduct a meta-analysis to explore the impact of gross total resection (GTR) and subtotal resection (STR) on survival outcomes in glioma patients. Relevant studies were searched in multiple databases from the available date of inception through 30 December 2021. The weighted mean differences (WMDs), relative risks (RRs), or hazard ratios (HRs) with 95% confidence intervals (CIs) were used to access the effect of GTR versus STR treatments on the outcomes. The histology (low-grade or high-grade) and study population (children and adults) were used for subgroup analysis. Sensitivity analysis was performed for all outcomes. Begg's test and trim-and-fill method were used for publication bias. Totally 100 studies enrolling 62,129 patients were selected in this meta-analysis. The summary results showed that GTR was superior in improving 1-, 2-, 3-, 5-, 10-, 15-year overall survival (OS), OS time, 1-, 3-, 5-year progression-free survival (PFS), recurrence, local control and seizure control among glioma patients. In addition, high-grade patients who underwent GTR had improvements in 1-, 2- and 3-year OS, OS time, and 1-year PFS, while low-grade patients receiving GTR had improvements in 2-, 5- and 15-year OS, recurrence, seizure control, and tumor progression compared with those receiving STR. GTR was likely to be more effective on survival outcomes than STR among patients with gliomas.

Valproic acid as a radio-sensitizer in glioma: A systematic review and meta-analysis

Background

Histone deacetylase inhibitors (HDACi) including valproic acid (VPA) have the potential to improve radiotherapy (RT) efficacy and reduce treatment adverse events (AE) via epigenetic modification and radio-sensitization of neoplastic cells. This systematic review and meta-analysis aimed to assess the efficacy and AE associated with HDACi used as radio-sensitizers in adult solid organ malignancy patients.

Methods

A systematic review utilized electronic searches of MEDLINE(Ovid), Embase(Ovid), The Cochrane Library, and the International Clinical Trials Registry Platform to identify studies examining the efficacy and AEs associated with HDACi treatment in solid organ malignancy patients undergoing RT. Meta-analysis was performed with overall survival (OS) reported as hazard ratios (HR) as the primary outcome measure. OS reported as median survival difference, and AEs were secondary outcome measures.

Results

Ten studies reporting on the efficacy and/or AEs of HDACi in RT-treated solid organ malignancy patients met inclusion criteria. All included studies focused on HDACi valproic acid (VPA) in high-grade glioma patients, of which 9 studies (n = 6138) evaluated OS and 5 studies (n = 1055) examined AEs. The addition of VPA to RT treatment protocols resulted in improved OS (HR = 0.80, 95% CI 0.67-0.96). No studies focusing on non-glioma solid organ malignancy patients, or non-VPA HDACi met the inclusion criteria for this review.

Conclusions

This review suggests that glioma patients undergoing RT may experience prolonged survival due to HDACi VPA administration. Further randomized controlled trials are required to validate these findings. Additionally, more research into the use of HDACi radio-adjuvant treatment in non-glioma solid organ malignancies is warranted.

Early EEG hyperexcitability is associated with decreased survival in newly diagnosed IDH-wildtype glioma

PURPOSE

The relationship between peritumoral neuronal activity, early onset clinical seizures, and glioma survival outcomes remains poorly understood. Hyperexcitability on continuous EEG in the peri-operative period was studied as a prognostic biomarker in patients with newly diagnosed IDH-wildtype diffuse glioma.

METHODS

A retrospective observational cohort study was performed including adults with newly diagnosed diffuse glioma, absence of IDH1/2 mutations, and continuous EEG monitoring prior to chemoradiation and within 1 month of initial resection. EEG hyperexcitability was defined by the presence of lateralized periodic discharges and/or electrographic seizures. The primary outcome of overall survival was estimated using the Kaplan-Meier method and compared between groups using multivariate Cox proportional hazards model.

RESULTS

There were 424 patients without continuous EEG and 32 with continuous EEG, of whom lateralized periodic discharges and/or electrographic seizures were seen in 17 (53%). Peri-operative EEG hyperexcitability was associated with decreased overall survival in multivariate analysis [median 12.5 (95% CI 6.2-25.6] months with hyperexcitability versus median 19.9 [95% CI 8.9-53.5] months without hyperexcitability, p = 0.043). Compared to patients without continuous EEG, overall survival was decreased in patients with hyperexcitability (p < 0.0001) and similar in patients without hyperexcitability (p = 0.193). Patients with and without hyperexcitability had similar rates of exposure to anti-seizure medication at baseline, and in long-term follow-up had no difference in number of medications required for seizure control.

CONCLUSIONS

These findings indicate the potential prognostic value of a clinical EEG biomarker of glioma aggressiveness prior to the initiation of chemoradiation.

Cerebral Edema Due to Chemotherapeutic Wafer Implantation for Malignant Glioma: Registry Study of Correlation with Perioperative Epileptic Seizures

Factors predicting adverse events following implantation with wafers containing 1,3-bis (2-chloroethyl) -1-nitrosourea (carmustine, BCNU), which is used in local chemotherapy for malignant gliomas (MGs), are unknown. The association between cerebral edema (CE), which often occurs after implantation, and perioperative seizures, which are often observed in MG cases, is under debate. This study investigated risk factors for CE associated with BCNU wafer implantation and their relationship with perioperative seizures. A total of 31 surgical cases involving 28 adult patients who underwent BCNU wafer implantation for MGs were investigated and classified into those with and without postoperative transient CE. We assessed the correlations between CE caused by BCNU implantation and various factors, including postoperative epileptic seizures. World Health Organization (WHO) grade III MGs significantly affected postoperative CE (p = 0.003) and the occurrence of seizures (p = 0.0004). Factors predictive of postoperative seizures were WHO grade III MGs (p = 0.0026), increased postoperative CE (p = 0.0272), and history of preoperative seizures (p = 0.0316). Postoperative CE, WHO grade III MGs, and a history of preoperative seizures might predict the postoperative occurrence of seizures, necessitating stringent management of seizures and CE in the affected patients.

Identification and Validation of a Seizure-Free-Related Gene Signature for Predicting Poor Prognosis in Lower-Grade Gliomas

Background

Lower-grade gliomas (LGGs) patients presented seizure-free have a worse survival than those presented with seizures. However, the current knowledge on its potential value in LGGs remains scarce.

Purpose

This study aimed to identify a novel gene signature associated with seizures-free for predicting poor prognosis for LGGs patients.

