The effects of selective nerve stimulation on upper airway airflow mechanics.
OBJECTIVE
To evaluate the effect of electrical stimulation of hypoglossal nerve branches and ansa cervicalis nerve branches on upper airway patency.


METHODS
Pressure-flow relationships obtained during supramaximal stimulation of hypoglossal nerve branches and ansa cervicalis nerve branches were analyzed in the isolated feline upper airway to determine the maximum inspiratory airflow as well as to determine pharyngeal collapsibility (upper airway critical pressure) and nasal resistance upstream from the site of pharyngeal collapse. Comparisons were performed between baseline and stimulation conditions with paired two-tailed t tests.


RESULTS
Stimulation of the proximal hypoglossal nerve trunk, distal medial hypoglossal nerve branch, nerve branches to the suprahyoid muscles, the infrahyoid muscles, and the suprahyoid and infrahyoid muscles simultaneously increased maximum inspiratory airflow significantly by decreasing airway collapsibility. A greater reduction in airway collapsibility was observed with stimulation of the tongue muscles compared with stimulation of the strap muscles.


CONCLUSIONS
Stimulation of specific hypoglossal and ansa cervicalis nerve branches consistently increased maximum inspiratory airflow by decreasing airway collapsibility. The major decrease in airway collapsibility from hypoglossal nerve stimulation is dependent on the action of the genioglossus muscle.
D000818:Animals; D002415:Cats; D003655:Decerebrate State / Q000503:physiopathology; D004558:Electric Stimulation; D007002:Hypoglossal Nerve / Q000502:physiology*; D009132:Muscles / Q000502:physiology; D009333:Neck / Q000294:innervation; D009334:Neck Muscles / Q000502:physiology; D015656:Respiratory Mechanics / Q000502:physiology*; D012143:Respiratory Physiological Phenomena; D014059:Tongue / Q000502:physiology