[Physiopathology of sleep obstructive respiratory disorders. Experimental methods and practical applications].
Recent progress in the physiology of the upper airways has led to significant advances in evaluating the dynamics of upper airway occlusion during sleep. Measuring the collapsibility of the upper airways and localizing the site of obstruction should theoretically lead to efficacious non-mechanical treatment and enable selection of patients susceptible of benefiting from surgical procedures. From a diagnostic point of view, fluctuations in the nasal pressure curve appear to give more precise information on ventilatory changes and their association with disrupted sleep pattern than conventional parameters such as thermistance signals or induction plethysmography. Again, from a pathophysiological point of view, little is known about the role or tissue inflammation and repeated upper airway trauma in the transition from simple snoring to sleep apnea syndrome. Current studies lead to the conclusion that the dilatroy muscles of the upper airways in the apneic subject are the target for adaptive trophic, immunohistochemical and metabolic phenomena in response to stimulation comparable to training against resistance. Although there is no evidence that sleep affects neuromuscular activity in apneic subjects, the disappearance of compensatory hyperactivity on awakening and the reduction of muscle contraction efficacy (transmission of the dilatory force to soft tissues) observed in patients may explain the greater instability of the upper airways characteristic of sleep apnea syndrome.
Sériès
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Unité de recherche, Hôpital Laval, Univesité Laval, Québec, Canada.
D006801:Humans; D007830:Larynx / Q000473:pathology / Q000503:physiopathology; D009666:Nose / Q000473:pathology / Q000503:physiopathology; D010614:Pharynx / Q000473:pathology / Q000503:physiopathology; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*