Nonsymptomatic Generalized Epilepsy in Children Younger than Six Years: Excellent Prognosis, but Classification Should Be Reconsidered after Follow‐up: The Dutch Study of Epilepsy in Childhood

Abstract

Summary:Purpose: To assess the prognosis and the accuracy of the epilepsy classification in young children with nonsymptomatic generalized epilepsy.Methods: Of the cohort of the Dutch Study of Epilepsy in Childhood (n ‫ס‬ 466), all children younger than 6 years with a diagnosis of idiopathic (IGE) or cryptogenic (CGE) generalized epilepsy either at intake (n ‫ס‬ 108) and/or after 2 years of follow-up (n ‫ס‬ 102) were included. The number of reclassifications after 2 years was determined, and the reasons for reclassification were analyzed. All children receiving a diagnosis of IGE or CGE at 2 years were followed up for 5 years to study their outcome in terms of terminal remission (TR). Data on their level of intellectual functioning were collected at the start of this analysis.Results: The epilepsy syndrome was reclassified in 17 children. In 14 of them, the seizure type also was reclassified, and in three, the course of the epilepsy determined the new epilepsy type. Two other children had a reclassification of their seizure types without a change of the epilepsy type. Many children were categorized as having IGE not otherwise specified. In all probability, this is a heterogeneous group, containing patients with various epilepsy syndromes, with generalized tonic-clonic seizures as a common hallmark. Of the 102 children with IGE or CGE at 2 years of follow-up, 75% had a TR of >6 months after 2 years, and 85% a TR of Ն1 year after 5 years.Conclusions: In a fair proportion of children with nonsymptomatic generalized epilepsy in this age group, it is not possible to classify firmly the epilepsy and/or the seizures immediately after the intake. Instead, they are reclassified during the course of the disease. This and the apparent heterogeneity of the category IGE not otherwise specified point to inherent drawbacks of the current International League Against Epilepsy (ILAE) classification of epilepsy and epileptic syndromes. The prognosis of IGE at this young age is generally excellent.

A ten-year follow-up cohort study of childhood epilepsy: Changes in epilepsy diagnosis with age

“…The reasons for these changes include: (1) the recognition of new epileptic syndrome such as PS; (2) age-dependent evolution of epileptic syndromes; (3) detection of underlying pathology particularly malformation of cortical development by advances of neuroimaging techniques; and (4) identification of genetic abnormalities associated with epilepsy. In previous studies, epilepsy classification was changed in 7-33% of patients during follow-up [14,15,[18][19][20][21]. Therefore, changes in the epilepsy classification are common, and could be determined by careful observation over a long period in the present study.…”

“…Our objective was to clarify the long-term clinical course of childhood epilepsy during a period of 10 years, using data that followed an epidemiological study in the restricted area of Okayama Prefecture, Japan [7]. The investigation into changes in the epilepsy diagnosis and classification in the present study, from an epidemiological point of view, is important because other studies on changes in the epilepsy classification were largely limited to certain epilepsy syndromes such as West syndrome and IGE [18][19][20][21]. There are still few comprehensive long-term epidemiological studies on such changes [14,15].…”

Specific Epileptic Syndromes Are Rare Even in Tertiary Epilepsy Centers: A Patient‐oriented Approach to Epilepsy Classification

“…Similar findings were reported by other studies in general pediatric neurology settings (21–23). In a pediatric cohort consisting only of patients with idiopathic generalized epilepsy, 76% of the 111 patients were classified as “idiopathic generalized epilepsy, not otherwise specified” even after 2 years of follow‐up (24). The authors suggested that most likely idiopathic generalized epilepsies form a continuum, and that the currently defined syndromes essentially delineate artificial borders.…”

Childhood Epilepsy: What Is the Evidence for What We Think and What We Do?

“…Dutch investigators recently described the follow-up of 108 children who had initially presented at < 6 years of age with idiopathic or cryptogenic generalized epilepsy (Middeldorp 2002 Class 1). 22 They noted that the syndrome classification changed in 17 of 108 children (16%) with 2 to 5 a. Prospective study of a well-defined cohort, which includes a description of the nature of the population, the inclusion/exclusion criteria, and demographic characteristics such as age and sex, and seizure type.…”