title: Sporadic occurrence of completely lateralized vertex sharp transients of sleep is a normal phenomenon: a retrospective, blinded, case-control study.
abstract: OBJECTIVE
  Vertex sharp transients (VSTs) of sleep often lateralize to the left or right frontocentral regions and can be mistaken as epileptiform. The aim of this study was to determine the prevalence of completely lateralized VSTs in pediatric-aged individuals and to assess their significance by comparing cohorts with and without epilepsy. The authors hypothesized that completely lateralized VSTs are normal and occur with similar frequencies in patients with and without epilepsy.
  
  
  METHODS
  The authors conducted a retrospective, blinded, case-control study comparing completely lateralized VSTs within a 5-minute EEG sleep epoch between cohorts of 100 patients with epilepsy and 100 age- and gender-matched controls.
  
  
  RESULTS
  The number of patients with completely lateralized VSTs was not significantly different between cases (62%) and controls (65%) (P = 0.66). The median number of completely lateralized VSTs was small but not significantly different between cases (median 3) and controls (median 4) (P = 0.11). The presence of completely lateralized VSTs in cases (generalized vs. focal epilepsy) was not significantly different (P > 0.95).
  
  
  CONCLUSIONS
  This is the first systematic study of the prevalence and significance of completely lateralized VSTs of sleep. This study provides class III evidence that completely lateralized VSTs, occurring in a sporadic fashion, are a normal phenomenon and should not be confused with epileptiform discharges.
authors.affiliation: *Department of Neurology, Division of Pediatric Neurology, University of Virginia, Charlottesville, Virginia, U.S.A.; and †Department of Pediatrics, Division of Pediatric Neurology, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, U.S.A.
authors.forename: J Nicholas
authors.initials: JN
authors.lastname: Brenton
authors.forename: John R
authors.initials: JR
authors.lastname: Mytinger
mesh_terms: D000293:Adolescent; D001921:Brain / Q000502:physiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology*