scholarly journals P005 The effect of alcohol on the motor control of the genioglossus muscle

2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A23-A23
Author(s):  
J Avraam ◽  
A Dawson ◽  
C Nicholas ◽  
A Kay ◽  
F O’Donoghue ◽  
...  
Keyword(s):  
Nasal Congestion ◽  
Upper Airway ◽  
Motor Units ◽  
Alcohol Concentration ◽  
Healthy Individuals ◽  
Depressant Effect ◽  
Genioglossus Muscle ◽  
Single Motor Units ◽  
Obstructive Sleep ◽  
Breath Alcohol Concentration

Abstract Rationale Alcohol is recognised to worsen snoring and obstructive sleep apnea (OSA). This effect is thought to be due to alcohol’s depressant effect on upper airway dilator muscles such as the genioglossus, but how alcohol reduces genioglossus activity is unknown. The aim of this study was to investigate alcohol’s effect on genioglossus single motor units (SMUs). Methods Healthy individuals visited the lab on two days (Alcohol: breath alcohol concentration ~0.08% or Placebo). They were instrumented with a nasal mask, 4 intramuscular genioglossus SMU EMG wires and an ear oximeter. They were exposed to 8–12 hypoxia trials (45-60s of 10%O2 followed by one breath of 100%O2) while awake. The SMUs were sorted according to their firing patterns with respect to respiration and were quantified during baseline, hypoxia, hyperoxia and recovery. Results The total number of SMUs recorded at baseline (68 and 67 respectively) and their distribution (ET: 29 vs 22, IP: 5 vs 10, IT: 8 vs 20 and TT: 26 vs 15 respectively) was similar between conditions. The discharge frequency did not differ between conditions (21Hz vs 22.4Hz, p>0.08). There was no difference between placebo and alcohol in the number (101 vs 88 respectively) and distribution (ET: 35 vs 32, IP: 22 vs 16, IT: 14 vs 22 and TT: 30 vs 17 respectively, p<0.05) of SMUs during hypoxia. Afterdischarge following hypoxia was also not different between conditions. Conclusion Alcohol has little effect on genioglossus SMUs and afterdischarge. OSA following alcohol may be related to increased upper airway resistance/nasal congestion.

scholarly journals O037 Genioglossus motor control following the return to sleep after brief arousal

2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A16-A16
Author(s):  
A Dawson ◽  
J Avraam ◽  
C Nicholas ◽  
A Kay ◽  
J Trinder ◽  
...  
Keyword(s):  
Motor Units ◽  
Firing Frequency ◽  
Nasal Mask ◽  
Persistent Activity ◽  
Genioglossus Muscle ◽  
Single Motor Units ◽  
Airway Collapse ◽  
Obstructive Sleep ◽  
Persistent Firing ◽  
Healthy Participants

Abstract Rationale Arousal from sleep has been shown to elicit a prolonged increase in genioglossus muscle activity that persists following the return to sleep and may protect against airway collapse. We hypothesised that this increased genioglossal activity following return to sleep after an arousal is due to persistent firing of inspiratory single motor units (SMUs) recruited during the arousal. Methods 34 healthy participants were studied overnight while wearing a nasal mask/pneumotachograph to measure ventilation and with 4 intramuscular genioglossus SMU electrodes. During stable N2 and N3 sleep, auditory tones were played to induce brief (3-15s) AASM arousals. Ventilation and genioglossus SMUs were quantified for 5 breaths before the tone, during the arousal and for 10 breaths after the return to sleep. Results A total of 1089 tones were played and gave rise to 236 SMUs recorded across arousal and the return to sleep in 20 participants (age 23±4.2 years and BMI 22.5±2.2kg/m2). Ventilation was elevated above baseline during arousal and the first post-arousal breath (p<0.001). The peak firing frequency of expiratory and tonic SMUs was unchanged during arousal and return to sleep, whereas inspiratory modulated SMUs were increased during the arousal and for 4 breaths following the return to sleep (p<0.001). Conclusions The prolonged increase in genioglossus activity that occurs on return to sleep after arousal is a result of persistent activity of inspiratory SMUs. Strategies to elevate inspiratory genioglossus SMU activity may be beneficial in preventing/treating obstructive sleep apnea.

