Evolution and course of early life developmental encephalopathic epilepsies: Focus on Lennox‐Gastaut syndrome

Summary Objectives Developmental encephalopathic epilepsies (DEEs) are characterized by refractory seizures, disability, and early death. Opportunities to improve care and outcomes focus on West syndrome/infantile spasms (WS/IS). Lennox‐Gastaut syndrome (LGS) is almost as common but receives little attention. We examined initial presentations of DEEs and their evolution over time to identify risk and indicators of developing LGS. Methods Data are from the Connecticut Study of Epilepsy, a prospective, longitudinal study of 613 children with newly diagnosed epilepsy recruited in 1993‐1997. Central review of medical records permitted classification of epilepsy syndromes at diagnosis and at reclassification 2, 5, and 9 years later. DEEs were compared to other epilepsies for seizure and cognitive outcomes and mortality. Analyses examined the evolution of DEE syndromes after initial presentation, with specific comparisons made between WS/IS and LGS. Statistical analyses were performed with t tests and chi‐square tests. Results Fifty‐eight children (9.4%) had DEEs, median onset age = 1.1 years (interquartile range ([IQR] 0.3‐1.3) in DEEs and 6.0 years (IQR 3.0‐9.0) in other epilepsies (P