Soft palate muscle responses to negative upper airway pressure

1999 ◽  
Vol 86 (2) ◽  
pp. 523-530 ◽  
Author(s):  
T. C. Amis ◽  
N. O’Neill ◽  
J. R. Wheatley ◽  
T. van der Touw ◽  
E. di Somma ◽  
...  
Keyword(s):  
Soft Palate ◽  
Muscle Activity ◽  
Airway Pressure ◽  
Upper Airway ◽  
Emg Activity ◽  
Afferent Activity ◽  
Afferent Pathways ◽  
Levator Veli Palatini ◽  
Anesthetized Dogs ◽  
Muscle Responses

The afferent pathways and upper airway receptor locations involved in negative upper airway pressure (NUAP) augmentation of soft palate muscle activity have not been defined. We studied the electromyographic (EMG) response to NUAP for the palatinus, tensor veli palatini, and levator veli palatini muscles in 11 adult, supine, tracheostomized, anesthetized dogs. NUAP was applied to the nasal or laryngeal end of the isolated upper airway in six dogs and to four to six serial upper airway sites from the nasal cavity to the subglottis in five dogs. When NUAP was applied at the larynx, peak inspiratory EMG activity for the palatinus and tensor increased significantly ( P< 0.05) and plateaued at a NUAP of −10 cmH2O. Laryngeal NUAP failed to increase levator activity consistently. Nasal NUAP did not increase EMG activity for any muscle. Consistent NUAP reflex recruitment of soft palate muscle activity only occurred when the larynx was exposed to the stimulus and, furthermore, was abolished by bilateral section of the internal branches of the superior laryngeal nerves. We conclude that soft palate muscle activity may be selectively modulated by afferent activity originating in the laryngeal and hypopharyngeal airway.

Respiratory-related activity of soft palate muscles: augmentation by negative upper airway pressure

1994 ◽  
Vol 76 (1) ◽  
pp. 424-432 ◽  
Author(s):  
T. Van der Touw ◽  
N. O'Neill ◽  
A. Brancatisano ◽  
T. Amis ◽  
J. Wheatley ◽  
...  
Keyword(s):  
Soft Palate ◽  
Airway Pressure ◽  
Upper Airway ◽  
Substantial Contribution ◽  
Emg Activity ◽  
Nasal Breathing ◽  
Related Activity ◽  
Tracheal Pressure ◽  
Upper Airway Muscles ◽  
Muscle Responses

We studied respiratory-related activity of the soft palate muscles in 10 anesthetized tracheostomized supine dogs. Moving time average (MTA) electromyographic (EMG) activity was measured in the palatinus (PAL), levator veli palatini (LP), and tensor veli palatini (TP) with bipolar fine-wire electrodes and in the diaphragm with bipolar hook electrodes. Measurements were made during tracheostomy breathing and nasal breathing with the mouth sealed (NB). During tracheostomy breathing, all soft palate muscles displayed respiratory-related phasic inspiratory and expiratory as well as tonic EMG activity. During NB, peak inspiratory EMG activity increased in PAL, LP, and TP because of an increase in both phasic inspiratory and tonic MTA activity. In contrast, phasic expiratory activity did not change. A constant negative pressure equal to peak inspiratory tracheal pressure during NB was applied to the caudal end of the isolated upper airway with the nose occluded. This was associated with soft palate muscle responses qualitatively similar to the responses during NB but accounted for only 39, 25, and 32% of the magnitude of the peak inspiratory MTA EMG responses to NB in PAL, LP, and TP, respectively. Our results demonstrate that the soft palate muscles exhibit respiratory-related activity in common with other upper airway muscles. Furthermore, such activity is augmented in each soft palate muscle during NB, and negative upper airway pressure makes a substantial contribution to the recruitment of soft palate muscle activity.

Effects of positive airway pressure on upper airway dilator muscle activity and ventilatory timing

1996 ◽  
Vol 81 (1) ◽  
pp. 470-479 ◽  
Author(s):  
P. C. Deegan ◽  
P. Nolan ◽  
M. Carey ◽  
W. T. McNicholas
Keyword(s):  
Muscle Activity ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Upper Airway ◽  
Normal Subjects ◽  
Emg Activity ◽  
Ventilatory Responses ◽  
Dilator Muscle ◽  
Before And After ◽  
Expiratory Positive Airway Pressure

To determine upper airway (UA) and ventilatory responses to nasal continuous positive airway pressure (CPAP) and expiratory positive airway pressure (EPAP), we quantitated changes in alae nasi (AN) and genioglossus (GG) electromyographic (EMG) activity, ventilatory timing, and end-expiratory lung volume (EELV) at various levels of CPAP and EPAP in six normal subjects during wakefulness and in seven during sleep. The same measurements were also made before and after UA anesthesia in six normal subjects during wakefulness. During both wakefulness and sleep, CPAP application significantly increased EELV and decreased AN and GG EMG activities. In contrast, EPAP significantly increased EMG activities of both muscles while also increasing EELV during wakefulness. The EMG responses were less marked during sleep. Anesthesia of the UA abolished the EMG responses to CPAP but not to EPAP. These results suggest that, in normal subjects, CPAP application causes a reflex reduction in UA dilator muscle activity mediated by UA sensory receptors. In contrast, EPAP increases UA dilator muscle activity, with the response mediated by conscious influences or reflexes arising outside of the UA.

