FULL-LENGTH ORIGINAL RESEARCH Epilepsy surgery in patients with normal or nonfocal MRI scans: Integrative strategies offer long-term seizure relief

SUMMARY Purpose: Excisional surgery achieves seizure freedom in a large proportion of children with intractable lesional epilepsy, but the outcome for children without a focal lesion on MRI is less clear. We report the outcome of a cohort predominantly of children with nonlesional intractable partial epilepsy undergoing resective surgery. Methods: We studied 102 patients with nonlesional intractable partial epilepsy who underwent excisional surgery. The epileptogenic region was identified by integrating clinical exam and videoEEG data complemented by ictal SPECT (n = 40), PET (n = 10), extraoperative subdural monitoring (n = 80), and electrocorticography (n = 22). All patients had follow-up greater than 2 years, 76 patients had 5-year follow-up, and 43 patients had 10year follow-up. Results: A total of 66 resections were unilobar; 36 were multilobar. One patient died of causes unrelated to seizures or surgery. At 2-year follow-up, 44 of 101 patients were seizure-free, 15 experienced >90% reduction, 17 had >50% reduction, and 25 were unchanged. At 5-year follow-up, 35 of 76 patients were seizure-free, 12 experienced >90% reduction, 12 had >50% reduction, and 17 were unchanged. At 10-year follow-up, 16 of 43 patients were seizure-free, 13 experienced >90% reduction, 7h ad>50% reduction, and 7 were unchanged. Outcomes correlated with the presence of convergent focal interictal spikes (p < 0.005) on the scalp EEG and completeness of resection (p < 0.0005).