Epilepsy in patients with brain tumours: epidemiology, mechanisms, and management

Glioma features and seizure control during long-term follow-up

Background

An epileptic seizure is a common presenting symptom of glioma, or epilepsy may develop later during the disease. Epileptic seizures affect the quality of life in patients with glioma. Good seizure control during 6-12 months follow-up has been associated with gross total resection, radiation therapy and chemotherapy of gliomas. Little is known about seizure control during long-term follow-up and about factors which may affect the prognosis of epilepsy in glioma patients.

Methods

We identified retrospectively all adult patients with diffuse glioma (grade 2-4) associated epilepsy (n = 123) living in Helsinki, who received treatment at Helsinki University Hospital neuro-oncology center during 2013-2015. We excluded patients with histopathological diagnosis prior to 2005. Data was collected from medical records for five years after diagnosis of glioma, or until death.

Results

In this patient cohort 49 (39.8 %) had grade 2 glioma, 19 (15.4 %) had grade 3 glioma and 55 (44.7 %) had grade 4 glioma. 29 (23.6 %) of tumors were astrocytomas, 24 (19.5 %) were oligoastrocytomas, 15 (12.2 %) were oligodendrogliomas and 55 (44.7 %) were glioblastomas. A seizure was the presenting symptom in 87 (70.7 %) of the patients. The majority, 68 (57.6 %) patients were seizure-free for at least 12 months at some point during follow-up and 47 (39.8 %) patients were seizure-free during the last year of follow-up. Survival for five years from glioma diagnosis (p < 0.001), lower grade of tumor (p < 0.001), IDH mutation (p < 0.001), epilepsy as first symptom (p < 0.001), younger age (p < 0.001) and lack of progression (p = 0.021) correlated with seizure freedom at the end of follow-up. When the results were analyzed separately in survivors and deceased patients, only progression correlated negatively with seizure freedom at the end of follow-up in surviving patients (p = 0.008). In 5-year survivors, longer seizure-free periods were achieved by patients without progression of glioma (p = 0.040) vs patients with progression, or without focal aware (p 0.003) or focal impaired awareness seizures (p = 0.002) vs patients with only focal to bilateral tonic-clonic seizures. In deceased patients, progression (p < 0.001) and lower grade of glioma (p = 0.003) correlated positively and focal aware seizures negatively (p = 0.021) with a longer seizure-free period. In all patients, freedom of seizures at the end of follow-up was less likely for patients who had focal aware (p = 0.015) than for patients without focal aware seizures.

Conclusion

There are differences in seizure-free times in patients with grade 2-4 glioma and epilepsy. The results suggest that the prognosis of glioma may be the most important factor influencing the prognosis of epilepsy.

Low-grade epilepsy-associated neuroepithelial tumors: Tumor spectrum and diagnosis based on genetic alterations

Brain tumors can always result in seizures when involving the cortical neurons or their circuits, and they were found to be one of the most common etiologies of intractable focal seizures. The low-grade epilepsy-associated neuroepithelial tumors (LEAT), as a special group of brain tumors associated with seizures, share common clinicopathological features, such as seizure onsets at a young age, a predilection for involving the temporal lobe, and an almost benign course, including a rather slow growth pattern and thus a long-term history of seizures. Ganglioglioma (GG) and dysembryoplastic neuroepithelial tumor (DNET) are the typical representatives of LEATs. Surgical treatments with complete resection of tumors and related epileptogenic zones are deemed the optimal way to achieve postoperative seizure control and lifetime recurrence-free survival in patients with LEATs. Although the term LEAT was originally introduced in 2003, debates on the tumor spectrum and the diagnosis or classification of LEAT entities are still confusing among epileptologists and neuropathologists. In this review, we would further discuss these questions, especially based on the updated classification of central nervous system tumors in the WHO fifth edition and the latest molecular genetic findings of tumor entities in LEAT entities.

Nonconvulsive status epilepticus as sign of tumor recurrence

Status epilepticus (SE) can be a sign of brain tumor progression or recurrence, but there are few reports of nonconvulsive status epilepticus (NCSE) being a sign of tumor progression or recurrence. Moreover, much remains to be elucidated about its clinical course, and outcome. This is the first report of NCSE associated with the progression of a metastatic brain tumor treated by surgical excision of the tumor. The patient was 74-year-old woman. She had a history of craniotomy for tumor resection and gamma knife treatment for multiple metastatic brain tumors originating from breast cancer. She suddenly developed dysarthria and right hemiparesis, followed by convulsive seizures in the right side of her body. Magnetic resonance imaging showed tumor recurrence in the left parietal lobe and worsening edematous changes around the tumor. Antiseizure medication was initiated, however her seizures did not improve; therefore, tumor resection was performed. Postoperatively, her consciousness, seizures, and electroencephalogram findings improved. NCSE caused by brain tumors may be refractory to treatment with antiseizure medications, and early surgical treatment may be useful for seizure control.

Variables associated with cortical motor mapping thresholds: A retrospective data review with a unique case of interlimb motor facilitation

Introduction

Intraoperative neuromonitoring (IONM) is crucial to preserve eloquent neurological functions during brain tumor resections. We observed a rare interlimb cortical motor facilitation phenomenon in a patient with recurrent high-grade glioma undergoing craniotomy for tumor resection; the patient's upper arm motor evoked potentials (MEPs) increased in amplitude significantly (up to 44.52 times larger, p < 0.001) following stimulation of the ipsilateral posterior tibial nerve at 2.79 Hz. With the facilitation effect, the cortical MEP stimulation threshold was reduced by 6 mA to maintain appropriate continuous motor monitoring. It likely has the benefit of reducing the occurrence of stimulation-induced seizures and other adverse events associated with excessive stimulation.

Methods

We conducted a retrospective data review including 120 patients who underwent brain tumor resection with IONM at our center from 2018 to 2022. A broad range of variables collected pre-and intraoperatively were reviewed. The review aimed to determine: (1) whether we overlooked this facilitation phenomenon in the past, (2) whether this unique finding is related to any specific demographic information, clinical presentation, stimulation parameter (s) or anesthesia management, and (3) whether it is necessary to develop new techniques (such as facilitation methods) to reduce cortical stimulation intensity during intraoperative functional mapping.

Results

There is no evidence suggesting that clinical presentation, stimulation configuration, or intraoperative anesthesia management of the patient with the facilitation effect were significantly different from our general patient cohort. Even though we did not identify the same facilitation effect in any of these patients, we were able to determine that stimulation thresholds for motor mapping are significantly associated with the location of stimulation (p = 0.003) and the burst suppression ratio (BSR) (p < 0.001). Stimulation-induced seizures, although infrequent (4.05%), could occur unexpectedly even when the BSR was 70%.

Discussion

We postulated that functional reorganization and neuronal hyperexcitability induced by glioma progression and repeated surgeries were probable underlying mechanisms of the interlimb facilitation phenomenon. Our retrospective review also provided a practical guide to cortical motor mapping in brain tumor patients under general anesthesia. We also underscored the need for developing new techniques to reduce the stimulation intensity and, hence, seizure occurrence.

Healthcare utilization and costs among intracranial meningioma patients during long-term follow-up

PURPOSE

Few studies have reported on healthcare utilization and costs for intracranial meningioma patients, while the tumor and its treatment profoundly affect patients' functioning and well-being. Here we evaluated healthcare utilization and costs, including their determinants.

METHODS

A multicenter cross-sectional study of adult meningioma patients ≥ 5 years after intervention. Patients completed three validated patient-reported outcome measures (PROMs) assessing patients 'functioning and wellbeing (SF-36, EORTC QLQ-BN20, and HADS) and a study-specific questionnaire assessing healthcare utilization over the previous twelve months. Healthcare costs of the twelve months prior were calculated using reported healthcare utilization ≥ 5 years after intervention by the Dutch Manual for Economic Evaluation in Healthcare. Determinants for healthcare utilization and costs were determined with regression analyses.

RESULTS

We included 190 patients with WHO grade I or II meningioma after a mean follow-up since intervention of 9.2 years (SD 4.0). The general practitioner (80.5%), physiotherapist (37.9%), and neurologist (25.4%) were visited most often by patients. Median annual healthcare costs were €871 (IQR €262-€1933). Main contributors to these costs were medication (45.8% of total costs, of which anti-seizure medication was utilized most [21.6%]), specialist care (17.7%), and physiotherapy (15.5%). Lower HRQoL was a significant determinant for higher healthcare utilization and costs.

