Ictal EEG recording is not mandatory in all candidates for paediatric epilepsy surgery with clear MRI lesions and corresponding seizure semiology

Objective. Epilepsy surgery can potentially cure drug-resistant epilepsy, but careful presurgical evaluation is vital to select patients who will profit from such an intervention. Many epilepsy surgery programs offer extensive presurgical evaluation including several days of video-EEG monitoring. Non-lesional epilepsy cases are rare among epilepsy surgery patients. We set up a lesionorientated paediatric epilepsy surgery program for patients with clearly localized lesions with limited presurgical diagnostics, in particular, with a maximum of 48 hours of non-invasive EEG monitoring that did not necessarily include ictal EEGs. Methods. We retrospectively evaluated the outcome of patients who were operated on within our epilepsy surgery program with respect to seizure freedom. Results. Fifty-two children and adolescents with MRI lesions at a mean age of 8.27 +/- 4.83 years (range: 0.17-18.87) underwent a resective procedure. The most frequent surgery was a hemispherotomy. Overall seizure freedom was 81.8% after 12 months and 85.6% after a median observation period of 20.45 months. Seizure frequency was reduced >50% in all other patients. Preoperative recording of an ictal EEG on the side of surgery had no effect on postoperative seizure outcome (p= 0.697), nor did recording of epileptiform discharges on the ipsilateral (p= 0.538) and contralateral side (p= 0.147). Significance. Our findings highlight the high success rate using a lesionorientated epilepsy surgical approach with reduced presurgical video-EEG monitoring in the paediatric epilepsy population. Our data show that it is possible to reduce the complex pre-surgical work-up for epilepsy in children and adolescents by asking the basic question: "Is there any reason why the lesion should not be resected".