Materials and Methods

The RNA expression and clinical information of LGGs patients were downloaded from the Cancer Genome Atlas database. Differentially expressed genes (DEGs) were screened out between LGGs patients presented seizures-free and seizures. The novel gene signature was constructed by Lasso and multivariate regression analyses for predicting prognosis in LGGs. Its prognostic value was assessed and validated by Kaplan-Meier analyses and receiver operating characteristic (ROC) curves. Multivariate regression analysis was applied to identify the independent prognostic value of the gene signature. Furthermore, bioinformatics analysis was performed to elucidate the molecular mechanisms.

Results

A total of 253 DEGs were screened out between LGG patients presented with seizures and free of seizures. A 5-gene signature (HIST1H4F, HORMAD2, LILRA3, PRSS33, and TBX20 genes) was constructed from these 253 DEGs. Kaplan-Meier analyses and ROC curves assessed and validated the good performance of the 5-gene signature in differentiating and predicting prognosis of high- and low-risk patients. Multivariate regression analysis determined the independent prognostic value of the 5-gene signature. According to bioinformatics analysis, DEGs were mainly enriched in biological processes related to positive regulation of transcription from RNA polymerase II promoter, G-protein coupled receptor signaling pathway, and pathways of cytokine-cytokine receptor interaction, chemokine signaling pathway.

Conclusion

Our findings suggested that the 5-gene signature might serve as a potential prognostic biomarker and provide guidance for the personalized LGGs management.

Seizure Outcome After Surgery for Insular High-Grade Glioma

BACKGROUND

The insular cortex is an eloquent island of mesocortex surrounded by vital structures making this region relatively challenging to neurosurgeons. Historically, lesions in this region were considered too high risk to approach given the strong chance of poor surgical outcome. Advances in recent decades have meant that surgeons can more safely access this eloquent region. Seizure outcome after excision of insular low-grade gliomas is well reported, but little is known about seizure outcomes after excision of insular high-grade gliomas.

METHODS

A retrospective analysis was performed of all patients presenting with new-onset seizures during 2015-2019 who underwent excision of an insular high-grade glioma at 3 regional neurosurgical centers in the United Kingdom.

RESULTS

We identified 38 patients with a mean (SD) age of 45.7 (15.3) years with median follow-up of 21 months. At long-term follow-up, of 38 patients, 23 were seizure-free (Engel class I), 2 had improved seizures (Engel class II), 6 had poor seizure control (Engel class III/IV), and 7 died.

CONCLUSIONS

Excision of insular high-grade gliomas is safe and results in excellent postoperative seizure control.

Multi-Omics Data Integration Analysis of an Immune-Related Gene Signature in LGG Patients With Epilepsy

Background

The tumor immune microenvironment significantly affects tumor occurrence, progression, and prognosis, but its impact on the prognosis of low-grade glioma (LGG) patients with epilepsy has not been reported. Hence, the purpose of this study is to explore its effect on LGG patients with epilepsy.

Methods

The data of LGG patients derived from the TCGA database. The level of immune cell infiltration and the proportion of 22 immune cells were evaluated by ESTIMATE and CIBERSORT algorithms, respectively. The Cox and LASSO regression analysis was adopted to determine the DEGs, and further established the clustering and risk score models. The association between genomic alterations and risk score was investigated using CNV and somatic mutation data. GSVA was adopted to identify the immunological pathways, immune infiltration and inflammatory profiles related to the signature genes. The Tumor Immune Dysfunction and Exclusion (TIDE) algorithm and GDSC database were used to predict the patient’s response to immunotherapy and chemotherapy, respectively.

Results

The prognosis of LGG patients with epilepsy was associated with the immune score. Three prognostic DEGs (ABCC3, PDPN, and INA) were screened out. The expression of signature genes was regulated by DNA methylation. The clustering and risk score models could stratify glioma patients into distinct prognosis groups. The risk score was an independent predictor in prognosis, with a high risk-score indicating a poor prognosis, more malignant clinicopathological and genomic aberration features. The nomogram had the better predictive ability. Patients at high risk had a higher level of macrophage infiltration and increased inflammatory activities associated with T cells and macrophages. While the higher percentage of NK CD56bright cell and more active inflammatory activity associated with B cell were present in the low-risk patients. The signature genes participated in the regulation of immune-related pathways, such as IL6-JAK-STAT3 signaling, IFN-α response, IFN-γ response, and TNFA-signaling-via-NFKB pathways. The high-risk patients were more likely to benefit from anti-PD1 and temozolomide (TMZ) treatment.

Conclusion

An immune-related gene signature was established based on ABCC3, PDPN, and INA, which can be used to predict the prognosis, immune infiltration status, immunotherapy and chemotherapy response of LGG patients with epilepsy.

Prediagnosis epilepsy and survival in patients with glioma: a nationwide population-based cohort study from 2009 to 2018

OBJECTIVE

Considering that epilepsy is common, and knowledge is lacking on its role especially for the prognosis of high-grade gliomas, the objective of this study was to investigate the association between epilepsy prior to glioma diagnosis and survival among glioma patients.

METHODS

In a nationwide population-based cohort study, we included 3763 adult glioma patients diagnosed between 2009 and 2018 according to the Danish Neuro-Oncology Registry. Information on epilepsy was redeemed through Danish Neuro-Oncology Registry, National Patient Registry, and National Prescription Registry. Cox proportional hazard models with 95% confidence intervals (CIs) were applied to examine hazard ratios (HRs) for the association between epilepsy (< 1 year prior to glioma including epilepsy at onset; 1-10 years prior to glioma; no prior epilepsy) and risk of death, and whether it differed according to tumor grade and size, performance status, and treatment modalities.

RESULTS

A 32% decreased risk of death in patients with epilepsy within 1 year prior to glioma compared to no prior epilepsy was found (HR = 0.68; CI 0.63-0.75). A favorable prognosis was seen for epilepsy in all glioma grades: II (HR = 0.55; CI 0.39-0.77), III (HR = 0.59; CI 0.48-0.73), and IV (HR = 0.85; CI 0.77-0.94).

CONCLUSIONS

Patients with epilepsy within 1 year prior to glioma diagnosis had significant survival benefits compared to patients with no prior epilepsy. This association was significant for both low-grade gliomas (grade II) and high-grade gliomas (grade III and IV). Survival benefits in glioma patients with epilepsy at onset are possibly primarily attributable to tumor-specific histopathology, molecular biomarkers, and early diagnosis.

