Cathy A. Pelletier

Effects of Chemesthetic Stimuli, Age, and Genetic Taste Groups on Swallowing Apnea Duration

Objective. This study tested the hypotheses that swallowing apnea duration (SAD) will increase given chemesthetic stimuli (ie, water < ethanol, acid, and carbonation), age (older > young), and genetic taste differences (supertasters > nontasters). Study Design. Prospective group design. Setting. University medical center. Subjects and Methods. Eighty healthy adult women were identified as nontasters and supertasters, equally comprising 2 age groups: 18 to 35 years (n = 40) and 60+ years (n = 40). The KayPentax Swallowing Signals Lab was used to acquire SAD via nasal cannula during individually randomized swallows of 5 mL deionized water, 2.7% w/v citric acid, seltzer water, and 50:50 diluted ethanol/water. Data were analyzed using path analysis, with the mediator of chemesthetic perception, adjusted for repeated measures. Results. Significant main effects of chemesthetic stimuli (P = .002), age (P < .001), and genetic taste differences (P = .04) on SAD were found. Older women and supertasters had longer SADs than young women and nontasters. Post hoc analyses revealed ethanol and acid boluses elicited significantly longer SADs than water boluses did. There was no significant effect of chemesthetic perception (P > .05). Conclusion. SAD in healthy women increased with changes in chemesthetic stimuli, older age, and in supertasters versus nontasters. It is unclear at this stage if increased SAD is a helpful mechanistic change (potentially protective against aspiration) or a maladaptive change (associated with aspiration). Future research should use these chemesthetic changes in bolus properties to assess if increased SAD decreases aspiration in patients with dysphagia while accounting for genetic taste differences.

Effects of Chemesthetic Stimuli Mixtures With Barium on Swallowing Apnea Duration

This study tested the hypotheses that swallowing apnea duration (SAD) will increase given barium versus water, chemesthetic stimuli (i.e., water < ethanol, acid, and carbonation) mixed with barium, age (older > younger), and genetic taste differences (supertasters > nontasters).

Main Taste Effects on Swallowing Apnea Duration in Healthy Adults

Objective This study examined swallowing apnea duration (SAD) and respiratory phase patterns as a function of taste, tastes combined with barium, age, and genetic taste group. Study Design Prospective group design. Setting University medical center. Subjects and Methods Eighty healthy adult women were identified as nontasters and supertasters and equally comprised 2 age groups: 18 to 35 years (n = 40) and 60+ years (n = 40). The KayPentax Swallowing Signals Lab was used to acquire SAD and respiratory phase patterns via nasal cannula during randomized 5-mL swallows of water, 1.0 M sucrose (sweet), 1.0 M sodium chloride (salty), and 0.032 M caffeine (bitter) alone and mixed with barium. The SAD and respiratory patterns were analyzed in a linear mixed model and a binary logistic regression generalized estimating equation model, respectively. Results A significant main effect of age was found (P = .007). Older women demonstrated longer SAD than younger women. There were no significant effects of taste or genetic taste group on SAD. There was a significant interaction between barium and supertaster status; SAD was shorter in supertasters when barium was included. There were no significant differences in respiratory patterns between age groups, genetic taste groups, or among taste stimuli. Conclusion Advanced age elicited longer SAD, a robust finding in repeated investigations from multiple laboratories. Main tastes did not affect SAD or respiratory phase patterns. Genetic taste group altered SAD when barium was combined with the taste. That is, taste + barium shortened SAD in supertasters. This finding may affect clinical management of dysphagia patients and warrants further investigation.

Differences in Swallowing between High and Low Concentration Taste Stimuli

Taste is a property that is thought to potentially modulate swallowing behavior. Whether such effects depend on taste, intensity remains unclear. This study explored differences in the amplitudes of tongue-palate pressures in swallowing as a function of taste stimulus concentration. Tongue-palate pressures were collected in 80 healthy women, in two age groups (under 40, over 60), stratified by genetic taste status (nontasters, supertasters). Liquids with different taste qualities (sweet, sour, salty, and bitter) were presented in high and low concentrations. General labeled magnitude scale ratings captured perceived taste intensity and liking/disliking of the test liquids. Path analysis explored whether factors of taste, concentration, age group, and/or genetic taste status impacted: (1) perceived intensity; (2) palatability; and (3) swallowing pressures. Higher ratings of perceived intensity were found in supertasters and with higher concentrations, which were more liked/disliked than lower concentrations. Sweet stimuli were more palatable than sour, salty, or bitter stimuli. Higher concentrations elicited stronger tongue-palate pressures independently and in association with intensity ratings. The perceived intensity of a taste stimulus varies as a function of stimulus concentration, taste quality, participant age, and genetic taste status and influences swallowing pressure amplitudes. High-concentration salty and sour stimuli elicit the greatest tongue-palate pressures.

The Role of Chemosenses in Swallowing Disorders Across the Lifespan

IntroductionThe act of swallowing saliva or food/liquid is a complex motor-sensory event that occurs for most people without any thought or concern. However, for individuals who are born with or acquire dysphagia (swallowing impairment), swallowing can be frightening, painful, difficult, and/or life-threatening.MethodsWhile it is well known that the physical and chemical composition of food and liquids can alter its acceptance and consumption, the role that these properties play in dysphagia is just beginning to be studied.ResultsTaste, smell, and oral touch are integral sensory systems of deglutition. These inputs are crucial for infants/children who are learning to safely chew and swallow increasingly more complex food textures. These sensory inputs are equally important for adults who may have acquired sensorimotor impairments due to trauma, cancer, or neurologic disease. This article describes how swallowing physiology and anatomy change from infancy to adulthood and how the attributes of food and liquids influence swallowing safety.ConclusionsThe manipulation of the taste/smell and physical properties of food and liquids in the treatment of dysphagia is an intriguing area of new research currently underway.

Is Taste Altered in Patients with ALS

Amyotrophic lateral sclerosis (ALS) is a degenerative neurological disease that affects the motor systems in patients but also may affect some sensory systems. Some ALS patients report taste changes that may decrease their oral intake and nutritional status. This study examined whether focal taste damage occurs in ALS patients compared to age/gender-matched adult healthy controls. An abbreviated Spatial Taste Test was administered to the fungiform and circumvallate papillae. Compared to healthy controls, ALS patients exhibited significantly lower taste intensities across the four basic tastes and significantly lower taste intensities at both the fungiform and vallate papillae, but no significant difference in whole mouth taste intensities. Seven out of nine ALS patients with self reported altered taste had tongue fasciculations, involuntary movements within the tongue dorsum due to lower motor neuron impairment (a common sign of bulbar ALS). Additionally, for patients taking riluzole taste perception at the fungiform papillae appears to be further reduced relative to the vallate papillae. This study suggests ALS decreases taste at both the fungiform and vallate papillae. In addition, riluzole may further damage the chorda tympani. Further studies need to be conducted to examine the etiology for taste loss.