Abstracts

Rationale: Central nervous system tumors are the most common solid tumors in childhood with an incidence of 10.71/100,000/year in the United States.1 They account for significant morbidity and mortality. Epilepsy is one of the most common presenting comorbidities of these tumors. Postsurgical seizure outcomes may be influenced by a variety of factors including tumor location, tumor genetics, and extent of resection. Little is known about the role of intraoperative electrocorticography (ECoG) in guiding resections and its association with seizure control after surgery. 1Central Brain Tumor Registry of the United States Methods: We performed a retrospective chart review of children with tumor-related epilepsy evaluated at our hospital from January 2003 to December 2016. Eligible patients were younger than 19 years of age at time of diagnosis and had seizures as an initial presenting symptom. Patients with tuberous sclerosis complex, neurofibromatosis, tumor locations that impeded the use of ECoG, and those who did not have their initial surgery at our center or were only seen for a second opinion were excluded. Primary measures included tumor location, pathology and grade of tumor, use of chemotherapy or radiation, extent of resection, use of intraoperative ECoG, types of scalp electroencephalogram (EEG) abnormalities, anti-seizure medications (ASM), and seizure outcomes. Engel Classes were assessed at 2 years, 5 years, 10 years, and at the most recent follow-up. Results: Of 406 children with brain tumors and epilepsy, 91 patients met inclusion criteria and were reviewed. Patients were followed an average of 62.7 months (range 1 to 168). The most common tumor types were gangliogliomas (N=31), dysembryoblastic neuroepithelial tumors (N=17) and other glioneuronal tumors (N=12). Fifty five (60.4%) patients had ECoG-guided resection with their initial surgery. Overall, fewer patients in the non-ECOG-guided group achieved seizure freedom (Engel Class I) than in the ECOG-guided group (17/36 (47%) vs. 41/55 (74.5%); p=0.008). The average time to seizure recurrence in the non-ECoG group was 48.8 weeks and 109 weeks in the ECoG-guided group (p=0.006). When we compared the seizure-free survival since surgery in patients who underwent ECoG-guided resection and those without ECoG, the difference was statistically significant (p < 0.0001; Figure 1). Conclusions: Our findings suggest that ECoG-guided resection is associated with better post-surgical seizure outcomes. Further research in this area is necessary to provide definitive evidence regarding the use of intraoperative ECoG-guidance and to support development of future guidelines.