Surgery of Intractable Epilepsy Associated with Cortical Dysplasia

Kim, Il Man; Son, Eun Ik

Abstract

Cortical dysplasia(CD) is recently known as a cause of intractable partial epilepsies that are amenable to surgical treatment. The development of new neuroimaging has facilitated the recognition of these neuronal migration disorders. Here we examine some clinical features that permit early suspicion of focal cortical dysplasia and better surgical results. From a consecutive surgical series of 239 patients with intractable epilepsy since 1992, pathologically verified 31 CD including 6 CD with dysembryoplastic neuroepithelial tumor(DNT) were selected for this study. The location and extent of resection were determined by both epileptogenic zones and the structural lesion, according to presurgical evaluation(neuroimaging, EEG, intracranial recording), intraoperative electrocorticography(ECoG) and functional brain mapping. The series consisted of 21 men and 10 women with ages at seizure onset ranging from 1 to 26 years(mean 11.1year). The duration of the epilepsy prior to surgery ranged from 3 to 30 years(mean 14.3). The CD was verified in 17(11.1%) of 153 cases with temporal lobe epilepsy and 8(16.6%) of 48 cases with extratemporal epilepsy, mainly peri-Rolandic area. The lesion location of CD with DNT were temporal(4 cases) and extratemporal(2 cases). The histology of the surgical specimens showed cortical dyslamination in 26 patients, additional dysplastic neurons in 2 patients, and additional balloon cells in 3 patients. Excellent and good clinical results were achieved in 29 cases. CD should be suspected when intractable partial epilepsy occur in children. Careful investigation of neuroimaging techniques with high resolution MRI and sophisticated presurgical and intraoperative tailoring is essential for better outcome with identification of CD.