After-Discharge in the Upper Airway Muscle Genioglossus Following Brief Hypoxia

SLEEP ◽  
2021 ◽  
Author(s):  
Joanne Avraam ◽  
Andrew Dawson ◽  
Nicole Feast ◽  
Feiven Lee Fan ◽  
Monika D Frigant ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Upper Airway ◽  
Motor Units ◽  
Firing Frequency ◽  
Healthy Individuals ◽  
Single Breath ◽  
Single Motor Units ◽  
Persistent Firing ◽  
Respiratory Modulation ◽  
Insight Into

Abstract Study Objectives Genioglossus after-discharge is thought to protect against pharyngeal collapse by minimising periods of low upper airway muscle activity. How genioglossus after-discharge occurs and which single motor units (SMUs) are responsible for the phenomenon are unknown. The aim of this study was to investigate genioglossal after-discharge. Methods During wakefulness, after-discharge was elicited 8-12 times in healthy individuals with brief isocapnic hypoxia (45-60s of 10%O2 in N2) terminated by a single breath of 100% O2. Genioglossus SMUs were designated as firing solely, or at increased rate, during inspiration (Inspiratory phasic [IP] and inspiratory tonic [IT] respectively); solely, or at increased rate, during expiration (Expiratory phasic [EP] or expiratory tonic [ET] respectively) or firing constantly without respiratory modulation (Tonic). SMUs were quantified at baseline, the end of hypoxia, the hyperoxic breath and the following 8 normoxic breaths. Results 210 SMU’s were identified in 17 participants. Genioglossus muscle activity was elevated above baseline for 7 breaths after hyperoxia (p<0.001), indicating a strong after-discharge effect. After-discharge occurred due to persistent firing of IP and IT units that were recruited during hypoxia, with minimal changes in ET, EP or Tonic SMUs. The firing frequency of units that were already active changed minimally during hypoxia or the afterdischarge period (P>0.05). Conclusion That genioglossal after-discharge is almost entirely due to persistent firing of previously silent inspiratory SMUs provides insight into the mechanisms responsible for the phenomenon and supports the hypothesis that the inspiratory and expiratory/tonic motor units within the muscle have idiosyncratic functions.

scholarly journals Maximum isometric tongue force in patients with obstructive sleep apnoea

2020 ◽  
Author(s):  
Richard Birk ◽  
Boris A. Stuck ◽  
Joachim T. Maurer ◽  
Angela Schell ◽  
C. Emika Müller ◽  
...  
Keyword(s):  
Isometric Force ◽  
Upper Airway ◽  
Sleep Apnoea ◽  
Matched Pair ◽  
Healthy Individuals ◽  
New Device ◽  
Obstructive Sleep ◽  
Posterior Direction ◽  
Maximum Isometric Force ◽  
Anterior Posterior

Abstract Background Obstructive sleep apnea (OSA) is a sleep disorder with a prevalence of 9–38%. The underlying pathology in OSA is a collapse of the upper airway. Especially in more severely affected patients, this collapse is often located at the level of the tongue base. Therefore, various implantable systems (anchors and ligament techniques) were developed to prevent or overcome this collapse. These systems are exposed to various forces. Different models have been developed to measure these forces and data comparing forces in healthy individuals with OSA patients are rare. Purpose Purpose of the study was to evaluate possible differences in tongue forces between healthy individuals and patients with OSA. Method To evaluate maximum isometric tongue forces, we conducted a matched pair design study including 20 healthy individuals and 20 patients suffering from OSA. Maximum isometric tongue forces were measured in an anterior/posterior direction with the help of self-designed new device that clamps the tongue. Results We could show that the maximum isometric force does not differ significantly in healthy individuals (10.7 ± 5.2N) from patients with OSA (14.4 ± 6.3N). Conclusion Currently there are no indications that maximum isometric tongue force does differ in healthy individuals and patients with OSA. Higher, as well as lower, tongue forces in patients with OSA seem not to differ from healthy subjects and therefore may not be needed to consider, in the development of tongue management devices, for OSA patients.

