Abstracts

Rationale: Seizures are commonly seen during treatment of acute lymphocytic leukemia (ALL). However, epilepsy may also result months to years after ALL therapy. Causative factors may include delayed response to intrathecal methotrexate and/or brain irradiation. To date, little has been published on the management of delayed seizures that result following completion of ALL treatment. We present two cases of intractable epilepsy that presented several years following treatment of ALL. Methods: Two cases of intractable epilepsy following treatment of ALL were identified via retrospective chart review Results: Patient 1: 21 month old male infant was diagnosed with ALL. Initial treatment included intravenous chemotherapy with vincristine, L-asparginase, prednisone, 6-mercaptopurine and methotrexate as well as cranial irradiation (14 Gy). At five years of age the patient received a successful bone marrow transplant and intrathecal methotrexate due to recurrent disease. At age 10, he presented to the pediatric neurology clinic due to daily periods of staring and confusion. EEG at that time was abnormal and showed frequent bursts of irregular generalized high amplitude spike and polyspike and slow wave discharges. Trials of phenobarbitol, topiramate, levetiracetam and valproate were ineffective in relieving seizures. The patient became seizure free two weeks after starting felbamate. He continues felbamate monotherapy (30mg/kg/day) and remains seizure free. Subsequent EEG’s have normalized. No drug side effects were noted. Patient 2: 3.5 year old boy diagnosed with ALL. He achieved remission following systemic chemotherapy with cytosine arabinoside as well as intrathecal methotrexate. The patient was diagnosed with epilepsy at age six with daily symptoms of staring, behavioral arrest and decreased responsiveness. Later, he developed both atonic and tonic seizures. His EEG showed multifocal independent spikes and polyspike and slow wave discharges as well as frequent generalized irregular bursts of polyspike, spike and slow wave discharges (2.5-3Hz). The patient was unsuccessfully treated with valproate, ethosuximide, ketogenic diet, topiramate, multiple homeopathic medications as well as a vagus nerve stimulator. Valproate therapy was complicated by thrombocytopenia. At age 15 the patient underwent a bone marrow harvest and was subsequently started on felbamate (42mg/kg/day). Within three months he became seizure free. Subsequent EEGs have been normal. He remains on felbamate monotherapy. The patient did not display any drug side effects and did not require an autologous bone marrow transplant. Conclusions: Intractable epilepsy may occur months to years following treatment of ALL. We present two cases of refractory epilepsy occurring several years after ALL remission. Both patients were successfully managed without side effects with felbamate monotherapy. Felbamate may be considered for the management of epilepsy in similar cases.