Abstracts

In the United States, all newer antiepilepsy drugs have initially received approval only in the treatment of focal onset seizures. This is also true of zonisamide, which does not have approval for generalized seizures. We present our data on use of zonisamide in patients with generalized seizures. Patients at Penn State, Milton S. Hershey Medical Center were evaluated for seizure type. Those with any form of generalized seizures were offered treatment with zonisamide (ZNS), either for continued seizures, or if patients had significant side effects from their current therapy. Forty-two patiets were identified. Nine patients had a diagnosis of juvenile myoclonic epilepsy (JME), 7 had Lennox-Gastaut Syndrome (LGS), 2 had only absence seizures, 1 had atypical absences, 3 had purely myoclonic seizures, 10 had only tonic-clonic seizures, and 10 had mixed seizure types but did not fit a particular syndrome. Patients were seen for an initial visit, then again at 3 months and 6 months. Patients were required to keep an accurate document of seizures and side-effects. One patient was lost to follow-up. The remaining 41 were available for follow-up at 3 months and 6 months. Eleven patients were already seizure-free (SF), but seeked change due to side-effects. The remaining 31 patients still had ongoing seizures. Four patients received ZNS as their initial antiepilepsy drug (AED). Of the remaining 38 patients, 18 patients had a previous AED replaced by ZNS and 20 had ZNS added to their existing regimen. Overall, 19 patient received ZNS as monotherapy. At the time of the 6 month follow-up, 22 patients were free of all seizure types. Thirteen were on monotherapy with ZNS. Of the 22 patients, 8 had previosly been SF on prior therapy, but had significant side-effects. Two additional patients had a 75% decrease in seizures, 2 had a 50% decrease in seizures, and 7 had no change in seizure control. No patients in these 3 groups were previously seizure-free. Eight patients discontinued ZNS therapy due to adverse events. Three patient that discontinued were previously SF but complained of side-effects with prior therapies. Following conversion to ZNS they remained seizure-free but continued to complain of side-effects. One patient received ZNS as initial therapy and became seizure-free, but discontinued due to adverse events. The remaining 4 had ZNS added to their current therapy but discontinued due to side-effects. No patients that were previously SF with therapy had a recurrence of seizures following conversion to ZNS therapy. Zonisamide proved to be an effective AED in patients with generalized seizures. At 6 months follow-up, 22 patients were seizure-free, 2 had a 75% decrease in seizures, 2 had a 50% decrease in seizures, 7 had no change in seizures, and 8 discontinued therapy. No patients had a worsening of seizures.