Upper-Airway Resistance Syndrome

Figure 1. A 42-year-old woman was evaluated because of excessive daytime sleepiness and habitual heavy snoring. A nocturnal polysomnogram revealed no evidence of obstructive or central sleep apnea, but it did show frequent periods of snoring and augmented negative esophageal pressure that was indicative of a high level of upper-airway resistance. Typically, these periods were terminated by transient arousal from sleep. The repeated arousals caused sleep fragmentation and, hence, daytime sleepiness. The combination of habitual heavy snoring, increased upper-airway resistance, sleep fragmentation, and daytime sleepiness is referred to as the upper-airway resistance syndrome, which is considered part of the continuum . . .