Prevalence, classification, and severity of epilepsy and epileptic syndromes in children.

PURPOSE

To determine the point prevalence of active childhood epilepsy in a defined area and evaluate the usefulness of ILAE classification of seizures, and epilepsies/syndromes with special interest in severe epilepsies.

METHODS

By using the latest ILAE International Classification of Epileptic Seizures (ICES, 1981) and Epilepsies and Epileptic Syndromes (ICE, 1989), we determined the age- and sex-specific prevalence rates of epilepsy, type of seizures, epilepsies, and recognizable epileptic syndromes, as well as the proportion of severe cases in each seizure/epilepsy/syndrome category in all children 0-15 years of age from a geographically defined area in Finland. All medical records, neurophysiological recordings and available clinical data were reviewed retrospectively.

RESULTS

Point prevalence of active epilepsy on December 12, 1992 was 3.94 per 1,000. According to ICES/ICE, we were able to classify 96% of seizures and 90% of epilepsies and syndromes. Generalized seizure and epilepsy/syndrome types were more prevalent in children 0-6 years of age and partial/localization-related in children 6-15 years of age. Epilepsy was intractable in 17% of all cases and correlated significantly with symptomatic etiology and early onset of epilepsy, as well as with additional neuroimpairments.

CONCLUSIONS

A considerable number of cases fell into the nonspecific categories of ICE, which limits the value of present epilepsy/syndrome classification in terms of prognosis, prediction, and indication for special investigations in individual cases. A number of intractable cases was relatively low, indicating good prognosis in many childhood epilepsies, especially when additional neuroimpairments are absent.