Valproate and lamotrigine combination therapy in children with drug-resistant focal epilepsy: an observational analysis focusing on neuroimaging abnormalities

This study aimed to investigate the efficacy of valproate and lamotrigine (VPA-LTG) combination therapy in pediatric patients with drug-resistant focal epilepsy (DRFE), focusing on the presence of neuroimaging abnormalities. Pediatric patients with epilepsy who visited the University of Tsukuba Hospital and Ibaraki Children's Hospital between October 2021 and September 2024 were included in this retrospective chart review. Patients with DRFE who received VPA-LTG combination therapy were enrolled. Data from 21 patients, including 16 males and 5 females, in the age range of 1.8-13.9 years were examined. The median numbers of previously failed anti-seizure medications (ASMs) and concurrent ASMs were 4 (range: 2-7) and 3 (range: 2-5), respectively. The overall responder rate (defined as the percentage of patients achieving ≥50 % seizure reduction over the last 12 months) was 38 %. The responder rate in patients without MRI abnormalities (67 %) was significantly higher than that in patients with MRI abnormalities (16 %). Patients with MRI abnormalities had more structural etiologies (42 %), whereas those without MRI abnormalities had more unknown etiologies (89 %). Our findings suggest that VPA-LTG combination therapy is a promising option for pediatric patients with DRFE without neuroimaging abnormalities.