Efficacy of felbamate in a cohort of patients with epilepsy with myoclonic atonic seizures (EMAtS).

Epilepsy with myoclonic atonic seizures (EMAtS) is a rare childhood onset developmental and epileptic encephalopathy which is frequently refractory to medical therapy. The optimal antiseizure medication remains unknown. This study reports the efficacy of felbamate in children with EMAtS. Six large pediatric epilepsy centers performed a retrospective chart review on patients diagnosed with EMAtS at their institutions and collected data on felbamate usage and efficacy. Responders were classified as patients who had a 50% or greater reduction in seizures with a given therapy. Out of 259 patients, 37 (14%) were treated with felbamate. The efficacy of felbamate was 62%, which was greater than that of either levetiracetam or valproic acid (15%, p < 0.001% and 32%, p = 0.001 respectively) and similar to that of the ketogenic diet (69%, p = 0.8). Felbamate appears to be an effective treatment for EMAtS and should be strongly considered in the treatment course of this disease.

Epilepsy panels in clinical practice: Yield, variants of uncertain significance, and treatment implications.

OBJECTIVE: There has been increasing utilization of genetic testing for pediatric epilepsy in recent years. Little systematic data is available examining how practice changes have impacted testing yields, diagnostic pace, incidence of variants of uncertain significance (VUSs), or therapeutic management. METHODS: A retrospective chart review was performed at Children's Hospital Colorado from February 2016 through February 2020. All patients under 18 years for whom an epilepsy gene panel was sent were included. RESULTS: A total of 761 epilepsy gene panels were sent over the study period. During the study period, there was a 292% increase in the average number of panels sent per month. The time from seizure onset to panel result decreased over the study period from a median of 2.9 years to 0.7 years. Despite the increase in testing, the percentage of panels yielding a disease-causing result remained stable at 11-13%. A total of 90 disease-causing results were identified, > 75% of which provided guidance in management. Children were more likely to have a disease-causing result if they were < 3 years old at seizure onset (OR 4.4, p < 0.001), had neurodevelopmental concerns (OR 2.2, p = 0.002), or had a developmentally abnormal MRI (OR 3.8, p < 0.001). A total of 1417 VUSs were identified, equating to 15.7 VUSs per disease-causing result. Non-Hispanic white patients had a lower average number of VUSs than patients of all other races/ethnicities (1.7 vs 2.1, p < 0.001). SIGNIFICANCE: Expansion in the volume of genetic testing corresponded to a decrease in the time from seizure onset to testing result. Diagnostic yield remained stable, resulting in an increase in the absolute number of disease-causing results annually-most of which have implications for management. However, there has also been an increase in total VUSs, which likely resulted in additional clinical time spent on VUS resolution.