Seizure Outcome After Surgery for Insular High-Grade Glioma

Insular Gliomas. Experience in a Latin American Center and Assessment of Variables Related to Surgical Management and Prognosis

OBJECTIVE

To describe our experience in the resection of gliomas involving the insula and analyze the variables implicated in the management and prognosis of these tumors.

METHODS

This retrospective, single-center, analytic study included a cohort of 83 patients who underwent surgery for insular gliomas by the same surgeon in a third-level Argentine center, in the period between 2010 and 2023. We analyzed the population's demographic, clinical, and radiologic features and surgical variables associated with postoperative results and prognosis using multivariate regression analysis.

RESULTS

A total of 53 patients (54% men) were included, with a mean follow-up of 40.7 months. The mean age at surgery was 41 years (range, 21-73) and 66.1% corresponded to low-grade gliomas (LGGs). Seizures were the initial symptom in most cases. There was evidence of tumor extension over the insula to the temporal or/and frontal lobe in 64.2% of patients. An extent of resection >90% was achieved in 62.3% of cases (27% of gross total resection), with an average resected volume of 89.4%. Awake craniotomy was indicated in 47% of patients and intraoperative magnetic resonance imaging was performed in 24%. Recurrence was observed in 44% of patients, with a mean progression-free survival of 31 months (42 months in LGG and 10 months in high-grade glioma [HGG]). Nine patients underwent reoperation. By the time of 2 years, survival was 100% for LGG and 46% for HGG, whereas 4-year overall survival was 92% for patients with LGG and 15.4% for those with HGG.

CONCLUSIONS

Surgery for insular gliomas is a complex task that needs to be managed with adequate preoperative and intraoperative assessment to achieve maximum safe resection with low morbidity for better functional and oncologic outcomes. Adequate anatomic understanding, radiologic analysis, awake craniotomy, and cortical and subcortical mapping are paramount to pursue this aim.

Surgical treatment for insular gliomas. A systematic review and meta-analysis on behalf of the EANS neuro-oncology section

Introduction

The appropriate surgical management of insular gliomas is controversial. Management strategies vary considerably between centers.

Research question

To provide robust resection, functional and epilepsy outcome figures, study growth patterns and tumor classification paradigms, analyze surgical approaches, mapping/monitoring strategies, surgery for insular glioblastoma, as well as molecular findings, and to identify open questions for future research.

Material and methods

On behalf of the EANS Neuro-oncology Section we performed a systematic review and meta-analysis (using a random-effects model) of the more current (2000-2023) literature in accordance with the PRISMA guidelines.

Results

The pooled postoperative motor and speech deficit rates were 6.8% and 3.6%. There was a 79.6% chance for postoperative epilepsy control. The postoperative KPI was 80-100 in 83.5% of cases. Functional monitoring/mapping paradigms (which may include awake craniotomies) seem mandatory. (Additional) awake surgery may result in slightly better functional but also worse resection outcomes. Transcortical approaches may carry a lesser rate of (motor) deficits than transsylvian surgeries.

Discussion and conclusions

This paper provides an inclusive overview and analysis of current surgical management of insular gliomas. Risks and complication rates in experienced centers do not necessarily compare unfavorably with the results of routine neuro-oncological procedures. Limitations of the current literature prominently include a lack of standardized outcome reporting. Questions and issues that warrant more attention include surgery for insular glioblastomas and how to classify the various growth patterns of insular gliomas.

Seizure Management and Prophylaxis Considerations in Patients with Brain Tumors

PURPOSE OF REVIEW

The article gives an overview of the current knowledge in the management of tumor related epilepsy, including systematic reviews and consensus statements as well as recent insight into a potentially more individualized treatment approach.

RECENT FINDINGS

Tumor molecular markers as IDH1 mutation and MGMT methylation status may provide future treatment targets. Seizure control should be included as a metric in assessing efficacy of tumor treatment. Prophylactic treatment is recommended in all brain tumor patients after the first seizure. Epilepsy has a profound effect on the quality of life in this patient group. The clinician should tailor the choice of seizure prophylactic treatment to the individual patient, with the goal of limiting adverse effects, avoiding interactions and obtaining a high degree of seizure freedom. Status epilepticus is associated with inferior survival and must be treated promptly. A multidisciplinary team should treat patients with brain tumors and epilepsy.

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.