title: Passive constriction of the upper airway during central apneas: fiberoptic and EMG investigations.
abstract: We studied five adult male patients with central sleep apnea syndrome (> 75% of the monitored events being central) during sleep using a fiberoptic scope and EMG monitoring of the superior and middle constrictors of the pharynx and the genioglossus and geniohyoid muscles. The fiberoptic investigation revealed a spontaneous decrease in the size of the airway during central apneas, without negative intrathoracic pressure or activation of the superior and middle pharyngeal constrictor muscles. We found a mean maximum decrease of 71 +/- 7% in the cross-sectional area of the airway and an absence of superior-middle pharyngeal constrictor EMG discharge. We did not observe any complete collapses of the airway.
authors.affiliation: Stanford University Sleep Disorders Clinic and Research Center, Palo Alto CA 94304, USA.
authors.forename: C
authors.initials: C
authors.lastname: Guilleminault
authors.forename: M H
authors.initials: MH
authors.lastname: Hill
authors.forename: F B
authors.initials: FB
authors.lastname: Simmons
authors.forename: N
authors.initials: N
authors.lastname: Powell
authors.forename: R
authors.initials: R
authors.lastname: Riley
authors.forename: R
authors.initials: R
authors.lastname: Stoohs
mesh_terms: D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000503:physiopathology*; D004576:Electromyography / Q000379:methods; D005336:Fiber Optic Technology / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D010614:Pharynx / Q000294:innervation / Q000503:physiopathology*; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*; D014741:Video Recording