Abstracts

Rationale: Epidemiologic data concerning idiopathic (genetic) generalized epilepsies (IGEs) are scarce or often unreliable. In the current study, we specifically analyzed the syndromes if IGE based on their demographic, clinical, and EEG findings. Methods: In this retrospective study, all patients with a clinical diagnosis of IGE were recruited in the outpatient epilepsy clinic at Shiraz University of Medical Sciences, from September 2008 through May 2011. Demographic variables and relevant clinical and EEG variables were summarized descriptively. Statistical analyses were performed using Chi square and Fisher's Exact tests. Results: 2190 patients with epilepsy were registered at our epilepsy clinic and 442 patients (20.2%) were diagnosed as having IGE. Age of seizure onset was 12 ± 7 years. Juvenile myoclonic epilepsy was the most frequent syndrome, followed by epilepsy with generalized tonic-clonic seizures only and juvenile absence epilepsy. Epilepsy risk factors, physical examination, MRI and even EEG could not differentiate various syndromes. Conclusions: IGE encompasses several different syndromes, which are diagnosed by strict clinical features. The key element in making the correct diagnosis is obtaining a detailed clinical history. An abnormal physical examination, if present, is often irrelevant and should not deter from the correct diagnosis. MRI or laboratory tests in a patient with seizures, in whom you are suspecting an IGE based on a detailed history, are not necessary. Even EEG has limitations and atypical findings in a patient with typical history for an IGE should not deter from the correct diagnosis. Recognition of the presence of absences or myoclonic seizures has important implications on the choice of antiepileptic drugs, but distinguishing various syndromes from each another is not always easy; sometimes they have overlapping features. This is particularly true with regards to JME and JAE. In order to prevent any confusion in classification, we recommend the term juvenile idiopathic generalized epilepsy to replace these currents terms (JAE and JME) in adolescents with both seizure types (absence and myoclonus) with or without GTCSs, while retaining JAE for patients with absences with or without GTCSs and no myoclonic seizures and retaining JME for adolescents with myoclonic seizures with or without GTCSs and no absences.