Glioma-Derived TSP2 Promotes Excitatory Synapse Formation and Results in Hyperexcitability in the Peritumoral Cortex of Glioma

Seizures are common in patients with glioma, especially low-grade glioma (LGG). However, the epileptogenic mechanisms are poorly understood. Recent evidence has indicated that abnormal excitatory synaptogenesis plays an important role in epileptogenesis. The thrombospondin (TSP) family is a key regulator of synaptogenesis. Thus, this study aimed to elucidate the role of TSP2 in epileptogenesis in glioma-related epilepsy. The expression of TSP2 was increased in tumor tissue specimens from LGG patients, and this increase may have contributed to an increase in the density of spines and excitatory synapses in the peritumoral area. A glioma cell-implanted rat model was established by stereotactic implantation of wild-type TSP2-expressing, TSP2-overexpressing or TSP2-knockout C6 cells into the neocortex. Similarly, an increase in the density of excitatory synapses was also observed in the peritumoral area of the implanted tumor. In addition, epileptiform discharges occurred in the peritumoral cortex and were positively correlated with the TSP2 level in glioma tissues. Moreover, α2δ1/Rac1 signaling was enhanced in the peritumoral region, and treatment with the α2δ1 antagonist gabapentin inhibited epileptiform discharges in the peritumoral cortex. In conclusion, glioma-derived TSP2 promotes excitatory synapse formation, probably via the α2δ1/Rac1 signaling pathway, resulting in hyperexcitability in the peritumoral cortical networks, which may provide new insight into the epileptogenic mechanisms underlying glioma-related epilepsy.

Effect of antiepileptic drugs in glioma patients on self-reported depression, anxiety, and cognitive complaints

Introduction

AEDs have been associated with depression, anxiety, and cognitive impairment, all frequent complications of glioma and its subsequent treatment, with considerable morbidity and an adverse effect on health-related quality of life. This study aimed to determine the independent association between AED use and self-reported depression, anxiety, and subjective cognitive impairment in glioma patients.

Methods

In this multicenter cross-sectional study, depression and anxiety were assessed with the HADS and subjective cognitive impairment was assessed with the MOS-CFS. Univariable logistic regression analyses were performed on all potential confounding predictor variables. Potential confounders were included in the multivariable analyses if p-value < 0.1, to evaluate whether use of AEDs was independently related to depression, anxiety, and/or subjective cognitive impairment.

Results

A total of 272 patients were included. Prevalence of depression differed significantly between patients not using (10%) and using AEDs (21%, unadjusted Odds Ratio [uOR] = 2.29 [95%CI 1.05–4.97], p = 0.037), but after correction for confounders the statistical significant difference was no longer apparent (adjusted Odds Ratio [aOR] = 1.94 [95%CI 0.83–4.50], p = 0.125). Prevalences of anxiety (aOR = 1.17 [95%CI 0.59–2.29], p = 0.659) and subjective cognitive impairment (aOR = 0.83 [95%CI 0.34–2.04], p = 0.684) did not differ significantly before or after adjustment of confounders between patients not using (19% and 16%, respectively) and using AEDs (26% and 21%, respectively).

Conclusions

Our results indicate AED use was not independently associated with concurrent depression, anxiety, or subjective cognitive impairment in glioma patients. Alternative factors seem to have a greater contribution to the risk of developing neuropsychiatric symptoms in glioma patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-021-03747-1.

Antiseizure medication in patients with Glioblastoma- a collaborative cohort study

PURPOSE

We investigated, whether epileptic seizures (ES) as presenting symptom in adult patients with GBM are associated with better Overall Survival (OS) compared to ES presenting later during the course of GBM, and efficacy and safety of different antiseizure medications (ASMs).

METHODS

Retrospective consecutive cohort study of adults with GBM: 50 from Norway and 50 from Italy. We compared the time to changing ASM treatments. OS was investigated with a Cox regression model adjusted for time dependency.

RESULTS

Median follow-up was 17 months from GBM diagnosis. ES were the presenting symptom in 49 patients. All patients received ASM treatment. LEV was the first ASM in the majority of patients and the most effective at one year from the first prescription, (p = 0.004). Occurrence of adverse events (AEs) was similar between LEV and other ASMs (p = 0.47). Poorer OS correlated with older age at GBM diagnosis, country and ASM therapy. A negative impact of ASMs on OS was observed for LEV in a univariate and multivariate analysis, and for VPA (only in multivariate analysis), even when adjusted for O6-methylguanine-DNA-methyltransferase (MGMT) methylation status. Patients with ES as the onset symptom of GBM and patients who had first ES later had similar OS (p = 0.87).

CONCLUSION

ES as the GBM debut symptom did not lead to a longer OS. LEV was a more effective ASM compared to other treatments with no differences regarding AEs between LEV and other ASMs. Surprisingly, in our patients LEV and VPA were associated with worse OS than other ASMs. This result should be interpreted with caution due to the retrospective nature of this study along with the many variables which may affect the outcome in this population.

Preoperative and early postoperative seizures in patients with glioblastoma-two sides of the same coin?

Background

Symptomatic epilepsy is a common symptom of glioblastoma, which may occur in different stages of disease. There are discrepant reports on association between early seizures and glioblastoma survival, even less is known about the background of these seizures. We aimed at analyzing the risk factors and clinical impact of perioperative seizures in glioblastoma.

Methods

All consecutive cases with de-novo glioblastoma treated at our institution between 01/2006 and 12/2018 were eligible for this study. Perioperative seizures were stratified into seizures at onset (SAO) and early postoperative seizures (EPS, ≤21days after surgery). Associations between patients characteristics and overall survival (OS) with SAO and EPS were addressed.

Results

In the final cohort (n = 867), SAO and EPS occurred in 236 (27.2%) and 67 (7.7%) patients, respectively. SAO were independently predicted by younger age (P = .009), higher KPS score (P = .002), tumor location (parietal lobe, P = .001), GFAP expression (≥35%, P = .045), and serum chloride at admission (>102 mmol/L, P = .004). In turn, EPS were independently associated with tumor location (frontal or temporal lobe, P = .013) and pathologic laboratory values at admission (hemoglobin < 12 g/dL, [P = .044], CRP > 1.0 mg/dL [P = 0.036], and GGT > 55 U/L [P = 0.025]). Finally, SAO were associated with gross-total resection (P = .006) and longer OS (P = .030), whereas EPS were related to incomplete resection (P = .005) and poorer OS (P = .009).

Conclusions

In glioblastoma patients, SAO and EPS seem to have quite different triggers and contrary impact on treatment success and OS. The clinical characteristics of SAO and EPS patients might contribute to the observed survival differences.

Effect of seizure timing on long-term survival in patients with brain tumor

OBJECTIVE

Seizures often occur in patients with primary brain tumor (BT). The aim of this study was to determine if there is an association between the time of occurrence of seizures during the course of BT and survival of these patients.

