Surgery of epilepsy associated with focal lesions in childhood

Object. Surgery in children with epilepsy is a new, evolving field. The imp ortant practical issues have been to define strategies for choosing the mos t suitable candidates and the type and optimal timing of epilepsy surgery. This study was undertaken to elucidate these points. Methods. To identify the factors that correlated with outcome, the authors analyzed a series of 200 children (aged 1-15 years (mean 8.7 years) who und erwent, surgery between 1981 and 1996 at the Hopital Necker-Enfants Malades . In 171 cases (85.5%) the epilepsy was medically refractory and was associ ated with focal cortical lesions. Surgery consisted of resection of the les ion without specifically attempting to identify and remove the "epileptogen ic area." In the group of children whose seizures were medically refractory, the mean follow-up period was 5.8 years. According to Engel's classification, 71.3% of these children became seizure free (Class Ia,) whereas 82% were in Clas s I. A multivariate statistical analysis revealed that among all the factor s studied, the success of surgery in a patient in whom there was a good cli nical/electroencephalogram/imaging correlation depended on the patient's ha ving undergone a minimally traumatic operation, a complete resection of the lesion, and a short preoperative seizure duration. After the surgical control of epilepsy, behavior disorders were more improv ed (31% of all patients) than cognitive function (25%). The patient age at onset, duration and frequency of seizures, intractability of the disease to therapy, and seizure characteristics were correlated with cognitive, behav ioral, and academic performance pre- and postoperatively. Multivariate stat istical analysis revealed that cognitive dysfunction correlated highly with the duration of epilepsy prior to surgery, whereas behavioral disorders co rrelated more with seizure frequency. Conclusions. These data must be taken into account when selecting patients for surgical treatment and when deciding the timing of surgery. Early surgi cal intervention allows for optimum brain development.