TY - CHAP M1 - Book, Section TI - Lennox–Gastaut and Related Syndromes A1 - Morita, Diego A. A1 - Glauser, Tracy A. A2 - Duchowny, Michael A2 - Cross, J. Helen A2 - Arzimanoglou, Alexis Y1 - 2017 N1 - T2 - Pediatric Epilepsy AB - The clinical features of the Lennox–Gastaut syndrome (LGS) have been recognized for more than 200 years. The current definition of LGS by the International League Against Epilepsy (ILAE) classification is: "LGS manifests itself in children aged 1–8 years, but appears mainly in preschool-age children. The most common seizure types are tonic-axial, atonic, and absence seizures, but other types such as myoclonic, generalized tonic–clonic seizures (GTCS), or partial seizures are frequently associated with this syndrome. Seizure frequency is high, and status epilepticus is frequent (stuporous states with myoclonias, tonic, and atonic seizures). The electroencephalography (EEG) usually has abnormal background activity, slow spike-waves less than 3 Hz and, often, multifocal abnormalities. During sleep, bursts of fast rhythms (10 Hz) appear. In general, there is mental retardation. Seizures are difficult to control, and the development is unfavorable. In 60% of cases, the syndrome occurs in children suffering from a previous encephalopathy, but is primary in other cases." SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accesspediatrics.mhmedical.com/content.aspx?aid=1138410943 ER -