Abstracts

Rationale: Localization of eloquent brain area involving language and memory function is essential to preserve verbal function for resective epilepsy surgery in children with drug-resistant epilepsy. We can estimate verbal dominance from result of neuropsychological test in subset of epilepsy children. In our institute, association of neuropsychological dysfunction area, as a part of epileptic network, decide the strategy for resectable epileptogenic zone. We hypothesize that neuropsychological evaluation can be a cardinal element to decide whether maximum or minimum resection of epilepsy surgery in developing brain. Methods: We retrospectively reviewed 71 children with drug-resistant epilepsy who underwent intracranial video EEG prior to resective surgery at The Hospital for Sick Children from 2009 to 2014. We estimated the dominant hemisphere for language using a combination of 1) preoperative verbal performance and 2) lateralization of epileptic hemisphere indicated by EEG and MEG. Pre- and post-VIQ were compered to age at seizure onset, seizure duration, seizure semiology, etiology, hemisphere of seizure onset and surgery for estimated(E)-dominant/nondominant hemisphere. Results: We analyzed 39 children. Seizure onset ranged 0.5-14years(6.14.0years, meanSD). Duration of seizure ranged 1-13.8years(5.53.5). Period of postoperative neuropsychological test ranged 0.8-2.5years(1.10.3).Post-VIQ(77.516.5) significantly declined comparison to pre-VIQ(83.418.5,p < 0.001). A regression analysis revealed a shorter seizure duration significantly correlated with the decline of VIQ after surgery(p=0.035). Post-VIQ significantly declined 1)with age of seizure onset >=5years(n=22,pre:86.4,post:78.8,p=0.002), 2)with focal seizure (n=32,pre:85.7,post:78.3,p < 0.001), 3)with the acquired etiology(n=20,pre:87.2,post:78.8,p < 0.001), 4) with left hemispheric seizure onset(n=26,pre:83.5,post:78,p=0.006) and right hemisphere(n=13,pre:83.4,post:76.5,p=0.023).In 25 patients who underwent surgery in E-dominant hemisphere, post-VIQ significantly declined(pre:79.7,post:73.6,p=0.002), and in 16 patients with age of seizure onset >=5years(pre:83.6,post:75.3,p=0.001).In 14 patients who underwent surgery in E-nondominant hemisphere, post-VIQ did not change(pre:90.1,post:84.6), but declined in 8 patients with age of seizure onset < 5years(pre:87.4,post:81.9,p=0.046). Conclusions: VIQ declined after resective surgery in children with drug-resistant epilepsy. Decline of post-VIQ was related with 1) age of seizure onset >=5years, 2) short seizure duration, 3) focal seizures 4) acquired etiology, 5) both left and right hemisphere seizure onset, 6) surgery in E-dominant hemisphere. The post-VIQ declined with age of seizure onset >=5years in E-dominant hemisphere, and with age of seizure onset < 5years in E-nondominant hemisphere. The language network in epileptic brain may require the extensive brain area in children. Preoperative neuropsychological evaluation and the estimation of dominant hemisphere could be essential for maximize/minimize the resectable epileptogenic zone with preserving verbal function in children with drug-resistant epilepsy. Funding: N/A