title: The secondarily generalized tonic-clonic seizure: a videotape analysis.
abstract: We studied 120 generalized tonic-clonic seizures (GTCSs) in 47 patients with video-EEG telemetry. GTCSs were preceded by antecedent seizures, including 13 simple partial, 70 complex partial, 17 simple partial leading to complex partial, seven tonic, seven clonic, and one typical absence. We divided GTCSs into the following phases: onset of generalization, pretonic clonic, tonic, tremulousness, and clonic. The mean GTCS duration was 62 seconds. There was a non-significant trend toward longer duration on reduced antiepileptic drug doses. Marked heterogeneity in GTCS phenomenology was present; only 27% of seizures included all five phases. Individual phase duration and clinical expression, including tonic and clonic phases, was highly variable. The clinical phenomena suggest that multiple cortical and subcortical routes of spread may exist. When GTCSs last longer than 2 minutes, intravenous antiepileptic drug treatment should be initiated.
authors.affiliation: Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
authors.forename: W H
authors.initials: WH
authors.lastname: Theodore
authors.forename: R J
authors.initials: RJ
authors.lastname: Porter
authors.forename: P
authors.initials: P
authors.lastname: Albert
authors.forename: K
authors.initials: K
authors.lastname: Kelley
authors.forename: E
authors.initials: E
authors.lastname: Bromfield
authors.forename: O
authors.initials: O
authors.lastname: Devinsky
authors.forename: S
authors.initials: S
authors.lastname: Sato
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D002648:Child; D004569:Electroencephalography / Q000379:methods; D004830:Epilepsy, Tonic-Clonic / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014743:Videotape Recording