1213 Vagal-nerve Stimulation Induced Refractory Central Sleep Apnea

Abstract Introduction Vagus nerve stimulation (VNS) is an effective therapy for epilepsy that has previously been suggested to worsen obstructive and central sleep apnea. Management of medically complex patients in the traditional sleep laboratory can present logistical barriers given the minimal medical oversight. Innovative forms of sleep monitoring offer new options to evaluate sleep serially. Report of case(s) A 69-year-old female with a history of medically refractory generalized epilepsy, on a vagal nerve stimulator, presented to sleep clinic in September of 2022 after undergoing a polysomnogram significant for severe sleep apnea with AHI 3% of 56, AHI 4% of 48, and oxygen nadir of 83%. A November 2022 titration was unsuccessful (residual AHI of 48 and oxygen desaturation nadir of 88%). Periodic breathing proved refractory to CPAP, BiPAP, BiPAP S/T, adaptive servo-ventilation, and attempts to mitigate high loop gain physiology with CO2 modulation techniques, acetazolamide, and supplemental oxygen. VNS setting could not be manipulated in the sleep laboratory safely. She was placed on CPAP setting of 5-10 cm H2O with compliance data showing average residual AHI of 24.3 and 29% of nights being in Hunter-Cheyne-Stokes breathing (HCSB). A planned hospital admission in July 2023 was arranged to monitor sleep with the SleepImage Ring system, which offered measurement of AHI and periodicity without the need for manual scoring. The VNS battery proved depleted during the stay but 5 nights on the same CPAP settings with the VNS off showed a residual AHI 4% of 1-3 with minimal periodic breathing. Patient underwent replacement of VNS generator with reduction of output current to 1/3 of prior value with gradual up-titration. Subsequent CPAP compliance data showed gradual increase in AHI and periodic breathing with rising VNS setting. Currently, the patient is undergoing VNS adjustments to optimize seizure control with plans to restudy sleep breathing at lower nocturnal settings when stabilized. Conclusion Sleep apnea induced by VNS can be refractory to therapy. Tracking sleep with the SleepImage system and PAP compliance data allowed understanding of the role of neurostimulation in inducing sleep dysfunction. Support (if any) Institute for Personalized Sleep Health, Beth Israel Deaconess Medical Center