EEG in Adult-onset Idiopathic Generalized Epilepsy
Article first published online: 6 FEB 2003
Volume 44, Issue 2, pages 252–256, February 2003
How to Cite
Yenjun, S., Harvey, A. Simon., Marini, C., Newton, Mark R., King, Mark A. and Berkovic, Samuel F. (2003), EEG in Adult-onset Idiopathic Generalized Epilepsy. Epilepsia, 44: 252–256. doi: 10.1046/j.1528-1157.2003.26402.x
- Issue published online: 6 FEB 2003
- Article first published online: 6 FEB 2003
- Accepted August 25, 2002.
Summary: Purpose: It remains controversial whether adult-onset idiopathic generalized epilepsy (IGE) is a distinct syndrome or a continuum among IGE syndromes. EEG is the only known biologic marker of IGE and helps differentiate many of its classic subsyndromes. In this study, we looked for the differences in the EEG findings of IGE of classic adolescent onset versus adult onset that may suggest syndromic heterogeneity.
Methods: Seventy-six patients (47 adolescent-onset IGE, 29 adult-onset IGE) with a clinical and EEG diagnosis of IGE were included. We defined IGE with age at onset of 11–20 years as adolescent-onset IGE and age at onset of 20 years or after as adult-onset IGE. Patients with first-decade onset of seizures, delayed EEGs, and no EEG available for review were excluded. The first EEG was performed within 24 h of the seizure, and if negative, a sleep-deprived EEG was done. All EEGs were reviewed in detail with respect to the background activity and the generalized spike–wave (GSW) characteristic.
Results: EEGs (87; 56 adolescent-onset IGE, 31 adult-onset IGE) were systematically reviewed. Background was normal in all patients. The morphology, amplitude, duration, frequency, occurrence, or activation of the GSW pattern did not differ between these two groups.
Conclusions: No differences of EEG features were found between the classic adolescent-onset and the adult-onset IGE. This supports the hypothesis that they share common biologic determinants and exist along a life-long age spectrum of classic IGE.