What are the predominant predictors of seizure relapse following discontinuation of anti-seizure medication in epileptic children?

OBJECTIVE: The aim of the study was to identify the predominant predictors of seizure relapse following discontinuation of ASM in epileptic children. METHODS: The study cohort consisted of 403 epileptic children who had a withdrawal process of ASM (monotherapy: 344; dual therapy or polytherapy: 59) after at least a 2-year seizure-free period. Patients were categorized if they had a well-defined epileptic syndrome. Epileptic children with ongoing ketogenic diet, vagal nerve stimulation, or surgery were excluded from the cohort due to the additional withdrawal process related to other therapy modalities. RESULTS: The cohort's seizure relapse rate was 12.7% (51/403). The highest rates of seizure relapse were defined for genetic etiology at 25% and structural etiology at 14.9%. An epilepsy syndrome was defined in 183 of 403 children (45.4%). There was no difference in the seizure relapse rate between the subgroups of well-defined epileptic syndromes; 13.8% for self-limited focal epileptic syndromes, 11.7% for developmental and epileptic encephalopathies, and 7.1% for generalized epileptic syndromes. Five predictors were defined as the most powerful predictors of seizure relapse in univariate analysis: age at epilepsy diagnosis >2 years (hazard ratio [HR]: 1.480; 95% confidence interval [CI]: 1.134-1.933), defined etiology (HR: 1.304; 95% CI: 1.003-1.696), focal seizure (HR: 1.499; 95% CI: 1.209-1.859), ≤3 months duration of the withdrawal process (HR: 1.654; 95% CI: 1.322-2.070), and a history of neonatal encephalopathy with or without seizures (HR: 3.140; 95% CI: 2.393-4.122). In multivariate analysis, the main predictor of seizure relapse was a history of neonatal encephalopathy with or without seizures (HR: 2.823; 95% CI: 2.067-3.854). SIGNIFICANCE: The duration of seizure freedom before discontinuation of ASM was not a predominant risk factor for seizure relapse: 2-3 years versus >3 years. The predictive values of five predictors of seizure relapse rate should be evaluated for patients with different epilepsy subgroups.

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.