CONCLUSION

In patients with meningioma, medication costs constituted the largest expenditure of total healthcare costs, in particular anti-seizure medication. Particularly a lower HRQoL was a determinant for healthcare utilization and costs. A patient-specific approach aimed at improving patients' HRQoL and needs could be beneficial in reducing disease burden and functional recovery.

Palliative care in brain tumors

The diagnosis of a brain tumor is a life-changing event for patients and families. High-grade gliomas (especially glioblastomas) are incurable, and long-term survival is limited. Metastatic brain lesions comprise the majority of intracranial neoplasms and are a significant source of morbidity and mortality in patients with systemic cancer. Response to treatment, prognosis, and survival depends not only on the underlying pathology, but more importantly on recently defined molecular features. Other crucial predictors of survival include age and performance status. Among patients with primary brain tumors, neurologic decline and psychological distress contribute to a high symptom burden and impaired quality of life (QoL) throughout the disease trajectory. While many symptoms in central nervous system (CNS) and non-CNS cancers overlap, others predominate in the brain tumor population, including seizures, headaches, depression, fatigue, and treatment-induced toxicity, all of which can be addressed with palliative interventions. Patients, families, and caregivers also report disproportionately high supportive care needs, which frequently differ from those of other systemic cancers. In addition, progressive neurologic decline often results in impaired communication and decision-making capacity at the end of life. Early palliative care (PC) integration has become more common in systemic cancers, but remains limited in neuro-oncology. These factors combined contribute to a uniquely challenging disease course that may benefit from a multidisciplinary approach with early involvement of specialized (PC) to address tumor-related symptoms and improve QoL. We review how to approach patients with brain tumors and address prognosis, symptom management, and advance care planning with the goal of improving QoL for patients, families, and caregivers.

Resective surgery for patients with frontal lobe diffuse low-grade glioma-related epilepsy: predictors of seizure outcomes

Background

Diffuse low-grade gliomas (DLGGs) are prone to invade the frontal lobes, with seizures being the most common symptom. However, limited attention has been paid to surgical outcomes and their predictors in patients with frontal DLGG-related epilepsy.

Objective

This study aimed to analyze predictors of postoperative seizure outcomes in patients with frontal DLGG-related epilepsy.

Design

This is a single-center retrospective study.

Methods

This study retrospectively collected data of 115 patients with frontal DLGG-related epilepsy who underwent resective surgery between January 2014 and January 2021. Patients were categorized into favorable and unfavorable seizure outcome groups based on the International League Against Epilepsy (ILAE) classification. Univariate and multivariate analyses were used to identify potential predictors of seizure outcomes.

Results

The mean follow-up was 4.11 ± 2.06 years, and 77.4% (89 of 115) of patients were seizure-free. Permanent neurological deficits were observed in 7.0% (8 of 115) of patients. Univariate and multivariate analyses revealed that total tumor removal [odds ratio (OR), 0.31; 95% confidence interval (CI), 0.12-0.82; p = 0.018] and older age at seizure onset (OR, 0.96; 95% CI, 0.93-0.99; p = 0.042) were independent predictors of favorable seizure outcomes.

Conclusion

Surgical resection is an effective treatment for frontal DLGG-related epilepsy. Favorable seizure outcomes are more likely to be achieved in patients with complete tumor removal and those with older age at seizure onset.

Predictors of seizure outcomes in patients with diffuse low-grade glioma-related epilepsy after complete glioma removal

AIMS

We aimed to identify predictors of postoperative seizures in patients with diffuse low-grade glioma (DLGG)-related epilepsy after complete tumor resection in this study.

METHODS

We retrospectively collected data from individuals with DLGG-related epilepsy whose tumors were completely resected at Xiangya Hospital, Central South University between January 2014 and January 2020. The predictors of seizure outcomes were assessed by employing univariate analysis and a multivariate logistic regression model in a backward binary logistic regression model.

RESULTS

Among the 118 cases that met the inclusion criteria, 83.05% were seizure-free following an average follow-up of 4.27 ± 1.65 years, all of whom were classified as International League Against Epilepsy class I outcome. Univariate and multivariate analyses indicated that seizure duration of >6 years (odds ratio [OR], 6.62; 95% confidence interval [CI], 1.76-24.98; p = 0.005) and first clinical symptoms other than seizures (OR, 4.51; 95% CI, 1.43-14.23; p = 1.010) were both independent predictors of unfavorable seizure outcomes.

CONCLUSION

Our results imply that satisfactory seizure outcomes can be achieved in most patients with DLGG-related epilepsy after complete tumor resection. Patients with seizure duration of >6 years or first clinical symptoms other than seizures were more likely to experience postoperative seizure recurrence.

Quantitative measurement of peritumoral concentrations of glutamate, N-acetyl aspartate, and lactate on magnetic resonance spectroscopy predicts glioblastoma-related refractory epilepsy

BACKGROUND

Increased extracellular glutamate is known to cause epileptic seizures in patients with glioblastoma (GBM). However, predicting whether the seizure will be refractory is difficult. The present study investigated whether evaluation of the levels of various metabolites, including glutamate, can predict the occurrence of refractory seizure in GBM by quantitative measurement of metabolite concentrations on magnetic resonance spectroscopy (MRS).

METHODS

Forty patients were treated according to the same treatment protocol for primary GBM at Ehime University Hospital between April 2017 and July 2021. Of these patients, 23 underwent MRS to determine concentrations of metabolites, including glutamate, N-acetylaspartate, creatine, and lactate, in the tumor periphery by applying LC-Model. The concentration of each metabolite was expressed as a ratio to creatine concentration. Patients were divided into three groups: Type A, patients with no seizures; Type B, patients with seizures that disappeared after treatment; and Type C, patients with seizures that remained unrelieved or appeared after treatment (refractory seizures). Relationships between concentrations of metabolites and seizure types were investigated.

RESULTS

In 23 GBMs, seizures were confirmed in 11 patients, including Type B in four and Type C in seven. Patients with epilepsy (Type B or C) showed significantly higher glutamate and N-acetylaspartate values than did non-epilepsy patients (Type A) (p < 0.05). No significant differences in glutamate or N-acetylaspartate levels were seen between Types B and C. Conversely, Type C showed significantly higher concentrations of lactate than did Type B (p = 0.001). Cutoff values of lactate-to-creatine, glutamate-to-creatine, and N-acetylaspartate-to-creatine ratios for refractory seizure were > 1.25, > 1.09, and > 0.88, respectively.

CONCLUSIONS

Extracellular concentrations of glutamate, N-acetylaspartate, and lactate in the tumor periphery were significantly elevated in patients with GBM with refractory seizures. Measurement of these metabolites on MRS may predict refractory epilepsy in such patients and could be an indicator for continuing the use of antiepileptic drugs.

Effect of perioperative seizures on mortality and recurrence in patients with brain metastases

Objective

To identify the independent risk factors for 30-day perioperative seizures, as well as to evaluate the effect of perioperative seizures on overall mortality and tumor recurrence among patients who underwent surgical resection of brain metastases.

Methods

Patients who underwent surgical resection of brain metastases at our institution between 2011 and 2019 were included. 30-day perioperative seizures were defined as the presence of any preoperative or postoperative seizures diagnosed by a neurosurgeon or neurologist within 30 days of metastases resection. Independent risk factors for 30-day perioperative seizures were evaluated using multivariate logistic regression models. Kaplan-Meier plots and Cox regression models were constructed to evaluate the effects of 30-day perioperative seizures on overall mortality and tumor recurrence. Subgroup analyses were conducted for 30-day preoperative and 30-day postoperative seizures.

Results

A total of 158 patients were included in the analysis. The mean (SD) age was 59.3 (12.0) years, and 20 (12.7%) patients had 30-day perioperative seizures. The presence of 30-day preoperative seizures (OR=41.4; 95% CI=4.76, 924; p=0.002) was an independent risk factor for 30-day postoperative seizures. Multivariate Cox regression revealed that any 30-day perioperative seizure (HR=3.25; 95% CI=1.60, 6.62; p=0.001) was independently and significantly associated with overall mortality but not tumor recurrence (HR=1.95; 95% CI=0.78, 4.91; p=0.154).

Conclusions

Among patients with resected brain metastases, the presence of any 30-day perioperative seizure was independently associated with overall mortality. This suggests that 30-day perioperative seizures may be a prognostic marker of poor outcome. Further research evaluating this association as well as the effect of perioperative antiepileptic drugs in patients with resected brain metastases may be warranted.

