Seizure freedom and therapy discontinuation in patients with idiopathic generalized epilepsy: retrospective cohort study from a tertiary epilepsy outpatient service.

Abstract

Background: Idiopathic generalized epilepsy (IGE) affects young individuals and is typically successfully managed with anti-seizure medications (ASMs). Discontinuing therapy in IGE patients is a critical decision due to the risk of seizure recurrence. This study aims to identify factors influencing seizure freedom (SF) or relapse after ASM discontinuation.

Methods: We retrospectively reviewed the medical records of patients seen at our clinic between 2002 and 2024. Collected data included demographics, disease history, seizure types, ASMs used, EEG findings, outcomes related to SF and ASM withdrawal.

Results: We identified 322 records, with a mean age of 30 ± 12.4 years and an age at onset of 16 ± 5.9 years. On average, patients tried 1.9 ASMs, 23% on polytherapy. The main seizure types were generalized tonic-clonic seizures (GTCS) in 53.1%, myoclonic seizures in 31.7%, absences in 15.2%. SF was achieved by 76.6%. Patients with GTCS as main seizure type or presenting with GTCS in the first year of disease experienced a delayed achievement of SF. ASM discontinuation was attempted in 64 patients. Predictors of relapse after discontinuation were myoclonic and generalized seizures as principal seizure type and higher seizure frequency. Early SF and lower seizure frequency were associated with successful discontinuation. EEG predictors of discontinuation failure included worsening during treatment tapering and specific abnormalities, such as spike waves, photosensitivity, and hyperpnoea sensitivity.

Conclusions: This study provides long-term follow-up data on IGE patients, highlighting key predictors of seizure control, including GTCS or myoclonic seizures and a rapid initial ASM response. EEG emerges as a valuable tool for the longitudinal monitoring of patients undergoing ASM discontinuation.