Dynamic extrathoracic airway obstruction
For a great video example of dynamic extra-thoracic airway obstruction, click the below link to the July 5, 2012 New England Journal of Medicine.
This 53-year-old woman had a traumatic laryngeal fracture as a child, and presented with daytime somnolence and inspiratory stridor. On laryngoscopy, she had proliferation of the mucosa over the vocal cords, which fluttered and obstructed her airway during inspiration. Flow–volume loop showed flattening of the inspiratory curve, as would be expected, with tiny sawtooth oscillations corresponding to the fluttering (click the link to see for yourself).
Supraglottoplasty was required to improve airway patency, but resulted in only a moderate improvement in her daytime somnolence.
Pradhan D, Berger K. Dynamic Extrathoracic Airway Obstruction. Images in Clinical Medicine. NEJM 2012;367:e2