Treatment outcomes in drug resistant juvenile myoclonic epilepsy: Valproate resistance may not be the end of the road

Objective: To determine treatment responses to various antiseizure medicines (ASMs) in patients with drug resistant juvenile myoclonic epilepsy (DRJME) METHODS: We reviewed records of all JME patients attending epilepsy clinics at 5 centers during a 5-year period. We used International Consensus Criteria to diagnose JME and International League Against Epilepsy Criteria to define drug resistance and sustained seizure freedom. We only used broad spectrum medicines which included valproate, lamotrigine, topiramate, levetiracetam, clobazam, phenobarbitone, clonazepam, and zonisamide. We considered an ASM successful if patient achieved seizure freedom within 3 months of attaining maintenance dose.

Results: We studied 116 patients (61 males) with DRJME. At terminal followup, 82 (70.7%) patients had achieved sustained seizure freedom with a mean followup of 3.2 ± 1.3 years after last dose change. In patients where valproate failed as first- or second-line ASM (n=70; 60.3%), 49(70%) became seizure-free. In this group, 33(67%) patients became seizure-free after addition of lamotrigine. Success rate of lamotrigine and valproate combination was 69% as compared to 9% with all other combinations (p = 0.001). In patients who were not exposed to valproate as initial therapy (n=46), 33 (71.7%) became seizure-free, 30 (91%) after adding valproate. At last follow-up, 75 (90%) seizure-free patients were receiving valproate including 45 (55%) patients with a combination of valproate and lamotrigine. Only one of 24 patients became seizure-free after failing valproate and lamotrigine combination.

Conclusion: Seizure freedom can be achieved in two-thirds of patients with DRJME. A combination of valproate and lamotrigine is the most effective duotherapy.