0862 POLYSOMNOGRAPHIC CHARACTERISICS OF PEDIATRIC DOWNS SYNDROME PATIENTS BEFORE AND AFTER HYPOGLOSSAL NERVE STIMULATOR IMPANT

We examined the effect of electrical stimulation of the hypoglossal nerve and pharyngeal lubrication with artificial surfactant (Surfactant T-A) on the opening of obstructed upper airway in nine anesthetized supine dogs. The upper airway was isolated from the lower airway by transecting the cervical trachea. Upper airway obstruction was induced by applying constant negative pressures (5, 10, 20, and 30 cmH2O) on the rostral cut end of the trachea. Peripheral cut ends of the hypoglossal nerves were electrically stimulated by square-wave pulses at various frequencies from 10 to 30 Hz (0.2-ms duration, 5–7 V), and the critical stimulating frequency necessary for opening the obstructed upper airway was measured at each driving pressure before and after pharyngeal lubrication with artificial surfactant. The critical stimulation frequency for upper airway opening significantly increased as upper airway pressure became more negative and significantly decreased with lubrication of the upper airway. These findings suggest that greater muscle tone of the genioglossus is needed to open the occluded upper airway with larger negative intraluminal pressure and that lubrication of the pharyngeal mucosa with artificial surfactant facilitates reopening of the upper airway.

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Hypoglossal Nerve Stimulator Implantable Pulse Generator Exchange for Battery Depletion

Otolaryngology ◽

10.1177/0194599820925767 ◽

2020 ◽

Vol 163 (2) ◽

pp. 389-390

Author(s):

Andrew J. Goates ◽

Erik K. St Louis ◽

Michael D. Olson

Keyword(s):

Hypoglossal Nerve ◽

Pulse Generator ◽

Nerve Stimulator ◽

Implantable Pulse Generator

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0674 Association Between Lateral Wall Collapse On Drug-induced Sleep Endoscopy And MRI Findings In Hypoglossal Nerve Stimulator Patients

SLEEP ◽

10.1093/sleep/zsaa056.670 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A257-A257

Author(s):

Y Liu ◽

A Wiemken ◽

A Steffen ◽

R Schwab ◽

R Dedhia

Keyword(s):

Hypoglossal Nerve ◽

Lateral Wall ◽

Inverse Association ◽

Sleep Endoscopy ◽

Nerve Stimulator ◽

Mri Findings ◽

Drug Induced ◽

Drug Induced Sleep Endoscopy ◽

Obstructive Sleep ◽

The Mean

Abstract Introduction Hypoglossal nerve stimulator (HNS) is an effective and safe alternative therapy for obstructive sleep apnea (OSA) in selected patients. Emerging evidence demonstrates that the outcome of HNS is variable, especially for patients with lateral wall collapse on drug-induced sleep endoscopy (DISE). Awake magnetic resonance imaging (MRI) offers detailed visualization of soft tissue. The aim of this study was to determine whether lateral wall collapse on DISE is associated with awake MRI findings in prospective HNS patients. Methods Patients from the ADHERE Registry, an international outcomes study for UAS were used for this study. At baseline, awake, supine MRI scans of each subject’s head and neck region were collected. The distance between the lateral walls was measured at the level of the hard palate, located by the appearance of the posterior nasal spine, using axial T2 turbo spin echo MRI. DISE assessments of the upper airway were recorded using the VOTE classification. All statistical analyses were performed using SPSS IBM 19.0 software program. Kendall’s Tau-b was performed to compare the association between VOTE scoring and MRI findings. Results Twenty-seven patients (N = 3 female, AHI = 28.8±10.5, BMI = 28.8 ±3.8 kg/m2, age = 53±9.9 years) were included in this study. The mean overall VOTE score and lateral wall score was 5.6±1.1 and 0.5±0.5, respectively. The mean lateral wall distance was 18.8±3.2 mm. A significant, inverse association was found between MRI lateral wall measurement and oropharyngeal lateral wall scoring on DISE (T=-.332,p=0.042) but not other anatomic subsites on DISE. Conclusion In our study, greater lateral wall collapse on DISE corresponded to narrower lateral airway distance on MRI. The utility of static imaging modalities such as MRI as patient selection tools for HNS warrants further study. Support Drs. Dedhia and Schwab receive related support for this project from the National Institutes of Health (NHBLI R01HL144859)

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Effect of upper airway negative pressure on proprioceptive afferents from the tongue

Journal of Applied Physiology ◽

10.1152/jappl.1999.86.4.1396 ◽

1999 ◽

Vol 86 (4) ◽

pp. 1396-1401 ◽

Cited By ~ 7

Author(s):

A. Brancatisano ◽

P. Davis ◽

T. van der Touw ◽

J. R. Wheatley

Keyword(s):

Hypoglossal Nerve ◽

Upper Airway ◽

Rapid Onset ◽

Firing Frequency ◽

Tongue Muscle ◽

Airway Mucosa ◽

Afferent Fibers ◽

Before And After ◽

Proprioceptive Afferents ◽

Passive Stretch

We examined whether receptors in the tongue muscle respond to negative upper airway pressure (NUAP). In six cats, one hypoglossal nerve was cut and its distal end was prepared for single-fiber recording. Twelve afferent fibers were selected for study on the basis of their sensitivity to passive stretch (PS) of the tongue. Fiber discharge frequency was measured during PS of the tongue and after the rapid onset of constant NUAP. During PS of 1–3 cm, firing frequency increased from 17 ± 7 to 40 ± 11 (SE) Hz ( P < 0.01). In addition, 8 of the 12 fibers responded to NUAP (−10 to −30 cmH2O), with firing frequency increasing from 23 ± 9 to 41 ± 9 Hz ( P < 0.001). In two fibers tested, the increase in firing frequency in response to NUAP was not altered by topical anesthesia (10% lignocaine) applied liberally to the entire upper airway mucosa. Our results demonstrate that afferent discharges from the hypoglossal nerve are elicited by 1) stretching of the tongue and 2) NUAP before and after upper airway anesthesia. We speculate that activation of proprioceptive mechanoreceptors in the cat’s tongue provides an additional pathway for the reflex activation of upper airway dilator muscles in response to NUAP, independent of superficially located mucosal mechanoreceptors.

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