title: Subclinical seizures in children diagnosed with localization-related epilepsy: clinical and EEG characteristics.
abstract: OBJECTIVE
  Subclinical seizures (SCSs) are characterized by paroxysmal rhythmic epileptiform discharges that evolve in time and space in the absence of objective clinical manifestation or report of a seizure. The aim of this study was to evaluate the frequency and characteristics of SCSs in children with localization-related epilepsy (LRE).
  
  
  METHODS
  The results of video/EEG monitoring were reviewed to identify patients with SCS. We identified 187 children diagnosed with LRE, in 32 of whom SCSs were reported in the EEG recording.
  
  
  RESULTS
  SCSs were reported only in the children who had received a diagnosis of either symptomatic or cryptogenic LRE. All children had a history of clinical seizure(s). The ictal onset of SCSs was most frequent from the temporal and frontal lobes. SCSs were lateralized to the left hemispheres in 19, right hemisphere in 8, and both hemispheres independently in 5 children. SCSs were more often reported in young children, and associated with a history of developmental delay, infantile spasms, and frequent seizures. EEG abnormalities included background slowing and lack of normal sleep architecture in addition to the epileptiform activity. Seizure freedom was reported less often in children with SCSs. Six patients seizure free at the time of the admission were found to have SCSs.
  
  
  CONCLUSIONS
  Subclinical seizures are not uncommon in children with LRE, in particular, with younger age, developmental disability, and medically refractory clinical course. Video/EEG monitoring will be informative in selected children with LRE to assess the seizure frequency more accurately.
authors.affiliation: Comprehensive Epilepsy Center, Department of Neurology, Columbia University College of Physician and Surgeons, New York, NY, USA. akman@bcm.tmc.edu
authors.forename: Cigdem I
authors.initials: CI
authors.lastname: Akman
authors.forename: Maria A
authors.initials: MA
authors.lastname: Montenegro
authors.forename: Susan
authors.initials: S
authors.lastname: Jacob
authors.forename: Karen
authors.initials: K
authors.lastname: Eck
authors.forename: Danielle
authors.initials: D
authors.lastname: McBrian
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Chiriboga
authors.forename: Marc C
authors.initials: MC
authors.lastname: Patterson
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004827:Epilepsy / Q000150:complications* / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D012640:Seizures / Q000175:diagnosis / Q000209:etiology*; D012890:Sleep / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology