Stereotactic surgery combined with intra-operative electrocorticography and neurophysiologic monitoring for epilepsy secondary to subcortex small tumors in the functional areas

Abstract

Objective To investigate the efficiency and complications of stereotactic surgery combined with intra-operative electrocorticography (ECoG) and intra-operative neurophysiologic monitoring (IOM) in treating epilepsy secondary to subcortex small tumors in the functional areas.Methods Fifteen patients with epilepsy secondary to subcortex small tumors in the functional areas,admitted to our hospital from June 2006 to June 2011, were chosen in our study. Resection was performed to these tumors. Guiding with stereotaxic apparatus, epileptogenic foci and boundary localizing by intra-operative ECoG monitoring,functional areas and neuronal structures in the epileptic region judging by IOM,the epileptogenic foci were resected or performed multiple subpial wansaction (MST) and/or cortices lower output powers thermocoagulation.The treatment efficacy was concluded.Results Total resection was achieved in 13 patients and subtotal resection in 2.Epileptogenic foei were ablated in 4 patients,and peri-lesioned cortex of epileptogenic foci in other 11 patients were performed lower output powers thermocoagulation or/and MST. ECoG monitoring found epileptiform discharge disappearance in 6 patients,residual of a few spikes in 6,residual of a lot of spikes as well as having mild to moderate abnormal basilic rhythms in EEG in 3.No permanent and severe complications were noted.All patients were followed up for 1 to 3 y; tumor recurrence was noted in 2; according to Engel's classification standards,Engel I was noted in 10,Engel Ⅱin 3 and Engel Ⅲ in 2,and the effective rate was 100％. Conclusion Stereotactic surgery combined with intra-operative ECoG and IOM is a safe,effective and microinvasive management for epilepsy secondary to subcortex small tumor in the functional areas; it can accuratly locate and totally resect the tumors,treating the epileptogenic foci and avoiding functional defects. Key words: Secondary epilepsy,Epileptogenic focus; Electrocorticography; Stereotaxy; Neurophysiologic monitoring