Bolus volume has been widely studied, and research has demonstrated a variety of physiologic impacts on swallowing and swallowing disorders. Oral perception of bolus volume has not, to our knowledge, been investigated in association with normal aging processes. Research suggests many sensory changes with age, some within the oral cavity, and changes in swallowing function with age have been defined. The role of perception in oropharyngeal deglutition with age requires further investigation.
To establish the psychophysical relationship between liquid volume and oral perception and examine changes with age.
Healthy young and older adults were prospectively assessed using a magnitude estimation task differentiating five volumes of water delivered randomly to the oral cavity.
A fourfold increase in liquid volume is required by older participants to perceive an approximate twofold increase in the perception of volume compared with younger healthy adults.
Sensory receptors in the oral cavity provide a feedback loop that modulates the swallowing motor response so that it is optimal for the size and consistency of the bolus. Changes in perception of bolus volume with age are consistent with other perceptual changes and may provide valuable information regarding sensorineural rehabilitation strategies in the future.
Dysphagia Grand Rounds 3
Article: Effects of Surface
Electrical Stimulation Both at Rest and During Swallowing in Chronic Pharyngeal
Authors: Christy L. Ludlow, Ianessa Humbert, Keith Saxon, Christopher Poletto, Barbara Sonies, and Lisa Crujido
Journal: Dysphagia. 2007; 22(1):1-10
Download DGR 3 article here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1790908/
We tested two hypotheses using surface electrical stimulation in chronic pharyngeal dysphagia: that stimulation 1) lowered the hyoid bone and/or larynx when applied at rest, and 2) increased aspiration, penetration or pharyngeal pooling during swallowing. Bipolar surface electrodes were placed on the skin overlying the submandibular and laryngeal regions. Maximum tolerated levels of stimulation were applied while patients held their mouth closed at rest. Videofluoroscopic recordings were used to measure hyoid movements in the superior-inferior (s-i) and anterior-posterior (a-p) dimensions and the subglottic air column (s-i) position while stimulation was on and off. Patients swallowed 5 ml liquid when stimulation was off, at low sensory stimulation levels, and at maximum tolerated levels (motor). Speech pathologists blinded to condition, tallied the frequency of aspiration, penetration, pooling and esophageal entry from videofluorographic recordings of swallows. Only significant (p=0.0175) hyoid depression occurred during stimulation at rest. Aspiration and pooling were significantly reduced only with low sensory threshold levels of stimulation (p=0.025) and not during maximum levels of surface electrical stimulation. Those patients who had reduced aspiration and penetration during swallowing with stimulation had greater hyoid depression during stimulation at rest (p= 0.006). Stimulation may have acted to resist patients’ hyoid elevation during swallowing.