Efficacy of vagus nerve stimulation over time: Review of 65 consecutive patients with treatment-resistant epilepsy treated with VNS >10years

• Published in: Epilepsy & behavior 2011-03, Vol.20 (3), p.478-483
• Main Authors: Elliott, Robert E., Morsi, Amr, Tanweer, Omar, Grobelny, Bartosz, Geller, Eric, Carlson, Chad, Devinsky, Orrin, Doyle, Werner K.
• Format: Article
• Language: English
• Subjects: Epilepsy surgery; Medically intractable epilepsy; Medically refractory epilepsy; Pharmacoresistant epilepsy; Vagus nerve stimulation
• ISSN: 1525-5050; 1525-5069
• DOI: 10.1016/j.yebeh.2010.12.042

Studies have reported improved seizure control with increased duration of vagus nerve stimulation (VNS) but are prone to methodological biases. We analyzed the efficacy of VNS over time in patients with treatment-resistant epilepsy (TRE) who underwent VNS therapy 10 or more years. We retrospectively reviewed 65 consecutive patients (29 females) who underwent VNS therapy ≥10years. The mean age at VNS insertion was 30.0years. Forty-four adults (≥18years; 67.7%) and 21 children (32.3%) were included. Seizure frequency and antiepileptic drug (AED) regimens were recorded prior to VNS and, following VNS insertion, at 6months, 1year, 2years, and every 2years thereafter. The mean duration of VNS therapy for this group was 10.4years, and the mean decrease in seizure frequency at last follow-up was 76.3%. The mean reduction in seizures at 6months and years 1, 2, 4, 6, 8, and 10years was 35.7, 52.1, 58.3, 60.4, 65.7, 75.5, and 75.5%, respectively. Seizure frequency was significantly reduced from baseline at each of the recorded intervals (P