Are there any differences between the tongue and posterior pharyngeal wall movement patterns during normal and Masako swallow?—An ultrasound analysis

Abstract

Parkinson's disease (PD) is a neurodegenerative movement disorder affecting volitional movement due to Dopamine-producing neuron death in the substantia nigra. Impaired swallow function is highly prevalent with nearly 100% involvement in PD during the disease course and involves all three phases of swallowing. The oral stage of swallowing is impaired first. Reduced bolus control and reduced interior-to-posterior movement of the bolus transfer lead to delayed swallowing response, premature spillage, decreased base of tongue (BOT) retraction and strength, decreased hyolaryngeal elevation and excursion, and reduced action of pharyngeal constrictors. Together, these result in bolus retention, residue throughout the pharynx, and reduced airway protection leading to significant aspiration. To target these deficits we have designed an exercise regime to teach early to mid-stage PD patients to do the Masako swallow maneuver of saliva (swallow with tongue-tip held between teeth), with high intensity and frequency (i.e., 120 repetitions per day) in one month. The preliminary results are very promising. All participants demonstrated positive changes. To understand the underlying mechanism, we used Ultrasound and recorded 20 normal subjects while they did three normal swallows and 3 Masako swallow maneuvers. The initial observations indicated the tongue and pharyngeal movement patterns differ between the two maneuvers.