Abstracts

Extra-temporal nonlesional intractable focal epilepsy in children is difficult to treat and has a poor prognosis without intervention. During the past 3 [frac34] years, we have pursued an aggressive surgical approach at our institution to localize and resect the seizure focus for these children. All patients underwent an extensive pre-surgical evaluation including video-EEG, standard or high resolution MRI, PET and/or SISCOM, and neuropsychological testing. Eighteen consecutive children with extra-temporal nonlesional seizure foci underwent surgery. The mean age at the initial surgery was 9.4 yrs (3-15 yrs). The etiology of the epilepsy was prenatal stroke (2), congenital hydrocephalus (1), encephalitis (2), childhood stroke (1), intrathecal chemotherapy and radiation (1), and unknown (11). No child had a tumor or vascular malformation.
Resections were performed in the frontal lobe in 11, parietal lobe in 4, frontal and parietal lobes in 2, and parietal and occipital lobes in one child. Three of these 18 children had repeated invasive monitoring when seizures recurred. One had 2 further resections along with VNS placement and became seizure-free after the last surgery with subsequent placement on the Adkins diet. Two patients had previously undergone a temporal lobectomy, one of whom was seizure-free for 16 months. Three children with foci in the motor strip had transient weakness after resection, and one had permanent worsening of her baseline hemiparesis secondary to cerebral edema.
Pathology showed focal cortical dysplasia in 6 and gliosis in 12. Mean follow-up was 25.6 months (2-45 months). Six children (33%) became seizure-free (Engel I), 2 had auras (Engel II), and 7 had at least an 80% reduction in seizure frequency (Engel III). Two of those with a marked reduction were in status epileptics preoperatively. Only 3 children (18%) had no significant improvement (Engel IV). Six children also had VNS placement, with only two experiencing partial improvement. The majority (14/18) experienced a marked improvement in ability to perform schoolwork associated with improved seizure control and medication reduction. Two previously nonverbal children developed over 50 word vocabularies and had communicative intent with seizure control. We conclude that advanced neuroimaging techniques and an aggressive surgical approach can identify patients who were previously not considered good surgical candidates. While not without risks, this strategy provides children with nonlesional extra-temporal intractable epilepsy a hope for a much improved quality of life.