Evolution of epilepsy in children with mental retardation: five-year experience in 78 cases.

Various aspects of epilepsy, including its evolution, were studied in 78 children with mental retardation in a prospective 5-year (1989-1994) follow-up study. Level of mental retardation was moderate or even more severe (IQ < 50) in 83% of children, and 56% suffered from significant cerebral palsy. Epilepsy remained uncontrolled in 28% of cases, 2-year remission was achieved by 26%, and mortality was 12% during the study period. Associated cerebral palsy was the most important single risk factor for severe epilepsy, and several handicaps seemed to have a strong multiplicative effect. Complexity of epilepsy in children with mental retardation was reflected by the evolutionary features described.