Severe myoclonic epilepsy of infancy: Seizure reduction during adjunctive eslicarbazepine in two cases

Objective: The aim of this study was to preliminarily determine, in a short open study, the effectiveness of eslicarbazepine acetate (ESL) in two patients with severe myoclonic epilepsy of infancy (SMEI). Methods: We report on a 17-year-old Italian boy and a 21-year-old Italian girl with SMEI and a severe clinical outcome, in whom we identified two mutations (5053del AA fs1685X1691 and 931G>T E311X) in the alpha subunit of the neuronal sodium channel SCN1A gene. No drug treatment, including carbamazepine, phenobarbital, valproate, vigabatrin, clonazepam, lamotrigine, phenytoin, nitrazepam, felbamate, zonisamide, or lacosamide, had proven effective, and in the first patient, a VNS pacemaker implantation was tried. The patients suffered from severe and profound mental retardation, respectively. Seizures started in the first year of their life. The last EEGs showed slow background activity and paroxysmal activity in the frontal regions in the boy and slow background activity and paroxysmal activity in the temporooccipital regions with secondary diffusion in the girl. Results: We observed in both patients after a few weeks from the start of ESL (at a dosage of 800 mg once daily) an important reduction in the frequency of complex partial seizures with secondary generalization. We observed an important change in seizure frequency from two seizures during the night to one seizure in ten days in the boy and from 6 daily seizures to one every four days with disappearance of daily seizures in the girl. The tolerability was good, and no adverse events were observed even if ESL was added to other antiepileptic drugs. Conclusions: Despite the short-term and open nature of our study and the small number of patients, ESL has proven to be effective and tolerated in our cases of severe myoclonic epilepsy