Surgical Treatment of Focal Cortical Dysplasia

Cho, Kwan Kook; Kim, Hyoung Ihl; Lee, Min Cheol; Kim, Keun Su; Kim, Yun Hee; Chung, Chang Oh; Neto, Pedro R

Abstract

Cortical Dysplasia(CD) is increasingly recognized as a cause of intractable epilepsy since it can be easily diagnosed with high resolution magnetic resonance imaging(MRI). We analyzed 24 consecutive cases with cortical dysplasia who underwent resective surgery at our institute between September, 1992 and December, 1995. MRI was demonstrated to be a decisive tool to identify CD in 16 cases(66.7%). However, the remaining 8 cases(33.3%) were confirmed to have CD based on histological examination. Location of the lesion included temporal(n=9), central(n=5), multilobar(n=5), and frontal(n=5). Intracranial EEG recording was performed to delineate the epileptogenic zone in 16 cases:subdural grid(10 cases) and depth electrode(6 cases). Resection was performed in temporal(n=9), frontal(n=7), central(n=6), parietal(n=1), and multilobar(n=1). Complete resection was possible in 15(62.5%) and partial resection in 9(37.5%). Histological examination revealed dyslamination of cortical layers only(n=9), additional dysplastic neurons(n=7), and additional balloon cells(n=8). Surgical outcome was graded as seizure free(n=14:58.3%), rare seizures(n=3:12.5%), <50% reduction of seizure frequency(n=2:8%), and no change(n=5:20.8%) after mena follow-up of 12.7 months. The most influencing factor on the surgical outcome was the degree of completeness of resection(p<0.05). However, detectability of CD on MRI, severity of histological findings, age of seizure onset, and duration of seizure were not significantly related with the surgical outcome. High suspicion is required to detect the CD among the patients with intractable epilepsy and surgical strategies should be well-planned to improve the surgical outcome in the patients with CD.