Abstracts

Rationale: Focal cortical dysplasia (FCD) can cause medically refractory epilepsy and in most require surgical resection. We looked at our FCD cases in children that had resection done using both intraoperative MRI (iMRI) and intraoperative Electrocorticography (ECoG) and looked at findings and surgical outcomes. Methods: We retrospectively identified patients who underwent both ECoG and iMRI assisted resection from January 2014 to Feb 2016. The database were queried for demographics, ECoG findings, iMRI, pathology, Engle outcome, morbidity and complications. Results: Thirteen patients were identified with age ranging from 2.1 to 21 years old (9 female and 4 male). All patients had focal seizures. The location of the FCD were insular (2), frontal (5) and parietal (6). Five out of the 13 were repeat surgeries. In eight of the 13 patients, the intraop MRI showed complete resection. In 5 of the 13 patients, iMRI images suggested residual dysplasia and the patient underwent reexploration and in 4, further resection was done. ECoG showed spikes in the area of the suspected dysplasia. In 5 patients, depth electrodes were additionally done since the FCD were in deep locations. Spikes were seen and corresponded to the neuronavigation imaging study. Only on one patient did the ECoG did not show any spikes (bottom of the sulcus FCD) but the iMRI showed residual dysplasia and the patient had further resection. Twelve had Engle 1 outcome with a mean follow up duration of 7.4 months (1 month to 19 months) and one had Engle outcome 2 (repeat surgery and deep FCD). Pathology showed Type IIA ( 7) , Type IIB (4), Type 1 (1) and 1 was undetermined. Post resection complications included either upper or lower extremity weakness that improved or resolved ( 3 patients) and transient hallucinations (1 ). None of the patients underwent reoperation after ECoG and iMRI assisted resection. Conclusions: The study shows that good surgical outcome can be achieved with resection of FCD using both ECoG and iMRI. The near real time complete resection provided by the iMRI with concordant findings of EcoG, showed in majority, seizure freedom and reduced need for reoperation. However, the residual FCD lesion identified by iMRI outweighed the ECoG findings in making decisions for further resection. Minimal or expected neurologic deficits were seen in a few. Funding: None