title: Ictal electroencephalography and electromyography features in symptomatic infantile epileptic encephalopathy with late-onset spasms.
abstract: OBJECTIVE
  Recently, epilepsy with late-onset epileptic spasms (ES) has been reported to be distinct from West syndrome and Lennox-Gastaut syndrome. We identified the characteristics of this clinical entity by analyzing clinical data, including ictal electroencephalography (EEG) and electromyography (EMG) in symptomatic patients.
  
  
  METHODS
  We evaluated retrospectively eight symptomatic patients with epilepsy with late-onset ES. All patients underwent video-EEG analysis for more than 24 hours and have been followed up for at least 1 year. Interictal EEG, ictal EEG, ictal EMG, coexistence seizures, response to treatment, and intellectual or daily activity level were assessed. Ictal EMG was evaluated by spectral analysis.
  
  
  RESULTS
  All patients exhibited neurological deterioration and had multiple seizure types; seven of them had intractable seizures. Interictal EEG showed no typical hypsarrhythmia in any case. Ictal EMG analysis revealed that the predominant seizure types presenting with the tonic component were distributed among ES, spasms followed by tonic seizures (SFT), and tonic seizures.
  
  
  CONCLUSIONS
  The clinical characteristics of our patients were identical to infantile epileptic encephalopathy with late-onset spasms. Our patients had ES, SFT, and tonic seizures as the core seizure types, developed ES beyond the age of 1 year, and showed neurological deterioration. These may be essential symptoms of this clinical entity.
authors.affiliation: Department of Pediatrics, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Nobustune
authors.initials: N
authors.lastname: Ishikawa
authors.affiliation: Department of Pediatrics, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Department of Pediatrics, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Fujii
authors.affiliation: Department of Pediatrics, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Tajima
authors.affiliation: Department of Pediatrics, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Kobayashi
mesh_terms: D017668:Age of Onset; D001921:Brain / Q000503:physiopathology*; D002675:Child, Preschool; D004569:Electroencephalography; D004576:Electromyography; D004827:Epilepsy / Q000145:classification / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D013036:Spasms, Infantile / Q000145:classification / Q000503:physiopathology*