METHODS

This retrospective cohort study at Henry Ford Hospital, an urban tertiary referral center, included all patients who were diagnosed with primary BTs at Henry Ford Health System between January 2006 and December 2014. Timing of seizure occurrence, if occurred at presentation or after the tumor diagnosis during follow-up period, in different grades of BTs, and survival of these patients were analyzed.

RESULTS

Of the 901 identified patients, 662 (53% male; mean age: 56 years) were included in final analysis, and seizures occurred in 283 patients (43%). Patients with World Health Organization (WHO) grade III BT with seizures as a presenting symptom only had better survival (adjusted hazard ratio (HR): 0.27; 95% confidence interval (CI), 0.11-0.67; P = 0.004). Seizures that occurred after tumor diagnosis only (adjusted HR: 2.11; 95% CI, 1.59-2.81; P < 0.001) in patients with WHO grade II tumors (adjusted HR: 3.41; 95% CI, 1.05-11.1; P = 0.041) and WHO grade IV tumors (adjusted HR: 2.14; 95% CI, 1.58-2.90; P < 0.001) had higher mortality. Seizures that occurred at presentation and after diagnosis also had higher mortality (adjusted HR: 1.34; 95% CI, 1.00-1.80; P = 0.049), in patients with meningioma (adjusted HR: 6.19; 95% CI, 1.30-29.4; P = 0.021) and grade III tumors (adjusted HR: 6.19; 95% CI, 2.56-15.0; P < 0.001).

CONCLUSION

Seizures occurred in almost half of the patients with BTs. The association between seizures in patients with BT and their survival depends on the time of occurrence of seizures, if occurring at presentation or after tumor diagnosis, and the type of tumor. Better survival was noted in patients with WHO grade III BTs who had seizures at presentation at the time of diagnosis, while higher mortality was noted in WHO grade II tumors who had seizure at presentation and after tumor diagnosis, and in grade IV tumors after tumor diagnosis.

Antiepileptic Drugs in the Management of Cerebral Metastases

Seizures represent a common and debilitating complication of central nervous system metastases. The use of prophylactic antiepileptic drugs (AEDs) in the preoperative period remains controversial, but the preponderance of evidence suggests that it is not helpful in preventing seizure and instead poses a significant risk of adverse events. Studies of postoperative seizure prophylaxis have not shown substantial benefit, but this practice remains widespread. Careful analysis of the risk of seizure based on patient-specific factors, such as tumor location and primary tumor histology, should guide the physician's decision on the initiation and cessation of prophylactic AED therapy.

Pre-Treatment Seizures in Patients With 1-3 Cerebral Metastases Receiving Local Therapies Plus Whole-brain Radiotherapy

BACKGROUND/AIM

Seizures impair patients' quality of life. The prognostic role of pre-treatment seizures in patients with 1-3 cerebral metastases receiving local therapies plus whole-brain radiotherapy (WBRT) was investigated.

PATIENTS AND METHODS

In 249 patients, prevalence, risk factors and associations of pre-treatment seizures with survival were retrospectively evaluated. Age, gender, performance score, tumor type, number of lesions, extra-cerebral metastases, and time from tumor diagnosis to treatment of cerebral metastasis were analyzed for associations with seizures. These characteristics and pre-treatment seizures were also analyzed for associations with survival.

RESULTS

The prevalence of pre-treatment seizures was 24.1%. Trends for associations were found between seizures and gender or performance score. On multivariate analysis, age (p=0.008), performance score (p=0.004), tumor type (p<0.001) and extra-cerebral metastasis (p<0.001) were significantly associated with survival.

CONCLUSION

Seizures were comparably common prior to local therapies plus WBRT for cerebral metastases. No factor was found to be significantly associated with seizures, and seizures were not associated with survival.

Pre-operative Seizures in Patients With Single Brain Metastasis Treated With Resection Plus Whole-Brain Irradiation and a Boost

BACKGROUND/AIM

Seizures can be the initial symptom of brain metastases. This study investigated pre-treatment seizures in patients with a single lesion.

PATIENTS AND METHODS

Pre-operative seizures were analyzed in 104 patients with a single brain metastasis receiving resection plus whole-brain irradiation and a boost. Prevalence of seizures, risk factors and associations with survival (OS) were evaluated.

RESULTS

Thirty patients (34.6%) had seizures prior to neurosurgery. Significant associations between seizures and investigated characteristics were not found. However, age ≤61 years showed a trend (p=0.117) for increased incidence of seizures. Time from diagnosis of malignancy until neurosurgery >12 months was significantly associated with improved OS on univariate analysis (p=0.003). Trends for a positive association with OS were found for no seizures (p=0.054), female gender (p=0.066) and breast cancer (p=0.098). On multivariate analysis, time until neurosurgery >12 months was independently associated (p=0.019) with better OS, and seizures showed a trend (p=0.119) for improved OS.

CONCLUSIONS

Considering the high prevalence of seizures in this cohort, regular screening and monitoring of these patients appears reasonable. This applies particularly to patients aged ≤61 years.

Effect of valproic acid on overall survival in patients with high-grade gliomas undergoing temozolomide: A nationwide population-based cohort study in Taiwan

High-grade gliomas (HGGs) are a rapidly progressive and highly recurrent group of primary brain tumors. Despite aggressive surgical resection with chemoradiotherapy, prognoses remained poor. Valproic acid (VPA), a histone deacetylase inhibitor has shown the potential to inhibit glioma cell growth in vitro through several diverse mechanisms. However clinical studies regarding the effect of VPA on HGGs are limited. This study aimed to investigate whether using VPA in patients with HGGs under temozolomide (TMZ) would lead to a better overall survival (OS).We used the Taiwan National Health Insurance Research database to conduct this population-based cohort study. A total of 2379 patients with HGGs under TMZ treatment were included and were further classified into VPA (n = 1212, VPA ≥ 84 defined daily dose [DDD]) and non-VPA (n = 1167, VPA < 84 DDD) groups. Each patient was followed from 1998 to 2013 or until death. A Cox proportional hazard regression was performed to evaluate the effect of VPA and OS.The VPA group had a longer mean OS time compared with the non-VPA group (OS: 50.3 ± 41.0 vs 42.0 ± 37.2 months, P < .001). In patients between 18 and 40 years old, the difference is most significant (OS: 70.5 ± 48.7 vs 55.1 ± 46.0, P = .001). The adjusted hazard ratio is 0.81 (95% confidence interval, 0.72-0.91) for the VPA group relative to the non-VPA group.VPA at over 84 DDD improved OS in HGGs TMZ treatment.

Seizures in Pediatric Patients With Primary Brain Tumors

BACKGROUND

Seizures are one of the most common symptoms of pediatric brain tumors. The purpose of this study was to define seizures related to primary central nervous system tumors and to identify risk factors predictive of seizure occurrence and recurrence.

