Quantitative Investigation of Effect of Age and Bolus Characteristics on Laryngeal Movement during Swallowing

Abstract

Objective: The purpose of this study was to investigate the physiologic changes of swallowing along with normal aging, and to study the influences on swallowing of gender and food consistency.Methods: One hundred adult men and women aged 24 to 80 participated. Each subject underwent a swallowing evaluation, in which a surface transducer was placed on the neck to detect laryngeal movement when they performed a dry swallow and wet swallow for different food consistencies. Main outcome measures included mean onset, mean amplitude and mean duration of the deglutition wave.Results: In this study, the onset of the dry swallow deglutition wave reached statistical difference with warm water, ice water and cookie swallows, but not with a pudding swallow. Prolonged onset and largest amplitude of deglutition wave were actually observed during dry swallow. There was no significant difference between the onset of the deglutition wave following the ice water and warm water swallow for each age group. The onset of deglutition for the subjects aged 61-80 was slower than for the younger subjects. The male subjects revealed significantly larger amplitude of deglutition wave than the females for each food consistency. The 21-40 year-old male subjects had significantly larger deglutition wave amplitude with the dry swallow; warm water and cookie swallow than the female groups.Conclusion: Our results suggest that even among normal populations, dry swallowing is not an easy task to do. Slowing of the initiation of swallowing reflex might begin as early as 60 years old. And, aging alone does not significantly affect the strength of oral pharyngeal muscles particularly in female population. (Tw J Phys Med Rehabil 2012; 40(1): 1 - 7)