Intrinsic and extrinsic risk factors in tumor-related epilepsy

Purpose: This study consolidated evidence on the association of tumor-intrinsic and investigated the underexplored association of tumor-extrinsic factors with tumor-related epilepsy, aiming to contribute to the overall risk assessment for clinical management in tumor-related epilepsy. Methods: Over a period of one year (2020), we prospectively collected imaging and clinical data of 373 patients with histopathologically confirmed brain tumors. Assessed tumor-intrinsic factors included histopathology, diameter and anatomical location, with the central lobe comprising the precentral, postcentral and subcentral gyrus and paracentral lobule. Tumor-extrinsic factors comprised sex, age, BMI, smoking, alcohol abuse, and Na ⁺ /K ⁺ imbalances. We applied univariable and multivariable binary logistic regression to characterize the associations between tumor-intrinsic and tumor-extrinsic factors with tumor-related epilepsy. Results: Preoperative seizures occurred in 29.5% (n = 110) of patients, with cortical locations — particularly the central lobe (91.3%, n = 21) — posing the highest seizure incidence among all factors. In univariable analysis, compared to WHO grade 3/4 gliomas, WHO grade 1/2 neuroepithelial tumors exhibited moderately higher, whereas pituitary adenomas/ craniopharyngiomas and schwannomas showed lower incidences of preoperative seizures. In multivariable analysis, the central lobe (OR 58.15), other cortical locations (OR 3.47–3.76), male sex (OR 1.77), low BMI (OR 4.61) and smoking (OR 1.013 per pack-year), revealed significant associations (p = < 0.05). Conclusion: Cortical location, especially in the central lobe, male sex, low BMI and smoking, are independently associated with tumor-related epilepsy. Our findings support the importance of considering both tumor-intrinsic and tumor-extrinsic factors to develop a holistic seizure-risk assessment and highlight the need for larger, prospective studies to refine clinical management and potentially pharmacological seizure prophylaxis.