Mental retardation subsequent to refractory partial seizures in infancy.

Whether seizures are the direct cause of cognitive deterioration in epileptic children is undetermined. This retrospective study aimed to delineate a subgroup of pediatric patients with cognitive deterioration and refractory seizures in the absence of recognized causes for mental retardation. Of the 80 children identified as having mental retardation and refractory seizure disorder, seven (8.7%) had normal cognitive development until at least 1 year of age. Their metabolic status was normal. Five of them suffered repeated frequent partial seizures with onset in the first year of life and two had repeated episodes of status epilepticus. All seven had similar characteristics of early onset partial seizures, six of them had partial seizures secondarily generalized and one had complex partial seizures. The time of peak cognitive deterioration correlated with increases in seizure frequency during that period. Evaluation revealed a well-defined epileptic focus in the absence of neuroimaging abnormality except for hippocampal atrophy in the two children with complex partial seizures and a small vascular malformation in one child. Uncontrolled partial seizures in the first months of life may result in cognitive deterioration. (C) 2000 Elsevier Science B.V. All rights reserved.