O1-E-17. Maximum resection of area with HFOs achieves good seizure outcome in epilepsy with tuberous sclerosis complex

Abstract

Background: High frequency oscillations (HFOs) on intracranial EEG (ICEEG) were reported correlating with epileptogenic zone. Hypothesis: Resection of cortex with HFOs in patients with tuberous sclerosis complex (TSC) achieves good seizure outcome. Methods: We analyzed occurrence rate (OR) of interictal HFOs at 80–200 Hz (ripple) and >200 Hz (fast ripple) between 2 groups: seizure free (group A) and residual seizure (group B). We analyzed resection ratio of cortices including seizure onset zone, high OR electrodes of ripple and fast ripple. Results: We analyzed 12 patients (group A: 9 patients; group B: 3 patients). The resection ratio of seizure onset zone (80–100%; mean94%) in group A, was higher than 63–100% (81%) in group B ( P = 0.18; correlation ratio = 0.50). The resection ratio of high OR electrodes of ripple (55–100%; 80%) in group A, was higher than 37–100% (65%) in group B ( P = 0.21; correlation ratio = 0.31). The resection ratio of high OR electrodes of fast ripple (66–100%, 80%) in group A was higher than 24–78% (51%) in group B ( P = 0.034; correlation ratio = 0.63). Conclusion: Maximum resection of area with interictal high OR fast ripples on ICEEG showed the strongest correlation with good seizure outcome in TSC patients.