AbstractEpilepsy syndromes have been recognized for >50 years, as distinct electroclinical phenotypes with therapeutic and prognostic implications. Nonetheless, no formally accepted International League Against Epilepsy (ILAE) classification of epilepsy syndromes has existed. The ILAE Task Force on Nosology and Definitions was established to reach consensus regarding which entities fulfilled criteria for an epilepsy syndrome and to provide definitions for each syndrome. We defined an epilepsy syndrome as “a characteristic cluster of clinical and electroencephalographic features, often supported by specific etiological findings (structural, genetic, metabolic, immune, and infectious).” The diagnosis of a syndrome in an individual with epilepsy frequently carries prognostic and treatment implications. Syndromes often have age‐dependent presentations and a range of specific comorbidities. This paper describes the guiding principles and process for syndrome identification in both children and adults, and the template of clinical data included for each syndrome. We divided syndromes into typical age at onset, and further characterized them based on seizure and epilepsy types and association with developmental and/or epileptic encephalopathy or progressive neurological deterioration. Definitions for each specific syndrome are contained within the corresponding position papers.
ILAE classification and definition of epilepsy syndromes with onset in neonates and infants: Position statement by the ILAE Task Force on Nosology and Definitions
Abstract The International League Against Epilepsy (ILAE) Task Force on Nosology and Definitions proposes a classification and definition of epilepsy syndromes in the neonate and infant with seizure onset up to 2 years of age. The incidence of epilepsy is high in this age group and epilepsy is frequently associated with significant comorbidities and mortality. The licensing of syndrome specific antiseizure medications following randomized controlled trials and the development of precision, gene‐related therapies are two of the drivers defining the electroclinical phenotypes of syndromes with onset in infancy. The principal aim of this proposal, consistent with the 2017 ILAE Classification of the Epilepsies, is to support epilepsy diagnosis and emphasize the importance of classifying epilepsy in an individual both by syndrome and etiology. For each syndrome, we report epidemiology, clinical course, seizure types, electroencephalography (EEG), neuroimaging, genetics, and differential diagnosis. Syndromes are separated into self‐limited syndromes, where there is likely to be spontaneous remission and developmental and epileptic encephalopathies , diseases where there is developmental impairment related to both the underlying etiology independent of epileptiform activity and the epileptic encephalopathy. The emerging class of etiology‐specific epilepsy syndromes, where there is a specific etiology for the epilepsy that is associated with a clearly defined, relatively uniform, and distinct clinical phenotype in most affected individuals as well as consistent EEG, neuroimaging, and/or genetic correlates, is presented. The number of etiology‐defined syndromes will continue to increase, and these newly described syndromes will in time be incorporated into this classification. The tables summarize mandatory features, cautionary alerts, and exclusionary features for the common syndromes. Guidance is given on the criteria for syndrome diagnosis in resource‐limited regions where laboratory confirmation, including EEG, MRI, and genetic testing, might not be available.
ILAE definition of the Idiopathic Generalized Epilepsy Syndromes: Position statement by the ILAE Task Force on Nosology and Definitions
Abstract In 2017, the International League Against Epilepsy (ILAE) Classification of Epilepsies described the “genetic generalized epilepsies” (GGEs), which contained the “idiopathic generalized epilepsies” (IGEs). The goal of this paper is to delineate the four syndromes comprising the IGEs, namely childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic–clonic seizures alone. We provide updated diagnostic criteria for these IGE syndromes determined by the expert consensus opinion of the ILAE’s Task Force on Nosology and Definitions (2017–2021) and international external experts outside our Task Force. We incorporate current knowledge from recent advances in genetic, imaging, and electroencephalographic studies, together with current terminology and classification of seizures and epilepsies. Patients that do not fulfill criteria for one of these syndromes, but that have one, or a combination, of the following generalized seizure types: absence, myoclonic, tonic‐clonic and myoclonic‐tonic‐clonic seizures, with 2.5–5.5 Hz generalized spike‐wave should be classified as having GGE. Recognizing these four IGE syndromes as a special grouping among the GGEs is helpful, as they carry prognostic and therapeutic implications.
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 2017 International League Against Epilepsy classification has defined a three‐tier system with epilepsy syndrome identification at the third level. Although a syndrome cannot be determined in all children with epilepsy, identification of a specific syndrome provides guidance on management and prognosis. In this paper, we describe the childhood onset epilepsy syndromes, most of which have both mandatory seizure type(s) and interictal electroencephalographic (EEG) features. Based on the 2017 Classification of Seizures and Epilepsies, some syndrome names have been updated using terms directly describing the seizure semiology. Epilepsy syndromes beginning in childhood have been divided into three categories: (1) self‐limited focal epilepsies, comprising four syndromes: self‐limited epilepsy with centrotemporal spikes, self‐limited epilepsy with autonomic seizures, childhood occipital visual epilepsy, and photosensitive occipital lobe epilepsy; (2) generalized epilepsies, comprising three syndromes: childhood absence epilepsy, epilepsy with myoclonic absence, and epilepsy with eyelid myoclonia; and (3) developmental and/or epileptic encephalopathies, comprising five syndromes: epilepsy with myoclonic–atonic seizures, Lennox–Gastaut syndrome, developmental and/or epileptic encephalopathy with spike‐and‐wave activation in sleep, hemiconvulsion–hemiplegia–epilepsy syndrome, and febrile infection‐related epilepsy syndrome. We define each, highlighting the mandatory seizure(s), EEG features, phenotypic variations, and findings from key investigations.
Systematic review of the screening, diagnosis, and management of ADHD in children with epilepsy. Consensus paper of the Task Force on Comorbidities of the ILAE Pediatric Commission
SummaryAttention‐deficit/hyperactivity disorder (ADHD) is a common and challenging comorbidity affecting many children with epilepsy. A working group under the International League Against Epilepsy (ILAE) Pediatric Commission identified key questions on the identification and management of ADHD in children with epilepsy. Systematic reviews of the evidence to support approaches to these questions were collated and graded using criteria from the American Academy of Neurology Practice Parameter. Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) requirements were followed, with PROSPERO registration (CRD42018094617). No increased risk of ADHD in boys with epilepsy compared to girls with epilepsy was found (Level A). Valproate use in pregnancy is associated with inattentiveness and hyperactivity in offspring (1 class I study), and children with intellectual and developmental disabilities are at increased risk of ADHD (Level A). Impact of early seizure onset on development of ADHD was unclear (Level U), but more evident with poor seizure control (Level B). ADHD screening should be performed from 6 years of age, or at diagnosis, and repeated annually (Level U) and reevaluated after change of antiepileptic drug (AED) (Level U). Diagnosis should involve health practitioners with expert training in ADHD (Level U). Use of the Strength and Difficulties Questionnaire screening tool is supported (Level B). Formal cognitive testing is strongly recommended in children with epilepsy who are struggling at school (Level U). Behavioral problems are more likely with polytherapy than monotherapy (Level C). Valproate can exacerbate attentional issues in children with childhood absence epilepsy (Level A). Methylphenidate is tolerated and effective in children with epilepsy (Level B). Limited evidence supports that atomoxetine is tolerated (Level C). Multidisciplinary involvement in transition and adult ADHD clinics is essential (Level U). In conclusion, although recommendations could be proposed for some of the study questions, this systematic review highlighted the need for more comprehensive and targeted large‐population prospective studies.