Emergency. 2018; 6 (1): e27 LE T T E R TO ED I TO R Vagus Nerve Stimulation and External Defibrillation dur- ing Resuscitation; a Letter to Editor Matthias Wittstock1∗, Johannes Buchmann2, Uwe Walter1, Johannes Rosche1,3 1. Department of Neurology, University Medicine Rostock, Rostock, Germany. 2. Department of Child and Adolescence Psychiatry and Neurology, University Medicine Rostock, Rostock, Germany. 3. Department of Neurology, Klinikum Kassel, GNH Holding AG, Kassel, Germany. Received: March 2018; Accepted: April 2018; Published online: 26 April 2018 Cite this article as: Vagus Nerve Stimulation and External Defibrillation during Resuscitation; a Letter to Editor. Emergency. 2018; 6(1): 27. Dear Editor; External defibrillation in patients with implanted neuromod- ulatory devices is a crucial therapeutic challenge. We report a 63-year-old male patient with refractory epilepsy (RE) af- ter recurrent ischaemic strokes in the middle cerebral artery and in the anterior cerebral artery territory 26 and 23 years ago. He received various therapeutic interventions to achieve seizure control with insufficient success. Therefore, vagus nerve stimulation (VNS) (model Pulse 102, Aspire SR, Cy- beronics Inc, Houston, Texas) was applied via insertion of a pulse generator in the left upper chest in 2011. VNS stimu- lation settings were: output current 1.0 mA, pulse width 500 µs, frequency 30 Hz, 30s ON, 3.0 minute OFF. A reduction of seizure frequency was achieved. Last antiepileptic therapy consisted of levetiracetam 1500 mg td, valproate 1000 mg td, and eslicarbazepine 800 mg td. In 2016, he was admitted because of generalized seizure and aspi- ration pneumonia. During hospital stay he suffered a car- diac arrest (CA) with pulseless ventricular tachycardia (VT) caused by fulminant pulmonary artery embolism. After suc- cessful resuscitation, the patient experienced return of spon- taneous circulation (ROSC). During resuscitation, biphasic electric shocks were applied using 150 Joule and subse- quently 360 Joule with patches placed approximately 10 cm parasternal and at the left chest below the VNS. After suc- cessful ROSC the VNS was checked again and no malfunction could be detected. Stimulation settings were not changed. Impedance was normal. Seizures were not observed during the remaining day. Unfortunately, the patient died within one day after successful resuscitation and ROSC because of ∗Corresponding Author: Matthias Wittstock; Department of Neurology, Uni- versity of Rostock, Gehlsheimer Str. 20, 18147 Rostock, Germany. Phone: 0049- 381-4944742 Fax: 0049-381-4944792 E-mail: matthias.wittstock@med.uni- rostock.de . therapy refractory circulatory insufficiency. VNS is an established therapeutic approach in treatment of TRE in children and adults to achieve reduction of seizure frequency with proven safety and efficacy (1). The safety of VNS in emergency situations like cardiac arrest due to VF with need of external defibrillation and application of large amounts of electrical energy is not clear. External defibrilla- tion in VNS patients may potentially be harmful. The liter- ature concerning external defibrillation during resuscitation or external cardioversion (EC) in patients with implanted electronic devices in neurological disorders is sparse (2). In patients with cardiac pacemakers external defibrillation may damage the cardiac device (3). EC applied to deep brain stim- ulation (DBS) patients may cause thalamotomy or DBS fail- ure (4, 5). Application of electroconvulsive therapy in psychi- atric disorders seems to be safe. Two cases of electroconvul- sive therapy (ECT) in VNS have been reported by Sharma et al. (6). The first patient was a 66-year old female with ma- jor depression and the second one, a 57-year-old male with a history of bipolar disorder. Both had VNS for therapy re- fractory psychiatric illness. ECT was applied because of fur- ther worsening of the mental state without malfunction of the VNS device. To our knowledge, this is the first case of external defibrillation in a patient with VNS for TRE without alteration of the neurostimulator’s function. External defib- rillation applied to VNS patients seem to be safe and effec- tive. Several steps should be taken to minimize the electri- cal current flowing through the neurostimulator. First, posi- tion the patches as far away as possible from the VNS at least 10 cm each. Second, position the patches perpendicular to the VNS; use the lowest clinically appropriate output setting, and, finally, confirm that the VNS is functioning properly af- ter defibrillation (2). This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: www.jemerg.com M. Wittstock et al. 2 1. Appendix 1.1. Acknowledgements None. 1.2. Author’s contribution All the authors meet the standard authorship criteria accord- ing to the recommendations of international committee of medical journal editors. 1.3. Conflict of interest The authors declare that there is no conflict. 1.4. Funding and support None. References 1. Sirven JI, Sperling M, Naritoku D, et al. Vagus nerve stim- ulation therapy for epilepsy in older adults. Neurology. 2000;54(5):1179-1182. 2. Venkatraghavan L, Chinnapa V, Peng P, Brull R. Non- cardiac implantable electrical devices: brief review and implications for anesthesiologists. Can J Anaesth. 2009;56(4):320-326. 3. Allen M. Pacemakers and implantable cardioverter defib- rillators. Anaesthesia. 2006;61(9):883-890. 4. 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