International League Against Epilepsy classification and definition of epilepsy syndromes with onset in childhood: Position paper by the ILAE Task Force on Nosology and Definitions

Abstract

The goal of this paper is to describe epilepsy syndromes that begin in childhood (age 2-12 years). Additional syndromes that have a variable age at onset, including in childhood, are described in the paper on epilepsy syndromes with onset at a variable age. 1 The childhood onset syndromes can be broadly divided into three main groups: (1) self-limited focal epilepsies (SeLFEs); (2) generalized epilepsy syndromes, which are thought to have a genetic basis; and (3) developmental and/or epileptic encephalopathies (DEEs), which often have both focal and generalized seizures, including Lennox-Gastaut syndrome (LGS), developmental epileptic encephalopathy with spike-and-wave activation in sleep (DEE-SWAS), and epileptic encephalopathy with spike-and-wave activation in sleep (EE-SWAS), or may have generalized seizures alone, such as epilepsy with myoclonic atonic seizures (EMAtS), or focal/multifocal seizures alone, such as hemiconvulsion-hemiplegia-epilepsy syndrome (HHE) and febrile infection-related epilepsy syndrome (FIRES).Childhood is also the typical age of onset of childhood absence epilepsy (CAE); this syndrome is covered in a separate paper on the idiopathic generalized epilepsy (IGE) syndromes. 2

Diagnostic utility of specific abnormal EEG patterns in children for determining epilepsy phenotype and presence of structural brain abnormalities

“…Taken together, these findings suggest that while clinicians can reasonably reserve ordering a brain MRI in children with centrotemporal spikes and a classical history for childhood epilepsy with centrotemporal spikes, there should be a low threshold for neuroimaging in those with unexpected clinical findings, particularly if the centrotemporal spikes are unilateral. This is consistent with the 2022 ILAE position paper which considers a causal lesion on MRI to be exclusionary, but notes "An MRI is not required for diagnosis but should be strongly considered in cases with alerts [20]".…”

“…These data will aid clinicians in interpreting the clinical significance of these EEG findings in different clinical scenarios. The data are particularly important as the 2022 ILAE position papers have made clear that specific EEG patterns are mandatory criteria in the definition of epilepsy syndromes [ 20 , 21 , 22 ].…”

“…For any patients for whom there was disagreement on the syndromic diagnosis, we used the International League Against Epilepsy (ILAE) website, epilepsydiagnosis.org , as a reference, and the final decision was made by a qualified epileptologist. The 2022 ILAE epilepsy syndrome classification and definitions were not used as they were not yet available at the time the study was conducted [ 20 , 21 , 22 ].…”

EEG biomarkers for the diagnosis and treatment of infantile spasms

“…Infantile spasms (IS) is a seizure type typified by brief muscle contractions, often occurring in clusters, with the peak incidence at 4–7 months of age ( 1 ). Recently, the syndrome associated with IS has been re-named “infantile epileptic spasms syndrome” (IESS) by the International League Against Epilepsy ( 2 ). While IESS represents only a fraction of all pediatric epilepsies, the consequences of the disease are among the most severe ( Table 1 ).…”

Transient, developmental functional and structural connectivity abnormalities in the thalamocortical motor network in Rolandic epilepsy

“…Rolandic epilepsy (RE, also called self-limited epilepsy with centrotemporal spikes; SeLECTS ( Specchio et al, 2022 )) is the most common focal developmental epilepsy, accounting for 8–23% of childhood epilepsy ( Astradsson et al, 1998 , Berg and Rychlik, 2015 , Camfield and Camfield, 2014 , Guerrini, 2006 , Ross et al, 2020 ), and characterized by a transient period of sleep-potentiated seizures and epileptiform discharges in the inferior Rolandic cortex during childhood ( Lin et al, 2003 ). RE usually presents during school-age years ( Ross et al, 2020 ), and seizures always remit by late adolescence ( Berg et al, 2008 ).…”