Sandra Hamlet

Mastication and swallowing in patients with postirradiation xerostomia

PURPOSE Very little objective data has been reported on mastication and swallowing in xerostomic patients, which would substantiate presumed causal relationships between xerostomia and patient complaints. The purpose was to elucidate which components of mastication and swallowing were abnormal, and most directly related to xerostomia, and which appeared unaffected. METHODS AND MATERIALS A retrospective analysis of timing events in mastication and swallowing was done using videofluoroscopic data for 15 cancer patients with xerostomia, and 20 normal controls. Scintigraphy was also used to determine oropharyngeal residue after a water swallow. Cancer treatment modalities included radiation therapy or chemoradiation therapy. RESULTS For barium liquid and paste substances, timing measures were equivalent for controls and patients. Xerostomic patients took 46% longer to masticate a shortbread cookie, and timing for the initiation of swallowing was shorter, but duration of swallowing appeared unaffected. Oral and pharyngeal residues following the swallow were greater in the patient group. CONCLUSIONS Xerostomia primarily affected mastication and oral manipulation of a dry, absorbent food material. Increased oral and pharyngeal residues after a water swallow are ambiguously related to xerostomia. The initiation and duration of the pharyngeal swallow was not abnormal.

Scintigraphic quantification of aspiration reduction with the Passy-Muir valve.

The Passy‐Muir “speaking” tracheostomy valve has been noted to aid in swallowing, based on videofluoroscopy to assess aspiration. In this study scintigraphy was used to quantify the amount of material aspirated.

Normal adult swallowing of liquid and viscous material: scintigraphic data on bolus transit and oropharyngeal residues.

Scintigraphic data are provided for 20 normal control subjects, 39–65 years of age. Each subject swallowed 10 cc of water and 10 cc of a more viscous material (1,100 centipoise) consisting of apple juice thickened with Thick-It, a commercial food thickener. The test substances were combined with 2.5 mCi Tc-99m sulfur colloid. Scintigraphic data were acquired in dynamic mode for 10 sec at 25 frames/sec as the subjects swallowed. Time-activity (TA) data were used to compute transit times, percentage residues in the mouth and pharynx, percent ingested, and a derived swallow efficiency score. The liquid was ingested in a single swallow by all subjects, and 9 cc was actually tranferred to the esophagus. In contrast, for the viscous material, 11/20 subjects performed a second clearing swallow within the 10-sec interval. On the first swallow with the viscous substance, an average of 7 cc was transferred to the esophagus. Scintigraphy offers an excellent technique for determining natural and preferred volumes for swallowing a variety of bolus consistencies, since it can quantify the volume of each swallow or partial swallow. In this group of subjects the oral discharge time was shorter with the viscous material than with the water, but the pharyngeal transit times were not significantly different for the two bolus consistencies. Numerical efficiency scores were lower for the viscous material, indicating that such a measure is bolus dependent.

Stethoscope Acoustics and Cervical Auscultation of Swallowing

Frequency response characteristics of six popular stethoscopes are reported for the higher frequency range (to 3000 Hz) to supplement equivalent measurements for the lower frequencies (35–1000 Hz) published previously. Spectra of the sounds of swallowing from the throat, transduced with an accelerometer, demonstrate important frequency composition in this higher range. Two stethoscope models were found to have superior transmission characteristics for use in cervical auscultation of swallowing sounds.

Pharyngeal transit time: Assessment with videofluoroscopic and scintigraphic techniques

The swallowing function of 31 normal and dysphagic subjects between the ages of 39 and 79 was tested with both videofluoroscopy and scintigraphy. Pharyngeal transit times for the pair of tests were compared. A statistically significant correlation of 0.66 was found. Normal pharyngeal transit time was under 1.2 s with either method, but mean values for scintigraphy were slightly longer than those for videofluoroscopy.

Sounds of swallowing following total laryngectomy

Accelerometer transduced sounds of swallowing in total laryngectomees did not show acoustical differences for liquid vs paste swallows, as are found in normals. Compared with normal swallows, tongue propulsion of the bolus in laryngectomee swallows occurred closer in time to a distinctive spectral change associated with bolus flow into the esophagus. Interpretation stressed the lack of mechanical traction from laryngeal elevation contributing to pharyngoesophageal sphincter opening, and the increased role of tongue propulsion in laryngectomee swallows.

Dynamic aspects of lingual propulsive activity in swallowing

This investigation concerned the effect of different bolus volumes on the characteristics of lingual propulsive activity in swallowing. Young normal subjects were asked to perform dry swallows and swallows of 5, 10, and 15 ml of water. Tongue activity was recorded by tracking multiple gold pellets affixed to the tongue, utilizing the specialized research capabilities of the X-ray Microbeam facility at the University of Wisconsin. The major differences were between dry and liquid swallows, with dry swallows showing smaller range of movement, higher tongue position at the initiation of lingual propulsive activity, a slightly different direction of motion, a humped or flat rather than grooved cross-sectional contour of the tongue, lower peak velocity of motion, and slower progression of activity from tongue blade to dorsum. Within the 5–15 ml range of liquid bolus volumes, fewer consistent differences were found as a function of bolus size, and some marked individual differences in swallowing patterns were seen. Data are presented on normal within-subject variability in swallowing, with discussion of the possible contribution of sensory assessment of bolus size to the modification of oral and pharyngeal characteristics of swallowing.

Bolus propulsive activity of the tongue in dysphagic cancer patients

Videofluoroscopic recordings were analyzed for liquid swallows in dysphagic patients with cancer involving the pharynx. Temporal measurements were made for the tongue stripping action in relation to velar and hyoid function. Dysphagic subjects as a group displayed an altered sequence of activity compared to normal controls, with the onset of stripping occurring after velar closure. Tongue stripping action and hyoid movement appeared to be time-locked to a greater extent than tongue stripping and velar closure. Duration of the stripping gesture was longer in dysphagic patients than in normal controls.

Posterior tongue grooving in deglutition and speech ; preliminary observations

Real-time ultrasound sector scanning was used to image the posterior tongue. Depth of tongue grooving and distance of the tongue surface from the transducer face were measured in 7 normal subjects, for vowels in a standardized speech context and for dry swallows. Tongue postures for the vowels |æ| or |e| were most similar to the maximum grooving found in deglutition, which occurred approximately 300 ms prior to ultrasound evidence of initiation of the reflexive pharyngeal phase of swallowing.

Tongue mobility in speech after partial glossectomy

Recovery of tongue mobility in speech was investigated in 5 partial glosectomy patients. Jaw range of motion used in speech, and tongue contour changes relative to the jaw, were assessed using sequential videofluoroscopic data recorded presurgery, postsurgery, and postradiotherapy. Data from 2 normal controls were included for comparison. Tongue mobility relative to the jaw was found to be restricted postsurgery. Approximately 4 months later, following radiotherapy, tongue mobility increased. Range of jaw motion used in speech was unchanged. Results are interpreted as preliminary evidence that in this small group of cancer patients, radiotherapy following surgery did not prevent continued recovery of tongue function for speech in the early postradiation period.