The Efficacy of Lacosamide in Children with Drug-Resistant Epilepsy: Three Cases in Pediatric Patients

Lacosamide is a relatively new anti-seizure medication (ASM) that is classified as a sodium channel blocker (SCB). Unlike conventional SCBs, such as carbamazepine, phenytoin, and oxcarbazepine, lacosamide stabilizes hyperexcitable neuronal membranes by selectively enhancing the slow inactivation of voltage-gated sodium channels [1-3]. In addition, it exhibits relatively little interaction with other ASMs and has high utility because it has both oral and intravenous (IV) formulations. In recent years, IV lacosamide has increasingly been recognized as a useful treatment for status epilepticus [4,5]. Lacosamide has shown efficacy and safety not only in adults, but also in children [2]. As such, lacosamide has been approved for use as monotherapy and adjunctive therapy for the treatment of focal-onset seizures in adults, adolescents, and children aged ≥ 4 years with epilepsy in the European Union and the United States [3,6-8]. However, further research on the efficacy and safety of lacosamide in children is still needed. In particular, in South Korea, lacosamide has not yet been approved for use in patients with epilepsy among children under 16 years of age. Here, we report three cases of pediatric intractable focal epilepsy that were effectively treated with lacosamide add-on therapy. This study was approved by the Institutional Review Board of the Gangnam Severance Hospital, Yonsei University College of Medicine for the study of ASMs, including lacosamide, in refractory childhood epilepsy (3-2022-0135). The review board waived the need for informed consent for this retrospective study. Case 1: A 10-year-old girl with normal development without a specific birth history had intractable focal seizures at 24 months of age. After the seizures, she began experiencing cognitive decline. She took several ASMs, but they had no significant effect on seizure control, and her condition progressed to intractable epilepsy. In the pre-surgical evaluation, brain magnetic resonance imaging (MRI) was normal; however, focality was found in the right frontal area on fluorodeoxyglucose-positron emission tomography (PET) and electroencephalography (EEG) (Fig. 1A). Hence, she qualified for epilepsy surgery on her right frontal lobe. Her full-scale intelligence quotient (FSIQ) at that time was 69 and she weighed 31 kg. While awaiting epilepsy surgery, she was administered lacosamide as an add-on therapy. She became seizure-free after the titration of lacosamide up to 200 mg/day. Her seizures stopped for more than a year after the treatment, with no