Recent advances in understanding the pathogenesis of obstructive sleep apnea.
OBJECTIVE
The pathogenesis of obstructive sleep apnea (OSA) is incompletely understood. Historically it was believed that patients with OSA have a small upper airway (often due to obesity) that is kept patent during wakefulness by the activity of upper airway dilating muscles. With the reduction in muscle tone at sleep onset, the airway collapses and causes apnea. While this appears to be the case for many patients with OSA, other patients show no major airway anatomic defects or minimal obesity.


RESULTS
This has led to the concept that other factors such as unstable ventilatory control and changes in lung volume during sleep may be involved in the pathogenesis of OSA. Recently there have been several advances in our understanding of how these mechanisms are involved in OSA pathogenesis.


CONCLUSIONS
A more complete understanding of apnea pathogenesis may improve therapeutic techniques and reduce the consequences of OSA.
Jordan
Amy S
AS
Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. ajordan@rics.bwh.harvard.edu
White
David P
DP
Fogel
Robert B
RB
D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D006801:Humans; D015656:Respiratory Mechanics / Q000502:physiology*; D012132:Respiratory Muscles / Q000503:physiopathology; D012137:Respiratory System / Q000033:anatomy & histology; D020181:Sleep Apnea, Obstructive / Q000209:etiology* / Q000503:physiopathology*