Surgical treatment of epilepsy in pediatric patients.

Surgery has become an accepted treatment modality for carefully selected adults with intractable focal epilepsy. More recently, increasing numbers of pediatric patients with intractable epilepsy are also being referred for surgical consideration. Key elements of surgical candidacy include medically intractable focal epilepsy, a localized epileptogenic zone, and a low risk for new postoperative neurologic deficits. The most common etiologies of the epilepsies in pediatric surgical candidates are malformation of cortical development and low grade tumor but some patients with childhood onset temporal lobe epilepsy due to hippocampal sclerosis also present for early surgery. Based on results from several recent pediatric surgical series, the chance for favorable seizure outcome after surgery is not adversely affected by young age, with seizure-free postoperative outcome reported for 60% to 65% of infants, 59% to 67% of children, and 69% of adolescents, compared to 64% reported in a large, predominantly adult series. Some subgroups of patients have higher percentages of seizure-free outcome, including those with hippocampal sclerosis or low grade tumor. In addition to seizures, developmental issues are also a major concern in children with intractable epilepsy. Few quantitative data are available, but some anecdotal experience suggests that surgical relief of catastrophic epilepsy may result in resumption of developmental progression after surgery, although the rate of development often remains abnormal. In one series, best developmental outcomes were seen in patients with earliest surgery and highest level of preoperative development. For each patient, the timing of surgery must be carefully considered, based on a full assessment of the relative risks and benefits, derived from a detailed presurgical evaluation.