Decision-making in stereotactic epilepsy surgery

Surgery can cure or significantly improve both the frequency and the intensity of seizures in patients with medication-refractory epilepsy. The set of diagnostic and therapeutic interventions involved in the path from initial consultation to definitive surgery is complex and includes a multidisciplinary team of neurologists, neurosurgeons, neuroradiologists, and neuropsychologists, supported by a very large epilepsy-dedicated clinical architecture. In recent years, new practices and technologies have emerged that dramatically expand the scope of interventions performed. Stereoelectroencephalography has become widely adopted for seizure localization; stereotactic laser ablation has enabled more focal, less invasive, and less destructive interventions; and new brain stimulation devices have unlocked treatment of eloquent foci and multifocal onset etiologies. This article articulates and illustrates the full framework for how epilepsy patients are considered for surgical intervention, with particular attention given to stereotactic approaches.

Management of epilepsy in brain tumor patients

PURPOSE OF REVIEW

A concise review of recent findings in brain tumor-related epilepsy (BTRE), with focus on the effect of antitumor treatment on seizure control and the management of antiepileptic drugs (AEDs).

RECENT FINDINGS

Isocitrate dehydrogenase mutation and its active metabolite d -2-hydroxyglutarate seem important contributing factors to epileptogenesis in BTRE. A beneficial effect of antitumor treatment (i.e. surgery, radiotherapy, and chemotherapy) on seizure control has mainly been demonstrated in low-grade glioma. AED prophylaxis in seizure-naïve BTRE patients is not recommended, but AED treatment should be initiated after a first seizure has occurred. Comparative efficacy randomized controlled trials (RCTs) are currently lacking, but second-generation AED levetiracetam seems the preferred choice in BTRE. Levetiracetam lacks significant drug-drug interactions, has shown favorable efficacy compared to valproic acid in BTRE, generally causes no hematological or neurocognitive functioning adverse effects, but caution should be exercised with regard to psychiatric adverse effects. Potential add-on AEDs in case of uncontrolled seizures include lacosamide, perampanel, and valproic acid. Ultimately, in the end-of-life phase when oral intake of medication is hampered, benzodiazepines via nonoral administration routes are potential alternatives.

SUMMARY

Management of seizures in BTRE is complex and with currently available evidence levetiracetam seems the preferred choice. Comparative efficacy RCTs in BTRE are warranted.

Symptoms of Depression and Anxiety in Adults with High-Grade Glioma: A Literature Review and Findings in a Group of Patients before Chemoradiotherapy and One Year Later

Simple Summary

High-grade glioma (HGG) is the most severe type of brain cancer. At different stages of the disease, affected persons are at high risk of symptoms of depression and anxiety. If undiagnosed and untreated, these symptoms might become severe and compromise the patient’s quality of life. Improved knowledge on the prevalence, mechanisms and clinical risk factors underlying the etiology of depression and anxiety in this population is required. This may help to increase awareness on the importance of integrating consistent assessment of mood symptoms with the clinical follow-up and provide insights for developing personalized psychosocial interventions.

Abstract

High-grade glioma (HGG) is associated with several external and internal stressors that may induce mood alterations at all stages of the disease. Symptoms of depression and anxiety in persons with glioma have multifactorial etiology and require active follow-up. We reviewed the literature data on the prevalence, mechanisms likely involved in the etiology of mood alterations in persons with HGG and psychosocial interventions found beneficial in treating these symptoms. We also investigated the prevalence and clinical variables that could increase the risk of depression and anxiety symptoms in a group of patients with HGG at two disease time-points: after surgery, before and 1 year after chemoradiotherapy. Literature findings revealed complex mechanisms underlying these symptoms and highlighted the importance of providing early access to palliative care. Our results show a high rate of anxiety and depression symptoms in the first stage of the disease and increased concomitance of these symptoms at the 1-year follow-up. Depression and anxiety symptoms at 1 year after the end of chemoradiotherapy were associated with the presence of symptoms at the first stage of the disease and tumor progression. Antiepileptic drugs and corticosteroid intake did not increase the risk of depressive and anxious symptoms among patients. Active management of mood alterations is an essential part of the care and contributes to patients’ well-being and quality of life.

Epilepsy treatment in neuro-oncology: A rationale for drug choice in common clinical scenarios

Epilepsy represents a challenge in the management of patients with brain tumors. Epileptic seizures are one of the most frequent comorbidities in neuro-oncology and may be the debut symptom of a brain tumor or a complication during its evolution. Epileptogenic mechanisms of brain tumors are not yet fully elucidated, although new factors related to the underlying pathophysiological process with possible treatment implications have been described. In recent years, the development of new anti-seizure medications (ASM), with better pharmacokinetic profiles and fewer side effects, has become a paradigm shift in many clinical scenarios in neuro-oncology, being able, for instance, to adapt epilepsy treatment to specific features of each patient. This is crucial in several situations, such as patients with cognitive/psychiatric comorbidity, pregnancy, or advanced age, among others. In this narrative review, we provide a rationale for decision-making in ASM choice for neuro-oncologic patients, highlighting the strengths and weaknesses of each drug. In addition, according to current literature evidence, we try to answer some of the most frequent questions that arise in daily clinical practice in patients with epilepsy related to brain tumors, such as, which patients are the best candidates for ASM and when to start it, what is the best treatment option for each patient, and what are the major pitfalls to be aware of during follow-up.

Early Epilepsy Surgery in Benign Cerebral Tumors: Avoid Your ‘Low-Grade’ Becoming a ‘Long-Term’ Epilepsy-Associated Tumor

Epilepsy surgery in low-grade epilepsy-associated neuroepithelial tumors (LEAT) is usually evaluated in drug-resistant cases, often meaning a time delay from diagnosis to surgery. To identify factors predicting good postoperative seizure control and neuropsychological outcome, the cohort of LEAT patients treated with resective epilepsy surgery at the Epilepsy Center Frankfurt Rhine-Main, Germany between 2015 and 2020 was analyzed. Thirty-five patients (19 males (54.3%) and 16 females, aged 4 to 40 years (M = 18.1), mean follow-up 33 months) were included. Following surgery, 77.1% of patients remained seizure-free (Engel IA/ILAE 1). Hippocampus and amygdala resection was predictive for seizure freedom in temporal lobe epilepsy. In total, 65.7% of all patients showed cognitive deficits during presurgical workup, decreasing to 51.4% after surgery, predominantly due to significantly less impaired memory functions (p = 0.011). Patients with presurgical cognitive deficits showed a tendency toward a longer duration of epilepsy (p = 0.050). Focal to bilateral tonic-clonic seizures (p = 0.019) and young age at onset (p = 0.018) were associated with a higher likelihood of cognitive deficits after surgery. Therefore, we advocate early epilepsy surgery without requiring proof of drug-resistance. This refers especially to lesions associated with the non-eloquent cortex.

Altered Extracellular Matrix as an Alternative Risk Factor for Epileptogenicity in Brain Tumors

Seizures are one of the most common symptoms of brain tumors. The incidence of seizures differs among brain tumor type, grade, location and size, but paediatric-type diffuse low-grade gliomas/glioneuronal tumors are often highly epileptogenic. The extracellular matrix (ECM) is known to play a role in epileptogenesis and tumorigenesis because it is involved in the (re)modelling of neuronal connections and cell-cell signaling. In this review, we discuss the epileptogenicity of brain tumors with a focus on tumor type, location, genetics and the role of the extracellular matrix. In addition to functional problems, epileptogenic tumors can lead to increased morbidity and mortality, stigmatization and life-long care. The health advantages can be major if the epileptogenic properties of brain tumors are better understood. Surgical resection is the most common treatment of epilepsy-associated tumors, but post-surgery seizure-freedom is not always achieved. Therefore, we also discuss potential novel therapies aiming to restore ECM function.

