Cortical dysgenesis: Clinical Electrographic, Radiological and Bistopathological Findings

Abstract

Cortical dysgenesis is one of the major pathologies in children with intractable epilepsy. We studied clinical, radiological and pathological features of 10 children (4 female, 6 male, aged 3 to 16 years) of cortical dysgenesis operated for intractable seizures and/or tumour. The age onset of the seizures were 2 days to 13 years. They were partial in 8cases and generalised in 2 cases. We detected focal neurological signs in 3 cases. Five cases had mild or moderate developmental mental retardation and 1 case had severe developmental retardation. Magnetic resonance imaging (MRI) demonstrated thickened gyri and increased T2 signal intensity in 7 cases, hemimegalencephaly in 1 case andcortical tuber in 1 case. One case had 2 distinct lesions; left occipito-parietal polymicrogria and left periventricular hyperintensity. Preoperative electroencephalography findings in 8 cases correlated to MRI abnormalities. The interval between the onset of seizures and surgery was 0.9 to 12 years. Peroperative corticography was done in 7 cases. Histopathological findings were cortical dyslamination in all cases, giant dysplastic neurons in 5 cases, neuronal heterotopia in 4 cases and 'baloon ' cells in 2 cases. Additionally 6 cases had low grade tumours associated to cortical dysplasia.Follow-up period was 1.5-4 years. Seizure control was complete in 2 cases (Engel's outcome scale: Stage IA). The other 2 cases with dual pathology had partial seizure control (stage IIA and IVA). ln conclusion, resection of the area displaying epileptogenic activity in addition to macroscopic lesion could be suggested to obtain a total or almost total seizure control in intractable patients. At that point the perplexing question comes up whether there is a casual relationship between cortical dysplasia and tumourogenesis.