DOES UPPER AIRWAY MUSCLE INJURY TRIGGER A VICIOUS CYCLE IN OBSTRUCTIVE SLEEP-APNEA - A HYPOTHESIS

Recent studies have indicated that the level of neural activation of u pper airway dilator muscles is abnormally elevated in patients with ob structive sleep apnea (OSA). This is presumed to represent an adaptive mechanism that partially compensates for the anatomically small upper airway found in individuals with OSA. We have reviewed evidence that pharyngeal dilator muscles undergo secondary changes in structure as a direct consequence of their increased activity level in OSA. These al terations have the potential to be both beneficial and harmful with re spect to the maintenance of upper airway patency. We propose a model o utlining the possible role of activity-induced upper airway muscle rem odeling and injury in the pathogenesis of OSA, and discuss potential i mplications for treatment of the disease.