Effect of Electrical Stimulation of the Hypoglossal Nerve on Airflow Mechanics in the Isolated Upper Airway

Schwartz, Alan R.; Thut, David C.; Russ, Brad; Seelagy, Marc; Xiao, Yuan; Brower, Roy G.; Permutt, S.; Wise, Robert A.; Smith, Philip L.

doi:10.1164/ajrccm/147.5.1144

Cited by 134 publications

(109 citation statements)

References 25 publications

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“…Based on the present experiments, whole XIIth nerve stimulation was most certainly associated with tongue retraction in the experiments of Schwartz et al (1993) and Hida et al (1995), indicating that improved pharyngeal mechanics and tongue retraction are somehow linked.…”

Section: Physiological Significancesupporting

confidence: 54%

“…However, recent evidence from both animal models and human subjects shows that tongue muscle co-activation improves pharyngeal airway mechanics. Schwartz et al (1993) found that whole XIIth nerve stimulation increased the maximal rate of inspiratory flow and decreased collapsibility of the isolated feline upper airway. In a similar experiment (Hida et al 1995) it was shown that whole XIIth nerve stimulation decreased the compliance of the isolated canine upper airway from 4 to 3 ml cmHµO¢.…”

Section: Physiological Significancementioning

confidence: 92%

See 1 more Smart Citation

Co‐activation of tongue protrudor and retractor muscles during chemoreceptor stimulation in the rat

Fuller

Mateika

Fregosi

1998

The Journal of Physiology

125

150

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Tongue position is controlled primarily by the mechanical actions of the extrinsic tongue muscles, which are innervated by separate branches of the hypoglossal (XIIth) nerve. The genioglossus (GG) muscle, which causes tongue protrusion, is innervated by the medial XIIth branch, while the hyoglossus (HG) and styloglossus (SG) muscles, which cause retraction of the tongue, are innervated by the lateral XIIth branch. A recent study showed that stimulating the XIIth nerve before its bifurcation into medial and lateral branches (i.e. co-activating the tongue protrudor and retractor muscles) caused tongue retraction in human subjects (Eisele, Smith, Alam & Schwartz, 1997). Consistent with these data, Gilliam & Goldberg (1995), using a rat model, found that the retractor muscles produce 10-20 times more force than the GG muscle, which explains why co-activation of both muscles results in strong tongue retraction. Thus, in both humans and rats, when protrudor and retractor muscle groups are activated maximally and 1. Our primary purpose was to test the hypothesis that the tongue protrudor (genioglossus, GG) and retractor (styloglossus, SG and hyoglossus, HG) muscles are co-activated when respiratory drive increases, and that co-activation will cause retraction of the tongue. This was addressed by performing two series of experiments using a supine, anaesthetized, tracheotomized rat in which tongue muscle force and the neural drive to the protrudor and retractor muscles could be measured during spontaneous breathing. In the first series of experiments, respiratory drive was increased progressively by occluding the tracheal cannula for thirty respiratory cycles; in the second series of experiments, the animals were subjected to hyperoxic hypercapnia and poikilocapnic hypoxia. 2. Airway occlusion for thirty breaths caused progressive, quantitatively similar increases in efferent motor nerve activity to protrudor and retractor tongue muscles. Net tongue muscle force was always consistent with tongue retraction during occlusion, and peak force rose in parallel with the neural activites. When airway occlusion was repeated following section of the lateral XIIth nerve branch (denervation of retractor muscles) the tongue either protruded (15Ï21 animals; 10 ± 2 mN at the 30th occluded breath) or retracted weakly (6Ï21 animals; 6 ± 2 mN at 30th occluded breath). 3. To ensure that our findings were not the result of damage to the muscle nerves, occlusion experiments were also done in eight animals in which GG EMG activity was recorded instead of nerve activities. Changes in peak integrated GG electryomyogram (EMG) activity and peak retraction force during occlusion were highly correlated (rÂ = 0·86, slope = 1·05). 4. In separate experiments in fourteen rats, we found that hyperoxic hypercapnia and poikilocapnic hypoxia also result in parallel increases in the respiratory-related EMG activity of the GG and HG muscles. Also, as in the occlusion experiments, augmentations of protrudor and retractor muscle EMG activities were associate...