Historical Overview of the "Firing" Liaison between Brain Tumors and Epilepsy

This review addresses, in a critical historical perspective, the link between seizures and endocranic neoplasms. Folkloric descriptions of epilepsy can be found in writings from ancient cultures. Hippocrates first provided a medical interpretation. In 1770, Tissot published Traité de l'épilepsie, a milestone in epileptology, whereas the 19th century is considered the golden era of epileptic studies. In 1882, the father of modern epileptology, Jackson, in his article Localized Convulsions from Tumour of the Brain, reported a case of a patient affected by typical Jacksonian seizures in the presence of a brain tumor. However, he did not establish a direct correlation between brain tumors and epilepsy, and an explanation for his clinical case was lacking. Before Jackson's article, other authors reported similar cases, but only Gairdner in 1834 published a report suggesting the concept of a direct relationship between epilepsy and a brain tumor. From the beginning until the mid of the 20th century several authors reported seizures attributed to intracranial tumors, and in recent years studies have focused on the pathogenesis of tumor-related seizures. Biochemical and molecular changes in brain tumors and their environment opened unprecedented working hypotheses on epileptogenesis and on treatment of epilepsy associated with brain tumors.

Brain Tumor Networks in Diffuse Glioma

Diffuse gliomas are primary brain tumors associated with a poor prognosis. Cellular and molecular mechanisms driving the invasive growth patterns and therapeutic resistance are incompletely understood. The emerging field of cancer neuroscience offers a novel approach to study these brain tumors in the context of their intricate interactions with the nervous system employing and combining methodological toolsets from neuroscience and oncology. Increasing evidence has shown how neurodevelopmental and neuronal-like mechanisms are hijacked leading to the discovery of multicellular brain tumor networks. Here, we review how gap junction-coupled tumor-tumor-astrocyte networks, as well as synaptic and paracrine neuron-tumor networks drive glioma progression. Molecular mechanisms of these malignant, homo- and heterotypic networks, and their complex interplay are reviewed. Lastly, potential clinical-translational implications and resulting therapeutic strategies are discussed.

Correlation of Clinicopathological Factors with Brain Tumor-Related Epilepsy in Glioma

Objectives. Glioma patients with brain tumor-related epilepsy (BTRE) have a complex profile due to the simultaneous presence of two pathologies, glioma and epilepsy; however, they have not traditionally received as much attention as those with more malignant brain tumors. The underlying pathophysiology of brain tumor-related epilepsy remains poorly understood. The purpose of this study was to investigate the possible correlation between molecular neuropathology and glioma with BTRE and a wide range of BTRE-associated molecular markers of glioma patients. Methods. A retrospective cohort study of 186 glioma patients was evaluated at our hospital, of which 64 had BTRE. The chi-square test, Spearman rank correlation, and multivariate logistic analyses were used to identify clinicopathological factors associated with BTRE in glioma patients. Results. Of the 186 patients examined in this study, 64 (34.4%) had BTRE. Based on the analysis of the characteristics of these patients, the results showed that patient age (over 40 years; $P=0.007$ ), low WHO grade (grade I, II; $P=0.001$ ), IDH-1 positive mutation ( $P=0.027$ ), low ATR-X expression level ( $\text{OR}=0.44$ ; 95% CI: 0.21, 0.92), and low Ki-67 PI ( $\text{OR}=0.25$ ; 95% CI: 0.10, 0.68) were associated with the occurrence of BTRE. In our cohort, BTRE patients did not differ by sex, tumor location, or expression of olig-2 and CD34. The results of the matching study showed that low Ki-67 PI and negative ATR-X expression levels were independent factors for a higher incidence of preoperative seizures in glioma patients. Conclusion. The current study updates existing information on genetic markers in gliomas with BTRE and explores the correlation of a wide range of clinicopathological factors and glioma patients with BTRE and suggests three putative biomarkers for BTRE: positive IDH1 mutation, low Ki-67 PI, and negative ATR-X expression. These factors may provide insights for developing a more thorough understanding of the pathogenesis of epilepsy and effective treatment strategies aimed at seizure control.

Pure and non-pure meningioangiomatosis of 36 Chinese patients: an analysis of clinical presentation, diagnosis, histopathology and prognosis

Meningioangiomatosis (MA) is a disease that is extremely rarely reported. Sporadic MA is occasionally combined with meningioma or other lesions (identified as non-pure MA). This retrospective study investigated the difference between pure MA and non-pure MA by exploring clinical manifestations, histopathology characteristics, and outcomes of MA after surgery. We reviewed the medical records of 36 histopathologically confirmed MA patients (18 pure MA and 18 non-pure MA) who received surgery at our institution between 2012 and 2021. We compared differences in demographic, clinical, imaging, pathological features, and surgical outcomes between pure MA and non-pure MA through descriptive statistics. Compared to non-pure MA, pure MA presented with a more prominent male predilection (5:1 vs. 1.57:1, P = 0.264), a higher seizure incidence (83.3% vs 50.0%, P = 0.038), a more seizure type of GTCS (14/15 vs 5/9, P = 0.047), a less prominent enhancement on MRI (27.8% vs 88.9%, P < 0.001) and a preference of temporal and frontal lobe (100% vs 44.4%, P < 0.001). The differences in clinical characteristics between pure MA and non-pure MA demonstrate their disparate biological natures. Pure MA seems to be a non-neoplastic lesion, while non-pure MA is commonly combined with meningioma, which is a neoplastic lesion. A correct differential diagnosis can be achieved via a triad of the type of seizure, the location of lesion and the radiological presentation. MA is curable and the prognosis is excellent as most patients are free of seizure and recurrence after surgical treatment.

Impact of seizures and antiseizure medication on survival in patients with glioma

PURPOSE

Seizures are a common presenting symptom among patients with low- and high-grade glioma. However, the impact and inter-relationship between the presence of seizures, anti-seizure medication (ASM) and survival are unclear. We retrospectively analyzed the incidence of seizures and identified the pattern and relationship of anti-seizure medication on survival in our cohort of patients with glioma.

METHODS

We evaluated all glioma patients who underwent treatment at the University of Malaya Medical Centre (UMMC) between 2008 and 2020. Demographic and clinical data of seizures and pattern of ASM administration in comparison to overall survival were analyzed.

RESULTS

A total of 235 patients were studied, with a minimum of one year clinical follow-up post-treatment. The median survival for low-grade glioma was 38 months whereas high-grade glioma was 15 months. One-third of our glioma patients (n = 74) presented with seizures. All patients with seizures and a further 31% of patients without seizures were started on anti-seizure medication preoperatively. Seizure and Levetiracetam (LEV) were significantly associated with OS on univariate analysis. However, only LEV (HR 0.49; 95% CI 0.23-0.87; p=0.02) was significantly associated with improving overall survival (OS) on multivariate analysis. Once ASM was adjusted for relevant factors and each other, LEV was associated with improved survival in all grade gliomas (HR 0.52; 95% CI 0.31-0.88; p=0.02) and specifically high-grade gliomas (HR 0.53; 95% CI 0.30-0.94; p=0.03).

CONCLUSIONS

Pre-operative seizures among patients with glioma indicated a better overall prognosis. The administration of ASM, specifically LEV was associated with a  significant survival advantage in our retrospective cohort of patients.

Pharmacokinetic considerations surrounding the use of levetiracetam for seizure prophylaxis in neurocritical care - an overview

INTRODUCTION

Levetiracetam (LEV) is one of the most widely used anti-seizure medications (ASMs) in clinical practice. This is due both to a different mechanism of action when compared to other ASMs and its easy handling. Indeed, because of its interesting pharmacokinetic properties, it is often used outside of the labelled indications, notably in the neurocritical setting as prophylaxis of epileptic seizures.

AREAS COVERED

A literature search was conducted and the most relevant studies on the pharmacokinetic properties of LEV were selected by two independent investigators. Current evidence on the use of ASM prophylaxis in the neurocritical setting was also reviewed, highlighting and discussing the strengths and limits of LEV as drug of choice for anti-epileptic prophylaxis in this scenario.

EXPERT OPINION

LEV has a "near-ideal" pharmacokinetic profile, which makes it an attractive drug for ASM prophylaxis in neurocritical care. However, current recommendations restrict ASMs prophylaxis to very selected circumstances and the role of LEV is marginal. Moreover, studies are generally designed to compare LEV versus phenytoin, whereas studies comparing LEV versus placebo are lacking. Further randomized trials will be needed to better elucidate LEV utility and its neuroprotective role in the neurocritical setting.

Disconnecting multicellular networks in brain tumours

Cancer cells can organize and communicate in functional networks. Similarly to other networks in biology and sociology, these can be highly relevant for growth and resilience. In this Perspective, we demonstrate by the example of glioblastomas and other incurable brain tumours how versatile multicellular tumour networks are formed by two classes of long intercellular membrane protrusions: tumour microtubes and tunnelling nanotubes. The resulting networks drive tumour growth and resistance to standard therapies. This raises the question of how to disconnect brain tumour networks to halt tumour growth and whether this can make established therapies more effective. Emerging principles of tumour networks, their potential relevance for tumour types outside the brain and translational implications, including clinical trials that are already based on these discoveries, are discussed.

