Predictors for long-term seizure outcome in juvenile myoclonic epilepsy: 25-63 years of follow-up

Abstract

Purpose: The long-term seizure outcome of juvenile myoclonic epilepsy (JME) is still controversial; the value of factors that are potentially predictive for seizure outcome remains unclear. The aim of this study was both to investigate the long-term seizure outcome in patients with JME after a follow-up of at least 25 years and to identify factors that are predictive for the seizure outcome.

Methods: Data from 31 patients (19 women) with JME were studied. All of them had a follow-up of at least 25 years (mean 39.1 years) and were reevaluated with a review of their medical records and direct telephone or face-to-face interview.

Key findings: Of 31 patients 21 (67.7%) became seizure-free; in six of them (28.6%) antiepileptic drug (AED) treatment was discontinued due to seizure freedom. The occurrence of generalized tonic-clonic seizures (GTCS) preceded by bilateral myoclonic seizures (BMS) (p = 0.03), a long duration of epilepsy with unsuccessful treatment (p = 0.022), and AED polytherapy (p = 0.023) were identified as significant predictors for a poor long-term seizure outcome, whereas complete remission of GTCS under AED significantly increased the chance for complete seizure freedom (p = 0.012). The occurrence of photoparoxysmal responses significantly increases the risk of seizure recurrence after AED discontinuation (p = 0.05).

Significance: This study shows conclusively that JME is a heterogeneous epilepsy syndrome. Life-long AED treatment is not necessarily required to maintain seizure freedom. Several long-term outcome predictors that can potentially increase the ability of clinicians and their confidence to recommend different treatment options to patients with JME were identified.