PREVALENCE AND DESCRIPTIVE EPIDEMIOLOGY OF LENNOX-GASTAUT SYNDROME AMONG ATLANTA CHILDREN

Purpose: To determine the prevalence and descriptive epidemiology of L ennox-Gastaut Syndrome (LGS) among metropolitan Atlanta children. Meth ods: We conducted a population-based study of LGS as part of the Metro politan Atlanta Developmental Disabilities Study (MADDS) using a multi ple-source surveillance system for epilepsy and developmental disabili ties. Children were defined as having LGS if they had onset of multipl e seizure types before age 11 years, with at least one seizure type re sulting in falls, and an EEG demonstrating slow spike-wave complexes ( <2.5 Hz). Mental retardation (MR) was not used as a diagnostic criteri on. Results: The lifetime prevalence of LGS at age 10 years was 0.26/1 ,000. Ninety-one percent of those with LGS had MR (IQ less than or equ al to 70), and 39% had a history of infantile spasms (IS). A compariso n of children with LGS and those with multiple seizure types without s low spike-wave complexes demonstrated that those with LGS were more li kely to have MR, history of IS, and multiple disabilities (MR, cerebra l palsy, blindness, hearing impairment). Seventeen percent of all chil dren in Atlanta with profound MR (IQ < 20) had LGS. Conclusions: LGS a ccounts for only 4% of all childhood epilepsy, yet is a significant co ntributor to childhood morbidity.