Owing to the nonspecific nature of multiple seizure types and cognitive dysfunction, two other pediatric epilepsy syndromes may be confused with Lennox-Gastaut syndrome (LGS):

• The myoclonic variant of LGS has:18,25
• less frequent and less severe mental retardation than classic LGS
• rarer tonic seizures
• an unusually marked myoclonic component
• frequently, faster (>2.5 Hz) spike and wave complexes on EEG
• Myoclonic-astatic epilepsy (Doose syndrome) includes the same three types of seizures as LGS, but major differences exist:20,26
• predominantly idiopathic and genetically determined (LGS is mainly symptomatic and not genetically determined.)
• usually favorable outcome (LGS outcome is usually unfavorable.)
• does not follow West syndrome (LGS can follow West syndrome.)

Adapted from: Glauser TA and Morita DA. Lennox-Gastaut syndrome. In: Devinsky O and Westbrook LE, eds. Epilepsy and Developmental Disabilities. Boston: Butterworth-Heinemann; 2001;65–78.
With permission from Elsevier (www.elsevier.com).
Reviewed and revised May 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.