Impact of Preoperative Daytime Sleepiness and Insomnia on Therapy Adherence and Neurostimulation Amplitude in Unilateral Hypoglossal Nerve Stimulation.

Introduction: Average adherence to hypoglossal nerve stimulation (HGNS) therapy is more than 5 h/night. Reported data on HGNS therapy adherence is often based on studies that performed in-lab titration of the neurostimulation parameters and may therefore not represent real-world therapy outcomes. Adherence to HGNS therapy is a major determinant of success of this kind of therapy. Factors with the potential to influence adherence to HGNS therapy should be further elucidated. The aims of this study were to investigate 1) details regarding therapy adherence under HGNS therapy and 2) the possible association between age, insomnia, daytime sleepiness, polysomnography (PSG)-based metrics, neurostimulation parameters and HGNS-therapy adherence. Methods: Forty-three consecutive patients with detailed information about therapy adherence time were included. About 225 ± 191 days after implantation, a PSG without any in-lab titration was performed. Adherence was assessed by interrogating the impulse generator's data at that time. Patient-reported insomnia was assessed using the insomnia severity index (ISI) and the Epworth Sleepiness scale (ESS) was used to assess daytime sleepiness before and after HGNS treatment. Results: An increased adherence in a real-world setting with 48.72 ± 14.74 hours per week (6.96 hours per night) was found. A strong negative correlation between preoperative ESS score and adherence time (r = - 0.43; p<0.005) was found. Neither pre-operative insomnia nor sleepiness had any impact on neurostimulation amplitude. A positive association between preoperative age and therapeutic amplitude levels could be shown. Discussion: In this cohort, average adherence was much higher than previously reported. We provide evidence that pre-operative excessive daytime sleepiness may seriously impair adherence to HGNS therapy.