METHODS

We reviewed the records of children treated from January 1, 2004, to January 1, 2018 and collected data including age, gender, tumor location, histology, extent of initial resection, seizure characteristics, treatment modalities, recurrence, and seizure control. A binomial logistic regression was performed to determine the risk factors of seizure occurrence.

RESULTS

During the observation period, 348 children were diagnosed with a primary brain tumor. The median age at diagnosis was 7.8 years, and the median follow-up interval was 3.9 years. There were 196 boys (56.3%). In our cohort, a total of 70 children (20.1%) experienced seizures. Most of them (64.3%) had cortical tumors. All patients with dysembryoplastic neuroepithelial tumors and 81.8% of patients with glioneuronal tumors presented seizures. Risk factors associated with an increased risk for seizures included cortical location, tumor recurrence, and age at diagnosis. Thirty-nine (86.7%) patients with seizures at diagnosis were seizure free at last follow-up (Engel 1). Significantly more patients (69.6%) with a gross total resection were withdrawn from their antiepileptic drugs when compared with those with subtotal resection (27.3%, P = 0.007).

CONCLUSIONS

Our study is the largest cohort in children with tumor-related seizures and brings new insight in terms of seizure risk according to tumor types and evolution following treatment.

Clinical characteristics associated with postoperative seizure control in adult low-grade gliomas: a systematic review and meta-analysis

Background

Epilepsy is the most common symptom in patients with supratentorial low-grade gliomas (LGGs), which adversely affects the patient's quality of life. Poor seizure control with anti-epileptic therapy is an indication for surgery in these patients. Recent studies have sought to identify predictors of postoperative seizure control after surgical resection of LGG; gross total resection was shown to be a significant predictor in this respect. However, the prognostic value of other factors is not clear.

Methods

We performed a systematic review and meta-analysis of 23 studies with a combined study population of 2641 patients with LGG, in order to identify potential factors associated with favorable postoperative seizure control. Data were extracted on age and sex of patient, tumor location, tumor histology, type of seizure, seizure duration, extent of resection, and imaging characteristics.

Results

Patients ≥45 years of age achieved better postoperative seizure control (risk ratio [RR], 0.89; 95% CI, 0.81-0.99). Focal seizures were associated with poor seizure control (RR, 1.32; 95% CI, 1.18-1.49) compared with generalized seizures (RR, 0.77; 95% CI, 0.68-0.87). Prolonged history of seizures (≥1 y) had a negative impact on postoperative seizure control (RR, 1.22; 95% CI, 1.10-1.34). Gross total resection was superior to subtotal resection with respect to postoperative seizure control (RR, 0.68; 95% CI, 0.63-0.73).

Conclusions

This systematic review and meta-analysis identified predictors of postoperative seizure control in patients undergoing surgical resection of LGGs. Our results provide a reference for clinical treatment of LGG-related epilepsy.

Diffuse Low-Grade Glioma - Changing Concepts in Diagnosis and Management: A Review

Though diffuse low-grade gliomas (dLGGs) represent only 15% of gliomas, they have been receiving increasing attention in the past decade. Significant advances in knowledge of the natural history and clinical diversity have been documented, and an improved pathological classification of gliomas that integrates histological features with molecular markers has been issued by the WHO. Advances in the radiological assessment of dLGG, particularly new magnetic resonance imaging scanning sequences, allow improved diagnostic and prognostic information. The management paradigms are evolving from “wait and watch” of the past to more active interventional therapy to obviate the risk of malignant transformation. New surgical technologies allow more aggressive surgical resections with a reduction of morbidity. Many reports suggest the association of gross total resection with longer overall survival and progression-free survival in addition to better seizure control. The literature also shows the use of chemotherapeutics and radiation therapy as important adjuncts to surgery. The goals of management have has been increasing survival with increasing stress on quality of life. Our review highlights the recent advances in the molecular diagnosis and management of dLGG with trends toward multidisciplinary and multimodality management of dLGG with an aim to surgically resect the primary disease, followed by chemoradiation in cases of progressive or recurrent 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.

Rapid Fire: Central Nervous System Emergencies

Neurologic complications are unfortunately common in oncology patients, with many presenting to the emergency department for diagnosis and management. This case-based review provides a brief overview of the key points in pathophysiology, diagnosis, and management of 2 oncologic central nervous system emergencies: malignant spinal cord compression and intracranial mass.

Choice of antiepileptic drugs affects the outcome in cancer patients with seizures

BACKGROUND

Seizures in cancer patients may occur as a result of CNS primary or metastatic tumor, brain surgery, vascular disease, pharmacologic treatment (including chemotherapy), radiation therapy, or metabolic disorders. The aims of the study were to a) determine whether seizures in cancer patients have prognostic implications and b) study patient outcome based on the antiepileptic drug used.

METHOD

This is a prospective comparative study that included adult cancer patients with and without seizures from May 2010 to November 2016 seen by the neuro-oncology unit at a cancer referral center. Variables included age, gender, oncologic characteristics, seizure features, treatment, and outcome. Parametric and non-parametric tests were used to compare groups, and Kaplan-Meier curves with the log-rank test were used to analyze survival. Cox multivariate regression tests were used to describe survival and compare groups.

RESULTS

A total of 823 patients were included; 419 (51%) patients had at least one seizure and were compared with 404 (49%) who did not experience seizures. Of the seizure group, 53% had brain metastases, 36% did not have a brain tumor, and 11% had a primary brain tumor. No survival differences were noted among patients with brain metastases or primary tumor with or without seizures. In the seizure group, 249 (59%) required only one antiepileptic drug, whereas 134 (32%) required 2 or more. A better overall survival was identified for patients prescribed carbamazepine (p = 0.02), lamotrigine (p = 0.015), levetiracetam (p = 0.03), and valproic acid (p = 0.009).

CONCLUSIONS

Patients with primary or metastatic brain tumors have the same overall survival with or without seizures. However, patients with seizures not treated with antiepileptics exhibit worse overall survival.

New-onset seizure during and after brain tumor excision: a risk assessment analysis

OBJECTIVE

Prophylactic use of antiepileptic drugs (AEDs) in seizure-naïve brain tumor patients remains a topic of debate. This study aimed to characterize a subset of patients at highest risk for new-onset perioperative seizures (i.e., intraoperative and postoperative seizures occurring within 30 days of surgery) who may benefit from prophylactic AEDs.