EANO - EURACAN - SNO Guidelines on circumscribed astrocytic gliomas, glioneuronal, and neuronal tumors

In the new WHO 2021 Classification of CNS Tumors the chapter "Circumscribed astrocytic gliomas, glioneuronal and neuronal tumors" encompasses several different rare tumor entities, which occur more frequently in children, adolescents, and young adults. The Task Force has reviewed the evidence of diagnostic and therapeutic interventions, which is low particularly for adult patients, and draw recommendations accordingly. Tumor diagnosis, based on WHO 2021, is primarily performed using conventional histological techniques; however, a molecular workup is important for differential diagnosis, in particular, DNA methylation profiling for the definitive classification of histologically unresolved cases. Molecular factors are increasing of prognostic and predictive importance. MRI finding are non-specific, but for some tumors are characteristic and suggestive. Gross total resection, when feasible, is the most important treatment in terms of prolonging survival and achieving long-term seizure control. Conformal radiotherapy should be considered in grade 3 and incompletely resected grade 2 tumors. In recurrent tumors reoperation and radiotherapy, including stereotactic radiotherapy, can be useful. Targeted therapies may be used in selected patients: BRAF and MEK inhibitors in pilocytic astrocytomas, pleomorphic xanthoastrocytomas, and gangliogliomas when BRAF altered, and mTOR inhibitor everolimus in subependymal giant cells astrocytomas. Sequencing to identify molecular targets is advocated for diagnostic clarification and to direct potential targeted therapies.

Giant cranial angiolipoma with arteriovenous fistula: A case report

Background:

Angiolipomas are benign mesenchymal tumors comprising mature adipocytes and abnormal blood vessels, commonly found in the subcutaneous tissue of the trunk and rarely in the skull. Furthermore, sporadic cases of angiolipoma with arteriovenous fistula (AVF) have been reported.

Case Description:

We reported the case of a 72-year-old woman who presented with head swelling, seizures, and cognitive dysfunction. Computed tomography and magnetic resonance imaging revealed a right frontal bone tumor exceeding a sagittal suture of up to 10.7 cm. Angiography revealed AVF and varices formation. Endovascular embolization was performed to treat the AVF and reduce blood loss during surgical resection. Two days after the embolization, a craniotomy was performed; however, uncontrollable bleeding was observed at the time of tumor resection. Postoperatively, the patient was symptom-free and has been stable for 2 years without recurrence.

Conclusion:

Despite careful preoperative evaluation and treatment planning, the patient in this case report was difficult to treat. Such cases require adequate preparation.

Perioperative levetiracetam for seizure prophylaxis in seizure-naive brain tumor patients with focus on neurocognitive functioning

Introduction

In seizure-naive brain tumor patients, the efficacy of perioperative prophylactic antiepileptic drug treatment remains controversial. In case of administration, the common preferred drug is levetiracetam (LEV) because of its favorable pharmacological profile. Research to date has not sufficiently determined how LEV affects cognition in the short term, as is the case in the perioperative period. The objective of this prospective study was to examine the neurocognitive functioning of seizure-naive brain tumor patients after receiving LEV perioperatively.

Methods

Fortythree patients with supratentorial brain tumor scheduled for surgery received LEV three days before until six days after surgery as seizure prophylaxis. Cognitive functioning (NeuroCogFX), LEV plasma-levels, hematotoxicity, side-effects, as well as health-related quality of life (HRQoL, Qolie31), were recorded preoperatively before (Baseline) and after onset of LEV (Pre-Op), 4–6 days postoperatively (Post-Op) and 21 days postoperatively (Follow-Up).

Results

No significant changes in cognitive functioning and HRQoL were seen after onset of preoperative LEV. There was a significant improvement of NeuroCogFX total-score at Follow-Up (p = 0.004) compared to Baseline. The overall-score Qolie31 showed simultaneous improvement patterns as cognitive functioning (p < 0.001). The most frequent side effect related to study drug was somnolence (in 28.6% of patients).

Conclusions

A significant improvement of cognitive functioning, as well as an improvement in HRQoL, were detected postoperatively. This is presumably due to the debulking effect of the surgery. Nevertheless, LEV has no detrimental effect on cognitive functioning in the perioperative phase in seizure-naive brain tumor patients.

Trial registration

This study was registered prospectively (Date: 25/11/2015; EudraCT: 2015–003,916-19).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02762-7.

Anti-Epileptic Drugs in Geriatric Neurosurgery: A Review of 669 Neurosurgical Cases

Background and Purpose

Patients over the age of 75 are more likely to develop epilepsy than children under the age of 10. Patients of all ages are prescribed anti-epileptic drugs; however, those over the age of 65 are the most typically prescribed group.

Methods

This is a retrospective study of geriatric cases admitted to the Neurosurgery Department in Khoula Hospital from January 1, 2016 to December 31, 2019. A medical records of 669 patients were identified. Patients’ demographics, risk factors, usage of anti-epileptic drug (AED), type of tumor, tumor location, neuro-vital signs diagnosis, Glasgow coma scale on arrival, treatment types, and length of stay (LOS) were recorded.

Results

The prevalence of AEDs use was 19%. Patients with traumatic brain injury (TBI) were found to have a higher rate of using AEDs (32.1%) followed by patients with oncological and vascular pathologies, respectively (30.1% and 21.6%). There was a significant relationship between the utilization of AEDs among different neurological diseases investigated (p<0.05). Patients who received surgical interventions were using AEDs much more than patients with conservative management (p=0.001). There was a significant difference in the LOS and the usage of AEDs. Added to that, the results signify a relationship between the intensive care unit (ICU) admission and the utilization of AEDs in which the majority of the patients who were not on AEDs were not admitted to the ICU (p<0.05). Phenytoin was the most commonly used AED among different neurosurgical pathologies in the present study (n=110).

Conclusions

AEDs are used as prophylaxis to prevent seizures before most neurosurgical procedures and were commonly prescribed in TBI patients. Phenytoin was found to be the commonest AEDs utilized among the different neurosurgical categories followed by levetiracetam.

Converging Mechanisms of Epileptogenesis and Their Insight in Glioblastoma

Glioblastoma (GBM) is the most common and advanced form of primary malignant tumor occurring in the adult central nervous system, and it is frequently associated with epilepsy, a debilitating comorbidity. Seizures are observed both pre- and post-surgical resection, indicating that several pathophysiological mechanisms are shared but also prompting questions about how the process of epileptogenesis evolves throughout GBM progression. Molecular mutations commonly seen in primary GBM, i.e., in PTEN and p53, and their associated downstream effects are known to influence seizure likelihood. Similarly, various intratumoral mechanisms, such as GBM-induced blood-brain barrier breakdown and glioma-immune cell interactions within the tumor microenvironment are also cited as contributing to network hyperexcitability. Substantial alterations to peri-tumoral glutamate and chloride transporter expressions, as well as widespread dysregulation of GABAergic signaling are known to confer increased epileptogenicity and excitotoxicity. The abnormal characteristics of GBM alter neuronal network function to result in metabolically vulnerable and hyperexcitable peri-tumoral tissue, properties the tumor then exploits to favor its own growth even post-resection. It is evident that there is a complex, dynamic interplay between GBM and epilepsy that promotes the progression of both pathologies. This interaction is only more complicated by the concomitant presence of spreading depolarization (SD). The spontaneous, high-frequency nature of GBM-associated epileptiform activity and SD-associated direct current (DC) shifts require technologies capable of recording brain signals over a wide bandwidth, presenting major challenges for comprehensive electrophysiological investigations. This review will initially provide a detailed examination of the underlying mechanisms that promote network hyperexcitability in GBM. We will then discuss how an investigation of these pathologies from a network level, and utilization of novel electrophysiological tools, will yield a more-effective, clinically-relevant understanding of GBM-related epileptogenesis. Further to this, we will evaluate the clinical relevance of current preclinical research and consider how future therapeutic advancements may impact the bidirectional relationship between GBM, SDs, and seizures.

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.

