Introduction: Lennox Gastaut syndrome (LGS) as an electroclinical diagnosis has been utilized as a clinical entity for more than 70 years. However, with the recognition of other distinct electroclinical epilepsy syndromes, no consistent single etiology, and the variability of criteria used in clinical trials, the clinical utility of such a diagnosis has been questioned. Recently, the International League Against Epilepsy for the first time defined diagnostic criteria for epilepsy syndromes, thereby allowing consistent language and inclusion criteria to be utilized.
Areas covered: Recent diagnostic criteria for syndrome diagnosis are explored as defined by the International League Against Epilepsy, with further literature reviewed to highlight relevant features, and differential diagnosis explored.
Expert opinion: Developmental and Epileptic Encephalopathy (DEE) is an overall term that may be descriptive of many different epilepsies, most of early onset, whether electroclinically or etiologically defined, of which LGS is one. Although we have moved forward in defining an increasing number of etiologically specific syndromes, this to date remains a minority of the DEEs. Although there is progress with precision medicine targeted at specific causes, the term LGS still remains useful as a diagnosis in defining treatment options, as well as overall prognosis.
Keywords: DEE; Lennox Gastaut syndrome; diagnostic challenge; early diagnosis; encephalopathy; syndrome-in-evolution; targeted therapy.