Neurologic sequelae of experimental febrile convulsions

A study was designed to investigate the effects of experimentally produced hyperthermic seizures on the brain of the developing rat. Severty-nine newborn Sprague-Dawley white rats were divided into five groups and exposed to one of the following: Nonseizure-producing hyperthermia at 5 or 15 days (febrile controls), seizure-producing hyperthermia at 5 or 15 days, or no hyperthermia (afebrile controls). As the animals matured, seven developmental reflexes were tested and there were no differences found among the five groups in the ages at which these reflexes were acquired. At age 3 1/2 months, the ability of rats to adapt to a maze, and later to solve 12 maze problems, was studied. Although there was no significant difference in the amount of time required for any of the groups to adapt to the maze, there was a significant difference in the number of maze errors made by the different groups of rats. The mean error score for the control group was 118.5, compared with 183.0 (p less than 0.001), for rats with seizures at 5 days and 161.4 (p less than 0.001), for rats which convulsed at 15 days. It is apparent that experimental induction of a single hyperthermic seizure in the young rat interferes significantly with the animal's maze-solving ability at a later age.