Evolution of Infantile Spasms to Lennox-Gastaut Syndrome: What Is There to Know?

Thirty-six percent of children with infantile spasms met criteria for Lennox-Gastaut syndrome. Risk factors for development of Lennox-Gastaut syndrome were developmental delay and seizures prior to the onset of infantile spasms and poor response to first treatment for infantile spasms. Children with an unknown etiology of infantile spasms were less likely to develop Lennox-Gastaut syndrome. Eighty percent of the children who met our criteria were not given a documented diagnosis of Lennox-Gastaut syndrome, which highlights the fact that many children may not be receiving a diagnosis of Lennox-Gastaut syndrome. We recommend establishing clear guidelines for the diagnosis of Lennox-Gastaut syndrome to ensure that the diagnosis is being made accurately.