Institute for Children and Adolescents with Epilepsy – IDEE, University Hospital of Lyon (HCL), Inserm U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Brain Dynamics and Cognition, University Lyon 1, Lyon and Inserm U821, Lyon, France, Department of Neurology, Miami Children's Hospital, Miami, Florida, USA
Lennox-Gastaut syndrome (LGS) is a severe, chronic, epileptic encephalopathy, primarily with childhood onset, which is characterised by a triad of features: multiple seizure types, including tonic seizures that may appear late in the course of the disorder; abnormal EEG features with slow spike-wave discharges; and cognitive impairment. Recognition of LGS is problematic, since the seizure types and EEG features that characterise it are not pathognomonic and often change over time. Furthermore, although seizures associated with LGS may occur
de novo, the appearance of core LGS seizures may be preceded by prolonged periods of other seizure types, including myoclonic seizures, partial seizures, or infantile spasms. This has led some authors to postulate that a continuum between LGS and other types of childhood epilepsy may exist. Accurate diagnosis requires careful assessment of both clinical and EEG features, in order to distinguish LGS from other childhood epilepsy syndromes, such as atypical benign partial epilepsy of childhood, Dravet syndrome or epilepsies with predominantly myoclonic-astatic seizures. Since there is no biological marker that can be used to confirm diagnosis of LGS and because of the multiple aetiologies that could lead to its development, early referral to a specialist team may prove to be crucial for facilitating both diagnosis and management. Such an approach ensures that patients receive the appropriate treatment at the correct time, providing the best opportunity for the clinical course and overall prognosis to be improved. Effective management of LGS requires regular reappraisal of the evolving symptoms and features, and adjustment of the treatment accordingly.