Effect of Levetiracetam Use Duration on Overall Survival of Isocitrate Dehydrogenase Wild-Type Glioblastoma in Adults

Effect of Levetiracetam Use Duration on Overall Survival of Isocitrate Dehydrogenase Wild-Type Glioblastoma in Adults: An Observational Study

Pallud J, Huberfeld G, Dezamis E, et al. Neurology. 2022;98(2):e125-e140. doi:10.1212/WNL.0000000000013005.

Background and Objectives:

The association between levetiracetam and survival with isocitrate dehydrogenase (IDH) wild type glioblastomas is controversial. We investigated whether the duration of levetiracetam use during the standard chemoradiation protocol affects overall survival (OS) of patients with IDH wild-type glioblastoma.

Methods:

In this observational single-institution cohort study (2010-2018), inclusion criteria were (1) age=18 years; (2) newly diagnosed supratentorial tumor; (3) histomolecular diagnosis of IDH wild-type glioblastoma; and (4) standard chemoradiation protocol. To assess the survival benefit of levetiracetam use during the standard chemoradiation protocol (whole duration, part time, and never subgroups), a Cox proportional hazard model was constructed. We performed a case-matched analysis (1:1) between patients with levetiracetam use during the whole du ration of the standard chemoradiation protocol and patients with levetiracetam use part time or never according to the following criteria: sex, age, epileptic seizures at diagnosis, Radiation Therapy Oncology Group recursive partitioning analysis (RTOG-RPA) class, tumor location, preoperative volume, extent of resection, and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. Patients with unavailable O6-methylguanine-DNA methyltransferase promoter methylation status (48.5%) were excluded.

Results:

A total of 460 patients were included. The median OS was longer in the 116 patients with levetiracetam use during the whole duration of the standard chemoradiation protocol (21.0 months; 95% confidence interval [CI] 17.2-24.0) than in the 126 patients with part-time levetiracetam use (16.8 months; 95% CI 12.4-19.0) and in the 218 patients who never received levetiracetam (16.0 months; 95% CI 15.5-19.4; P = .027). Levetiracetam use during the whole duration of the standard chemoradiation protocol (adjusted hazard ratio [aHR] .69; 95% CI .52-.93; P = .014), MGMT promoter methylation (aHR .53; 95% CI .39-.71; P < .001), and gross total tumor resection (aHR .57; 95% CI .44-.74; P < .001) were independent predictors of longer OS. After case matching (n = 54 per group), a longer OS was found for levetiracetam use during the whole duration of the standard chemoradiation protocol (hazard ratio .63; 95% CI .42-.94; P = .023).

Discussion:

Levetiracetam use during the whole standard chemoradiation protocol possibly improves OS of patients with IDH wild-type glioblastoma. It should be considered in the antitumor strategy of future multicentric trials.

Classification of evidence:

This study provides Class III evidence that in individuals with IDH wild-type glioblastoma, levetiracetam use throughout the duration of standard chemotherapy is associated with longer median OS.

Pre- and Post-surgical Poor Seizure Control as Hallmark of Malignant Progression in Patients With Glioma?

Background

Regarding brain tumor-related epilepsy (BTRE), there is an increasing number of evidence about a relationship between epileptogenesis and oncogenesis. A recent study suggests a role of post-surgery seizure outcome on the survival of patients with low-grade glioma (LGG), underlying the need for a targeted and aggressive epilepsy treatment.

Objective

This study aims at investigating the possible correlation between pre- and post-surgical seizure control and tumor progression in patients who underwent surgery for LGG.

Methods

We performed a retrospective analysis of patients affected by LGGs and BTRE, in a single high-volume neurosurgical center. Seizure control was assessed before surgery and at 3 years of follow-up. Patients with histological progression in high-grade glioma (HGG) have been evaluated. Clinical features, pre-surgical electroencephalograms (EEGs), and electrocorticography (ECoG) have been analyzed.

Results

Among 154 subjects, we collected 32 patients who presented a tumor progression in HGG during the follow-up period. The majority had poor seizure control both pre- and post-surgery, never being in Engel class Ia throughout the whole history of their disease. Almost all patients with poor seizure control had pathological ECoG recording. Clinical features of seizures did not correlate with seizure outcome. On the univariate analysis, the age, the post-operative Engel class, and the extent of resection (EOR) were the prognostic factors significantly associated with oncological outcome; nevertheless, on multivariate analysis, Engel class significance was not confirmed, and the only predicting factor were age and EOR.

Conclusions

Although not confirmed on multivariate analysis, post-surgical seizure control could be a relevant factor to consider during follow-up of BRTE, in particular, when gross total resection is not achieved. Pathological findings on the ECoG may suggest a “hidden” propensity to malignant progression, strictly related to the persistent neuronal hyper-excitability. Further studies with longer follow-up period are needed to confirm our observations.

Clinical and Magnetic Resonance Imaging (MRI) Features, Tumour Localisation, and Survival of Dogs with Presumptive Brain Gliomas

Brain gliomas are common tumours diagnosed in dogs. However, limited information is available on the clinical features and overall survival time (OS) in dogs receiving palliative treatment. The aim of this study was to evaluate possible associations between presenting complaint, tumour localisation, Magnetic Resonance Imaging (MRI) features, survival times, and reason for the death of dogs with suspected intracranial glioma treated palliatively. Sixty dogs from a single institution were retrospectively included (from September 2017 to December 2021). Dogs were included if a presumptive diagnosis of brain glioma was obtained based on an MRI scan and medical history. French Bulldogs were overrepresented (40/60); 46 out of 60 dogs (77%) presented due to epileptic seizures (ES) and in 25/60 dogs (42%), cluster seizures or status epilepticus were the first manifestation of the disease. Dogs with suspected gliomas located in the piriform lobe showed a higher probability of presenting due to epilepsy compared to dogs with glioma in other regions, and more frequently died or were euthanised because of increased ES. Magnetic Resonance Imaging (MRI) features differed between localisations. Fronto-olfactory tumours were more frequently, whereas piriform tumours were less frequently, classified as suspected high-grade glioma. The median survival time was 61 days. Dogs with contrast-enhancing suspected gliomas had significantly shorter OS. This study provides additional information on the clinical features and survival of dogs with suspected brain gliomas treated palliatively.

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.

Brain somatic mutations as RNA therapeutic targets in neurological disorders

Research into the genetic etiology of a neurological disorder can provide directions for genetic diagnosis and targeted therapy. In the past, germline mutations, which are transmitted from parents or newly arise from parental germ cells, were considered as major genetic causes of neurological disorders. However, recent evidence has shown that somatic mutations in the brain, which can arise from neural stem cells during development or over aging, account for a significant number of brain disorders, ranging from neurodevelopmental, neurodegenerative, and neuropsychiatric to neoplastic disease. Moreover, the identification of disease-causing somatic mutations or mutated genes has provided new insights into molecular pathogenesis and unveiled potential therapeutic targets for treating neurological disorders that have few, or no, therapeutic options. RNA therapeutics, including antisense oligonucleotide (ASO) and small interfering RNA (siRNA), are emerging as promising therapeutic tools for treating genetic neurological disorders. As the number of approved and investigational ASO and siRNA drugs for neurological disorders associated with germline mutations increases, they may also prove to be attractive modalities for treating neurologic disorders resulting from somatic mutations. In this perspective, we highlight several neurological diseases caused by brain somatic mutations and discuss the potential role of RNA therapeutics in these conditions.

Neurocognitive Outcome and Seizure Freedom After Awake Surgery of Gliomas

Objectives

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

Materials and Methods

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

Results

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

Conclusions

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

Radiomics Nomogram Improves the Prediction of Epilepsy in Patients With Gliomas

Purpose

To investigate the association between clinic-radiological features and glioma-associated epilepsy (GAE), we developed and validated a radiomics nomogram for predicting GAE in WHO grade II~IV gliomas.

Methods

This retrospective study consecutively enrolled 380 adult patients with glioma (266 in the training cohort and 114 in the testing cohort). Regions of interest, including the entire tumor and peritumoral edema, were drawn manually. The semantic radiological characteristics were assessed by a radiologist with 15 years of experience in neuro-oncology. A clinic-radiological model, radiomic signature, and a combined model were built for predicting GAE. The combined model was visualized as a radiomics nomogram. The AUC was used to evaluate model classification performance, and the McNemar test and Delong test were used to compare the performance among the models. Statistical analysis was performed using SPSS software, and p < 0.05 was regarded as statistically significant.

