Clinical efficacy of zonisamide in Lennox–Gastaut syndrome: Korean multicentric experience

Purpose: To evaluate the efficacy and safety of zonisamide (ZNS) as long-term adjunctive therapy in children with Lennox–Gastaut syndrome (LGS). Method: We evaluated the seizure frequency, cognitive outcomes, and side effects of 62 LGS patients maintained on ZNS for at least 12 months in three tertiary centers. Results: Of the 62 LGS patients maintained on ZNS, 3 (4.8%) had 100% seizure control; 14 (22.6%) had >75% to <100% reduction in seizure frequency; 15 (24.2%) had >50% to <75% reduction in seizure frequency; 6 (9.7%) had >0% to <50% reduction in seizure frequency, and 24 (38.7%) had no seizure reduction. Seizure outcomes were not related to seizure types or etiologies. Adverse events included somnolence and anorexia, but all were transient and successfully managed by careful follow-up. Conclusion: Our results indicate that adjunctive treatment with ZNS is safe and effective in pediatric LGS patients.