Epilepsy surgery for glioneuronal tumors in childhood: avoid loss of time.

1 Background: In contrast to the abundance of seizure outcome reports in epilepsy surgery for 2 glioneuronal tumors in childhood and adolescence, there is a dearth of information regarding 3 cognitive outcomes. Objective: To investigate these outcomes and determine their predictive 4 factors. Methods: We retrospectively analyzed the presurgical findings, resection types and 5 outcomes over 1.3-12.3 years (mean 7.3) of 29 consecutive patients, who underwent resection in 6 2000-2011. The mean age at epilepsy onset was 7.9 years (range 0-15.4), the mean age at surgery 7 was 11.7 years (range 2.6-17.3), and the mean epilepsy duration to surgery was 3.8 years (range 8 0.3-15.3). Etiology comprised 13 dysembryoplastic neuroepithelial tumors and 16 gangliogliomas, 9 with additional focal cortical dysplasia in 5 cases. Results: 86% of children were seizure free 12 10 months after surgery; at final follow-up 76% remained seizure free and 62% had discontinued 11 antiepileptic drugs. Gross-total resection was related to significantly higher rates of seizure12 freedom. Higher presurgical cognitive functioning (full scale IQ, verbal IQ) was related to shorter 13 epilepsy duration to surgery independent of age at epilepsy onset, thus determining postsurgical 14 functioning. Improvements in verbal IQ, performance IQ and visual memory as well as a trend 15 towards improvement in full scale IQ were established after surgery. Despite individual losses in 16 full scale IQ, verbal or visual memory, no deterioration was noted in any cognitive variable on a 17 group level. Conclusion: Completeness of resection predisposes to favorable outcomes regarding 18 seizure alleviation. Whereas cognitive functioning deteriorates with time in glioneuronal tumor19 related refractory epilepsy, surgery is linked to improvement rather than to deterioration on a group 20 level. 21 22