Results

The combined model reached the highest AUC with the testing cohort (training cohort, 0.911 [95% CI, 0.878-0.942]; testing cohort, 0.866 [95% CI, 0.790-0.929]). The McNemar test revealed that the differences among the accuracies of the clinic-radiological model, radiomic signature, and combined model in predicting GAE in the testing cohorts (p > 0.05) were not significantly different. The DeLong tests showed that the difference between the performance of the radiomic signature and the combined model was significant (p < 0.05).

Conclusion

The radiomics nomogram predicted seizures in patients with glioma non-invasively, simply, and practically. Compared with the radiomics models, comprehensive clinic-radiological imaging signs observed by the naked eye have non-discriminatory performance in predicting GAE.

Bursting of excitatory cells is linked to interictal epileptic discharge generation in humans

Knowledge about the activity of single neurons is essential in understanding the mechanisms of synchrony generation, and particularly interesting if related to pathological conditions. The generation of interictal spikes—the hypersynchronous events between seizures—is linked to hyperexcitability and to bursting behaviour of neurons in animal models. To explore its cellular mechanisms in humans we investigated the activity of clustered single neurons in a human in vitro model generating both physiological and epileptiform synchronous events. We show that non-epileptic synchronous events resulted from the finely balanced firing of excitatory and inhibitory cells, which was shifted towards an enhanced excitability in epileptic tissue. In contrast, interictal-like spikes were characterised by an asymmetric overall neuronal discharge initiated by excitatory neurons with the presumptive leading role of bursting pyramidal cells, and possibly terminated by inhibitory interneurons. We found that the overall burstiness of human neocortical neurons is not necessarily related to epilepsy, but the bursting behaviour of excitatory cells comprising both intrinsic and synaptically driven bursting is clearly linked to the generation of epileptiform synchrony.

The Concept of «Peritumoral Zone» in Diffuse Low-Grade Gliomas: Oncological and Functional Implications for a Connectome-Guided Therapeutic Attitude

Diffuse low-grade gliomas (DLGGs) are heterogeneous and poorly circumscribed neoplasms with isolated tumor cells that extend beyond the margins of the lesion depicted on MRI. Efforts to demarcate the glioma core from the surrounding healthy brain led us to define an intermediate region, the so-called peritumoral zone (PTZ). Although most studies about PTZ have been conducted on high-grade gliomas, the purpose here is to review the cellular, metabolic, and radiological characteristics of PTZ in the specific context of DLGG. A better delineation of PTZ, in which glioma cells and neural tissue strongly interact, may open new therapeutic avenues to optimize both functional and oncological results. First, a connectome-based “supratotal” surgical resection (i.e., with the removal of PTZ in addition to the tumor core) resulted in prolonged survival by limiting the risk of malignant transformation, while improving the quality of life, thanks to a better control of seizures. Second, the timing and order of (neo)adjuvant medical treatments can be modulated according to the pattern of peritumoral infiltration. Third, the development of new drugs specifically targeting the PTZ could be considered from an oncological (such as immunotherapy) and epileptological perspective. Further multimodal investigations of PTZ are needed to maximize long-term outcomes in DLGG patients.

Enhanced Recovery After Surgery (ERAS) for Cranial Tumor Resection: A Review

Enhanced Recovery After Surgery (ERAS) protocols describe a standardized method of preoperative, perioperative, and postoperative care to enhance outcomes and minimize complication risks surrounding elective surgical intervention. A growing body of evidence is being generated as we learn to apply principles of ERAS standardization to neurosurgical patients. First applied in spinal surgery, ERAS protocols have been extended to cranial neuro-oncological procedures. This review synthesizes recent findings to generate evidence-based guidelines to manage neurosurgical oncology patients with standardized systems and assess ability of these systems to coordinate multidisciplinary, patient-centric care efforts. Furthermore, we highlight the potential utility of multimedia, app-based communication platforms to facilitate patient education, autonomy, and team communication within each of the three settings.

Glutamic Acid and Total Creatine as Predictive Markers for Epilepsy in Glioblastoma by Using Magnetic Resonance Spectroscopy Before Surgery

OBJECTIVE

Epilepsy in glioblastoma patients significantly reduces their quality of life; however, little is known about the association between predicting epilepsy and metabolites in tumors. In this study, we used 3.0-T magnetic resonance imaging and ¹H-magnetic resonance spectroscopy (MRS) to quantify metabolite concentrations in patients with varying epilepsy histories.

METHODS

Fifty-one patients with glioblastoma underwent pretreatment 3.0-T MRI/¹H-MRS scanning. Single-voxel (1.5 cm³) MRS, in an enhanced lesion, was acquired using a double-echo point-resolved spectroscopic sequence with chemical-shift selective water suppression. MRS data were quantified with linear combination model (LC-Model) software. We compared the MRS data between groups with and without epilepsy during the postoperative course (EP).

RESULTS

The ratios of glutamate (Glu) and glutamate + glutamine (Glx) to total creatine (Glu/tCr and Glx/tCr) in the tumor were associated with epilepsy history. The receiver operating characteristic curve analysis showed that a Glu/tCr value of 1.81 was 70% sensitive and 90% specific for the prediction of EP (area under curve: 0.82). In the analysis excluding patients with preoperative epilepsy, a Glu/tCr value of 1.81 was 75% sensitive and 88% specific for the prediction (area under curve: 0.87).

CONCLUSIONS

Intratumoral metabolite concentrations measured using pretreatment 3.0-T MRI/¹H-MRS changed characteristically in the group with EP. Our study suggests that the Glu/tCr ratio in tumors has adequate reliability in predicting EP. Pretreatment MRS is a minimally invasive and simple procedure that can provide useful information on glioblastoma patients.

Neuro-oncologic Emergencies

PURPOSE OF REVIEW

Patients with brain and spine tumors are at high risk of presenting cancer-related complications at disease presentation or during active treatment and are usually related to the type and location of the lesion. Here, we discuss presentation and management of the most common emergencies affecting patients with central nervous system neoplastic lesions.

RECENT FINDINGS

Tumor-related emergencies encompass complications in patients with central nervous system neoplasms, as well as neurologic complications in patients with systemic malignancies. Brain tumor patients are at high risk of developing multiple complications such as intracranial hypertension, brain herniation, intracranial bleeding, spinal cord compression, and others. Neuro-oncologic emergencies require immediate attention and multi-disciplinary care. These emergent situations usually need rapid decision-making and management on an inpatient basis.

Relevant pharmacologic interactions in the concurrent management of brain tumor-related epilepsy and venous thromboembolism: a systematic review

INTRODUCTION

Co-administration of direct oral anticoagulants (DOACs) with antiepileptic drugs (AEDs) is increasingly common in brain tumor patients. We therefore performed a systematic review of the current evidence for potential drug interactions between DOACs and AEDs in this patient population.

METHODS

We conducted a systematic review of the literature via PubMed according to PRISMA guidelines (last accessed December 15, 2021). Included were clinical studies and case reports, written in English language and published between 2010 and 2021, that investigated concurrent clinical use of AEDs with DOACs for any indication. Non-English articles, articles not related to our research question, review articles and commentaries were excluded. Full-text articles were evaluated for possible confounding factors and results were summarized using a data table highlighting the key characteristics of each article.

RESULTS

We identified a total of 122 unique articles, of which 27 were deemed relevant to our research question. Of these, 8 articles were clinical studies (n = 295,415 patients) and 19 were case reports (n = 25 patients). Only 3 clinical studies and 2 case reports reported interactions between AEDs and DOACs in patients with active cancer and none reported interactions in patients with brain tumors.

CONCLUSION

We have identified low (class IV) level evidence of potential drug interactions between DOACs and AEDs. Even though there is no current report of interactions in brain tumor patients, neuro-oncology providers should be aware of the emerging evidence regarding drug interactions between DOACs and AEDs and take this into consideration when concurrently prescribing these to patients.

Clinical and radiographic characteristics of diffuse astrocytic glioma, IDH-wildtype, with molecular features of glioblastoma: a single institution review

PURPOSE

Genetic analyses of gliomas have identified key molecular features that impact treatment paradigms beyond conventional histomorphology. Despite at-times lower grade histopathologic appearances, IDH-wildtype infiltrating gliomas expressing certain molecular markers behave like higher-grade tumors. For IDH-wildtype infiltrating gliomas lacking traditional features of glioblastoma, these markers form the basis for the novel diagnosis of diffuse astrocytic glioma, IDH-wildtype (wt), with molecular features of glioblastoma (GBM), WHO grade-IV (DAG-G). However, given the novelty of this approach to diagnosis, literature detailing the exact clinical, radiographic, and histopathologic findings associated with these tumors remain in development.

