Sulcus-centered resection for focal cortical dysplasia type II: surgical techniques and outcomes

Abstract

Focal cortical dysplasia type II (FCD II) is a common histopathological substrate of epilepsy surgery. Here, the authors propose a sulcus-centered resection strategy for this malformation, provide technical details, and assess the efficacy and safety of this technique. The main purpose of the sulcus-centered resection is to remove the folded gray matter surrounding a dysplastic sulcus, particularly that at the bottom of the sulcus. The authors also retrospectively reviewed the records of 88 consecutive patients with FCD II treated with resective surgery between January 2015 and December 2018. The demographics, clinical characteristics, electrophysiological recordings, neuroimaging studies, histopathological findings, surgical outcomes, and complications were collected. After the exclusion of diffusely distributed and gyrus-based lesions, 71 patients (30 females, 41 males) who had undergone sulcus-centered resection were included in this study. The mean (± standard deviation) age of the cohort was 17.78 ± 10.54 years (38 pediatric patients, 33 adults). Thirty-five lesions (49%) were demonstrated on MRI; 42 patients (59%) underwent stereo-EEG monitoring before resective surgery; and 37 (52%) and 34 (48%) lesions were histopathologically proven to be FCD IIa and IIb, respectively. At a mean follow-up of 3.34 ± 1.17 years, 64 patients (90%) remained seizure free, and 7 (10%) had permanent neurological deficits including motor weakness, sensory deficits, and visual field deficits. The study findings showed that in carefully selected FCD II cases, sulcus-centered resection is an effective and safe surgical strategy.