Abstracts

RATIONALE: Zonisamide is a novel antiepileptic drug (AED) approved in the past year as adjunctive therapy for partial seizures with or without secondary generalization. The purpose of this study was to review our clinical experience with zonisamide in a variety of epilepsy syndromes.
METHODS: A retrospective review of medical charts from the Epilepsy Management Program at Stony Brook University Hospital identified 12 patients treated with zonisamide from June 2000 until April 2001. Ages ranged between 2 and 39 years. The patients were followed with regard to efficacy ([gt]50% seizure reduction) and adverse events.
RESULTS: We identified six children ([lt]16 years old) and six adults in whom zonisamide was administered as adjunctive therapy for various intractable epilepsy syndromes including partial epilepsies, Lennox-Gastaut syndrome and other generalized epilepsies. Patients were taking 1-3 other AED[ssquote]s and six had vagal nerve stimulators implanted at the time zonisamide was added. In the pediatric group, efficacy was seen in 1/2 with partial seizures with or without generalization, 2/4 with primary generalized epilepsy including one patient in whom zonisamide was used as monotherapy after the failure of valproic acid and ethosuximide. In adults, efficacy was reported in 2/5 with partial seizures and 0/1 with primary generalized epilepsy. Overall, the efficacy was 2/6 (33.3%) in adults, 3/6 (50%) in children and 5/12 (41.6%) in all patients. Two patients were seizure free for the duration of the study. Zonisamide was discontinued in nine patients (75%), three due to lack of efficacy, three due to side effects (1 lethargy, 1 weight loss, 1 rash), one increase in seizure frequency and two of the responding patients that had to stop zonisamide after 5-6 months due to late onset side effects (1 rash, 1 incontinence).
CONCLUSIONS: Zonisamide appears to have broad-spectrum efficacy for both partial and generalized epilepsies. The indicated use is as adjunctive therapy for intractable seizures but further studies should evaluate its role as monotherapy given that we have one patient with primary generalized epilepsy who did well on monotherapy. Due to small sample size, it is difficult to judge our results and a larger study is in progress.