Surgical Treatment of Seizures in Malformations of Cortical Development (MCD)

Kang, Kwan Soo; Hong, Seung Chyul; Seo, Dae Won; Hong, Seung Bong; Lee, Moon Hyang; Kim, Jong Hyun

Abstract

OBJECT: Surgical treatment of cortical dysplasias (CDs) presenting with intractable seizures is challenging, because isualization/localization of the lesion is difficult, correlation with seizure foci needs comprehensive investigations, and the reported surgical results are not satisfactory. We report our result of surgical treatment of CD classified from the surgical point of view.
METHODS
Definition of CD was a visible dysplastic lesion on MRI or MRI-negative (normal MRI) case with pathological diagnosis of moderate to severe dysplasia. During the last 4.5 years, we had operated on 36 cases of intractable epilepsy with CDs. We divided the 36 cases into 4 groups ; Group A : diffuse bilateral hemispheric dysplasia, Group B : diffuse lobar dysplasia, Group C : focal dysplasia, and Group D : moderate to severe degree of cortical dysplasia with normal MRI. All but one patient in Group C were monitored at EMU using subdural electrodes for seizure localization and functional mapping.
RESULTS
The incidence of CD in the whole epilepsy surgery cases was 12.4%. Mean age was 21.3 years. Mean age at seizure onset was 8.5 years. Mean follow up period was 26.0 months. Twenty-six (72.2%) patients (20 and 6, respectively) belong to Engel Class I and II. There were 5, 9, 9, and 13 cases in Groups A, B, C, and D, respectively. Groups A and B had significantly lower age at seizure onset and significantly poorer surgical outcome compared to Groups C and D (p<0.05). If the outcome was compared on the extent of removal of CD, patients with completely removed CD had very significantly better outcome than those with partial removal (p<0.001).
CONCLUSIONS
We conclude that intractable epilepsy with CD can be treated surgically with comprehensive preoperative approaches. Deliberate resective procedures aiming at complete removal of dysplastic tissue ensure excellent seizure control without permanent neurological deficit.