Abstracts

Rationale: Focal Cortical Dysplasia (FCD) are abnormalities of cortical development and can cause medically refractory epilepsy requiring surgical resection in most. In some patients, the FCD can be located in deep locations such as the depth of a sulcus. We retrospectively reviewed patients with confirmed FCD by pathology with deep locations and looked at their surgical outcomes. Methods: We identified patients from our epilepsy surgery database from 2011- 2014 who had FCD resection with a deep location. Only patients with follow up of more than 6 months post resection were included. The database and medical records were queried for demographics, seizure type, video EEG, MRI, Engle outcome, morbidity and complications. Results: Eleven patients were identified to have deep FCD with age ranging from 9 months to 16 years. Age of seizure onset was 5 weeks to 7 years + 5 months. All had focal epilepsy and all had daily seizures to multiple seizures per day. All patients failed more than 2 appropriate seizure medications. All the EEG/video EEG were concordant to the area of the FCD. MRI showed FCD in all patients except for 4 patients that were initially read as "normal". PET was done in 2 and 1 had a MEG done which revealed the FCD. One of the patients initially had a normal MRI and then after 2 years of age the FCD became more apparent. All the FCD were seen in extratemporal locations with the following distribution: occipital (1), parietal (3), insular (2), frontal (4). Seven patients had resections with electrocorticography (ECoG) and 3 had grids +/- depth electrode for language and motor mapping; Two had relapse of the seizures 4-7 months post resection and required repeat surgery. Seven had Engel 1 (free of disabling seizures) outcome (63%), 1 had Engel 3 (worthwhile improvement) and 3 had Engel 4 (no worthwhile improvement). Complications were seen in 3 patient and included: transient one sided weakness (2) and transient word finding difficulty (1) and one patient had a scalp stich granuloma 2 months post resection. Pathology included Type 1a (5), Type 1b (1), type 2a (1) and type 2b (4). Seven (63%) patients had good postoperative outcome with Engel 1 outcome. Those that had relapse had incomplete resections (2) due to the FCD being near an eloquent cortex which limited the resection. Follow up MRI showed residual dysplasia on all 4. Conclusions: The study shows that good surgical outcome can be achieved with resection of deep focal cortical dysplasia in children. In some of those that relapsed, a somewhat limited resection was done because of its proximity to eloquent areas. Minimal or expected neurologic deficits were seen. Persistent evaluation by doing other tests (PET, MEG) are needed to identify subtle lesions.