title: One-year outcome after a first clinically possible epileptic seizure: predictive value of clinical classification and early EEG.
abstract: OBJECTIVE
  To assess the one-year outcome of patients referred to the emergency room for a first paroxysmal event of clinically certain or uncertain epileptic origin.
  
  
  METHODS
  This prospective observational cohort study included 175 adult patients who were consecutively referred for a first paroxysmal event and excluding clinically certain syncope faints. Simple descriptive clinical criteria were used by emergency room physicians for epileptic assessment. Follow-up and final diagnosis were made by neurologists specialized in epilepsy. The risk of recurrence and epilepsy over time was described using Kaplan-Meier estimates. The effect of risk factors (including EEG results) was assessed using univariate log-rank tests and a Cox regression multivariate model. Negative and positive predictive values (NPV and PPV) at 1 year of significant factors were calculated.
  
  
  RESULTS
  Clinical criteria were positive in 67 patients and negative in 108. At 1 year, the rate of recurrence was respectively 8% in the negative clinical criteria group (NCC) and 30% in the positive clinical criteria group (PCC) (RR=9.3; 95% CI=[1.22; 71.4]). The risk of subsequent epilepsy was respectively 16% in the NCC group and 57% in PCC group (RR=5.6; 95% CI=[2.0; 15.6]). Positive predictive value (PPV) of clinical criteria was 28.8% for recurrence and 57.6% for definite epilepsy. Negative predictive value (NPV) of clinical criteria was 93.2% for recurrence and 83.5% for definite epilepsy. The presence of significant abnormalities on early EEG (paroxysms or focal abnormalities) supported an epileptic origin in 17% of clinically uncertain seizures. It was associated with a higher risk of subsequent epilepsy (RR=2.50; 95% CI [1.37; 4.41]; P=0.007), but did not significantly improve the PPV of clinical criteria alone.
  
  
  CONCLUSIONS
  These results may help provide a prognosis at 1 year after a first paroxysmal event of certain or uncertain epileptic origin. Future studies focusing on the outcome after a first epileptic seizure should take into consideration the degree of certainty of the clinical diagnosis and integrate the group of patients with uncertain epileptic seizure.
authors.affiliation: Service de neurologie, CHU de Nancy, 29, avenue du Mal-de-Lattre-de-Tassigny, 54035 Nancy, France. l.maillard@chu-nancy.fr
authors.forename: L
authors.initials: L
authors.lastname: Maillard
authors.forename: J
authors.initials: J
authors.lastname: Jonas
authors.forename: R
authors.initials: R
authors.lastname: Boyer
authors.forename: S
authors.initials: S
authors.lastname: Frismand
authors.forename: G
authors.initials: G
authors.lastname: Mathey
authors.forename: J-P
authors.initials: JP
authors.lastname: Vignal
authors.forename: F
authors.initials: F
authors.lastname: Guillemin
authors.forename: M
authors.initials: M
authors.lastname: Maignan
authors.forename: H
authors.initials: H
authors.lastname: Vespignani
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology* / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D016896:Treatment Outcome