Sleep-stage- and event-specific interpretation during concurrent natural sleep endoscopy and polysomnography

Polysomnography (PSG) defines sleep stage, respiratory event type, and respiratory effort, but does not directly identify the visible anatomic correlate of individual events. We examined whether concurrent natural sleep endoscopy (NSE) with PSG could support event-level interpretation of selected sleep-disordered breathing events.

Four adults were selected from archived synchronized NSE-PSG recordings acquired between 2007 and 2009. Cases were chosen to illustrate interpretive scenarios in which PSG context changed, refined, or constrained visible airway interpretation.

The selected cases illustrated sleep-stage-dependent obstruction, possible laryngeal contribution to hypopneas, central apnea without a discrete visible collapse site, and incomplete rapid eye movement (REM) sleep sampling. In post-treatment residual obstructive sleep apnea (OSA), a non-rapid eye movement (NREM) hypopnea was associated with epiglottic obstruction, whereas a REM obstructive respiratory event with arousal was associated with tongue-base collapse. In bilateral vocal fold paralysis, a hypopnea with arousal was accompanied by reduced vocal fold abduction without clear palatal, tongue-base, or epiglottic narrowing. In predominantly central apnea, no discrete collapse site was observed, and absent effort was supported by esophageal pressure monitoring. In the fourth case, REM-specific localization could not be established because relevant sleep-stage sampling was incomplete.

Concurrent NSE-PSG allowed selected events to be interpreted with PSG-defined sleep stage, event type, and respiratory effort. These observations are illustrative and hypothesis-generating, and NSE-PSG should be viewed as a selective adjunct rather than a routine alternative to drug-induced sleep endoscopy (DISE).