Aspiration as a Function of Age, Sex, Liquid Type, Bolus Volume, and Bolus Delivery Across the Healthy Adult Life Span.

OBJECTIVES: The purpose of this investigation was to examine, via flexible endoscopic evaluation of swallowing (FEES), factors that affect penetration and aspiration during swallowing across the adult lifespan. METHODS: Healthy adults (N = 203) across the third to ninth decades of life participated. Penetration Aspiration Scale (PAS) scores were assessed during FEES as a function of age, sex, liquid type (water and skim, 2%, and whole milk), volume (5, 10, 15, and 20 ml), and delivery (cup and straw). RESULTS: The PAS scores differed significantly by liquid type ( P < .0001) and age group ( P < .0001). In general, PAS scores were higher for milk versus water swallows and for older age groups. Significant interactions of liquid type by age ( P = .0042) and sex by volume ( P = .020) were also evidenced. In addition, the odds of penetration and aspiration increased significantly with milks compared to water and age ( P < .05). Increased bolus volume also increased the odds of aspiration ( P < .05). CONCLUSIONS: Aspiration may be an underappreciated phenomenon in healthy adults. The inclusion of both water and milk test boluses of various volumes during FEES may be important for the appropriate assessment of adult penetration and aspiration.

Ultrasonographic evaluation of geniohyoid muscle and hyoid bone during swallowing in young adults.

OBJECTIVES/HYPOTHESIS: The geniohyoid muscle plays an important role in hyoid bone movement. Adequate hyoid bone movement during swallowing is important for effective bolus flow and pharyngeal clearing. The aim of this study was to estimate the relationship between the geniohyoid muscle size and function and hyoid bone movement during swallowing in healthy young adults, as measured via ultrasound, in different body positions. STUDY DESIGN: Cross-sectional study. METHODS: Forty young (20-40 years old) adults (20 male and 20 female) participated. The cross-sectional area of the geniohyoid muscle at rest (seated position), the geniohyoid muscle contraction velocity, and the hyoid bone displacement during swallowing 10 mL of mineral water were measured by ultrasound in seated, supine, and right lateral decubitus positions. RESULTS: The size of the geniohyoid muscle correlated with body height. Males had larger geniohyoid cross-sectional area than females and greater maximal and anterior hyoid displacement during swallowing than females, and maximal and anterior hyoid bone displacement during swallowing correlated with the size of geniohyoid muscle only when the body was in the supine position; these two movements were positively correlated to each other. CONCLUSIONS: Genders vary in hyoid bone movement during swallowing, and the correlation between geniohyoid muscle size and hyoid bone displacement varies among different body positions during swallowing. This investigation also illuminates the use of ultrasound in providing quantitative measures of geniohyoid muscle and hyoid bone displacement during swallowing. LEVEL OF EVIDENCE: 2c.

Effect of Lidocaine on Swallowing During FEES in Patients With Dysphagia.

PURPOSE: The aims of this study were to assess the effects of 0.2 mL of 4% atomized lidocaine on swallowing and tolerability during Fiberoptic Endoscopic Evaluation of Swallowing (FEES). METHODS: A single blinded study was conducted with 17 dysphagic patients, who received 4 standardized boluses in 2 sequential FEES exams under 2 conditions: non-anesthetized (decongestant only) and anesthetized (lidocaine 4%+decongestant). After each procedure, patients rated their pain on the Wong Baker FACES Pain Rating Scale. Clinicians scored each swallow with the Penetration Aspiration Scale (PAS) and an author-developed Residue Rating Scale. Because the assessments were ordinal, a series of Wilcoxon signed-rank tests were conducted to detect differences between the 2 conditions. RESULTS: No significant differences were detected between groups on PAS or residue in the 4 boluses. Pain scores, however, were significantly lower in the anesthetized condition than the decongested-only condition (P=.035). CONCLUSION: The findings of this study indicated that 0.2 mL of 4% lidocaine enhanced exam tolerability and did not impair the swallow in dysphagic patients.

Reliability of the penetration aspiration scale with flexible endoscopic evaluation of swallowing.

