Epilepsy surgery in children and non-invasive evaluation

The technique of EEG recording using subdural and depth electrodes has became established, and such invasive EEG is available for epilepsy surgery. However, a non-invasive procedure is required for evaluation of surgical indication for epilepsy patients, particular for children. We analyzed the relationship between the results of presurgical evaluation and seizure outcome, and investigated the role of invasive EEG in epilepsy surgery for children. Over the past decade, 22 children under 16 years of age have been admitted to our hospital for evaluation of surgical indication. High-resolution MR imaging, MR spectroscopy, video-EEG monitoring, and ictal and interictal SPECT were used for presurgical evaluation. Organic lesions were found on MR images from 19 patients. Invasive EEG was recorded in only one patient with occipital epilepsy, who had no lesion. Surgical indication was determined in 17 children, and 6 temporal lobe and 11 extratemporal lobe resections were performed under intraoperative electrocorticogram monitoring. The surgical outcome was excellent in 14 patients who had Engel's class I or II. Surgical complications occurred in two children who had visual field defects. The results showed that a good surgical outcome could be obtained using an intraoperative electrocorticogram, without presurgical invasive EEG, for localization-related epilepsy in children. The role of invasive EEG should be reevaluated in such children. (author)