title: Nonconvulsive seizures in the pediatric intensive care unit: etiology, EEG, and brain imaging findings.
abstract: OBJECTIVE
  To determine the occurrence of nonconvulsive seizures (NCS) in the Pediatric Intensive Care Unit (PICU); to ascertain the relationship of NCS to past medical history, etiology, EEG, and brain imaging; and to determine the concordance between abnormal EEG findings and neuroimaging abnormalities.
  
  
  METHODS
  A retrospective review was conducted of all pediatric patients who were admitted or transferred to the PICU from January 2000 to December 2003 with an unexplained decrease in level of consciousness, no overt clinical seizures, and EEG recordings performed within the 24 h of onset of an altered state of consciousness.
  
  
  RESULTS
  Twenty-three of 141 patients who met criteria for inclusion in the study (16.3%) were found to have NCS. The male to female ratio was 1.9:1. The largest group of patients (43%) had no preexisting neurological condition prior to the onset of NCS. In the remainder, the etiology of NCS included: acute structural brain lesion (48%), acute nonstructural brain lesion (22%), epilepsy-related seizure (13%), and others (17%). Epileptic foci were lateralized to the right side in 39.2%, the left side in 30.4%, and were bilateral in 30.4%. Of 23 patients with NCS, 18 (78.3%) demonstrated abnormal neuroimaging. In 10 of 18 of these patients (55.6%), the findings on neuroimaging were concordant with the lateralization found on EEG (p < 0.05, Fisher's exact test).
  
  
  CONCLUSIONS
  NCS are not uncommon in pediatric patients with an altered state of consciousness. Almost half of the patients were previously healthy especially if they were under 6 months of age. This report highlights the importance of clinical awareness of NCS in the PICU.
authors.affiliation: Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Montri
authors.initials: M
authors.lastname: Saengpattrachai
authors.forename: Rohit
authors.initials: R
authors.lastname: Sharma
authors.forename: Amrita
authors.initials: A
authors.lastname: Hunjan
authors.forename: Manohar
authors.initials: M
authors.lastname: Shroff
authors.forename: Ayako
authors.initials: A
authors.lastname: Ochi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Otsubo
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cortez
authors.forename: O
authors.initials: O
authors.lastname: Carter Snead
mesh_terms: D001921:Brain / Q000473:pathology*; D004569:Electroencephalography / Q000706:statistics & numerical data*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015278:Intensive Care Units, Pediatric; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D013226:Status Epilepticus / Q000175:diagnosis* / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D014474:Unconsciousness / Q000175:diagnosis / Q000473:pathology