OBJECTIVES: The Penetration Aspiration Scale (PAS), although designed for videofluoroscopy, has been utilized with flexible endoscopic evaluation of swallowing (FEES) in both research and clinical practice. The purpose of this investigation was to determine inter- and intrarater reliability of the PAS with FEES as a function of clinician FEES experience and retest interval. METHODS: Three groups of 3 clinicians (N=9) with varying FEES experience (beginning, intermediate, and advanced) assigned PAS scores to 35 swallows. Initial ratings were repeated following short-term (ie, 1 day) and long-term (ie, 1 week) retest intervals. RESULTS: Intraclass correlation coefficients were calculated to assess interrater reliability on the first rating for each group. The coefficients were .91, .82, and .89 for the beginning, intermediate, and advanced clinicians, respectively. Overall interrater reliability across all 9 clinicians, irrespective of experience, was .85. Intraclass correlation coefficients were also calculated to assess intrarater reliability. The intrarater reliability for short- and long-term ratings was .90, .94, and .96 and .96, .97, and .94 for the beginning, intermediate, and advanced clinicians, respectively. Overall intrarater reliability across all 9 clinicians and all 3 ratings was .94. CONCLUSIONS: Excellent inter- and intrarater reliability was evidenced with the application of the PAS for FEES regardless of clinician experience and retest interval.

Use of topical nasal anesthesia during flexible endoscopic evaluation of swallowing in dysphagic patients.

OBJECTIVE: This study aimed to determine the effect of topical lidocaine on Penetration-Aspiration Scale (PAS) scores and patient comfort and tolerance of flexible endoscopic evaluation of swallowing (FEES) examinations in dysphagic patients. METHODS: Adults with dysphagia referred for swallowing evaluation were recruited to participate in consecutive nonanesthetized and then anesthetized FEES examinations. Under endoscopic visualization, participants consumed 6 swallows consisting of graduated volumes of milk, pudding, and cracker in each condition and recorded their discomfort and tolerance in the 2 conditions. Penetration-Aspiration Scale scores were assigned in blinded fashion for each swallow. RESULTS: Twenty-five adults participated in the study. Although there was no statistically significant effect of anesthesia on PAS scores (P=.065), the odds of a higher PAS score were 33% higher during anesthetized swallows. The anesthetized condition yielded significantly less discomfort and pain during the examination, significantly less pain and discomfort during insertion and removal of the endoscope, and significantly greater overall tolerance than the nonanesthetized condition. CONCLUSION: The use of topical lidocaine during FEES may impair swallowing ability in patients with dysphagia, but this result does not achieve statistical significance. Topical nasal anesthesia significantly reduces subjective pain and discomfort and improves tolerance during FEES.

Age-related changes of hyoid bone position in healthy older adults with aspiration.

OBJECTIVES/HYPOTHESIS: Aspiration, the passage of a bolus below the vocal folds, increases morbidity and mortality in the elderly by increasing the risk of aspiration pneumonia and other conditions. We hypothesized that altered position of the hyoid bone associated with aging may negatively affect airway protection during swallowing (i.e., aspiration) in older adults. STUDY DESIGN: Retrospective study. METHODS: We re-reviewed computed tomography (CT) scans of the head from 40 older adults (65-80 years old), comprised of 20 aspirators and 20 nonaspirators, obtained from a previous cohort study. In addition, CT scans of the head from 40 young adults (20-40 years old) were retrieved from a medical records database. Three-dimensional reconstruction and 2-dimensional sagittal views were used to measure the distance between the mandible and hyoid bone. Comparisons between age groups, genders, and aspiration status were made. RESULTS: Older adults had a larger distance between the hyoid and mandible in both latitude and longitudinal positions compared to the young adults. Among older males, there was evidence that the hyoid bone in the aspirators tended to be positioned more posterior compared to the nonaspirators. CONCLUSIONS: The distance between the hyoid and mandible is increased with aging, and a more posterior position of the hyoid bone is correlated with aspiration in older males. These findings suggest that age-related changes in hyoid bone position may be a component of decreased swallowing safety and aspiration in older adults and warrant further investigation. LEVEL OF EVIDENCE: N/A.

Computed tomography pulmonary findings in healthy older adult aspirators versus nonaspirators.

