Abstracts

Rationale: Perampanel® is an antiepileptic drug approved as add-on therapy in focal seizures with or without generalization in patients aged ≥ 12 years with epilepsy. Our objective was to evaluate the effectiveness and tolerability of perampanel when used as add-on treatment in patients with drug resistant myoclonic seizures.Methods: This was a retrospective multicenter study including 19 patients with drug resistant myoclonic seizures who were prescribed perampanel as add-on treatment. Demographic data, epileptic syndrome, seizure types, seizure frequency, titration rate of perampanel, effectiveness and tolerability were analyzed.Results: There were 8 men and 11 women, mean age was 35 years, mean time of evolution of epilepsy was 15 years. Patients displayed a combination of myoclonic seizures (100%, daily in 72%), generalized tonic-clonic seizures (GTCS, 52.6%) and absence seizures (15.8%). Diagnosis included postanoxic myoclonus (4), MERRF (3), Lennox-Gastaut syndrome (2), juvenile myoclonic epilepsy (2), progressive myoclonic epilepsy of undetermined cause (3) and others (5) like mitochondrial disease, Jeavons syndrome, subependymal nodular heterotopia, subcortical heterotopia and dento-rubro-pallidoluysian atrophy. The most common associated neurological problems were cognitive decline and ataxia. They had taken previously a mean of 5.6 antiepileptic drugs (AEDs) and were taking a mean of 2.8 concomitant AEDs (mainly VPA, LEV and BZD). The most frequently used titration rate was 2 mg every 4 weeks. Mean time with perampanel was 6.5 months (3-16). Most common final dose was 6 mg. 10/19 patients had at least 6 months of follow-up. There was a 75% decrease in myoclonic seizures in 54.5% of patients, and 75% decrease in GTCS in 20% of patients; 27.3% of patients were free of myoclonic seizures and 80% were free of GTCS. The most frequent side effects were psychiatric (ranging from irritability to psychosis), dizziness and instability, mostly resolved with dose reduction. Only two patients discontinued perampanel due to side effects.Conclusions: Perampanel seems to be a very effective drug to reduce seizure frequency in patients with drug resistant myoclonic seizures associated or not with GTCS. It is generally well tolerated, but may cause psychiatric and other side effects which require follow-up and sometimes dose-reduction.