title: A reappraisal of rhythmic coma patterns in children.
abstract: OBJECTIVE
  This study was designed to determine the prevalence of rhythmic coma patterns in comatose children and to ascertain the prognostic significance of reactive rhythmic coma patterns.
  
  
  METHODS
  We retrospectively analyzed and classified electroencephalogram (EEGs) in comatose children between two months and 18 years of age during the period 1996 - 2003 according to modified Young's classification. Outcome at one-year was scored according to the Paediatric Cerebral and Overall Performance Category Scale. Outcomes were compared using Fisher's exact test and Mann-Whitney test.
  
  
  RESULTS
  Analysis of 63 electroencephalogram (EEG) records in 38 patients showed rhythmic patterns in 19 records (30.2%; 9 alpha, 4 spindle, 4 theta and 2 beta coma patterns, total number of children = 14). Aetiology and outcome of alpha coma patterns and other rhythmic coma patterns were similar. In five children, one type of rhythmic pattern changed to another. Records with reactive rhythmic coma 66.7% (6/9), were associated with favourable outcome. Sixty percent of the records (6/10 records in seven children) with non-reactive pattern were associated with unfavourable outcome. This clinically significant difference did not reach statistical significance (lower Paediatric Cerebral and Overall Performance Category Scale score p= 0.14; favourable outcome p=0. 19).
  
  
  CONCLUSIONS
  Rhythmic coma patterns in comatose children are not uncommon. Aetiology, reactivity and outcome of individual patterns are similar and thus make the rhythmic coma patterns distinct EEG signatures in comatose children. There was a clinically significant better outcome with reactive rhythmic coma patterns.
authors.affiliation: Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Rajesh
authors.initials: R
authors.lastname: RamachandranNair
authors.forename: Rohit
authors.initials: R
authors.lastname: Sharma
authors.forename: Shelly K
authors.initials: SK
authors.lastname: Weiss
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Otsubo
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cortez
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003128:Coma / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies