The usefulness of intraoperative electrocorticography ( iECoG ) in pediatric temporal lobe epilepsy surgery

OBJECTIVE: This study aimed to evaluate the usefulness of intraoperative electrocorticography (iECoG) in providing a more accurate surgical strategy, thereby yielding seizure freedom following resective surgery in children with temporal lobe epilepsy (TLE). METHODS: The authors conducted a retrospective review of pediatric patients with drug-resistant TLE due to various etiologies, within a relatively long follow-up (range 8.5-11.5 years). Patients were divided into two groups based on whether they were operated on using iECoG or not, which was employed in cases of uncertain delineation of the EZ or anticipated extended resection. The efficacy of surgical treatment was assessed using Engel's classification. Seizure-freedom rate for each etiology was compared between groups using Fisher's exact test with a 95% confidence interval. RESULTS: A total of 81 patients were included in the study (mean age 11.8 years, range 1-18 years), of whom 63 (77.8%) achieved Engel I status after 10 years. The main etiology was hippocampal sclerosis (34/81, 41.9%), followed by tumors (25/81, 30.8%) and focal cortical dysplasia (22/81, 27.1%). iECoG was performed in 29 (35.8%) patients. Overall, there were no significant differences in the proportion of Engel I (p = .78) among those who performed iECoG (22/29, 75.9%) and did not perform iECoG (n = 41/52, 78.8%). Among tumor-associated cases, Engel I was achieved in 100% of patients with iECoG, compared with 76.5% without iECoG (p = .27). No significant differences were observed in focal cortical dysplasia (p = .61) or hippocampal sclerosis (p = .35). SIGNIFICANCE: The study did not show that intraoperative iECoG improved Engel class I outcomes. Refinement of iECoG methods and future studies controlling for confounders are warranted.