Dual-Device Neuromodulation in Epilepsy

Objective: Current methods of neuromodulation have been shown to reduce seizures in patients with drug-resistant epilepsy, and in a small percentage of patients it has rendered them seizure-free when surgical resection is not feasible. While polytherapy with antiseizure medication is not uncommon, dual neurostimulation has received limited attention. We set out to identify trends and changes in the use of dual neurostimulation to understand choosing device combinations. Methods: We reviewed the Mayo Clinic database in Florida of patients who underwent vagus nerve stimulation (VNS), deep brain stimulation (DBS), and responsive neurostimulation (RNS) from October 1998 through September 2021. The prevalence of active VNS with DBS or RNS was considered dual therapy. Results: In total, 131 patients (71 female) underwent 164 VNS-associated procedures, 28 received RNS, and 8 received DBS (6 anterior thalamic DBS; 2 thalamic centromedian nucleus DBS). Active dual stimulation occurred in 3 of 28 patients who received RNS and 8 of 8 patients who received DBS (P = 0.006), mean duration of 28 and 16.3 months, respectively. Patients who received VNS-DBS were more likely to have a previous response to VNS (P = 0.025) and were unresponsive to more antiseizure medications (P = 0.020). The VNS-RNS group had focal seizures more likely to have electroclinical localization (P = 0.005) and more frequently underwent invasive electroencephalographic monitoring (P = 0.026). Conclusions: The ability to localize was the primary decision-maker in prompting RNS versus DBS. RNS surgery was more likely to be preceded by invasive electroencephalographic monitoring. Previous VNS responsiveness was more prominent in patients with DBS. Dual therapy was safe. Prospective multicenter studies of dual-device neuromodulation are needed.