Clinical Neurology and Neurosurgery 137 (2015) 89–93 Contents lists available at ScienceDirect Clinical Neurology and Neurosurgery jo ur nal home p age: www.elsevier.com/locate/clineuro Vagus nerve stimulation therapy for treatment-resistant epilepsy: A 15-year experience at a single institution L. Galbarriatu a,* , I. Pomposo a , J. Aurrecoechea a , A. Marinas b , M. Agúndez b , J.C. Gómez b , M.A. Acera b , M.J. Martínez c , E. Valle d , I. Maestro d , B. Mateos e , A. Cabrera e , J. Fernández f , F. Iturri g , I. Garamendi b a Department of Neurosurgery, Cruces University Hospital, Barakaldo, Spain b Department of Neurology, Cruces University Hospital, Barakaldo, Spain c Department of Neuropediatrics, Cruces University Hospital, Barakaldo, Spain d Department of Neurophysiology, Cruces University Hospital, Barakaldo, Spain e Department of Radiology, Cruces University Hospital, Barakaldo, Spain f Department of Psychiatry, Cruces University Hospital, Barakaldo, Spain g Department of Anesthesiology, Cruces University Hospital, Barakaldo, Spain a r t i c l e i n f o Article history: Received 16 August 2014 Received in revised form 19 June 2015 Accepted 28 June 2015 Available online 2 July 2015 Keywords: Vagus nerve stimulation Treatment-resistant epilepsy Right-sided VNS Pregnancy Off-label indications a b s t r a c t Objective: Treatment-resistant epilepsy (TRE) occurs in 20–30% of patients. The goal of this study is to assess the efficacy and safety of vagus nerve stimulation (VNS) in this group of patients, including adult and pediatric populations and several off-label indications. Methods: This is a retrospective review of 59 consecutive patients in whom 60 VNS devices were implanted at a single institution during a 15-year period. Patients were evaluated in the Multidisciplinary Epilepsy Committee and complete presurgical workup was performed. The series included indications not approved by the FDA, such as children under 12 years of age, pregnancy and right-sided VNS. Performing the procedure on an out-patient basis was recently adopted, minimizing hospital length of stay. Results: There were 42 adults and 17 children (14 under 12 years of age) and the mean age at implantation was 26 years. Duration of VNS therapy ranged from 6 months to 9 years. For the entire cohort, the mean percentage seizure reduction was 31.37%. Twenty patients (34.48%) were considered responders (seizure reduction ≥50%); 7 patients (12.06%) had seizure reduction of ≥75% and 2 patients had seizure control of ≥90% (3.4%). The patient in whom right-sided VNS was implanted achieved the same reduction in seizure burden and the patient who became pregnant could reduce antiepileptic drugs dosage, without complications. Side-effects were mild and there were no permanent nerve injuries. One patient died in the follow-up due to psychiatric disorders previously known. Conclusions: VNS is a safe and effective palliative treatment for TRE patients. There are an increasing number of indications and further randomized trials would potentially expand the number of patients who may benefit from it. A multidisciplinary team is crucial for a complete preoperative evaluation and selection of the optimal candidates for the treatment. © 2015 Elsevier B.V. All rights reserved. 1. Introduction Approximately 50 million people worldwide are affected by epilepsy [1] and it represents the second neurological disorder in incidence and prevalence after cerebrovascular disease [2]. It has a significant psychological and social impact on patients and * Corresponding author at: Cruces University Hospital, Plaza Cruces s/n 48903, Barakaldo, Spain. Tel.: +34946006361. E-mail address: lara.galbarriatugutierrez@osakidetza.net (L. Galbarriatu). relatives, and its high morbidity and low mortality create increasing and disproportionately high costs of illness compared with other diseases [3,4]. Most of the patients are successfully controlled with antiepileptic drugs (AEDs); however, treatment-resistant epilepsy (TRE) has been reported to occur in 20–30% of patients [1,5–7] and only 20–40% of them meet criteria for surgical treatment [8]. Vagus nerve stimulation (VNS; VNS Therapy System; Cyberonics, Inc., Houston, TX, USA) is the most widely used and studied neurostim- ulation procedure and it constitutes an alternative of treatment for this group of patients. It was approved by U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) in http://dx.doi.org/10.1016/j.clineuro.2015.06.023 0303-8467/© 2015 Elsevier B.V. All rights reserved.