Should spikes on post-resection ECoG guide pediatric epilepsy surgery?

Area of Science:

• Pediatric Neurosurgery
• Epileptology
• Clinical Neurophysiology

Background:

• Electrocorticography (ECoG) immediately after resection (post-resection ECoG) is used in pediatric epilepsy surgery to guide further resection.
• Clinical practice varies regarding the utility of post-resection ECoG in identifying and resecting epileptogenic tissue.
• The role of post-resection ECoG as a biomarker for seizure outcome is not well-established in pediatric epilepsy surgery.

Purpose of the Study:

• To investigate if post-resection ECoG spiking is a biomarker of the epileptogenic zone in children undergoing epilepsy surgery.
• To determine if post-resection ECoG spiking predicts seizure outcome after epilepsy surgery in pediatric patients.
• To evaluate the impact of further resection based on post-resection ECoG findings on seizure control.

Main Methods:

• Retrospective review of 124 pediatric patients who underwent post-resection ECoG following epilepsy surgery.
• Blinded scoring of ECoG records for the presence of frequent spiking on resection margins.
• Analysis of seizure outcomes at a minimum 12-month follow-up, correlating with ECoG findings and completeness of resection.

Main Results:

• Nearly half of the patients (48%) exhibited spike populations on post-resection ECoG.
• Fifty percent of those with spikes underwent further resection based on clinical interpretation.
• A trend towards better seizure outcomes was observed when spiking was completely resected (p=0.099), with 51% good outcome versus 35% in patients with persistent spikes.

Conclusions:

• Post-resection ECoG can identify residual epileptogenic tissue in a significant proportion of pediatric epilepsy surgery patients.
• Complete resection of spiking on post-resection ECoG did not significantly improve seizure outcomes, suggesting a prognostic rather than a remediable role in all cases.
• Further resection of residual spike-generating cortex may be beneficial in selected pediatric epilepsy surgery patients, particularly those with tumors.