OBJECTIVES/HYPOTHESIS: In previous studies, we consistently found that approximately 30% of asymptomatic healthy older adults silently aspirated liquids during a flexible endoscopic evaluation of swallowing (FEES) and that their aspiration status was stable for the following year. However, no studies have systematically evaluated effects of silent aspiration on lung parenchyma and airways. We used computed tomography (CT) to compare lungs of healthy older adult aspirators versus nonaspirators. We hypothesized that CT images would show pulmonary differences in healthy older adult aspirators versus nonaspirators. STUDY DESIGN: Prospective study. METHODS: Fifty healthy older adults (25 aspirators and 25 nonaspirators) who participated in a previous FEES were randomly selected. CT scans were performed; on inspiration, lung views were taken at 1.25 mm and 2.5 mm windows, and on expiration, lung views were taken at 2.5 mm. CT scans were reviewed by radiologists blinded to group assignment. Outcomes included bronchiectasis, bronchiolectasis, bronchial wall thickening, parenchymal band, fibrosis, air trapping, intraluminal airway debris, and tree-in-bud pattern. RESULTS: χ(2) analyses between aspirators and nonaspirators found no statistically significant differences between aspirators and nonaspirators for any outcomes (P > .05). Logistic regression analyses adjusted for smoking did not change the results. CONCLUSIONS: There were no differences in pulmonary CT findings between healthy older adult aspirators and nonaspirators. This study adds to the evidence that some aspiration may be within the range of normal for older adults, or at least does not contribute to a change in pulmonary appearance on CT images. LEVEL OF EVIDENCE: 3b.

Isometric and swallowing tongue strength in healthy adults.

OBJECTIVES/HYPOTHESIS: The tongue contributes to a safe swallow. It facilitates bolus control during mastication, maintains a bolus in the oral cavity to prevent premature entry of the bolus into the hypopharynx, and helps generate pressure in the hypopharynx during swallowing. This study examined isometric tongue strength and tongue pressure measured during swallowing in healthy young and older adults. STUDY DESIGN: Prospective group design. METHODS: One hundred twenty-six healthy individuals who were recruited as part of a larger study on swallowing participated in this study. Participants were divided into three age groups: 20 to 40 years, 41 to 60 years, and ≥61 years. A KayPentax Digital Swallowing Workstation with an air-filled bulb array was placed on the tongue of each participant (anterior to posterior). Participants completed three isometric tongue presses and three swallows. RESULTS: Repeated measures analyses of variance revealed a significant main effect of age (P = .01) and gender by tongue bulb location interaction (P = .02) for isometric tongue strength. That is, older adults had lower isometric tongue strength than young adults, and females had a greater difference between anterior and posterior tongue strength than males. Tongue strength during swallowing yielded significantly greater anterior versus posterior tongue pressure. CONCLUSIONS: This study comprises one of the largest in terms of number of healthy participants reported to date and confirms previous findings that isometric tongue strength decreases with age. Furthermore, given young and older adults generate similar swallowing pressures, swallowing is a submaximal strength activity, yet older adults have less functional reserve. LEVEL OF EVIDENCE: 4.

Stability of aspiration status in healthy adults.

OBJECTIVES: In multiple separate studies, we consistently found that approximately 30% of asymptomatic healthy older adults silently aspirated liquids during flexible endoscopic evaluation of swallowing (FEES). We subsequently questioned whether aspiration status remained stable in healthy older adults over time. The purpose of this study was to determine the stability of aspiration status in healthy older adults over time. METHODS: Eighteen healthy older participants, comprising of 9 aspirators and 9 nonaspirators whose aspiration status was identified in a previous study, underwent a second FEES approximately 6 to 21 months later. The participants contributed 36 swallows, comprising 5-, 10-, 15-, and 20-mL boluses of milk (ie, 1 bolus of each volume of skim, 2%, whole, and soy milk) and water via cup and straw delivery, during the original FEES. An abbreviated protocol was administered for the repeat FEES. The Penetration-Aspiration Scale was used to rate all swallows. RESULTS: A McNemar test demonstrated no change in aspiration status among participants between the initial test and the retest (p > 0.999). CONCLUSIONS: In this cohort, the aspiration status was stable over about 12 months. This finding lends credence to the premise that trace aspiration of liquids may be a normal and consistent finding in some healthy older adults.

The effects of topical anesthetic on swallowing during nasoendoscopy.