METHODS

The authors conducted a retrospective case-control study of all adults who had undergone tumor resection or biopsy at the authors’ institution between January 1, 2004, and June 31, 2015. All patients with a history of preoperative seizures, posterior fossa tumors, pituitary tumors, and parasellar tumors were excluded. A control group was matched to the seizure patients according to age (± 0 years). Demographic data, clinical status, operative data, and postoperative course data were collected and analyzed.

RESULTS

Among 1693 patients who underwent tumor resection or biopsy, 549 (32.4%) had never had a preoperative seizure. Of these 549 patients, 25 (4.6%) suffered a perioperative seizure (Group 1). A total of 524 patients (95.4%) who remained seizure free were matched to Group 1 according to age (± 0 years), resulting in 132 control patients (Group 2), at an approximate ratio of 1:5. There were no differences between the patient groups in terms of age, sex, race, relationship status, and neurological deficits on presentation. Histological subtype (infiltrating glioma vs meningioma vs other, p = 0.041), intradural tumor location (p < 0.001), intraoperative cortical stimulation (p = 0.004), and extent of resection (less than gross total, p = 0.002) were associated with the occurrence of perioperative seizures.

CONCLUSIONS

While most seizure-naïve brain tumor patients do not benefit from perioperative seizure prophylaxis, such treatment should be considered in high-risk patients with supratentorial intradural tumors, in patients undergoing intraoperative cortical stimulation, and in patients in whom subtotal resection is likely.

Glioma-related seizures in relation to histopathological subtypes: a report from the glioma international case-control study

BACKGROUND

The purpose of this study was to evaluate the distribution of glioma-related seizures and seizure control at the time of tumor diagnosis with respect to tumor histologic subtypes, tumor treatment and patient characteristics, and to compare seizure history preceding tumor diagnosis (or study enrollment) between glioma patients and healthy controls.

METHODS

The Glioma International Case Control study (GICC) risk factor questionnaire collected information on demographics, past medical/medication history, and occupational history. Cases from eight centers were also asked detailed questions on seizures in relation to glioma diagnosis; cases (n = 4533) and controls (n = 4171) were also asked about seizures less than 2 years from diagnosis and previous seizure history more than 2 years prior to tumor diagnosis, including childhood seizures.

RESULTS

Low-grade gliomas (LGGs), particularly oligodendrogliomas/oligoastrocytomas, had the highest proportion of glioma-related seizures. Patients with low-grade astrocytoma demonstrated the most medically refractory seizures. A total of 83% of patients were using only one antiepileptic drug (AED), which was levetiracetam in 71% of cases. Gross total resection was strongly associated with reduced seizure frequency (p < 0.009). No significant difference was found between glioma cases and controls in terms of seizure occurring more than 2 years before diagnosis or during childhood.

CONCLUSIONS

Our study showed that glioma-related seizures were most common in low-grade gliomas. Gross total resection was associated with lower seizure frequency. Additionally, having a history of childhood seizures is not a risk factor ***for developing glioma-related seizures or glioma.

Brain metastasis: clinical manifestations, symptom management, and palliative care

Patients who have brain metastases can suffer from a medley of symptoms, including headaches, seizures, cognitive impairment, fatigue, and focal deficits. As therapies have evolved, so has the management of these symptoms as patients survive longer. This chapter focuses on the clinical presentation of brain metastases, the treatment of those symptoms, and palliation in end-of-life management. Brain metastases are the most common cerebral malignancy. They can present with various symptoms, which can have significant impact on patients' quality of life throughout the course of their disease. Most of these symptoms are related to direct brain compression from the tumor or from edema. The location of the metastases will determine the focal deficits incurred and most patients will be on a course of steroids tapered according to their clinical status. The chapter includes a list of potential side-effects and considerations for management. Palliative care is an essential and important part of approaching patients with metastases. Early and clear communication about end-of-life decision making is encouraged with multiple easily accessible tools. For patients near the end of life, comfort is the ultimate goal in providing a good quality of life.

Association Between IDH1 and IDH2 Mutations and Preoperative Seizures in Patients with Low-Grade Versus High-Grade Glioma: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with brain tumors, particularly gliomas, commonly present with seizures. Higher incidence of seizure has been reported in low-grade gliomas and tumors located within the temporal and insular area. The association between IDH1 and IDH2 mutations with preoperative seizures in glioma and the magnitude of this association in low-grade versus high-grade gliomas are unclear. To clarify this relationship, a systematic review and meta-analysis was performed.

METHODS

Following accepted guidelines and systematic review recommendations, electronic searches were performed in journal databases up to May 2017. Data were extracted and pooled via meta-analysis.

RESULTS

We compared 782 patients with IDH1 and IDH2 mutations with 803 patients with wild-type IDH1 and IDH2 before surgery. There was a significant difference in seizure incidence between the IDH1 mutation group (61.6%) and wild-type IDH1 group (32.1%) (odds ratio 2.76; 95% confidence interval, 1.26-6.02; I² = 73%; P = 0.01). Similar findings were observed in analysis of IDH1 and IDH2 mutations (odds ratio 2.74; 95% confidence interval, 1.74-4.33; I² = 58%; P < 0.0001). The difference remained in both mutation groups (IDH1, IDH1 and IDH2) with grade II gliomas but not with grade III and IV gliomas. Patients with grade II gliomas showed a higher rate of IDH1 and IDH2 mutations and seizures than patients with grade III and IV gliomas.

CONCLUSIONS

This study demonstrated a significant association of IDH1 and IDH2 mutations with incidence of preoperative seizures. This association was significant only in patients with low-grade glioma (grade II) and not in patients with higher grade gliomas (grade III and IV).

Quantifying the prognostic significance in glioblastoma of seizure history at initial presentation: A systematic review and meta-analysis

The role of prognostic factors in the management of glioblastoma (GBM) is very important given the stasis in improving its clinical outcomes. Patients who initially present with a positive seizure history at diagnosis have anecdotally experienced superior survival outcomes. The aim of this review was to perform a systematic review and meta-analysis to quantify the potential prognostic significance of positive seizure history in GBM patients. A search strategy was performed using the PRISMA guidelines for article identification, screening, eligibility and inclusion. Relevant articles were identified from six electronic databases from their inception to August 2017. These articles were screened against established criteria for inclusion into this study. Meta-analysis was conducted by pooling results with multivariate-adjusted hazard ratios (HRs). After screening, 6 relevant studies were included for analysis. There was a total cohort of 1836 GBM patients, of which 488 (27%) had a positive seizure history at initial presentation. There was a significant association found between positive seizure history in GBM patients and less mortality events, with an overall HR of 0.71 (95%CI=0.63-0.81, p<0.00001, I²=4%). Positive seizure history at initial presentation of GBM can be associated with improved prognosis. However, there are a number of variables that need to be considered further, including genetic profiling, lead time bias, and anti-epileptic drug (AED) therapy. This review represents the highest level of evidence to date, and its result will be validated by future, prospective study of larger cohorts.

