The epidemiology of the epilepsies in children

Abstract

The epilepsies are a heterogeneous collection of neurological conditions and syndromes characterized by recurrent, unprovoked, paroxysmal seizure activity. There are several types of epileptic seizures and syndromes that are unique to children, including infantile spasms, Lennox-Gastaut syndrome and absence seizures. Febrile seizures and neonatal seizures, while not epilepsy, are relatively common types of seizures in infants and children and are likely markers of risk of later epilepsy. Thus, it is important to consider the epidemiological features of the epilepsies as they occur specifically in infants and children. The purpose of this review is to summarize what is currently known about the epidemiology of the childhood epilepsies and to identify promising areas for further population-based studies. The epilepsies are an important cause of neurological morbidity in children. The average annual rate of new cases (incidence) of epilepsy is approximately 5-7 cases per 10,000 children from birth to age 15 years, and in any given year, about 5 of every 1,000 children will have epilepsy. There is evidence that the incidence of the epilepsies in some populations of children may be decreasing over time, and this possibility merits further investigation. Factors that are known to increase risk of the epilepsies in children include congenital malformations of the central nervous system (CNS), moderate or severe head trauma, CNS infections, certain inherited metabolic conditions, and genetic factors. However, these account for only 25% to 45% of cases, and thus, the etiology of most cases of the epilepsies remains obscure. The paucity of well-controlled etiological studies is due largely to formidable methodological problems in conducting epidemiological studies of the epilepsies. The prognosis for seizure control is generally good, although children with remote symptomatic seizures and those with additional neurological disabilities do less well.