The predictive value of electroencephalography in recurrence of the first-ever unprovoked idiopathic seizure

Abstract

Aim of the study We aimed to study the role of electroencephalography (EEG) and its predictive value for recurrence after the first-ever seizure. Patients and methods Patients who presented with first idiopathic seizure attack were included in this prospective study. The study group included 70 patients (39 male and 31 female). Their ages ranged from 1 to 58 years. All patients included were subjected to history taking and full analysis of the seizure, full neurological examination, routine laboratory tests, neuroimaging, and EEG evaluation, and then all patients were interviewed monthly for 3 successive months. Results Sixteen patients (23%) had focal seizures and 54 patients (77%) had generalized seizure. Nocturnal seizures were found in 45.7% of patients, whereas diurnal seizures were found in 54.3% patients. Aura was recorded in 17% of cases, whereas postictal state (confusion, headache, muscle ache, and Todd’s paralysis) occurred in 60% of cases. Past history of febrile seizures was present in 17% of cases, family history of epilepsy was positive in 10% of cases, and 31.4% of cases had positive consanguinity. Abnormal EEG was found in 54.3% of patients [31.4% of patients had generalized epileptiform discharge, 15.7% of patients had focal epileptiform discharge with or without secondary generalization, and 7.2% of patients had no specific changes (focal or generalized slowness)] and lastly normal EEG was found in 45.7% of patients. After 3 months of follow-up, 37 patients (52.9%) had recurrence of seizure: 75.6% of patients had generalized seizures and 24.4% of patients had focal seizures. The percent of recurrence among patients with abnormal EEG was 70.3% and that among those with normal EEG was 29.7%. As regards EEG findings, there were a significant correlation between abnormal EEG and generalized epileptiform discharge and recurrence of seizure. Conclusion EEG, especially during the first 48 h after seizure, had a prognostic value for recurrence of seizure.