NCMP-31. High seizure burden in oligodendroglioma patients: overview and suggestions for more aggressive treatment

INTRODUCTION It is well known that seizures are a common comorbidity of brain tumors, particularly oligodendrogliomas. Resection, radiation, or chemotherapy may decrease seizure burden, but a significant proportion of patients continue to suffer from epilepsy. METHODS We reviewed the charts of 37 patients with oligodendroglioma who were treated at our institution, 32 of whom had seizures. RESULTS 24 patients (75% of seizure patients) continued to have seizures after resection. As in other studies, gross total resection significantly reduced the incidence of post-resection seizures (43% vs 79% with subtotal resection). 10 patients (31% of seizure patients) went through three or more seizure medications because of side effects, breakthrough seizures, or issues with compliance. These patients reported decreased quality of life, increased hospital admissions, and significant anxiety regarding seizures at the end of life. Multiple patients were admitted with status epilepticus, and one patient was left comatose after one such episode. Of the 10 patients who tried more than two seizure medications, 7 were seen by an epileptologist. DISCUSSION This population experiences both a high morbidity from epilepsy as well as a relatively long life expectancy, with a median of 10-12 years survival after diagnosis. Therefore, we suggest a more aggressive approach to seizure control, starting with a low threshold to refer to epilepsy specialists. Since the extent of resection is such a strong predictor of seizure freedom, we also advocate the use of stereotactic EEG, intraoperative monitoring, and fluorescent adjuncts whenever possible in order to maximize safe resection. Some studies have even suggested that supratotal resection may be of benefit, both to lengthen time to recurrence and to remove epileptogenic cortex that may be outside the T2-hyperintense borders of the lesion. Finally, in the event that epileptogenic foci cannot be resected, vagus nerve stimulation or responsive neurostimulation should be considered.