DAY 3 | Vagus Nerve Stimulation Is a Viable Long-Term Treatment Option for Patients with Drug-Resistant Epilepsy

Vagus nerve stimulation (VNS) therapy achieved long-term reduction in seizure activity and significant improvements in quality of life in children and adults with drug-resistant epilepsy, according to a series of studies presented at the 2025 American Epilepsy Society Annual Meeting (AES 2025) in Atlanta, Georgia. 

A retrospective analysis showed that a vast majority of the children with drug-resistant epilepsy who underwent VNS implantation at Children’s Mercy Hospital at the University of Missouri-Kansas City (UMKC) over two decades experienced a decrease of at least 50% in seizure episodes. The study included 400 children with a mean age of 9 years at the time of VNS implantation, who were treated at the UMKC hospital between January 2003 and December 2023. VNS demonstrated long-term efficacy in 90.5% of these patients, whose seizure frequency decreased by at least 50%. Moreover, 20.5% of the treated children reported freedom from seizures at their last follow-up visits. The results showed that 35 patients were seizure-free for longer than 2 years and 42 patients reported between 6 and 23 months of seizure freedom. Eight children were able to discontinue all anti-seizure medications. Quality of life also improved in 90% of the cohort, which translated into developmental gains, enhanced attention, and increased academic performance. 

Age at seizure onset, gender, and the number of previous lines of therapy did not influence the outcomes of VNS therapy. However, factors such as early VNS implantation and higher stimulation parameters, particularly ultra-rapid duty cycling, were associated with the best outcomes. The analysis also showed that VNS therapy was most effective in patients with focal onset seizures, who had a 93% response rate. 

VNS therapy, a well-established adjunctive therapy for drug-resistant epilepsy in adults and children, was previously found to be highly effective in the treatment of drug-resistant pediatric epilepsy, with response rates around 56% at a mean follow-up of 2.5 years (Jain P, Arya R. Neurology 2021; 96:1041-51). The high response rates recorded at the Children’s Mercy Hospital reinforced the previous findings, suggesting that earlier referral for VNS implantation may improve outcomes in this population, lead author Lalit Bansal, MD, assistant professor at the UMKC School of Medicine, noted during a poster presentation. The author remarked that the clinical workflow should incorporate routine screening for obstructive sleep apnea, a side effect that was reported in nearly 17% of the patients treated with VNS therapy at the Children’s Mercy Hospital, which should be managed proactively. 

A separate analysis presented at AES 2025 showed that patients with refractory epilepsy who reside in underserved communities could benefit from VNS therapy, which may be as effective as more invasive surgical therapies in this population. 

A study of 74 adults with refractory focal epilepsy who underwent VNS therapy at the Kern Medical Epilepsy Center in Bakersfield, California between 2016 and 2024 showed that nearly 80% of the cohort experienced reductions in seizure frequency. The retrospective review of the patients’ charts showed that 13.5% of the included patients were seizure-free for 12 months or for at least three times the duration of their longest interval of seizure freedom during the 12 months preceding VNS implantation, and 36% of the cohort experienced a reduction of at least 80% in seizure frequency. While 20.3% of the patients had no reductions in seizure frequency after a minimum of 6 months post-implantation, those patients reported less severe seizure episodes after implantation. 

“A lot of people from the neighboring areas make the commute to Bakersfield to go to Kern Medical Center because they don’t have a lot of specialty care in their area,” said presenting author Wefaq Alshami, BS, a program specialist at Kern Medical Center. “This often affects whether they get early intervention. They may [notice] their symptoms but they do not make the trip to Kern Medical, mostly because of contributing factors such as lack of education, low income, difficulty balancing between work and healthcare, and limited resources at the hospital itself. Based on the overall results that we have [so far], we have concluded that, the earlier the intervention and the longer that you have the VNS, the better the outcomes. That is why we advocate for early intervention.”  

Alshami and co-authors will continue to monitor the patients included in the study and are planning to record additional data over time. Future analyses may also be conducted to assess the impact of socioeconomic factors, including income and the level of education, on the outcomes on VNS therapy. “A lot of these patients are lower-income,” Alshami added.” We have not looked at this specific aspect yet, but I think for many of these patients, the highest level of education is high school or lower. That might contribute to their lack of access to [specialty] care.”