scholarly journals Role of common hypnotics on the phenotypic causes of obstructive sleep apnoea: paradoxical effects of zolpidem

2017 ◽  
Vol 50 (6) ◽  
pp. 1701344 ◽  
Author(s):  
Jayne C. Carberry ◽  
Lauren P. Fisher ◽  
Ronald R. Grunstein ◽  
Simon C. Gandevia ◽  
David K. McKenzie ◽  
...  
Keyword(s):  
Obstructive Sleep Apnoea ◽  
Muscle Activity ◽  
Upper Airway ◽  
Sleep Apnoea ◽  
Double Blind ◽  
Genioglossus Muscle ◽  
Airway Narrowing ◽  
Arousal Threshold ◽  
Obstructive Sleep ◽  
Airway Collapsibility

Hypnotics are contraindicated in obstructive sleep apnoea (OSA) because of concerns of pharyngeal muscle relaxation and delayed arousal worsening hypoxaemia. However, human data are lacking. This study aimed to determine the effects of three common hypnotics on the respiratory arousal threshold, genioglossus muscle responsiveness and upper airway collapsibility during sleep.21 individuals with and without OSA (18–65 years) completed 84 detailed sleep studies after receiving temazepam (10 mg), zolpidem (10 mg), zopiclone (7.5 mg) and placebo on four occasions in a randomised, double-blind, placebo-controlled, crossover trial (ACTRN12612001004853).The arousal threshold increased with zolpidem and zopicloneversusplacebo (mean±sd−18.3±10 and −19.1±9versus−14.6±7 cmH2O; p=0.02 and p<0.001) but not with temazepam (−16.8±9 cmH2O; p=0.17). Genioglossus muscle activity during stable non-REM sleep and responsiveness during airway narrowing was not different with temazepam and zopicloneversusplacebo but, paradoxically, zolpidem increased median muscle responsiveness three-fold during airway narrowing (median −0.15 (interquartile range −1.01 to −0.04)versus−0.05 (−0.29 to −0.03)% maximum EMG per cmH2O epiglottic pressure; p=0.03). The upper airway critical closing pressure did not change with any of the hypnotics.These doses of common hypnotics have differential effects on the respiratory arousal threshold but do not reduce upper airway muscle activity or alter airway collapsibility during sleep. Rather, muscle activity increases during airway narrowing with zolpidem.

Physiological Responses and Perceived Comfort to High Flow Nasal Cannula Therapy in Awake Adults: Effects of Flow Magnitude and Temperature

2021 ◽  
Author(s):  
Indra Narang ◽  
Jayne C. Carberry ◽  
Jane E. Butler ◽  
Simon C. Gandevia ◽  
Alan K.I. Chiang ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Upper Airway ◽  
High Flow ◽  
Nasal Cannula ◽  
Respiratory Support ◽  
High Flow Nasal Cannula ◽  
Genioglossus Muscle ◽  
Obstructive Sleep