OBJECTIVES/HYPOTHESIS: To assess the effects of a typical otolaryngologic dose of 1 mL of 4% lidocaine on penetration aspiration scale scores and participant discomfort during flexible endoscopic evaluation of swallowing. STUDY DESIGN: A prospective pilot study. METHODS: Twenty healthy participants consumed 12 swallows consisting of graduated volumes of milk, water, pudding, and cracker in anesthetized and nonanesthetized conditions. Each participant was randomly selected to begin with the anesthetized or nonanesthetized condition. Each participant returned within 7 days to repeat the study in the other condition. Digital recordings of their evaluations were scored via the penetration-aspiration scale in a blinded fashion. Participants recorded their discomfort and tolerance of each flexible endoscopic evaluation of swallowing. RESULTS: The anesthetized condition yielded significantly worse swallowing function (P = .001) than the nonanesthetized condition. The nonanesthetized condition yielded greater discomfort and pain during the procedure (P = .006, .018), greater pain during insertion and removal of the endoscope (P = .002, .003) and less overall tolerance (P = .016) than the anesthetized condition. CONCLUSIONS: A typical otolaryngologic anesthetic dose of 1 mL of 4% lidocaine during flexible endoscopic evaluation of swallowing predisposed healthy young adults to higher penetration aspiration scale scores (less safe swallowing) than the nonanesthetized condition; however, the anesthetic reduced discomfort and provided better overall tolerance. Future studies need to evaluate the effects of lower doses of lidocaine (0.2 and 0.5 mL) on swallowing function and comfort.

Aging-related geniohyoid muscle atrophy is related to aspiration status in healthy older adults.

BACKGROUND: Age-related muscle weakness due to atrophy and fatty infiltration in orofacial muscles may be related to swallowing deficits in older adults. An important component of safe swallowing is the geniohyoid (GH) muscle, which helps elevate and stabilize the hyoid bone, thus protecting the airway. This study aimed to explore whether aging and aspiration in older adults were related to GH muscle atrophy and fatty infiltration. METHOD: Eighty computed tomography scans of the head and neck from 40 healthy older (average age 78 years) and 40 younger adults (average age 32 years) were analyzed. Twenty aspirators and 20 nonaspirators from the 40 older adults had been identified previously. Two-dimensional views in the sagittal and coronal planes were used to measure the GH cross-sectional area and fatty infiltration. RESULTS: GH cross-sectional area was larger in men than in women (p < .05). Decreased cross-sectional area was associated with aging (p < .05), and cross-sectional area was significantly smaller in aspirators compared with nonaspirators, but only among the older men (p < .01). Increasing fatty infiltration was associated with aging in the middle (p < .05) and posterior (p < .01) portions of the GH muscle. There was no significant difference in fatty infiltration of the GH muscle among aspirators and nonaspirators. CONCLUSION: GH muscle atrophy was associated with aging and aspiration. Fatty infiltration in the GH muscle was increased with aging but not related to aspiration status. These findings suggest that GH muscle atrophy may be a component of decreased swallowing safety and aspiration in older adults and warrants further investigation.

Effects of chemesthetic stimuli mixtures with barium on swallowing apnea duration.

OBJECTIVES/HYPOTHESIS: 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). STUDY DESIGN: Prospective group design. SETTING: University Medical Center. METHODS: Eighty healthy women were identified as nontasters and supertasters, equally comprising two age groups: 18 to 35 years and 60+ years. The KayPentax Swallowing Signals Lab was used to acquire SAD via nasal cannula during individually randomized swallows of 5 mL barium, 2.7% w/v citric acid with barium, carbonation with barium, and 50:50 diluted ethanol with barium. Data were analyzed using path analysis, with the mediator of chemesthetic perception, adjusted for repeated measures. RESULTS: Significant main effects of age (P = .012) and chemesthetic stimuli (P = .014) were found, as well as a significant interaction between chemesthetic stimuli and age (P = .028). Older women had a significantly longer SAD than younger women. Post hoc analyses revealed that barium mixed with ethanol elicited a significantly longer SAD than other bolus conditions, regardless of age group. There were no significant differences in SAD between barium and water conditions, and no significant effect of chemesthetic perception (P > .05). CONCLUSIONS: Ethanol added to barium elicited longer SAD compared to plain barium, but not the other chemesthetic conditions. Older women had a longer SAD than younger women in all conditions. These findings may influence design of future studies examining effects of various stimuli on SAD.

Effects of aging and levodopa on the laryngeal adductor reflex in rats.

