Does adjunctive Cenobamate lead to a reduction in the use of vagal nerve stimulation? A long-term observational study of patients on the epilepsy surgery pathway

OBJECTIVES: To assess the effectiveness of adjunctive Cenobamate (CNB) in reducing seizure frequency and influencing concomitant antiseizure medication (ASM) use for adults with refractory epilepsy on the VNS pathway. To assess whether addition of CNB leads to deferral of VNS insertion or deactivation in those with a VNS in situ. METHODS: This retrospective cohort study evaluated adult patients on the epilepsy surgery pathway who were both awaiting and had already undergone VNS insertion (the latter conducted over two years prior to study onset and not requiring imminent battery replacement over a 36-month period. Seizure frequency, changes in concomitant ASMs and decisions regarding VNS were ascertained from electronic records at baseline (T1), 12-month (T2) and 36-month (T3) post initiation of Cenobamate. RESULTS: 65 patients (29 male) were assessed, 42 patients (64.6 %) had a VNS in situ, the remainder were awaiting VNS. 64 patients had a minimum duration of epilepsy of 10 years. 18 patients (28 %) were classified as LGS spectrum. At T2, 40 patients (61.5 %) attained significant seizure reduction of at least 50 % (p < 0.0001). There was no significant difference between the LGS spectrum and non LGS cohorts. 9 of 23 patients awaiting VNS elected not to undergo insertion in light of seizure reduction. 22 (52 %) of the 42 VNS patients attained significant seizure reduction, of whom 3 (8 %) attained seizure freedom. 2 patients requested VNS deactivation. At T3, 13 patients of 23 deferred VNS insertion on account of seizure control with Cenobamate. CONCLUSIONS: Adjunctive CNB has the potential to influence decision making in people with epilepsy. VNS deferral and/or deactivation as a result of significant seizure reduction with CNB has a significant economic impact.