Supraglottic airway pressure-flow relationships during oronasal airflow partitioning in dogs

1996 ◽  
Vol 81 (5) ◽  
pp. 1958-1964 ◽  
Author(s):  
T. C. Amis ◽  
N. O’Neill ◽  
T. Van Der Touw ◽  
A. Tully ◽  
A. Brancatisano
Keyword(s):  
Electrical Stimulation ◽  
Soft Palate ◽  
Airway Pressure ◽  
Airway Resistance ◽  
Upper Airway ◽  
Oral Route ◽  
Supraglottic Airway ◽  
Respiratory Drive ◽  
Pressure Flow ◽  
Oral Airway

Amis, T. C., N. O’Neill, T. Van der Touw, A. Tully, and A. Brancatisano. Supraglottic airway pressure-flow relationships during oronasal airflow partitioning in dogs. J. Appl. Physiol. 81(5): 1958–1964, 1996.—We studied pressure-flow relationships in the supraglottic airway of eight prone mouth-open anesthetized (intravenous chloralose or pentobarbital sodium) crossbred dogs (weight 15–26 kg) during increasing respiratory drive (CO2administration; n = 4) and during graded-voltage electrical stimulation (SV; n = 4) of the soft palate muscles. During increased respiratory drive, inspiratory airflow occurred via both the nose (V˙n) and mouth (V˙m), with the ratio of V˙n toV˙m [%(V˙n/V˙m)] decreasing maximally from 16.0 ± 7.0 (SD) to 2.4 ± 1.6% ( P < 0.05). Simultaneously, oral airway resistance at peak inspiratory flow decreased from 2.1 ± 1.0 to 0.4 ± 0.4 cmH2O ( P < 0.05), whereas nasal airway resistance did not change (14.4 ± 7.2 to 13.1 ± 5.4 cmH2O; P = 0.29). Inspiratory pressure-flow plots of the oral airway were inversely curvilinear or more complex in nature. Nasal pathway plots, however, demonstrated a positive linear relationship in all animals ( r = 0.87 ± 0.11; all P < 0.001). During electrical stimulation of soft palate muscle contraction accompanied by graded constant-inspiratory airflows of 45–385 ml/s through an isolated upper airway, %(V˙n/V˙m) decreased from 69 ± 50 to 10 ± 13% at a SV of 84 ± 3% of maximal SV ( P < 0.001). At a SV of 85 ± 1% of maximum, normalized oral airway resistance (expressed as percent baseline) fell to 5 ± 3%, whereas normalized nasal resistance was 80 ± 9% (both P< 0.03). Thus control of oronasal airflow partitioning in dogs appears mediated more by alterations in oral route geometry than by closure of the nasopharyngeal airway.

Soft palate muscle activity in response to hypoxic hypercapnia

1994 ◽  
Vol 77 (6) ◽  
pp. 2600-2605 ◽  
Author(s):  
T. Van der Touw ◽  
N. O'Neill ◽  
T. Amis ◽  
J. Wheatley ◽  
A. Brancatisano
Keyword(s):  
Soft Palate ◽  
Minute Ventilation ◽  
Upper Airway ◽  
Emg Activity ◽  
Respiratory Drive ◽  
Breathing Control ◽  
Fine Wire ◽  
Time Average ◽  
Reflex Control ◽  
Local Reflex

We studied the effects of increasing respiratory drive on electromyographic (EMG) soft palate muscle (SPM) activity in nine anesthetized tracheostomy-breathing dogs during hypoxic hypercapnia (HH) with a 14% O2–8% CO2–78% N2 inspired gas mixture. Moving time average EMG activity was recorded from palatinus (PAL), levator veli palatini (LP), and tensor veli palatini (TP) muscles (with bipolar fine-wire electrodes) and diaphragm (DIA; with bipolar hook electrodes). During HH, peak inspiratory DIA activity increased from 18.8 +/- 1.3 to 30.1 +/- 2.0 arbitrary units and minute ventilation increased from 6.2 +/- 0.3 to 18.3 +/- 1.8 l/min (both P < 0.001). Phasic inspiratory, expiratory, and/or tonic EMG activity was present in each SPM during room air breathing (control) and increased during HH (P < 0.05), except for phasic inspiratory PAL and phasic expiratory TP activities. Peak inspiratory LP and TP activities increased during HH to 250 and 179% of control, respectively, and peak expiratory activity increased to 187, 235, and 181% of control in PAL, LP, and TP, respectively. These findings demonstrate respiratory-related regulation of SPM activity independent of local reflex control from the upper airway. However, the combined inspiratory and expiratory phasic recruitment of these muscles differs from the inspiratory recruitment of known upper airway dilator muscles.