Dopaminergic neurotransmission plays an essential role in sensorimotor function, and declines with age. Previously, we found the laryngeal adductor reflex (LAR) was increased in excitation by a dopamine receptor antagonist. If this airway-protective reflex is similarly affected by aging, it will interfere with volitional control in older adults. The current study tested whether the LAR was affected by aging, and whether such deficits were reversed by levodopa administration in aging rats. We recorded thyroarytenoid (TA) muscle activity at rest and during elicitation of LAR responses by stimulation of the internal branch of the superior laryngeal nerve (iSLN) in 6-, 18- and 30-month-old rats under alpha-chloralose anesthesia. Using paired stimuli at different inter-stimulus intervals (ISIs), LAR central conditioning, resting muscle activity, and reflex latency and amplitudes were quantified. Numbers of dopaminergic neurons in the substantia nigra pars compacta (SNpc) were measured using tyrosine hydroxylase staining. We found: (1) increased resting TA muscle activity and LAR amplitude occurred with fewer dopaminergic neurons in the SNpc in 18- and 30-month-old rats; (2) decreases in LAR latency and increases in amplitude correlated with reduced numbers of dopaminergic neurons in the SNpc; (3) test responses were greater at 1000ms ISI in 18-month-old rats compared with 6-month-old rats; and (4) levodopa administration further increased response latency but did not alter muscle activity, response amplitude, or central conditioning. In conclusion, increases in laryngeal muscle activity levels and reflex amplitudes accompanied age reductions in dopaminergic neurons but were not reversed with levodopa administration.

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.

Tongue adiposity and strength in healthy older adults.

OBJECTIVES/HYPOTHESIS: To identify treatable risk factors for aspiration in older adults, particularly those associated with sarcopenia, we examined tongue composition. We hypothesized that isometric and swallowing posterior tongue strength would positively correlate with posterior tongue adiposity, and healthy older adults who aspirate would have greater tongue adiposity than healthy older adults who did not aspirate. STUDY DESIGN: Prospective. METHODS: Participants were 40 healthy adults, comprised of 20 aspirators (mean age, 78 years) and 20 nonaspirators (mean age, 81 years), as identified via flexible endoscopic evaluation of swallowing. Measures of maximal isometric posterior tongue strength and posterior swallowing tongue strength were acquired via tongue manometry. An index of posterior tongue adiposity was acquired via computed tomography for a 1-cm region of interest. RESULTS: Posterior tongue adiposity was correlated with posterior tongue isometric (r = 0.32, P = .05) but not swallowing pressures (P > .05) as examined with separate partial correlation analyses. Tongue adiposity did not significantly differ as a function of age, gender, or aspiration status (P > .05). CONCLUSIONS: Lower posterior isometric tongue strength was associated with greater posterior tongue adiposity. However, aspiration in healthy older adults was not affected by posterior tongue adiposity. This finding offers insight into the roles of tongue composition and strength in healthy older adults.

Factors influencing bolus dwell times in healthy older adults assessed endoscopically.

OBJECTIVES/HYPOTHESIS: Scant data exist on normal bolus dwell time assessed during flexible endoscopic evaluation of swallowing (FEES). The purpose of this study was to examine bolus dwell time in healthy older adults. Because it has been previously reported that some healthy older adults aspirate, we also sought to determine if bolus dwell time varied as a function of aspiration status. STUDY DESIGN: Prospective. METHODS: Seventy-six healthy volunteers from the seventh, eighth, and ninth decades of life participated. Dwell times were analyzed via FEES as a function of pharyngeal location, liquid type, delivery method, purée type, viscosity, age, and gender. RESULTS: Longer dwell times were evidenced with the eldest participants, straw delivery, and the smallest volume. Adults in the ninth decade were 4.8 (P = .01) and 3.8 (P = .02) times more likely to have longer dwell times at the vallecula and 7.1 (P = .002) and 3.8 (P = 0.02) at the pyriform sinus than those in the seventh and eighth decades, respectively. Longer dwell times at the vallecula and pyriform sinuses were 2 and 2.38 times (P < .0001) more likely for straw than cup delivery, respectively. Boluses of 5 mL were 1.5 times (P < .05) more likely to result in longer dwell times than larger volumes. Bolus dwell times did not significantly differ as a function of aspiration status. CONCLUSIONS: Advanced age, straw delivery, and small volumes yielded longer dwell times. These variables should be considered before diagnosing an abnormal bolus dwell time in elder patients.

Effects of liquid type, delivery method, and bolus volume on penetration-aspiration scores in healthy older adults during flexible endoscopic evaluation of swallowing.

