The Spectrum of Self-Limited Infantile Epilepsy Syndromes

Abstract Infantile epilepsy syndromes' nomenclature has changed over time. The International League Against Epilepsy (ILAE) revised its 2021 classification and definition of epilepsy syndromes in neonates and infants, replacing the term “benign” with “self-limited,” and now identifies them as “self-limited infantile epilepsy” (SeLIE). SeLIE is characterized by seizures that begin during infancy and resolve spontaneously with normal developmental progress. The recognition of infantile seizures with favorable outcomes dates back more than 60 years, as noted by Fukuyama in Japan. Thirty years later, Watanabe et al reported benign focal seizures in infancy, with the majority of cases being nonfamilial. These seizures' self-limited nature during infancy has since been acknowledged in various countries, spanning diverse ethnic populations beyond Japan. Infants who undergo such seizures are now recognized as having self-limited nonfamilial infantile epilepsy (SeLNFIE). Initially, Vigevano et al detailed the familial variant in five infants, coining the term “benign familial infantile seizures” to characterize this condition, now known as self-limited familial infantile epilepsy (SeLFIE). SeLNFIE and SeLFIE may present similarly with the exception of a positive family history. After the initial description and classification of these syndromes (familial and nonfamilial) in the ILAE's 1989 Classification of Epilepsies and Epileptic Syndromes, several less frequently encountered related syndromes have been recognized. These conditions comprise a spectrum including SeLFIE with choreoathetosis and paroxysmal dyskinesia, now termed infantile convulsions with paroxysmal choreoathetosis syndrome (ICCA); self-limited focal epilepsy in infancy with midline spikes and waves during sleep (SeLIMSE); self-limited infantile seizures with mild gastroenteritis (SeLISwG); SeLFIE associated with familial hemiplegic migraine (FHM); and self-limited familial neonatal-infantile epilepsy (SeLFNIE). This review aims to document the prevalence of these SeLIEs, elucidate their unique characteristics, and underscore their self-limited nature.