medical student Georgetown University School of Medicine Washington, DC, US
Disclosure(s):
Georgia Wong, MS: No financial relationships to disclose
Introduction: Stereoelectroencephalography (SEEG) is valuable for determining the seizure onset zone (SOZ) in drug-resistant epilepsy when non-invasive presurgical techniques are inconclusive. Secondary surgery after initial epilepsy surgical failure is challenging and there is limited research on SEEG following failed epilepsy surgery. We present the outcomes of children who underwent SEEG after failed epilepsy surgery.
Methods: In a single-institution retrospective study, demographics, previous surgery data, SEEG characteristics, management, and follow-up were analyzed for thirteen pediatric patients who underwent SEEG after unsuccessful epilepsy surgery. The SOZ identified by SEEG was categorized as either contiguous with the previous resection cavity (the SOZ occurred focal to the surgical cavity) or non-contiguous (the SOZ occurred in a site(s) distant from the surgical cavity).
Results: Seven patients (54%) experienced initial unsuccessful epilepsy surgery that targeted the temporal lobe, whereas 6 patients (46%) underwent surgery involving the frontal lobe. SEEG analysis revealed 5/7 patients with temporal lobe involvement (71%) had the insula included in the SOZ. Six patients (46%) had contiguous SOZ and 7 patients (54%) had non-contiguous SOZ identified by SEEG. All 13 patients (100%) had a subsequent surgery after SEEG which was either VisualaseTM ablation (54%) or surgical resection (46%). After the subsequent surgery, a favorable outcome (Engel class I/II, 62%) was achieved by 8 patients, while 5 patients experienced a relatively unfavorable outcome (Engel class III/IV, 38%). Patients who received VisualaseTM ablation exhibited a significantly higher likelihood of achieving longer seizure freedom compared to those who underwent resection, as indicated by the statistically significant difference observed in the Kaplan-Meier survival curves (p=0.0494). Average follow-up after the subsequent surgery was 37 months ± 23 months.
Conclusion : SEEG following initial failed epilepsy surgery is effective at identifying residual epileptogenic cortex, contiguous or non-contiguous to the previous surgical cavity, and is associated with good seizure control outcomes.