OBJECTIVES: The type of liquid (eg, water or milk) that should be used during flexible endoscopic evaluation of swallowing (FEES) has received little investigation. Aspiration may vary as a function of the thin liquid type used during FEES. METHODS: We measured the effects of liquid type (water, skim milk, 2% milk, and whole milk; all dyed with green food coloring), delivery method (cup and straw), and bolus volume (5, 10, 15, and 20 mL) on Penetration-Aspiration Scale (PAS) scores in 14 healthy older adults (mean, 75 years; range, 69 to 85 years). Each participant generated 32 swallows. RESULTS: The PAS scores differed significantly by liquid type (p = 0.003) and by bolus volume (p = 0.017), but not by delivery method (p = 0.442). The PAS scores were significantly greater for 2% milk and whole milk than for skim milk and water (p < 0.05), and for 20 mL versus smaller volumes. Penetration and aspiration were observed on 113 (25%) and 15 (3%) of 448 swallows, respectively. CONCLUSIONS: These findings suggest that both milk and water should be used during FEES for an accurate assessment of aspiration status.

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.

Maximum phonation time in healthy older adults.

OBJECTIVES/HYPOTHESIS: Maximum phonation time (MPT), a clinical measurement of the longest time one can phonate a vowel, typically /a/, is a frequently used measure of vocal function, but normative data are lacking for MPT in healthy older adults. The aim of this study was to provide data on MPT in healthy older adults and to determine the effect of advanced age, gender, and repeated measures on MPT. STUDY DESIGN: Prospective. METHODS: Sixty-nine healthy older adult volunteers participated (ie, 15, 26, and 28 in the seventh, eighth, and ninth decades of life, respectively). The effects of age, gender, and repeated measures (three trials in a single session) on MPT were assessed. Mean, standard deviation, compound symmetry covariance, analysis of variance, and analysis of covariance were used for statistical analysis. RESULTS: Neither age group, gender, trial, nor their interactions was statistically significant (P>0.05). Adults in the seventh, eighth, and ninth decades of life had mean MPTs of 22.27 (standard error [SE]=1.56), 22.97 (SE=1.11), and 21.14 (SE=0.97) seconds, respectively. Females and males had mean MPTs of 20.96 (SE=0.92) and 23.23 (SE=0.96) seconds, respectively. Finally, MPTs for trials 1, 2, and 3 were 21.77 (SE=1.09), 21.67 (SE=1.12), and 22.80 (SE=1.27), respectively. CONCLUSIONS: MPTs were longer in this group of older adults than previously reported and did not vary significantly with age or gender. Additionally, across a single short sampling session, measurements were relatively stable across three trials of MPTs.

The relationship of aspiration status with tongue and handgrip strength in healthy older adults.

BACKGROUND: Recently, subclinical aspiration has been identified in approximately 30% of community-dwelling older adults. Given that the tongue is a key component of the safe swallow, we hypothesized healthy older adults who aspirate will generate less tongue strength than adults who do not aspirate. Furthermore, as muscle weakness may reflect a global effect of aging, we further investigated whether tongue strength is correlated with handgrip strength. METHODS: We assessed 78 healthy community-dwelling older adults (M = 77.3 years, SD = 7.26) for aspiration status (37% aspirators) via flexible endoscopic evaluation of swallowing. Maximal isometric anterior and posterior tongue strength, anterior and posterior swallowing tongue strength, and maximum handgrip strength were measured. RESULTS: Isometric tongue strength was significantly lower in aspirators versus nonaspirators (p = .03) at both the anterior (463 vs 548 mmHg, respectively) and posterior lingual locations (285 vs 370 mmHg, respectively). Likewise, swallowing tongue strength was significantly lower in aspirators versus nonaspirators at both the anterior (270 vs 317 mmHg, respectively) and posterior lingual locations (220 vs 267 mmHg, respectively). There was no difference between aspirators and nonaspirators' handgrip strength (p > .05), although handgrip strength was correlated with posterior tongue strength (r = .34, p = .005). CONCLUSIONS: Lower anterior and posterior isometric and swallowing tongue strength were dependent on aspiration status. Lower lingual strength in healthy adults may predispose them to aspiration. The correlation between tongue and handgrip strength is consistent with the hypothesis that impaired oropharyngeal strength reflects global age-related declines in muscle strength.