title: Value of re-interpretation of controversial EEGs in a tertiary epilepsy clinic.
abstract: OBJECTIVE
  Diagnostic value and efficacy of re-interpretation of previous EEGs in 100 patients admitted to a tertiary epilepsy center with EEG results conflicting with the clinical diagnosis after the first visit.
  
  
  METHODS
  EEGs were reclassified. A matched control group was included to assess the efficiency of the re-interpretation process. Efficacy was assessed by questionnaires and costs as number of technician hours needed.
  
  
  RESULTS
  In 85 patients the previous EEG conclusion was known. In 43 the conclusion was altered. In 23 the epileptic activity changed from positive to negative (17) or the reverse (6). In 15 the focus changed (7 originally classified as generalized epileptic activity). In 5 the syndrome changed. 57% of the re-interpretation group needed no extra EEG afterwards. 96% of the re-interpretations were considered useful by requesting and 72% by not involved neurologists. The average time per EEG technologist per patient was 8,81h in controls and 5,40 in the re-interpretation group.
  
  
  CONCLUSIONS
  In 43 from the 85 patients (51%) re-interpretation of 'controversial' EEGs led to a different opinion. The re-interpretations were useful and less time consuming, compared to new EEGs in controls.
  
  
  CONCLUSIONS
  Re-interpretation of 'controversial' EEGs is useful and cost effective.
authors.affiliation: Kempenhaeghe, Heeze, The Netherlands; Technological University Eindhoven, Eindhoven, The Netherlands. Electronic address: ArendsJ@kempenhaeghe.nl.
authors.forename: Johan B
authors.initials: JB
authors.lastname: Arends
authors.affiliation: Kempenhaeghe, Heeze, The Netherlands.
authors.forename: Inge
authors.initials: I
authors.lastname: van der Linden
authors.affiliation: Kempenhaeghe, Heeze, The Netherlands.
authors.forename: Saskia C
authors.initials: SC
authors.lastname: Ebus
authors.affiliation: Kempenhaeghe, Heeze, The Netherlands.
authors.forename: Mariëtte H
authors.initials: MH
authors.lastname: Debeij
authors.affiliation: Stichting Epilepsie Instellingen Nederland, Zwolle, The Netherlands.
authors.forename: Boudewijn W
authors.initials: BW
authors.lastname: Gunning
authors.affiliation: Kempenhaeghe, Heeze, The Netherlands.
authors.forename: Machiel J
authors.initials: MJ
authors.lastname: Zwarts
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003951:Diagnostic Errors / Q000517:prevention & control / Q000706:statistics & numerical data; D004569:Electroencephalography / Q000191:economics / Q000379:methods / Q000592:standards*; D004827:Epilepsy / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D062606:Tertiary Care Centers / Q000706:statistics & numerical data
keywords: Comparative diagnostic study; EEG interpretation; Epilepsy