Acute postoperative seizures and long-term outcome following pediatric epilepsy surgery

PURPOSE Acute post-operative seizures (APOS) after epilepsy surgery, previously believed to be benign, are increasingly associated with poor long-term prognosis. Prior literature has focused primarily on adult temporal lobe epilepsy. This retrospective study aimed to identify the prevalence, prognostic significance and risk factors for APOS in pediatric epilepsy surgery at a single center. METHOD Retrospective chart review of all children aged 0-21 years undergoing resective surgery for epilepsy between 2009 and 2012 at a single center. APOS were defined as seizures within 30 days of resection. Surgical outcome was determined, using a minimum of 12 months postoperative follow-up for inclusion. RESULTS APOS, defined as a seizure within 30 days of resection, were identified in 50/112 (44%) of patients. APOS were a significant predictor of poor postoperative seizure outcome (ILAE 4-6); only 26% of those with APOS had a good outcome (ILAE 1-3), compared to 76% without APOS. Timing of postoperative seizure was not correlated with outcome. Most (54%) with APOS and good outcome had continued seizures between 14-30 days postoperatively. Patients with APOS after temporal (p=0.05) and extratemporal (p<0.001) resections had a significantly worse prognosis. APOS after hemispherectomy were not associated with a worse prognosis (p=0.22). Key risk factors for APOS include lack of ictal EEG lateralization to operated hemisphere/side of MRI abnormality. CONCLUSION This study shows an association between APOS and poor outcome in both temporal and extratemporal pediatric epilepsy surgery. Findings support the expansion of APOS duration to 30 days.