Abstract Introduction Hypoglossal nerve stimulation (HNS) is an emerging alternative treatment option for moderate-to-severe obstructive sleep apnea (OSA) in patients who are unable to use or benefit from positive airway pressure therapy. Hypoglossal nerve neurapraxia is a mild nerve injury characterized by a transient and reversible nerve conduction block, without axonal disruption, resulting in temporary tongue deviation, weakness, dysphagia, and dysarthria. We present two patients with transient hypoglossal dysfunction after upper-airway stimulator placement. Report of case(s) Patient 1: A 49 y.o. female presented with daytime somnolence, fatigue, and snoring, diagnosed with severe OSA on home sleep study. Inspire device was implanted due to intolerance to CPAP secondary to facial rash and suffocation. Activation of inspire therapy was delayed due to post-surgical neurapraxia despite of going up to 3.0 volts on setting A, B or C. Her device was successfully activated 3 months later, after she noticed gradual improvement. The patient was put on setting A with functional voltage of 1.8 volts which was then changed to setting B with incoming voltage of 1.5 volt because of discomfort. Patient 2: A 79 y.o. overweight female presented with fatigue and snoring, was found to have nocturnal hypoxemia attributable to moderate OSA diagnosed on home sleep study, intolerant to CPAP. An attempt was made to activate her device 2 months after her Inspire implant placement but she developed neurapraxia and did not get tongue movement at that time. A successful re-attempt was carried out 5 months later, after she noticed improvement in her tongue movement and function. The patient responded well to setting C with a voltage range of 2.2-3.2 volts. Conclusion Up to now, attempts have been made to activate the nerve stimulator just a couple of weeks after its placement, even though minor hypoglossal nerve injury is not an uncommon side effect. For transient or neurapraxic injuries, about 50% of patients recover within 8 weeks and 80% within 16 weeks. Our experience highlights the importance of delaying the activation of the Hypoglossal Nerve Stimulator by 12 to 16 weeks, as it can lead to more successful outcomes and less patient discomfort as compared to premature activation. Support (if any)
Zubair et al. (Fri,) studied this question.