Seizure Burden and Clinical Risk Factors in Glioma‐Related Epilepsy: Insights From MRI Voxel‐Based Lesion‐Symptom Mapping

Abstract

BackgroundEpilepsy is the most common preoperative symptom in patients with supratentorial gliomas. Identifying tumor locations and clinical factors associated with preoperative epilepsy is important for understanding seizure risk.PurposeTo investigate the key brain areas and risk factors associated with preoperative seizures in glioma patients.Study TypeRetrospective.PopulationA total of 735 patients with primary diffuse supratentorial gliomas (372 low grade; 363 high grade) with preoperative MRI and pathology data.Field Strength/SequenceAxial T2‐weighted fast spin‐echo sequence at 3.0 T.AssessmentSeizure burden was defined as the number of preoperative seizures within 6 months. Tumor and high‐signal edema areas on T2 images were considered involved regions. A voxel‐based lesion‐symptom mapping analysis was used to identify voxels associated with seizure burden. The involvement of peak voxels (those most associated with seizure burden) and clinical factors were assessed as risk factors for preoperative seizure.Statistical TestsUnivariable and multivariable binary and ordinal logistic regression analyses and chi‐square tests were performed, with results reported as odds ratios (ORs) and 95% confidence intervals. A P‐value <0.05 was considered significant.ResultsA total of 448 patients experienced preoperative seizures. Significant seizure burden‐related voxels were located in the right hippocampus and left insular cortex (based on 1000 permutation tests), with significant differences observed in both low‐ and high‐grade tumors. Tumor involvement in the peak voxel region was an independent risk factor for an increased burden of preoperative seizures (OR = 6.98). Additionally, multivariable binary logistic regression results indicated that 1p/19q codeletion (OR = 1.51), intermediate tumor volume (24.299–97.066 cm3), and involvement of the peak voxel (OR = 6.06) were independent risk factors for preoperative glioma‐related epilepsy.ConclusionVoxel areas identified through voxel‐based lesion‐symptom mapping analysis, along with clinical factors, show associations with clinical seizure burden, offering insights for assessing seizure burden for glioma patients.Level of Evidence4Technical EfficacyStage 1