Afferent pathways for hypoglossal and phrenic responses to changes in upper airway pressure

1984 ◽  
Vol 55 (3) ◽  
pp. 341-354 ◽  
Author(s):  
Ji-Chuu Hwang ◽  
Walter M. St. John ◽  
Donald Bartlett
Keyword(s):  
Airway Pressure ◽  
Upper Airway ◽  
Afferent Pathways

Effects of continuous positive airway pressure on upper airway and respiratory muscle activity

1987 ◽  
Vol 62 (5) ◽  
pp. 2026-2030 ◽  
Author(s):  
C. G. Alex ◽  
R. M. Aronson ◽  
E. Onal ◽  
M. Lopata
Keyword(s):  
Continuous Positive Airway Pressure ◽  
Respiratory System ◽  
Muscle Activity ◽  
Airway Pressure ◽  
Respiratory Muscle ◽  
Positive Airway Pressure ◽  
Upper Airway ◽  
Afferent Input ◽  
Residual Capacity ◽  
Respiratory Muscle Activity

To study the effects of continuous positive airway pressure (CPAP) on lung volume, and upper airway and respiratory muscle activity, we quantitated the CPAP-induced changes in diaphragmatic and genioglossal electromyograms, esophageal and transdiaphragmatic pressures (Pes and Pdi), and functional residual capacity (FRC) in six normal awake subjects in the supine position. CPAP resulted in increased FRC, increased peak and rate of rise of diaphragmatic activity (EMGdi and EMGdi/TI), decreased peak genioglossal activity (EMGge), decreased inspiratory time and inspiratory duty cycle (P less than 0.001 for all comparisons). Inspiratory changes in Pes and Pdi, as well as Pes/EMGdi and Pdi/EMGdi also decreased (P less than 0.001 for all comparisons), but mean inspiratory airflow for a given Pes increased (P less than 0.001) on CPAP. The increase in mean inspiratory airflow for a given Pes despite the decrease in upper airway muscle activity suggests that CPAP mechanically splints the upper airway. The changes in EMGge and EMGdi after CPAP application most likely reflect the effects of CPAP and the associated changes in respiratory system mechanics on the afferent input from receptors distributed throughout the intact respiratory system.

Thoracic influence on upper airway patency

1988 ◽  
Vol 65 (5) ◽  
pp. 2124-2131 ◽  
Author(s):  
W. B. Van de Graaff
Keyword(s):  
Muscle Activity ◽  
Upper Airway ◽  
Constant Flow ◽  
Airway Patency ◽  
Anesthetized Dogs ◽  
Measured Resistance ◽  
Flow Through ◽  
Phrenic Nerves ◽  
Tracheostomy Tubes ◽  
Spontaneously Breathing

Patency of the upper airway (UA) is usually considered to be maintained by the activity of muscles in the head and neck. These include cervical muscles that provide caudal traction on the UA. The thorax also applies caudal traction to the UA. To observe whether this thoracic traction can also improve UA patency, we measured resistance of the UA (RUA) during breathing in the presence and absence of UA muscle activity. Fifteen anesthetized dogs breathed through tracheostomy tubes. RUA was calculated from the pressure drop of a constant flow through the isolated UA. RUA decreased 31 +/- 5% (SEM) during inspiration. After hyperventilating seven of these dogs to apnea, we maximally stimulated the phrenic nerves to produce paced diaphragmatic breathing. Despite absence of UA muscle activity, RUA fell 51 +/- 11% during inspiration. Graded changes were produced by reduced stimulation. In six other dogs we denervated all UA muscles. RUA still fell 25 +/- 7% with inspiration in these spontaneously breathing animals. When all caudal ventrolateral cervical structures mechanically linking the thorax to the UA were severed, RUA increased and respiratory fluctuations ceased. These findings indicate that tonic and phasic forces generated by the thorax can improve UA patency. Inspiratory increases in UA patency cannot be attributed solely to activity of UA muscles.