Clinical use of heated, high flow nasal cannula (HFNC) for non-invasive respiratory support is increasing and may have a therapeutic role in stabilizing the upper airway in obstructive sleep apnea (OSA). However, physiological mechanisms by which HFNC therapy may improve upper-airway function and effects of different temperature modes are unclear. Accordingly, this study aimed to determine effects of incremental flows and temperature modes (heated and non-heated) of HFNC on upper airway muscle activity (genioglossus), pharyngeal airway pressure, breathing parameters and perceived comfort. Six participants (2 females, aged 35±14 years) were studied during wakefulness in supine position and received HFNC at variable flows (0-60 L/min) during heated (37ºC) and non-heated (21ºC) modes. Breathing parameters via calibrated Respitrace inductance bands (chest and abdomen), upper-airway pressures via airway transducers, and genioglossus muscle activity via intra-muscular bipolar fine wire electrodes were measured. Comfort levels during HFNC were quantified using a visual analogue scale. Increasing HFNC flows did not increase genioglossus muscle activation despite increased negative epiglottic pressure swings (p=0.009). HFNC provided ~7cmH2O positive airway pressure at 60 L/min in non-heated and heated modes. In addition, increasing the magnitude of HFNC flow reduced breathing frequency (p=0.045), increased expiratory time (p=0.040), increased peak inspiratory flow (p=0.002), and increased discomfort (p=0.004). Greater discomfort occurred at higher flows in non-heated versus heated mode (p=0.034). These findings provide novel insight into key physiological changes that occur with HFNC for respiratory support and indicate the primary mechanism for improved upper-airway stability is positive airway pressure, not increased pharyngeal muscle activity.

scholarly journals Genioglossus motor unit activity in supine and upright postures in obstructive sleep apnea

SLEEP ◽  
2019 ◽  
Vol 43 (6) ◽  
Author(s):  
Billy L Luu ◽  
Julian P Saboisky ◽  
Rachel A McBain ◽  
John A Trinder ◽  
David P White ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Motor Unit ◽  
Unit Activity ◽  
Upper Airway ◽  
Motor Units ◽  
Healthy Controls ◽  
Quiet Breathing ◽  
Supine Posture ◽  
Obstructive Sleep

Abstract This study investigated whether a change in posture affected the activity of the upper-airway dilator muscle genioglossus in participants with and without obstructive sleep apnea (OSA). During wakefulness, a monopolar needle electrode was used to record single motor unit activity in genioglossus in supine and upright positions to alter the gravitational load that causes narrowing of the upper airway. Activity from 472 motor units was recorded during quiet breathing in 17 males, nine of whom had OSA. The mean number of motor units for each participant was 11.8 (SD 3.4) in the upright and 16.0 (SD 4.2) in the supine posture. For respiratory-modulated motor units, there were no significant differences in discharge frequencies between healthy controls and participants with OSA. Within each breath, genioglossus activity increased through the recruitment of phasic motor units and an increase in firing rate, with an overall increase of ~6 Hz (50%) across both postures and participant groups. However, the supine posture did not lead to compensatory increases in the peak discharge frequencies of inspiratory and expiratory motor units, despite the increase in gravitational load on the upper airway. Posture also had no significant effect on the discharge frequency of motor units that showed no respiratory modulation during quiet breathing. We postulate that, in wakefulness, any increase in genioglossus activity to compensate for the gravitational effects on the upper airway is achieved primarily through the recruitment of additional motor units in both healthy controls and participants with OSA.

THE COMPARISON OF CONFIGURATION, DEGREE AND SITES OF OBSTRUCTION IN PATIENTS WITH SLEEP DISORDERED BREATHING: EXAMINATION USING DRUG-INDUCED SLEEP ENDOSCOPY, MUELLER MANEUVER AND POLYSOMNOGRAPHY

2020 ◽  
pp. 54-57
Author(s):  
NIKEN AGENG RIZKI ◽  
SUSYANA TAMIN ◽  
FAUZIAH FARDIZZA ◽  
RETNO S. WARDANI ◽  
ARIEF MARSABAN ◽  
...  
Keyword(s):  
Airway Obstruction ◽  
Laryngopharyngeal Reflux ◽  
Nasal Congestion ◽  
Upper Airway ◽  
Upper Airway Obstruction ◽  
Sleep Endoscopy ◽  
Drug Induced ◽  
Drug Induced Sleep Endoscopy ◽  
Obstructive Sleep ◽  
Mueller Maneuver

