Lacosamide Was Effective for Epilepsy in Two Infants with KCNQ2-related Developmental and Epileptic Encephalopathy

Abstract

We report two cases harboring a KCNQ2 variant and having developmental and epileptic encephalopathy (DEE) in whom lacosamide (LCM) was effective in treating their epilepsy. Case 1: A 5-year-old boy presented focal onset hypoventilation and tonic seizure after birth. Interictal electroencephalogram showed suppression-burst patterns. At 3 years and 10 months of age, he presented unknown onset tonic followed by atonic seizures. LCM was effective for seizures. Case 2: A 5-year-old boy presented hyperexcitability and focal onset tonic seizure after birth. At 3 years and 2 months of age, he presented focal onset right versive followed by bilateral tonic clonic seizures. LCM was effective for seizures. Severe intellectual disability, spastic quadriplegia, and DEE were demonstrated in both patients. Genetic testing revealed a missense variant in KCNQ2 in both patients. Sodium channel blockers have been reported to be effective in managing seizures in patients with KCNQ2 variants. Our experiences suggest that LCM is effective for epilepsy management in DEE with KCNQ2 variants.