METHODS

Data for 25 patients matching the DAG-G diagnosis were obtained from our institution's retrospective database. Information regarding patient demographics, treatment regimens, radiographic imaging, and genetic pathology were analyzed to determine association with clinical outcomes.

RESULTS

The initial radiographic findings, histopathology, and symptomatology of patients with DAG-G were similar to lower-grade astrocytomas (WHO grade 2/3). Overall survival (OS) and progression free survival (PFS) associated with our cohort, however, were similar to that of IDH-wt GBM, indicating a more severe clinical course than expected from other associated features (15.1 and 5.39 months respectively).

CONCLUSION

Despite multiple features similar to lower-grade gliomas, patients with DAG-G experience clinical courses similar to GBM. Such findings reinforce the need for biopsy and subsequent analysis of molecular features associated with any astrocytoma regardless of presenting characteristics.

Levetiracetam Prophylaxis Therapy for Brain Tumor-Related Epilepsy (BTRE) Is Associated With a Higher Psychiatric Burden

Purpose: Brain tumor-related epilepsy (BTRE) is a condition characterized by the development of seizures in the context of an undergoing oncological background. Levetiracetam (LEV) is a third-generation anti-seizure medication (ASM) widely used in BTRE prophylaxis. The study evaluated LEV neuropsychiatric side effects (SEs) in BTRE prophylaxis.

Method: Twenty-eight patients with brain tumors were retrospectively selected and divided into two groups. In one group, we evaluated patients with a BTRE diagnosis using LEV (BTRE-group). The other group included patients with brain tumors who never had epilepsy and used a prophylactic ASM regimen with LEV (PROPHYLAXIS-group). Neuropsychiatric SEs of LEV were monitored using the Neuropsychiatric Inventory Questionnaire (NPI-Q) at the baseline visit and the 6- and 12-month follow-up.

Results: Eighteen patients of the BTRE-group and 10 patients of the PROPHYLAXIS-group were included. Compared to the BTRE-group, the PROPHYLAXIS-group showed a higher severity of neuropsychiatric symptoms. According to Linear Mixed Models (LMM), a multiplicative effect was observed for the interaction between group treatment and time. For the caregiver distress score (CDS), only a time-effect was observed.

Conclusion: Prophylactic ASM with LEV is associated with an increased frequency of neuropsychiatric SE. Accurate epileptological evaluations in patients with brain tumors are mandatory to select who would benefit most from ASM.

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

PURPOSE

Postoperative epilepsy is common in glioma patients and has been suggested to indicate disease progression, yet knowledge of its role as a prognostic factor is limited. This study investigates the association between postoperative epilepsy and survival amongst patients with gliomas.

METHODS

We included 3763 patients with histopathologically diagnosed grade II, III, and IV gliomas from 2009 to 2018 according to the Danish Neuro-Oncology Registry. Information on epilepsy diagnosis was redeemed from the Danish National Patient Registry, the National Prescription Registry and the Danish Neuro-Oncology Registry. We used Cox proportional hazards models with 95% confidence intervals (CIs) to examine hazard ratios (HRs) for the association between postoperative epilepsy and risk of death. We examined the role of the timing of epilepsy in three different samples: Firstly, in all glioma patients with postoperative epilepsy; secondly, in patients with postoperative de novo epilepsy; thirdly, exclusively in a homogeneous sub-group of grade IV patients with postoperative de novo epilepsy.

RESULTS

Glioma patients with postoperative epilepsy had an increased risk of death, regardless of prior epilepsy status (HR = 4.03; CI 2.69-6.03). A similar increase in the risk of death was also seen in patients with postoperative de novo epilepsy (HR = 2.08; CI 1.26-3.44) and in the sub-group of grade IV patients with postoperative de novo epilepsy (HR = 1.83; CI 1.05-3.21).

CONCLUSIONS

Postoperative epilepsy may negatively impact survival after glioma diagnosis, regardless of preoperative epilepsy status. Postoperative epilepsy may be an expression of a more invasive growth pattern of the gliomas following primary tumor treatment.

Research progress on SLC7A11 in the regulation of cystine/cysteine metabolism in tumors

Solute carrier family 7 member 11 (SLC7A11) is a major transporter regulating cysteine metabolism and is widely expressed in a variety of tumor cells. SLC7A11 plays an important role in the occurrence, development, invasion and metastasis of tumors by regulating the transport of cysteine in the tumor microenvironment. SLC7A11 is expected to become a new therapeutic target and prognostic indicator for the individualized treatment of patients. According to relevant research reports, SLC7A11 can predict the stages and metastasis of liver, breast and lung cancer. Therefore, an in-depth exploration of the role of SLC7A11 in tumors may be important for the screening, early diagnosis, treatment and prognosis of patients with tumors. The current review summarizes the research progress on SLC7A11 in liver cancer, lung cancer and other tumors on the basis of previous primary studies. In addition, the present review systematically elaborates on the three main aspects of SLC7A11 pathways in some tumors, the cancer-promoting mechanisms, and the therapeutic relationship between SLC7A11 and tumors. Finally, the present review aims to provide a reference for assessing whether SLC7A11 can be used as a prognostic indicator and treatment target for tumor patients, and the future research direction with regard to SLC7A11 in tumors.

IDH-mutated gliomas promote epileptogenesis through d-2-hydroxyglutarate-dependent mTOR hyperactivation

BACKGROUND

Uncontrolled seizures in patients with gliomas have a significant impact on quality of life and morbidity, yet the mechanisms through which these tumors cause seizures remain unknown. Here, we hypothesize that the active metabolite d-2-hydroxyglutarate (d-2-HG) produced by the IDH-mutant enzyme leads to metabolic disruptions in surrounding cortical neurons that consequently promote seizures.

METHODS

We use a complementary study of in vitro neuron-glial cultures and electrographically sorted human cortical tissue from patients with IDH-mutant gliomas to test this hypothesis. We utilize micro-electrode arrays for in vitro electrophysiological studies in combination with pharmacological manipulations and biochemical studies to better elucidate the impact of d-2-HG on cortical metabolism and neuronal spiking activity.

RESULTS

We demonstrate that d-2-HG leads to increased neuronal spiking activity and promotes a distinct metabolic profile in surrounding neurons, evidenced by distinct metabolomic shifts and increased LDHA expression, as well as upregulation of mTOR signaling. The increases in neuronal activity are induced by mTOR activation and reversed with mTOR inhibition.

CONCLUSION

Together, our data suggest that metabolic disruptions in the surrounding cortex due to d-2-HG may be a driving event for epileptogenesis in patients with IDH-mutant gliomas.

Seizures in patients with IDH-mutated lower grade gliomas

PURPOSE

Most patients with Lower Grade Gliomas (LGG) present with epileptic seizures. Since the advent of molecular diagnostics, more homogenous sub-entities have emerged, including the isocitrate dehydrogenase-mutated (IDH-mutated) astrocytomas and 1p19q-codeleted oligodendrogliomas. We aimed to describe the occurrence of seizures in patients with molecularly defined LGG pre- and postoperatively and to analyze factors affecting seizure status postoperatively.

METHODS

A population-based cohort of 130 adult patients with IDH-mutated WHO grade 2 or 3 astrocytomas and oligodendrogliomas was assessed pertaining to seizure burden before and after surgery.

RESULTS

Fifty-four (79.4%) patients with astrocytoma and 45 (72.6%) patients with oligodendroglioma had a history of seizures before surgery. At 12 months postoperatively, 51/67 (76.1%) patients with astrocytoma and 47/62 (75.8%) patients with oligodendrogliomas were seizure free. In a multivariable logistic regression analysis, lower extent of resection (EOR) (OR 0.98; 95% CI 0.97-1.00, p = 0.01) and insular tumor location (OR 5.02; 95% CI 1.01-24.87, p = 0.048) were associated with presence of seizures within 1 year postoperatively in the entire LGG cohort. In sub-entities, EOR was in a similar manner associated with seizures postoperatively in astrocytomas (OR 0.98; 95% CI 0.96-0.99, p < 0.01) but not in oligodendrogliomas (p = 0.34).

CONCLUSION

Our results are well in line with data published for non-molecularly defined LGG with a large proportion of patients being seizure free at 1 year postoperative. Better seizure outcome was observed with increased EOR in astrocytomas, but this association was absent in oligodendrogliomas.