Factors Controlling the Cricothyroid Muscle during Sleep

Abstract

The larynx plays a role in regulating air flow and pressure in the lower airway, and it is considered that there is a certain adjusting mechanism by which impulses are sent from the center through receptors in the periphery. The activity of the internal laryngeal muscles, a component of the larynx is, however, still poorly defined without an established theory, excepted for the posterior cricoarytenoid muscle.
Several studies related to the activity of the human cricothyroid muscle during sleep have recentry been reported. Ten adults in good health aged 36 to 61 years and 20 patients with obstructive sleep apnea syndrome (OSAS) aged 24 to 61 years were examined. In the healthy adults, the activity of the cricothyroid muscle was studied during sleep. In patients with OSAS, the activity of the cricothyroid muscle was studied during sleep while OSAS was developing and while they were inspiring pure oxigen.
In healthy adults, slight activity of the cricothyroid muscle was observed during inspiration. In OSAS patients, the activity of the cricothyroid muscle was stepped up by the appearance of OSAS and its activity was also observed during expirating, whereas the activity of the cricothyroid muscle was reduced by the inspiration of pure oxygen when OSAS was recognized.