title: Incidental epileptiform discharges in patients of a tertiary centre.
abstract: OBJECTIVE
  This controlled study set out to assess the rate of incidental epileptiform discharges (ED) during routine EEG and the incidence of epilepsy within a 4-year follow-up period in patients without a history of epilepsy.
  
  
  METHODS
  We retrospectively analyzed electroencephalography (EEG) recordings of 1750 consecutive patients referred to the Department of Neurology at the Vienna General Hospital between January 1 and December 31, 2009. The incidence of epilepsy in patients with ED and no prior history of epilepsy was compared with a disease control group matched for gender and neuroimaging findings.
  
  
  RESULTS
  ED were identified in 26 (4%) of 629 patients without a history of epilepsy. Sixteen (62%) of these patients developed epilepsy during follow-up compared with five (19%) of the disease controls (p=0.01), yielding an adjusted odds ratio of 8.8 (95% CI 2.1-37.7) for developing epilepsy in patients with ED and no prior history of epilepsy.
  
  
  CONCLUSIONS
  Incidental ED during routine EEG significantly increase the likelihood of developing epilepsy.
  
  
  CONCLUSIONS
  Patients with incidental ED should be specifically asked for any signs and symptoms suggestive of seizures, since they appear more prone to develop epilepsy.
authors: Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria. Electronic address: stefan.seidel@meduniwien.ac.at.
authors: Stefan
authors: S
authors: Seidel
authors: Department of Medical Statistics, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors: Eleonore
authors: E
authors: Pablik
authors: Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors: Susanne
authors: S
authors: Aull-Watschinger
authors: Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors: Birgit
authors: B
authors: Seidl
authors: Department of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors: Ekaterina
authors: E
authors: Pataraia
mesh_terms: D000328:Adult; D000368:Aged; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D062606:Tertiary Care Centers / Q000706:statistics & numerical data*
keywords: Disease controls; Epilepsy; Follow-up; Incidental epileptiform discharges; Routine EEG