From the Guidelines
The principle of pharyngeal closure is a complex neuromuscular process involving the coordinated contraction of pharyngeal muscles to prevent aspiration of food or liquid into the airway, as described in the context of oropharyngeal dysphagia in neurological disorders 1.
Key Components of Pharyngeal Closure
- The process involves the sequential activation of the soft palate, pharyngeal constrictors, and laryngeal elevators to seal off the pharynx during swallowing.
- The soft palate elevates to close off the nasopharynx, preventing food from entering the nasal cavity.
- The superior, middle, and inferior pharyngeal constrictors contract in a top-down sequence, creating a wave-like motion that propels the food bolus toward the esophagus.
- The larynx elevates and tilts forward, while the epiglottis folds backward to cover the laryngeal inlet, and the true and false vocal folds adduct to provide additional protection.
Control and Coordination
- This complex process is controlled by cranial nerves IX (glossopharyngeal), X (vagus), and XII (hypoglossal), coordinated by swallowing centers in the medulla oblongata, as implied by the discussion on the central coordination of swallowing in neurological diseases 1.
Clinical Implications
- Dysfunction in pharyngeal closure can lead to dysphagia and aspiration, which may occur in neurological disorders such as stroke, Parkinson's disease, and amyotrophic lateral sclerosis, as well as in structural abnormalities or following head and neck surgeries, highlighting the importance of understanding this principle in clinical practice 1.
From the Research
Pharyngeal Closure Principle
The principle of pharyngeal closure is crucial in understanding swallowing disorders, including dysphagia. Dysphagia is a common symptom in Parkinson's disease (PD) patients, which can lead to severe complications such as aspiration pneumonia.
- The pharyngeal closure principle involves the coordination of various muscles to prevent the entry of food and liquids into the airway during swallowing.
- Studies have shown that PD patients often experience pharyngeal dysphagia, which can be characterized by premature bolus spillage, penetration/aspiration, and pharyngeal residue 2.
- The effect of levodopa-carbidopa intestinal gel (LCIG) on pharyngeal dysphagia in PD patients has been investigated, with some studies suggesting that LCIG may improve swallowing function by reducing premature bolus spillage and pharyngeal bradykinesia 2, 3.
- However, other studies have found that levodopa intake is not associated with a significant improvement in swallowing dysfunction in PD patients 4.
- A consensus statement on the treatment of dysphagia in PD patients emphasizes the importance of a multi-disciplinary approach, involving neurologists, otorhinolaryngologists, gastroenterologists, phoniatricians, speech-language pathologists, dieticians, and clinical nutritionists 5.
- Dysphagia has been found to be a significant risk factor for mortality in PD patients, particularly those treated with LCIG, highlighting the need for effective management of this symptom 3.
- A general framework for assessing, diagnosing, and managing dysphagia in adult patients has been proposed, emphasizing the importance of basic diagnostic screening procedures and techniques for management 6.