1094 Hypoglossal Nerve Stimulation in Central Sleep Apnea

The hypoglossal nerve stimulator (HNS) has been FDA approved for the treatment of obstructive sleep apnea (OSA). To date, use of HNS for central sleep apnea (CSA) has not been described. Here, we describe a case of predominantly CSA with response to HNS. A 73-year-old female patient diagnosed with OSA (AHI 30.6/hr), intolerant of CPAP therapy, was implanted with a HNS. Following implantation and a healing period, she presented to the sleep medicine clinic for activation of the HNS. During the activation of the HNS, the sensation threshold was 0.4V and the functional threshold was established at 0.5V. Patient limits were set between 0.5 to 1.5V. The patient returned several weeks later with clinical improvement in her symptoms. A sleep study was performed to determine therapeutically appropriate HNS settings. Unexpectedly, central apneas were observed with an overall AHI of 37.5/hr, and CAI 32.3/hr. Initial sleep study results were reviewed which revealed predominantly central apneas with CAI of 22.6/hr. Given the patient’s clinical improvement with HNS, therapy was continued despite CSA on the titration study. Approximately three months later (usage 46hr/week), she reported continued clinical improvement and a portable sleep study at 0.8V demonstrated an AHI of 7.8/hr and CAI 1.3/hr. While the HNS has been approved for use in OSA, data on its use in CSA is scarce. This case describes a patient with predominantly CSA who has responded well to HNS. This illustrates that consideration for therapy with HNS should be given for selected patients with CSA and some obstructive elements. Reporting of further cases and randomized, controlled studies or comparative-effectiveness trials are warranted in the future.