This year we focused on the study of a) normal swallow, b) tongue/hyoid activity with pellet referent, c) effects of xerostomia on swallow, and d) modification of the ultrasound system. A. Normal Studies: 50 normals age 18-75 were studied during dry and wet swallows. We determined that normal swallowing is affected by aging. We see a different durational pattern for dry and wet swallows. Older female's swallows were longer and more effortful than males. After age 55 extra effort was needed to swallow by using initiatory gestures of the tongue and hyoid. Significant durational differences appeared at age 65+. B. Pellet Studies: This work is the first to use a referent for tracking tongue movement during swallowing. From studies of 6 normals, the wavelike motion of the tongue was able to be documented during swallow. Direction rate and extent of pellet movement were measured and used to create 4 stages of tongue blade action. Pellet movement was then compared to the ascent, steady and descent stages of hyoid movement. Raising of the tongue blade was synchronous with ascent of the hyoid as the bolus passed into the pharynx. C. Xerostomia: Data of 50 Xerostomics was completed. Preliminary results confirmed that lack of oral lubrication delayed and altered ability to initiate a swallow. Lack of saliva appears to change the pattern of tongue/hyoid activity. This same pattern was evident to a lesser extent during wet swallows but not seen in our normal subjects. This finding will require further study. D. Equipment Modifications: In order to synchronously measure tongue, lip and jaw motion, modification of the transducer holder and head positioner are underway. We will fabricate a device for strain gauges to measure lip and jaw activity. The transducer positioner will be modified to study more complex tongue-jaw-lip activity during rapid speech to reduce positioning variability.
