• We prospectively studied the reliability and accuracy of the electroencephalogram as a predictor of the risk of recurrence within 2 years in 157 patients with untreated idiopathic first seizures. In all patients, a standard electroencephalogram and, if necessary, an electroencephalogram after partial sleep deprivation were obtained. All electroencephalograms were scored by one observer according to a fixed protocol. The finding of epileptic discharges was associated with a risk of recurrence of 83% (95% confidence interval, 69% to 97%) vs 41% (95% confidence interval, 29% to 53%) in patients with nonepileptic abnormalities and 12% (95% confidence interval, 3% to 21%) in patients in whom both electroencephalograms were normal. The sensitivity proved to be 48%. Interobserver agreement among four neurologists, who independently read 50 electroencephalograms, was found to be moderate. Predictive value for each observer, however, was good. We conclude that electroencephalogram findings may play a role in the decision to initiate or delay treatment after an idiopathic first seizure.
van Donselaar CA, Schimsheimer R, Geerts AT, Declerck AC. Value of the Electroencephalogram in Adult Patients With Untreated Idiopathic First Seizures. Arch Neurol. 1992;49(3):231–237. doi:10.1001/archneur.1992.00530270045017