Objective: The purpose of this study is to evaluate the location, configuration, and degree of differences in upper airway obstruction between the Mueller Maneuver (MM) and Drug-induced sleep endoscopy (DISE), thus acquiring a better diagnostic value for SDB patients. Methods: A cross-sectional and analytical descriptive study using retrospective secondary data to evaluate the location, configuration and degree of upper airway obstruction in SDB subjects using the Mueller Maneuver and DISE. Polysomnography (PSG) type 2 was used to determine the SDB degree. Results: Subjects with SDB non-Obstructive sleep apnea (OSA) and OSA show a multilevel obstruction with a different location and configuration due to the various risk factors, such as nasal congestion, laryngopharyngeal reflux, obesity and menopause. Conclusion: Statistical differences in upper airway obstruction configuration between MM and DISE were found in the level of the velum (p=0,036), oropharynx (p<0,001) and epiglottis (p=0,036) and were also found in the obstruction degree of the velum, oropharynx, tongue base and epiglottis with p=0,002; p<0,001; p<0,001 and p<0,001. No statistical difference was found on the lowest oxygen saturation between PSG and DISE (p=0,055).

Mechanical Properties, Anatomy, and Control of the Upper Airway

2021 ◽  
pp. 27-64
Author(s):  
Denise Dewald ◽  
Kingman P. Strohl
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Neuromuscular Control ◽  
Sleep Health ◽  
Genioglossus Muscle ◽  
Obstructive Sleep ◽  
Wall Stiffness ◽  
Maxilla And Mandible ◽  
And Control

The physiology of the upper airway is fundamental to current and trending therapy for obstructive sleep apnea and neurostimulation in particular. Proper functioning of the upper airway will promote sleep health by supporting the requisite airflow without snoring or significant flow limitation. Dysfunction produces snoring, obstructive hypopneas, and the metabolic sequelae of sleep disordered breathing. How a particular section of the upper airway (e.g., velopharynx, oropharynx, or hypopharynx) remains open while it is suspended from the skull base, maxilla, and mandible is the result of anatomy and neuromuscular control. The genioglossus muscle, originally designed for bringing food into the mouth and swallowing, along with multiple other muscles, participates in the maintenance of patency of the muscular pharynx during wakefulness and sleep. If the genioglossus were the only muscle important for airway stability, then hypoglossal nerve stimulation would likely be universally rather than selectively effective; instead, its effectiveness is predicted by velopharyngeal functions, which in terms of sleep health are poorly described. Literature clearly indicates a fundamental role for muscles other than the genioglossus in maintaining airway diameter, shape, and wall stiffness. Models that incorporate a more complete neuromechanical coupling of these components are necessary to understand a stable airway during sleep and helpful for decisions in management of obstructive sleep apnea.

Preventing Upper Airway Collapse Using CPAP With and Without Pressure Oscillations

2016 ◽  
Author(s):  
Sherif Ashaat ◽  
Ahmed M. Al-Jumaily ◽  
Loulin Huang
Keyword(s):  
Nasal Congestion ◽  
Upper Airway ◽  
Operating Pressure ◽  
Invasive Treatment ◽  
Pressure Oscillations ◽  
Pressure Distributions ◽  
Airway Collapse ◽  
Upper Airway Collapse ◽  
Obstructive Sleep ◽  
Mri Scans

During respiration, upper airway collapse occurs when the forces generated from the airway negative pressures become greater than the forces of the airway wall muscles. For patients diagnosed with moderate to severe obstructive sleep apnea (OSA), Continuous Positive Airway Pressure (CPAP) is the most effective non-invasive treatment. The CPAP provides a continuous humidified and pressurized air to prevent airway collapse. The use of the CPAP has been reported to be associated with some side effects including nasal congestion and dry nose. Also stroke symptoms were recorded for cardiovascular disease patients due to the high operating pressure. Using MRI scans, this paper investigates the effects of using the pressure oscillations superimposed on the CPAP to keep the airway open at lower pressure distributions inside the upper airway and consequently increase the patients’ comfort and reduce their rejection to the CPAP.

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