CHILDHOOD GANGLIOGLIOMA AND MEDICALLY INTRACTABLE EPILEPSY - A CLINICOPATHOLOGICAL STUDY OF 15 PATIENTS AND A REVIEW OF THE LITERATURE

Gangliogliomas are an increasingly recognized cause of epilepsy in chi ldren. Several studies have shown that early surgical treatment is ben eficial, but controversy exists regarding the type of surgical treatme nt required for optimal seizure control and to prevent tumor recurrenc e. To address this issue, we performed a retrospective review of 15 ch ildren operated on at the Cleveland Clinic during a 7-year period with medically intractable epilepsy who were found to harbor a ganglioglio ma during the course of their work-up. Nine patients with mostly nondo minant hemisphere tumors underwent tumor resection without the use of electrocorticography to guide additional resection of epileptogenic fo ci, while 6 other patients with dominant hemisphere tumors had subdura l electrode grids placed to extraoperatively map zones of ictal onset and eloquent areas. The extent of tumor resection was then correlated to seizure outcome and tumor recurrence. Of the 11 patients who receiv ed a gross total resection, 9 are seizure-free while 2 have a greater than 90% reduction in their seizure frequency (100% 'good' outcome). T here was no tumor recurrence in this group. Of the 4 patients who unde rwent a subtotal tumor resection, 1 is seizure-free while 3 have persi stent seizures (25% 'good' outcome). Ah patients in this group have st able disease on follow-up magnetic resonance imaging. In those patient s who received subdural electrode grids, the extent of resection of th e zones of ictal onset did not correlate with seizure outcome. The mea n follow-up was 42 months. We conclude that complete tumor resection i s the most important factor for optimal seizure control and to prevent tumor recurrence.