Efficacy and tolerability of lacosamide in pediatric and young adult epilepsy patients with severe motor and intellectual disabilities

Objective: Epilepsy is common among patients with severe motor and intellectual disability (SMID) patients, often taking a prolonged and intractable course. Lacosamide (LCM) is widely used to treat epilepsy in both adults and children. We assess the efficacy and tolerability of LCM among pediatric and young adult epilepsy patients with SMID who suffer from intractable seizures. Methods: This retrospective analysis reviewed the medical records of SMID patients undergoing LCM treatment for more than a year. The study included 24 patients (14 males) aged 3–29 years. Epilepsy was classified as focal in 17 patients, generalized in 4 patients, and combined generalized and focal in 3 patients. Results: The retention rates were 70.8%, 65%, and 52.9% at 1 year, 2 years, and 3 years after LCM initiation, respectively. The 50% responder rate (achieving > 50% seizure reduction) for LCM treatment was 50%, with two patients experiencing complete seizure control (absence of seizures for 6 months before the follow-up visit). The 50% responders included a higher proportion of patients with focal epilepsy (58.8%) compared to those with generalized epilepsy (25.0%). Treatment-emergent adverse events (TEAEs) included somnolence in five patients and nausea in two patients. TEAEs, particularly nausea, developed within 1 month after treatment initiation in two patients, leading to LCM discontinuation. Conclusion: LCM demonstrated good efficacy for intractable epilepsy in pediatric and young adult SMID patients. It was generally well-tolerated, resulting in a favorable retention rate. LCM emerged as a useful ASM for epilepsy treatment in pediatric and young adult SMID patients.