Surgical outcome of epilepsy patients evaluated with a noninvasive protocol

Abstract

Surgery is now an accepted treatment for some medically intractable epilepsies. Presurgical evaluation is particularly important for the localization of the epileptogenic zone, which may necessitate sophisticated imaging techniques and intracranial electroencephalogram (EEG) recordings. If patients are carefully selected, however, successful results can be achieved with noninvasive evaluation methods. Seventy-seven patients were operated on for intractable seizures. All patients underwent EEG, neuropsychological, psychiatric, and magnetic resonance imaging investigations. Ictal EEG-video recording was performed in all nonlesional and in some lesional cases that had discordant data. Selective amygdalo-hippocampectomy was performed on patients with mesial temporal lobe epilepsy (MTLE), an extended or a limited lesionectomy was performed on patients with structural lesions, and a lesionectomy with deafferentation was performed on two patients with West syndrome. Electrocorticography was not used. Temporal lobe directed surgery was performed in 63.6% of the cases. The pathological examinations of all cases showed hippocampal sclerosis (HS) in 43%, tumor or tumor-like lesions in 36%, and cortical dysplasia in 5% of patients. After a mean follow-up of 17 months (range, 2-53), 75% of the patients were seizure-free with or without aura and 15% had a marked improvement, whereas 10% did not benefit from surgery. Neuropsychological outcome of patients with MTLE and I-IS also showed worthwhile results. Our patients, who were evaluated without pre- and perioperative intracranial recordings and other sophisticated techniques, had an outcome comparable to those in other series from more experienced centers. Our experience indicates that successful results, especially for patients with MTLE-HS and lesion-related epilepsies, can be obtained at centers with limited resources if the diagnoses and evaluation procedures are performed carefully.