Improved Survival with Decreased Wait Time to Surgery in Glioblastoma Patients Presenting with Seizure

BACKGROUND

Preoperative seizure is reported to confer favorable prognosis in glioblastoma patients, but studies to date have not investigated how broadly applicable seizure is as a prognostic factor.

OBJECTIVE

To investigate if prompter surgical intervention affects the relationship between preoperative seizure and prognosis in glioblastoma patients, focusing on the development of tumor growth and/or additional preoperative symptoms after seizure.

METHODS

Retrospective analysis of 443 patients (mean age = 60.2; 60% male) undergoing first glioblastoma resection at our institution (2005-2011).

RESULTS

Preoperative seizure(s) occurred in 28% of patients (n = 124), of which 63 (51%) had only seizure at presentation. Patients experiencing seizure as their only preoperative symptom ("seizure-only"; n = 45) survived over twice as long as patients who presented with seizure and then later developed additional preoperative symptoms (n = 18; "other symptoms postseizure"; 26.8 vs 10.2 months, P < .001) and patients without preoperative seizure ("no seizure"; 26.8 vs 13.1 months, P < .001). Multivariate stepwise analysis revealed preoperative seizures only (hazard ratio 0.54 [0.37-0.75]; P < .001) to be independently associated with increased survival. Longer wait time from presentation (ie, diagnostic magnetic resonance imaging) to surgery was a risk factor for developing additional symptoms. Eleven "other symptoms postseizure" patients (69%) vs 6 of the "seizure-only" patients (15%) had wait times >45 days (P < .001).

CONCLUSION

Seizure as the only preoperative symptom independently improved survival, however, when patients developed additional preoperative symptoms, typically due to surgical delay, no prognostic benefit was observed. Prompt diagnosis and neurosurgical intervention is warranted in patients with seizures without other preoperative symptoms to preserve their favorable prognosis.

Epileptic seizures heralding a relapse in high grade gliomas

PURPOSE

Seizures are a common clinical symptom in high-grade gliomas (HGG). The aim of the study was to investigate the relationship between seizures and HGG relapse (HGG-R).

METHODS

We retrospectively evaluated 145 patients who were surgically treated for HGG-R. By analyzing clinical characteristics in these patients (all operated and treated by the same protocol), we identified 37 patients with seizures during follow-up. This cohort was divided into four subgroups according to a) presence or absence of seizures at the time of diagnosis and b) temporal relationship between seizure occurrence and HGG-R during follow-up: subgroup A (25pts) had seizures at follow-up but not at onset, subgroup B (12pts) had seizures both at follow-up and onset, subgroup C (30pts) had seizures before MRI-documented HGG-R, and subgroup D (7pts) had seizures after MRI-documented HGG-R.

RESULTS

Although the datum was not statistically significant, survival was longer in patients with seizures during follow-up than in those without seizures (59.3% vs 51.4% alive at 2 years). In 30 patients (subgroup C) seizures heralded HGG-R. In a correlation analysis for this last subgroup, the time interval between seizure and the HGG-R was significantly associated with the number of chemotherapy cycles (r=0.470; p=0.009) and follow-up duration (r=0.566; p=0.001). A linear regression model demonstrated a reciprocal association between the above factors and that it may be possible to estimate the timing of HGG-R by combining these data.

CONCLUSIONS

Seizures may herald HGG-R before MRI detection of relapse, thus suggesting that seizures should always be considered a red flag during follow-up.

An extent of resection threshold for seizure freedom in patients with low-grade gliomas

OBJECTIVE Seizures are the most common presenting symptom of newly diagnosed WHO Grade II gliomas (low-grade glioma [LGG]) and significantly impair quality of life. Although gross-total resection of LGG is associated with better seizure control, it remains unclear whether an extent of resection (EOR) "threshold" exists for long-term seizure control. Specifically, what proportion of FLAIR-positive tissue in patients with newly diagnosed LGG must be removed to achieve Engel Class I seizure freedom? To clarify the EOR threshold for long-term seizure control, the authors analyzed data from a consecutive series of patients with newly diagnosed LGG who presented with seizures and subsequently underwent microsurgical resection. METHODS The authors identified consecutive patients with newly diagnosed LGG who presented with seizures and were treated at the Barrow Neurological Institute between 2002 and 2012. Patients were dichotomized into those who were seizure free postoperatively and those who were not. The EOR was calculated by quantitative comparison of pre- and postoperative MRI. Univariate analysis of these 2 groups included the chi-square test and the Mann-Whitney U-test, and a multivariate logistic regression was constructed to predict the impact of multiple independent variables on the likelihood of postoperative seizure freedom. To determine a threshold of EOR that optimizes seizure freedom, a receiver operating characteristic curve was plotted and the optimal point of discrimination was determined. RESULTS Data from 128 patients were analyzed (male/female ratio 1.37:1; mean age 40.8 years). All 128 patients presented with seizures, usually generalized (n = 57, 44.5%) or simple partial (n = 57, 44.5%). The median EOR was 90.0%. Of 128 patients, 46 (35.9%) had 100% volumetric tumor resection, 64 (50.0%) had 90%-99% volumetric tumor resection, and 11 (8.6%) had 80%-89% volumetric tumor resection. Postoperatively, 105 (82%) patients were seizure free (Engel Class I); 23 (18%) were not (Engel Classes II-IV). The proportion of seizure-free patients increased in proportion to the EOR. Predictive variables included in the regression model were preoperative Karnofsky Performance Scale score, seizure type, time from diagnosis to surgery, preoperative number of antiepileptic drugs, and EOR. Only EOR significantly affected the likelihood of postoperative Engel Class I status (OR 11.5, 95% CI 2.4-55.6; p = 0.002). The receiver operating characteristic curve generated based on Engel Class I status showed a sensitivity of 0.65 and 1 - specificity of 0.175, corresponding to an EOR of 80%. CONCLUSIONS For adult patients with LGG who suffer seizures, the results suggest that seizure freedom can be attained when EOR > 80% is achieved. Improvements in both the proportion of seizure-free patients and the durability of seizure freedom were observed beyond this 80% threshold. Interestingly, this putative EOR seizure-freedom threshold closely approximates that reported for the overall survival benefit in newly diagnosed hemispheric LGGs, suggesting that a minimum level of residual tumor burden is necessary for both disease and symptomatic progression.

