Rationale:
Cenobamate (CNB) is a newer antiseizure medication (ASM) that is approved for focal onset seizures in adults and showed significant efficacy. It requires titration to avoid allergic reactions like drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and the exact optimal dose is not clear yet. However, initial clinical trials showed a dose-dependent response with higher percentage of seizure control with higher doses. The responsive neurostimulation (RNS) device is a closed loop neuromodulation device that is implanted in the brain for drug resistant epilepsy and provides long term electrocorticography which was used before to assess the response to ASMs and provide early biomarkers to the ASMs response with objective data rather than subjective seizure count.
Methods:
We reviewed the long term electrocorticography data of a 64-year-old female with bitemporal epilepsy and RNS with depth electrodes implanted in the bilateral mesial temporal regions. The patient was on multiple ASMs (Lacosamide, Valproate, Clobazam and Brivaracetam) and was placed on Cenobamate and the response was tracked over the titration period and the following months.
Results:
The patient’s clinical seizures improved from focal unaware seizures once weekly to once every three months after starting Cenobamate and reaching 100 mg daily, however, the intracranial EEG long episodes (Figure 1.0) which correlated with her clinical seizures did not significantly improve and stayed steady for the six month period. Once CNB was increased to 150 mg daily, there was a steady decrease in the long episodes over the following four month period and electrographic seizures decreased by about 80% less and went from an average of 19 electrographic seizures a month to four electrographic seizures a month (Figure 2.0). The patient denied any clinical seizure during the same period.
Conclusions:
This case showed a significant dose-dependent response of Cenobamate using long term intracranial electrocorticography showing a significant seizure reduction after reaching Cenobamate 150 mg daily which highlights the importance of reaching higher doses to get the desired clinical response.
Funding: None