Abstracts

Rationale: Zonisamide (ZNS) was proven to be an effective, and well-tolerated antiepileptic drug with a broad therapeutic spectrum. However, there are a few studies evaluating the cognitive and mood effects of ZNS. This study was done to evaluate the long-term effects of ZNS monotherapy on cognition and mood of epilepsy patients. Methods: Forty-three epilepsy patients received ZNS, with target doses of 100, 200, and 300 mg/day. Cognitive and mood tests were performed twice, at baseline and 1 year after starting medication.Results: Nine patients were withdrawn prior to their performance of follow-up tests. Three patients (33%) dropped out during titration period due to cognitive and mood problems. Thirty-four patients completed the follow-up neuropsychological tests. After I year of treatment, 16 patients (47%) complained of cognitive deficits. Only 5 patients (15%) experienced mood changes. Although ZNS decreased seizure frequency and EEG abnormalities and did not elicit significant mood changes, it had negative effects on several cognitive tests. Some of cognitive effects were dose-related.Conclusions: ZNS has harmful effects on cognition even after I year of treatment.