title: Generalized-onset seizures with secondary focal evolution.
abstract: The international seizure classification recognizes that partial-onset seizures can become secondarily generalized, but generalized-onset seizures are expected to remain generalized. We report six patients who had recorded seizures with generalized onset, but subsequent evolution into a focal discharge. The clinical seizure onset was generalized absence or myoclonic, and the most common subsequent clinical pattern was prolonged behavioral arrest with mild automatisms, and then postictal confusion. The ictal discharge started with generalized spike-and-wave activity and then acquired a focal predominance. Interictal epileptiform activity was generalized. There were no focal magnetic resonance imaging abnormalities. Four patients were misdiagnosed with complex partial seizures. All patients were initially refractory, but three became seizure-free and three improved after treatment with antiepileptic medications appropriate for absence or myoclonic seizures. Generalized-onset seizures that acquire focal features are easily misdiagnosed as complex partial. These seizures have a more favorable response to medications effective against generalized absence and myoclonic seizures.
authors.affiliation: Department of Neurology, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Randy
authors.initials: R
authors.lastname: Williamson
authors.forename: Samrina
authors.initials: S
authors.lastname: Hanif
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Mathews
authors.forename: Andre H
authors.initials: AH
authors.lastname: Lagrange
authors.forename: Bassel
authors.initials: B
authors.lastname: Abou-Khalil
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000927:Anticonvulsants / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography / Q000379:methods / Q000706:statistics & numerical data*; D004828:Epilepsies, Partial / Q000145:classification / Q000175:diagnosis* / Q000188:drug therapy; D004829:Epilepsy, Generalized / Q000145:classification / Q000175:diagnosis* / Q000188:drug therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014743:Videotape Recording
chemical_list: D000927:Anticonvulsants