Biopsy versus resection for the management of low-grade gliomas

BACKGROUND

This is an updated version of the original Cochrane review published in 2013, Issue 4.Low-grade gliomas (LGG) constitute a class of slow-growing primary brain neoplasms. Patients with clinically and radiographically suspected LGG have two initial surgical options, biopsy or resection. Biopsy can provide a histological diagnosis with minimal risk but does not offer a direct treatment. Resection may have additional benefits such as increasing survival and delaying recurrence, but is associated with a higher risk for surgical morbidity. There remains controversy about the role of biopsy versus resection and the relative clinical outcomes for the management of LGG.

OBJECTIVES

To assess the clinical effectiveness of biopsy compared to surgical resection in patients with a new lesion suspected to be a LGG.

SEARCH METHODS

The following electronic databases were searched in 2012 for the first version of the review: Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 11), MEDLINE (1950 to November week 3 2012), Embase (1980 to Week 46 2012). For this updated version, the following electronic databases were searched: Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 5), MEDLINE (Nov 2012 to June week 3 2016), Embase (Nov 2012 to 2016 week 26). All relevant articles were identified on PubMed and by using the 'related articles' feature. We also searched unpublished and grey literature including ISRCTN-metaRegister of Controled Trials, Physicians Data Query and ClinicalTrials.gov for ongoing trials.

SELECTION CRITERIA

We planned to include patients of any age with a suspected intracranial LGG receiving biopsy or resection within a randomized clinical trial (RCT) or controlled clinical trial (CCT). Patients with prior resections, radiation therapy, or chemotherapy for LGG were excluded. Outcome measures included overall survival (OS), progression-free survival (PFS), functionally independent survival (FIS), adverse events, symptom control, and quality of life (QoL).

DATA COLLECTION AND ANALYSIS

A total of 1375 updated citations were searched and critically analyzed for relevance. This was undertaken independently by two review authors. The original electronic database searches yielded a total of 2764 citations. In total, 4139 citations have been critically analyzed for this updated review.

MAIN RESULTS

No new RCTs of biopsy or resection for LGG were identified. No additional ineligible non-randomized studies (NRS) were included in this updated review. Twenty other ineligible studies were previously retrieved for further analysis despite not meeting the pre-specified criteria. Ten studies were retrospective or were literature reviews. Three studies were prospective, however they were limited to tumor recurrence and volumetric analysis and extent of resection. One study was a population-based parallel cohort in Norway, but not an RCT. Four studies were RCTs, however patients were randomized with respect to varying radiotherapy regimens to assess timing and dose of radiation. One RCT was on high-grade gliomas (HGGs) and not LGG. Finally, one RCT evaluated diffusion tensor imaging (DTI)-based neuro-navigation for surgical resection.

AUTHORS' CONCLUSIONS

Since the last version of this review, no new studies have been identified for inclusion and currently there are no RCTs or CCTs available on which to base definitive clinical decisions. Therefore, physicians must approach each case individually and weigh the risks and benefits of each intervention until further evidence is available. Some retrospective studies and non-randomized prospective studies do seem to suggest improved OS and seizure control correlating to higher extent of resection. Future research could focus on RCTs to determine outcomes benefits for biopsy versus resection.

Mutant IDH1 and seizures in patients with glioma

OBJECTIVE

Because the d-2-hydroxyglutarate (D2HG) product of mutant isocitrate dehydrogenase 1 (IDH1^mut) is released by tumor cells into the microenvironment and is structurally similar to the excitatory neurotransmitter glutamate, we sought to determine whether IDH1^mut increases the risk of seizures in patients with glioma, and whether D2HG increases the electrical activity of neurons.

METHODS

Three WHO grade II-IV glioma cohorts from separate institutions (total N = 712) were retrospectively assessed for the presence of preoperative seizures and tumor location, WHO grade, 1p/19q codeletion, and IDH1^mut status. Rat cortical neurons were grown on microelectrode arrays, and their electrical activity was measured before and after treatment with exogenous D2HG, in the presence or absence of the selective NMDA antagonist, AP5.

RESULTS

Preoperative seizures were observed in 18%-34% of IDH1 wild-type (IDH1^wt) patients and in 59%-74% of IDH1^mut patients (p < 0.001). Multivariable analysis, including WHO grade, 1p/19q codeletion, and temporal lobe location, showed that IDH1^mut was an independent correlate with seizures (odds ratio 2.5, 95% confidence interval 1.6-3.9, p < 0.001). Exogenous D2HG increased the firing rate of cultured rat cortical neurons 4- to 6-fold, but was completely blocked by AP5.

CONCLUSIONS

The D2HG product of IDH1^mut may increase neuronal activity by mimicking the activity of glutamate on the NMDA receptor, and IDH1^mut gliomas are more likely to cause seizures in patients. This has rapid translational implications for the personalized management of tumor-associated epilepsy, as targeted IDH1^mut inhibitors may improve antiepileptic therapy in patients with IDH1^mut gliomas.

Epileptic features and survival in glioblastomas presenting with seizures

INTRODUCTION

The prognostic value of seizures in patients with glioblastoma is currently under discussion. The objective of this research was to study the risk factors associated with seizures occurring at the diagnosis of glioblastoma and the role of seizures as a predictive factor for survival.

MATERIAL AND METHODS

We prospectively analyzed the clinical data over the course of the disease, baseline MR imaging, and histological characteristics (p53 overexpression, the Ki67 proliferation index, and presence of the IDH1 R132H mutation), in glioblastomas treated in a single hospital from November 2012 to July 2014. The study follow-up cutoff point was October 2015.

RESULTS

In total, 56 patients were recruited (57% men, mean age 57 years). Median baseline score on the Karnofsky performance scale was 80. Complete tumor debulking followed by radiochemotherapy was achieved in 58.9%. Mean survival was 13.6 months. Epileptic seizures were the presenting symptom in 26.6% of patients, and 44.6% experienced seizures at some point during the course of the disease. On multivariate analysis, the single factor predicting shorter survival was age older than 60 years (hazard ratio 3.565 (95%CI, 1.491-8.522), p=0.004). Seizures were associated with longer survival only in patients younger than 60 years (p=0.035). Younger age, the IDH1 R132H mutation, and p53 overexpression (>40%) were related to seizures at presentation. Baseline MRI findings, including tumor size, and the Ki67 proliferation index were not associated with the risk of epileptic seizures or with survival. Prophylactic antiepileptic drugs did not increase survival time.

CONCLUSIONS

Seizures as the presenting symptom of glioblastoma predicted longer survival in adults younger than 60 years. The IDH1 R132H mutation and p53 overexpression (>40%) were associated with seizures at presentation. Seizures showed no relationship with the tumor size or proliferation parameters.