Abstracts

Children and adolescent usually present with intractable catastrophic epileptic syndromes, with progressive neurological deficits and cognitive impairment. Hemispheric brain lesions are common causes in this group and includes Malformations of Cortical Development (MCD), tumors, hypoxic-ischemic lesions, Rasmussen and Sturge-Weber syndromes. Patients may exhibit early seizure onset and multiple seizure types. Daily seizures are often present and EEG findings are usually diffuse, involving even contralateral hemisphere. Hemispheric surgery is indicated for patients with unilateral intractable epilepsy when epileptic seizures originate in the abnormal hemisphere, with no evidence of contralateral lesions or contralateral seizure onset. Surgical approaches have been progressively improved to minimize postoperative complications and similar seizure outcome. Thirty patients with medically intractable epilepsy were operated upon between January 1996 and August 2003. The following variables were analyzed: age at epilepsy onset, history of an initial precipitating injury, etiology, seizure semiology, interictal and ictal EEG findings, age at surgery, surgical complications and post-surgical seizure outcome. There were 70% males. Focal motor and tonic seizures respectively occurred in 33% of patients. Almost all patients had abnormal neurological examination. The most common etiology was Rasmussen Encephalitis (33%), porencephalic lesions (26.6%) and MDC (18.6%). EEG showed interictal and ictal unilateral abnormalities in 60% and 42% of patients. Postoperative seizure outcome was Engel classes I and II for 60% of patients. In general, 74% of patients exhibited at least a 90% reduction in seizure frequency. All patients had acute worsening of hemiparesis after surgery. In our series, good surgical outcome described in the literature in 54 to 69%. In our report, the seizure free outcome was of 60% for MDC. Patients with progressive acquired lesions (Rasmussen and Sturge-Weber Syndromes) had a worst outcome, with only 27% of seizure free, while 75% of patients with non-progressive, porencephalic lesions were seizure free. Although patients with Rasmussen syndrome had a worst seizure outcome (only 22.2% of patients became seizure free), patients with Engel III class presented with only non disabling minor facial jerks seizures. In conclusion, seizure outcome in patients with hemispheric brain lesions give rises to good surgical outcome and an improvement of neurological development, even in patients witch persisted with mild frequent seizures. (Supported by FAEPA.)