Abstracts

Early-infantile epileptic encephalopathy (EIEE, Ohtahara Syndrome) is an early and severe age dependent encephalopathy with protean manifestations that is characterized by tonic spasms and a suppression-burst EEG pattern. The long-term prognosis is unfavorable and affected patients experience intractable seizures, near continuous epileptic EEG abnormalities, mental retardation, and poor response to medical treatment. We report two cases of successful surgical treatment in children with malformations of cortical development who presented initially with EIEE. Magnetic resonance imaging revealed unilateral abnormalities including cortical thickening and hemimegalencephaly. At time of surgical evaluation (ages 16 months; 38 days) a focal epileptic pattern was recorded on EEG. Scalp recorded ictal video-EEG revealed seizure onset from the abnormal hemisphere and ictal SPECT demonstrated regional posterior hyperperfusion. Electrocorticography revealed near-continuous spike and slow wave discharges over the entire hemisphere. Functional hemispherectomies were performed in both cases without complication. Tissue histopathology revealed Taylor Type cortical dysplasia. At postoperative follow-ups of 2 and 5.5 years, both patients are seizure-free on monotherapy and exhibit significant improvement in development. These findings emphasize the benefit of early aggressive surgical treatment for children who present with EIEE due to a unilateral malformation of cortical development.