Colaco, Clinton

Abstract Introduction Hypoglossal nerve stimulation (HNS) for the treatment of obstructive sleep apnea (OSA) in patients who have failed positive airway pressure (PAP) therapy for one reason or the other is now standard of care. Once the device is implanted and activated, voltage to stimulate the nerve has to be titrated over time, ultimately leading to an HNS titration study. There are 4 possible electrode configurations to stimulate different fibers in the nerve that can be employed for treatment. We present a case of a patient who was a challenge with worsening of OSA with Inspire. Report of case(s) A 65-year-old woman with hypertension, and severe OSA, intolerant of positive airway pressure or oral appliances was implanted with Inspire. Post activation, there was symptomatic improvement with reduction of overall apnea-hypopnea index (AHI) from 34 per hour of sleep to 6.3 per hour. However, patient slept exclusively on the sides with evidence of significant residual disease in REM sleep. During subsequent weeks, patent reported inability to restrict position and discomfort and anxiety associated with up titration. Both awake endoscopy and advanced overnight HNS titration were pursued. All 4 electrode configurations were tested during both procedures. With the exception of (minus-plus-minus) configuration, there was worsening of sleep disordered breathing and higher residual AHI of 60 per hour on polysomnography and evidence of poor tongue motion and collapsed velopharynx on awake endoscopy. Inspire settings were readjusted to (minus-plus-minus) configuration with instructions for very slow outpatient uptitration and co-management of anxiety and discomfort with anxiolytics and sleep aids. Conclusion We make two important conclusions from this case. Firstly, although there are established criteria for patient selection for hypoglossal nerve stimulation therapy, certain other factors that impact success which are not as easily defined include the patients’ expectations, tolerance of discomfort, propensity to anxiety and personality type which impact the ability to successfully titrate voltage with the Inspire device over time. Secondly, as the tongue is a complex muscle, both under titration and over titration may be counterproductive and additionally, electrode configuration may also have varying effects on tongue protrusion and impact success. Support (if any)

Abstract Introduction Multisystem atrophy (MSA) is a neurological degenerative progressive disease affecting multiple systems. These patients are frequently seen in the sleep clinic at specialty centers by sleep neurologists for co-management of sleep disordered breathing and nocturnal respiratory issues. Stridor is a life-threatening condition seen in these patients and requires emergent action. We present a case of MSA with worsening stridor that was missed in the era of virtual telemedicine. Report of case(s) A 53-year-old female with a history of obstructive sleep apnea (OSA) on BiPAP S and multiple system atrophy with parkinsonian subtype presented virtually to sleep clinic for follow up evaluation of her sleep disordered breathing. Six months prior to her visit she was noted to have bilateral vocal fold hypomobility without stridor. At that time, she had a residual apnea-hypopnea index (AHI) of 1.4 with BiPAP-S 16/13 cm H2O and no nocturnal stridor. She was wheelchair bound. She had routine follow up visits with various providers however these were telemedicine visits with her husband doing most of the talking due to weakness. Over the next 5 months she had worsening fatigue and was using BiPAP S during the day intermittently and was referred to the sleep medicine clinic for consideration of supplemental oxygen at night. A repeat overnight oximetry revealed residual oxygen desaturation index (ODI) of 2.5/hr while on BiPAP S. Repeat pulmonary function testing was ordered and patient was recommended to return for immediate in person follow up. When seen in person, patient was noted to have significant stridor which had been ongoing and worsening over last few months including being appreciated while on PAP therapy. Emergent same-day ENT consultation was arranged by sleep providers. Posterior cordectomy was performed shortly thereafter. The patient was scheduled for an AVAPS titration study. Conclusion In cases with progressive neuromuscular disease, stridor may be missed during virtual appointments for a variety of reasons including technical difficulties, or the virtual medium not being sensitive enough to convey stridor. This case highlights the importance of having a high index of suspicion for stridor and impending respiratory failure requiring emergent intervention in patients with neuromuscular disease. Support (if any)