EMG in Common Migraine: Changes in Absolute and Proportional EMG Levels During Real-Life Stress

Cephalalgia ◽  
1988 ◽  
Vol 8 (3) ◽  
pp. 163-174 ◽  
Author(s):  
Plona Goudswaard ◽  
Jan Passchier ◽  
Jacobus F Orlebeke
Keyword(s):  
Muscle Activity ◽  
Life Stress ◽  
Muscle Tension ◽  
Real Life ◽  
Emg Activity ◽  
Experimental Stress ◽  
Facial Muscle ◽  
Long Duration ◽  
The Absolute ◽  
Muscle Responses

The absolute and proportional EMG levels of the frontal, temporal, and corrugator muscles of 37 migraine patients and 37 matched controls were recorded during three experimental sessions: adaptation and real-life and experimental stress, both of long duration. Migraine patients did not show significantly different absolute EMG levels but had higher proportional EMG levels of the corrugator muscle than controls in each session. Migraine patients did not have different facial muscle responses to stress, and the two experimental groups reacted similarly to real-life and experimental stress. No relation was found between muscle activity and reported headache within 24 h after real-life stress. Increased EMG activity due to stress does not seem to be a significant cause of headache in common migraine as defined in this study, but rather a response to pain. Migraine patients with headache during stress showed lower muscle tension than patients without headache.

Movement of the human upper airway during inspiration with and without inspiratory resistive loading

2011 ◽  
Vol 110 (1) ◽  
pp. 69-75 ◽  
Author(s):  
S. Cheng ◽  
J. E. Butler ◽  
S. C. Gandevia ◽  
L. E. Bilston
Keyword(s):  
Soft Palate ◽  
Soft Tissues ◽  
Upper Airway ◽  
Spatial Modulation ◽  
Emg Activity ◽  
Anterior Border ◽  
Resistive Loading ◽  
Airway Walls ◽  
Upper Airway Muscles ◽  
The Relationship

The electromyographic (EMG) activity of human upper airway muscles, particularly the genioglossus, has been widely measured, but the relationship between EMG activity and physical movement of the airway muscles remains unclear. We aimed to measure the motion of the soft tissues surrounding the airway during normal and loaded inspiration on the basis of the hypothesis that this motion would be affected by the addition of resistance to breathing during inspiration. Tagged MR imaging of seven healthy subjects was performed in a 3-T scanner. Tagged 8.6-mm-spaced grids were used, and complementary spatial modulation of magnetization images were acquired beginning ∼200 ms before inspiratory airflow. Deformation of tag line intersections was measured. The genioglossus moved anteriorly during normal and loaded inspiration, with less movement during loaded inspiration. The motion of tissues at the anterior border of the upper airway was nonuniform, with larger motions inferiorly. At the level of the soft palate, the lateral dimension of the airway decreased significantly during loaded inspiration (−0.15 ± 0.09 and −0.48 ± 0.09 mm during unloaded and loaded inspiration, respectively, P < 0.05). When resistance to inspiratory flow was added, genioglossus motion and lateral dimensions of the airway at the level of the soft palate decreased. Our results suggest that genioglossus motion begins early to dilate the airway prior to airflow and that inspiratory loading reduces the anterior motion of the genioglossus and increases the collapse of the lateral airway walls at the level of the soft palate.

Influence of muscle activity on the elastance of the upper airway of rabbits

1989 ◽  
Vol 66 (2) ◽  
pp. 755-758 ◽  
Author(s):  
L. G. Olson ◽  
L. G. Ulmer ◽  
N. A. Saunders
Keyword(s):  
Confidence Interval ◽  
Muscle Activity ◽  
Airway Pressure ◽  
Upper Airway ◽  
Spontaneous Respiration ◽  
Upper Airways ◽  
Dominant Mechanism ◽  
Volume Properties ◽  
Upper Airway Muscles ◽  
Closing Pressure

This study sought to assess the effect of variations in upper airway muscle activity on upper airway pressure-volume properties. Upper airway elastance, closing pressure, and reserve volume were measured in the isolated upper airways of anesthetized rabbits under control conditions and after administration of gallamine (2 mg/kg iv) or after 10 min of spontaneous respiration of 7% CO2 in O2. Administration of gallamine to seven animals was associated with a fall in reserve volume from 0.94 +/- 0.24 to 0.69 +/- 0.17 (95% confidence interval) ml (P less than 0.01) and of closing pressure from -7.53 +/- 0.23 to -5.75 +/- 1.05 cmH2O (P less than 0.01), but airway elastance did not change significantly. Hypercapnia in seven animals was associated with a rise in elastance from 7.06 +/- 0.91 to 7.67 +/- 0.86 cmH2O/ml (P less than 0.001) and in reserve volume from 0.68 +/- 0.06 to 0.86 +/- 0.13 ml (P less than 0.05). Closing pressure also changed from -5.88 +/- 0.94 to -7.92 +/- 1.85 cmH2O. This change was correlated with the change in reserve volume but not with the change in elastance. In three animals exposed to hypercapnia, return to room air breathing was associated with return of elastance, reserve volume, and closing pressure to control levels. It is concluded that muscle activity in the upper airway affects both the size and elastance of the airway, but the dominant mechanism by which upper airway muscles increase the resistance of the upper airway to collapse is by increasing airway volume.

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