Short-term cortical activation changes associated with postural compensation in swallowing

Area of Science:

• Neuroscience
• Physiology
• Speech-Language Pathology

Background:

• Compensatory swallowing strategies, such as chin-down and chin-up positions, are utilized by speech-language pathologists to improve swallowing safety.
• The precise effects of these head positions on cortical neural responses during swallowing are not well understood.

Purpose of the Study:

• To investigate the cortical hemodynamic responses to swallowing in three head positions: chin-down, chin-neutral, and chin-up.
• To explore the immediate neural adaptations associated with postural changes during the swallowing process.

Main Methods:

• Functional near-infrared spectroscopy (fNIRS) was used to measure cortical activity.
• Twenty-six healthy adults participated, performing 32 water swallows in each of the three head positions.
• Data were collected from bilateral precentral and postcentral gyrus regions of interest.

Main Results:

• Chin-up swallowing elicited significantly higher short-term cortical activation compared to both chin-neutral and chin-down positions.
• These findings indicate immediate neural adaptations in response to postural variations during swallowing in healthy individuals.
• The observed changes suggest adjustments in sensory and neuromuscular control necessary for safe swallowing across different head postures.

Conclusions:

• Postural modifications during swallowing induce rapid cortical neural adaptations in healthy adults.
• The chin-up position requires greater neural engagement, potentially reflecting increased sensory and motor demands.
• While the chin-up position may have therapeutic implications for dysphagia, its safety risks necessitate careful consideration and further investigation.