Abstracts

Rationale: Neuromodulation-based interventions are an important therapeutic component for patients with DRE. Currently, there are three FDA approved procedures: Vagus Nerve Stimulation (VNS), Responsive NeuroStimulation (RNS), or Deep Brain Stimulation (DBS). VNS is indicated in patients ≥4 years old, and RNS/DBS is indicated in patients ≥18 years old. We analyzed the profiles of patients treated with these interventions.

Methods: We identified patients with epilepsy who underwent VNS or RNS/DBS from 2012 through 2019 using the IBM MarketScan® Commercial and Medicare Supplemental database. Neurostimulation procedures were identified using all relevant procedure codes. RNS and DBS were grouped together due to coding commonalities. The index date was the date of the earliest neurostimulation procedure. Patients were defined in VNS or RNS/DBS groups based on the procedure received on the index date. For inclusion, patients had prescriptions for >1 anti-seizure medication (ASM) during the pre-index period. Included patients had records for a minimum of 24 months before the index surgical date. Patient characteristics, comorbidities, and ASM use were summarized descriptively using information from the 24-month pre-index period. Compliance to ASM (as a class) was evaluated using the medication possession ratio (MPR).

Results: A total of 1,795 patient records were identified following the above methodology, of which 454 received VNS and 1,341 received RNS/DBS procedures. Mean age was 36.3 years and 51% were female. Patients treated with VNS were younger and included twice as many children ( < 18 years) as RNS/DBS (Table). The comorbidity burden as measured by Charlson comorbidity index was higher with RNS/DBS than with VNS (≥2 Charlson comorbidities 62.2% vs. 48.9%). Patients treated with VNS were prescribed a higher number of unique ASMs (mean, 4.2 vs. 3.2) than those treated with RNS/DBS. Nearly two-thirds (63.7%) of patients treated with VNS were prescribed ≥4 ASMs compared with 39.2% of patients treated with RNS/DBS. Overall compliance with ASMs was high; patients receiving VNS had higher compliance (as measured by mean MPR 0.94) than those receiving RNS/DBS (0.79) (p < 0.001).

Conclusions: Patients undergoing RNS/DBS had an overall higher Charlson comorbidity burden reflected in an older patient population. Those undergoing VNS had a higher number of prescribed ASMs compared to RNS/DBS patients, suggesting preoperative differences and epilepsy that is more difficult to control in this patient group. More research is needed to confirm why VNS patients have more frequent changes to their ASMs.

Funding: Please list any funding that was received in support of this abstract.: Funding source: LivaNova.