title: [Pathologic changes of palatopharyngeal soft tissue in obstructive sleep apnea syndrome].
abstract: OBJECTIVE
  To study the pathologic changes of palatopharyngeal soft tissues in patients with OSAS.
  
  
  METHODS
  Different analyses have been done on uvular muscles (UM) and/or palatopharyngeal muscles (PPM) in patients with OSAS(n = 27), SS(n = 17) and controls (n = 15). The transverse sections were sequentially stained for HE, myofibrillar ATPase, NADH-TR, Lillie Oil Red-O. Ten specimens were evaluated by transmission electron microscopy(TEM).
  
  
  RESULTS
  Patients with OSAS have a significantly smaller percentage of muscle in the uvula than that of SS patients (15.0 +/- 3.0 vs 20.3 +/- 5.5), The percentage of muscle is inversely related to the percentage of fibrous tissue in OSAS group (r = -0.75, Y = 42.6 - 0.64X); The total number and area of muscle fibers, the number and area of type I muscle fibers are significantly lower in OSAS than those in SS (800 +/- 345 vs 1200 +/- 360n; 1.10 +/- 0.56 vs 1.70 +/- 0.60 micron 2; 156 +/- 95 vs 360 +/- 225 n; 920 +/- 350 vs 1365 +/- 540 micron 2 respectively); PPM: The percentage of type I muscle fibers within total muscles and its area are significantly lower in OSAS than those in SS and normal controls(20.5 +/- 4.0 vs 34.5 +/- 4.5 n; 20.5 +/- 4.0 vs 35.5 +/- 4.7; 860 +/- 360 vs 1260 +/- 340 micron 2; 860 +/- 360 vs 1350 +/- 370 micron 2; respectively); the muscles from OSAS patients seemed to show neurogenic alterations. Structurally altered fibers shows myofibrillar loss, increased number of vesicles, and rough Z line and so on.
  
  
  CONCLUSIONS
  Our finding suggest that the neurogenic functional disturbance of pharyngeal dilator muscles may play an important role in causing the airway collapse in OSAS.
authors.affiliation: ENT Department, Beijing Tongren Hospital, Beijing 100730.
authors.forename: X
authors.initials: X
authors.lastname: Yu
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: S
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D010156:Palatal Muscles / Q000473:pathology*; D010609:Pharyngeal Muscles / Q000473:pathology*; D020181:Sleep Apnea, Obstructive / Q000473:pathology*; D014609:Uvula / Q000473:pathology