The normal process of swallowing or deglutition can be disrupted due to a stroke. Normally the swallowing process is a complex integrated group of behaviors emerging from an interaction of nerves from the brain stem, regulated by nuclei in the medulla, and sensorimotor cortical systems. A relationship between sensory stimuli, motor action, and reflexive movements coordinates into a relatively quick action during the swallowing of the food we consume.
The consequences of disruption of this complex process jeopardizes the health of the stroke patient due to aspiration. Aspiration is the unintentional inspiration of food material into the lungs via the trachea. The normal functioning mechanism of the hypopharynx and larynx are designed to keep food out of the trachea during swallowing.
Swallowing disorders, also called dysphagia (dis FAY juh), can occur at different stages in the swallowing process:
Oral
phase- sucking, chewing, and moving food or
liquid into the throat. Seen here in an x-ray the food bolus is
evident above the jaw bone and bottom teeth. Problems in the oral phase of
the swallow include difficulty with mastication, bolus formation trouble,
difficulty propelling the bolus posterior, and piece-meal
deglutition.
Pharyngeal
phase- triggering the swallowing reflex,
squeezing food down the throat, and closing off the airway to prevent food
or liquid from entering the airway (aspiration) or to prevent choking.
Seen here in x-ray the bolus starts in the mouth, just above the jawbone.......
.....then
is propelled back to trigger the swallow reflex. Difficulty during this
stage can be a delay in the triggering of the swallow reflex, incomplete
epiglottic inversion, poor laryngeal excursion, pooling in the sinuses,
penetration of material into the laryngeal vestibule, and
aspiration.
Esophageal
phase- relaxing and tightening the openings
at the top and bottom of the feeding tube in the throat (esophagus)
and squeezing food through the esophagus into the stomach.
To view a movie of a Modified Barium Swallow study on an adult male click here