High rates of early remission pattern in adult-onset compared with earlier-onset idiopathic generalized epilepsy: A long-term follow-up study

Objective: To investigate electroclinical characteristics and prognostic patterns of adult-onset vs. younger-onset idiopathic generalized epilepsy (IGE) patients during long-term follow-up. Methods: In this single-center retrospective cohort comparative study, adult-onset IGE was defined as onset after 20 years of age. Patients with a follow-up duration between 10 and 30 years from epilepsy diagnosis were enrolled. Maximum follow-up duration was limited to 30 years to ensure a better comparison of prognostic data between adult-onset and younger-onset patients. The Benjamini-Hochberg false discovery rate (FDR) method was applied to obtain FDR-adjusted p-values. Results: A total of 177 IGE patients were recruited and 27 adult-onset IGE patients were identified (15.3%). Follow-up duration was similar between younger- and adult-onset IGE patients and 74% of subjects performed at least one 24-hour EEG recording. Of adult-onset IGE patients, 8/27 were diagnosed with juvenile myoclonic epilepsy, while 19/27 were diagnosed with generalized tonic-clonic seizures (GTCS) only. EEG photosensitivity and absence seizures were significantly less frequent among adult-onset IGE patients as compared with younger subjects. When considering prognostic patterns, an early remission pattern was significantly higher among adult-onset IGE patients as compared with younger-onset IGE patients (55.6% vs. 24%, adjusted p value = 0.007). Antiseizure medication withdrawal was attempted in 3/27 adult-onset patients, and all had GTCS relapses. Conclusion: Our study contributes to better defining the electroclinical characteristics and long-term follow-up of adult-onset IGE patients. A favorable long-term seizure outcome was found in adult-onset IGE patients, as evidenced by the high rates of early remission pattern when compared with younger onset patients.