Abstracts

Rationale: We want to evaluate the clinical characteristics and outcome of three different hemispherotomy technique in children and adult with refractory hemispherical epilepsy. Methods: We retrospectively studied the clinical course and outcome of 92 patients with refractory epilepsy who underwent hemispherotomy in three Italian epilepsy center between 2006 and 2016. In these centers three different approaches for hemispherotomy were used (parasagittal vertical, parasagittal vertical modified and lateral). Results: The average age of onset for epilepsy in the study population was 1.8 ± 2.5 years; the average duration of epilepsy was 7.4 ± 7.3 years. The mean age at surgery of the study population was 9.2 ± 8.08 years. At a mean follow-up of 2.81 ± 2.4 years, 66 of 90 patients (2 lost at the follow-up, 73.3 %) were seizure-free (Engel class 1). Encephalomalacia, due to presumed childhood infarct or other sequelae of brain trauma and infection, were  the most common etiologies, observed in 41 (44.6%) children, followed by focal cortical dysplasia in 23 (25.0%). There was no significant difference between the three different approaches for seizure outcome (p = 0.34). Hydrocephalus was the most common post-surgical complication (14,1%), and was slightly more prevalent in the parasagittal approach (21,0 vs 11%). No permanent, non-expected, deficit were present at last follow-up. The seizure freedom rate was quite high (73%) and similar between the etiologies (congenital vs acquired vs progressive), and not statistically significant (p = 0.74). Acute postoperative seizures correlate to a worse outcome (p > 0.05). On multivariate analysis, partial secondary generalized seizures (risk ratio 5 2.53, 95% CI 5 1.02–5.85) independently predicted seizure recurrence. Conclusions: Most of the patients of the present cohort achieved seizure freedom independently from the different surgical approach used. This study will assist in better candidate selection for hemispherotomy.  Funding: No funding