Genioglossal but not palatal muscle activity relates closely to pharyngeal pressure

A. Malhotra, G. Pillar, R. B. Fogel, J. Beauregard, J. K. Edwards, D. I. Slamowitz, S. A. Shea, D. P. White

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Abstract

The stimuli controlling pharyngeal dilator muscles are poorly defined. Local mechanoreceptors are a leading possibility. To address this, we assessed the relationship between two dilator muscle electromyograms (EMGs, i.e., genioglossus [GG - An inspiratory phasic muscle], tensor palatini [TP - A tonically active muscle]) and potential stimuli (i.e., epiglottic pressure [Pepi], airflow [V̇], and pharyngeal resistance [Rpha]). Fifteen normal subjects were studied, during wakefulness and stable non-rapid eye movement (NREM) sleep. The GGEMG and TPEMG were assessed during basal breathing and during inspiratory resistive loading (four loads, done in triplicate), while quantifying Pepi and choanal pressures (Pcho, Millar catheters) plus V̇. There was a strong correlation between Pepi and GGEMG during wakefulness in most subjects (9 of 15 had absolute R > 0.7 [p < 0.05], group mean R = -0.62, p < 0.05). These correlations were less robust during NREM sleep (8 of 15 absolute R > 0.6 [p < 0.05], group mean R = -0.39, ns). The slope of the Pepi versus GGEMG relationship was greater during wakefulness than sleep (-0.67 versus -0.39% max/cm H2O, p < 0.05). No significant correlations were observed between TPEMG and any of the measured potential stimuli. We conclude that intrapharyngeal pressure may modulate genioglossus activity during wakefulness, with a fall in muscle responsiveness during sleep. The activity of the TP was not clearly influenced by any measured local stimulus either awake or asleep.

Original languageEnglish (US)
Pages (from-to)1058-1062
Number of pages5
JournalAmerican journal of respiratory and critical care medicine
Volume162
Issue number3 I
DOIs
StatePublished - Jan 1 2000

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ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Critical Care and Intensive Care Medicine

Cite this

Malhotra, A., Pillar, G., Fogel, R. B., Beauregard, J., Edwards, J. K., Slamowitz, D. I., Shea, S. A., & White, D. P. (2000). Genioglossal but not palatal muscle activity relates closely to pharyngeal pressure. American journal of respiratory and critical care medicine, 162(3 I), 1058-1062. https://doi.org/10.1164/ajrccm.162.3.9912067