Context Concern has been raised about possible increases in the prevalence of autism. However, few population-based studies have been conducted in the United States.Objectives To determine the prevalence of autism among children in a major US metropolitan area and to describe characteristics of the study population. Design, Setting, and PopulationStudy of the prevalence of autism among children aged 3 to 10 years in the 5 counties of metropolitan Atlanta, Ga, in 1996. Cases were identified through screening and abstracting records at multiple medical and educational sources, with case status determined by expert review.Main Outcome Measures Autism prevalence by demographic factors, levels of cognitive functioning, previous autism diagnoses, special education eligibility categories, and sources of identification.Results A total of 987 children displayed behaviors consistent with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for autistic disorder, pervasive developmental disorder-not otherwise specified, or Asperger disorder. The prevalence for autism was 3.4 per 1000 (95% confidence interval [CI], 3.2-3.6) (malefemale ratio, 4:1). Overall, the prevalence was comparable for black and white children (black, 3.4 per 1000 [95% CI, 3.0-3.7] and white, 3.4 per 1000 [95% CI, 3.2-3.7]). Sixty-eight percent of children with IQ or developmental test results (N=880) had cognitive impairment. As severity of cognitive impairment increased from mild to profound, the male-female ratio decreased from 4.4 to 1.3. Forty percent of children with autism were identified only at educational sources. Schools were the most important source for information on black children, children of younger mothers, and children of mothers with less than 12 years of education. ConclusionThe rate of autism found in this study was higher than the rates from studies conducted in the United States during the 1980s and early 1990s, but it was consistent with those of more recent studies.

Summary: Purpose:To determine the population-based epidemiology of infantile spasms (IS) among Atlanta children.Methods: By using data from a cross-sectional, populationbased surveillance system that included 21 EEG laboratories, we identified children born in 1975-1977 in metropolitan Atlanta with IS.

Summary:Purpose: To determine the prevalence and descriptive epidemiology of Lennox-Gastaut Syndrome (LGS) among metropolitan Atlanta children.Methods: We conducted a population-based study of LGS as part of the Metropolitan Atlanta Developmental Disabilities Study (MADDS) using a multiple-source surveillance system for epilepsy and developmental disabilities. Children were defined as having LGS if they had onset of multiple seizure types before age 11 years, with at least one seizure type resulting in falls, and an EEG demonstrating slow spike-wave complexes (<2.5 Hz). Mental retardation (MR) was not used as a diagnostic criterion.Results: The lifetime prevalence of LGS at age 10 years was LGS accounts for only 4% of all childhood epilepsy, yet is a significant contributor to childhood morbidity.