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Section: Physiological Significancesupporting

confidence: 54%

Section: Physiological Significancementioning

confidence: 92%

Co‐activation of tongue protrudor and retractor muscles during chemoreceptor stimulation in the rat

Fuller

Mateika

Fregosi

1998

The Journal of Physiology

125

150

View full text Add to dashboard Cite

show abstract

“…Although it is believed that these muscles act in unison, the genioglossus is the most easily measured. Selective activation of the genioglossus has been shown to reduce airway collapsibility in both humans (3) and animal models (17). During wakefulness, children with OSAS have an elevated EMGgg compared with normal control subjects (4), likely a product of negative airway pressure on laryngeal mucosal mechanoreceptors (5).…”

Section: Discussionmentioning

confidence: 99%

Influence of Airway Pressure on Genioglossus Activity during Sleep in Normal Children

Katz

Marcus

White

2006

Am J Respir Crit Care Med

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“…Moreover, as Pcrit fell below a minimally negative threshold of approximately 25 cm H 2 O, sleep apnea remitted, suggesting that changes in Pcrit play a pivotal role in the pathogenesis of this disorder (see Figure 1, right) (25,(57)(58)(59)(60)(61). In further studies, investigators have demonstrated that Pcrit is determined by mechanical and neural factors that regulate pharyngeal collapsibility (62)(63)(64)(65)(66)(67). Investigators measuring airway collapsibility in the absence of neuromuscular activity have demonstrated small, but consistent elevations in Pcrit in patients with sleep apnea compared with normal subjects (68)(69)(70).…”

Section: Obesity and Upper Airway Neuromechanical Control Modeling Upmentioning

confidence: 95%

Obesity and Obstructive Sleep Apnea: Pathogenic Mechanisms and Therapeutic Approaches

Schwartz

Patil²,

Laffan

et al. 2008

Proceedings of the American Thoracic Society

574

395

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Obstructive sleep apnea is a common disorder whose prevalence is linked to an epidemic of obesity in Western society. Sleep apnea is due to recurrent episodes of upper airway obstruction during sleep that are caused by elevations in upper airway collapsibility during sleep. Collapsibility can be increased by underlying anatomic alterations and/or disturbances in upper airway neuromuscular control, both of which play key roles in the pathogenesis of obstructive sleep apnea. Obesity and particularly central adiposity are potent risk factors for sleep apnea. They can increase pharyngeal collapsibility through mechanical effects on pharyngeal soft tissues and lung volume, and through central nervous system-acting signaling proteins (adipokines) that may affect airway neuromuscular control. Specific molecular signaling pathways encode differences in the distribution and metabolic activity of adipose tissue. These differences can produce alterations in the mechanical and neural control of upper airway collapsibility, which determine sleep apnea susceptibility. Although weight loss reduces upper airway collapsibility during sleep, it is not known whether its effects are mediated primarily by improvement in upper airway mechanical properties or neuromuscular control. A variety of behavioral, pharmacologic, and surgical approaches to weight loss may be of benefit to patients with sleep apnea, through distinct effects on the mass and activity of regional adipose stores. Examining responses to specific weight loss strategies will provide critical insight into mechanisms linking obesity and sleep apnea, and will help to elucidate the humoral and molecular predictors of weight loss responses.

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Effect of Electrical Stimulation of the Hypoglossal Nerve on Airflow Mechanics in the Isolated Upper Airway

Cited by 134 publications

References 25 publications

Co‐activation of tongue protrudor and retractor muscles during chemoreceptor stimulation in the rat

Co‐activation of tongue protrudor and retractor muscles during chemoreceptor stimulation in the rat

Influence of Airway Pressure on Genioglossus Activity during Sleep in Normal Children

Obesity and Obstructive Sleep Apnea: Pathogenic Mechanisms and Therapeutic Approaches

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