0988 Vagal Nerve Stimulation and OSA

Abstract

Abstract Introduction We present a case of obstructive sleep apnea (OSA) worsened by implantation of a vagal nerve stimulator (VNS). A 22-year-old M with PMH of autism and refractory epilepsy s/p VNS implantation was diagnosed with moderate OSA. His parents noted that his sleep-disordered breathing worsened after VNS implantation. He was started on APAP 4-12 cm H2O. Review of adherence data revealed an elevated residual apnea-hypopnea index (AHI) despite nightly usage. PAP titration study was obtained with improvement of AHI on 16 cm H2O. Despite consequent use of determined pressure settings, residual AHI remained elevated. In consultation with the patient’s neurologist, VNS settings were gradually down titrated. Residual AHI improved and remained low as CPAP settings were subsequently weaned. Report of case(s) The vagus nerve is part of the parasympathetic nervous system. Afferent fibers project to cortical regions involved in seizure activity. Vagal nerve activation leads to desynchrony, thereby decreasing seizure activity.3 VNS, an adjunctive non-pharmacologic treatment of refractory epilepsy, consists of a generator with multiple adjustable settings and a lead connected to the left vagus nerve.1 VNS activation, in conjuction with medical therapy, can lead to decreased seizures. However, VNS may cause complications such as vocal cord dysfunction, laryngeal spasm, and dyspnea.2 In this case, VNS was noted to cause OSA due to increased airway obstruction, though the pathophysiological mechanism behind this has not been clearly delineated. 3 Conclusion Based on current evidence of precipitation or worsening OSA with VNS activation, screening and diagnostic testing for OSA in patients under evaluation for VNS placement should be considered. A multidisciplinary approach between Sleep Medicine and Neurology in conjunction with patient goals can lead to a balanced optimization of both epilepsy and OSA management via adjustments of VNS settings, anti-epileptics, and CPAP. Support (if any) 1. VNS therapy epilepsy. Epilepsy Foundation. https://www.epilepsy.com/sites/default/files/atoms/files/516VNS_VNS_FINAL.pdf. December 20, 2022. 2. Ebben MR, Sethi NK, Conte M, Pollak CP, Labar D. Vagus nerve stimulation, sleep apnea, and CPAP titration. J ClinSleepMed. 2008 Oct 15;4(5):471-3. PMID: 18853706. 3. Parhizgar F, Nugent K, Raj R. Obstructive sleep apnea and respiratory complications associated with vagus nerve stimulators. J ClinSleepMed. 2011 Aug 15;7(4):401-7. doi: 10.5664/JCSM.1204. PMID: 21897779.