Pharyngeal Swallowing During Wake and Sleep

Area of Science:

• Physiology
• Gastroenterology
• Neurology

Background:

• Sleep involves reduced cortical activity, potentially affecting volitional physiological processes like swallowing.
• Understanding swallowing mechanics during sleep is crucial for evaluating dysphagia and related neurological conditions.

Purpose of the Study:

• To measure and characterize pharyngeal swallow characteristics during sleep and wakefulness using high-resolution manometry (HRM).
• To compare pharyngeal swallowing parameters between upright-wake, supine-wake, and sleep conditions.

Main Methods:

• High-resolution manometry (HRM) recorded pharyngeal swallows in 20 healthy adults across three conditions: upright-wake, supine-wake, and sleep.
• Analysis focused on velopharyngeal and hypopharyngeal segments, measuring contractile integral, mean peak pressure, inverse velocity, and time to maximum pressure.

Main Results:

• No significant differences in pharyngeal swallow measures were found between upright-wake and supine-wake conditions.
• Mean peak pharyngeal pressure was significantly lower during sleep for both velopharynx and hypopharynx compared to supine-wake.
• Pharyngeal contractile integral and hypopharyngeal inverse velocity were also significantly reduced during sleep.

Conclusions:

• Pharyngeal swallowing pressures and dynamics are significantly reduced during sleep compared to wakefulness.
• Cortical input plays a vital role in modulating pharyngeal swallowing, as evidenced by the differences observed between awake and sleep states.
• Findings support the validity of supine pharyngeal manometry, relevant for studies like fMRI, as it mirrors upright awake conditions.