Two-year efficacy of lacosamide as adjunctive therapy for generalized tonic-clonic seizures in patients with juvenile myoclonic epilepsy

Abstract

Objective: To report the long-term efficacy of adjunctive lacosamide therapy in patients with juvenile myoclonic epilepsy whose generalized tonic-clonic seizures were significantly reduced by treatment.

Methods: A retrospective study was conducted in patients who visited the Department of Child Neurology, National Hospital Organization Nishiniigata Chuo Hospital and the Department of Pediatrics, National Hospital Organization Nagasaki Medical Center. Among patients who had been diagnosed with juvenile myoclonic epilepsy, those who received lacosamide as adjunctive therapy for refractory generalized tonic-clonic seizures for at least 2 years from January 2017 to December 2022, and who achieved seizure freedom or >50% seizure reduction in tonic-clonic seizures were included. The medical records and neurophysiological data of the patients were reviewed retrospectively.

Results: Four patients met the inclusion criteria. The mean age at the onset of epilepsy was 11.3 years (range 10-12), and the mean age of starting lacosamide was 17.5 years (range 16-21). All patients received two or more antiseizure medications prior to lacosamide. Three of four patients had seizure freedom for more than 2 years, and the one remaining patient had >50% seizure reduction for more than one year. Only one patient had recurrent myoclonic seizures after starting lacosamide. The mean lacosamide dose at the last visit was 425 mg/day (range 300-600).

Conclusion: Adjunctive lacosamide therapy might be a treatment option for juvenile myoclonic epilepsy with generalized tonic-clonic seizures, which are not responsive to standard antiseizure medications.

Keywords: Adjunctive therapy; Drug-resistant epilepsy; Generalized tonic-clonic seizure; Juvenile myoclonic epilepsy; Lacosamide.