The effects of aspiration status, liquid type, and bolus volume on pharyngeal peak pressure in healthy older adults

A Novel Exercise to Improve Suprahyoid Muscle Area and Intensity as Evaluated by Ultrasonography

Insufficient suprahyoid muscle strength with poor opening of the upper esophageal sphincter can cause dysphagia. This study investigated whether an exercise of the suprahyoid muscle, named forehead exercise for suprahyoid muscles (FESM, "Enge-Odeko-Taiso" in Japanese), improves the geniohyoid muscle area and intensity using ultrasonography. Sixty-four participants (15 men and 49 women, 82.8 ± 6.0 years) living independently with no symptoms of swallowing difficulties were enrolled. The participants were divided into the FESM and the control group. The FESM is an isometric exercise involving repetitions of looking into the navel as if the chin is pulled back with little neck motion using a hand pushed against the forehead for resistance. This exercise is performed five times in 10 courses a day (total 50 times) for 8 weeks. Participants in the control group did not conduct any exercises. Body mass index, hand grip strength, gait speed, calf circumference, Mini Nutritional Assessment short-form, eating assessment tool, repetitive saliva swallowing test (RSST), and Food Intake LEVEL Scale scores were examined. The ultrasonographic geniohyoid muscle area, intensity, and RSST were investigated before and after the program. In the FESM group, the geniohyoid muscle area increased from 2.24 to 2.52 cm2 (P < 0.05), intensity decreased from 34.6 to 32.0 (P < 0.05), and the median RSST increased from 5 to 6 (P < 0.05) significantly. Conversely, no significant differences were observed in the control group. The FESM was effective to increase the area and decrease the intensity of the geniohyoid muscle and may improve swallowing function.

Latent changes in the pharyngeal stage of swallowing in non-aspirating older adults

PURPOSE

The characteristic changes in the swallowing mechanism with aging are collectively termed presbyphagia. Although several studies have investigated presbyphagia in older adults, few have assessed oldest-old adults. We aimed to characterize the latent changes of swallowing function in oldest-old adults and to consider risk ages for presbyphagia.

METHODS

We analyzed the records of 85 individuals (44 males and 41 females, aged 25-101 years) who underwent videofluoroscopic swallowing studies. The included participants had penetration and aspiration scores of ≤ 2 and no history of aspiration, pneumonia, or diseases that affect swallowing. They were divided into four age groups: 25-64 years (non-older), 65-74 years (young-old), 75-84 years (middle-old), and ≥ 85 years (oldest-old). We analyzed and compared the pharyngeal delay time (PDT), duration of tongue base and posterior pharyngeal wall contact, duration and dimension of upper esophageal sphincter opening (UES-O), and maximal hyoid bone displacement between the age groups.

RESULTS

Among the older groups, the oldest-old showed significantly longer PDT than younger-old adults, and the UES-O tended to be wider in the former. However, no other remarkable differences were found between the oldest-old and other old groups. Statistical comparisons between the < 75 and ≥ 75-year age groups revealed significant age-related changes in the PDT and duration and dimension of UES-O.

CONCLUSION

On videofluoroscopic evaluation, physiological changes with aging affected few parameters of swallowing in our cohort. These findings indicate that in non-aspirating oldest-old adults, any deterioration may be adjusted for by compensatory changes to maintain swallowing function.

Surface Electromyographic Biofeedback and the Effortful Swallow Exercise for Stroke-Related Dysphagia and in Healthy Ageing

Dysphagia is common after stroke, leading to adverse outcome. The Effortful Swallow (ES) is recommended to improve swallowing but it is not known if dysphagic patients can increase muscle activity during the exercise or if age affects performance. Providing surface electromyographic (sEMG) biofeedback during dysphagia therapy may enhance exercise completion, but this has not been investigated and the technique’s acceptability to patients is not known. Aims: To determine if age or post-stroke dysphagia affect the ability to increase submental muscle activity during the ES, if sEMG biofeedback improves ES performance and if sEMG is an acceptable addition to therapy. In a Phase I study submental sEMG amplitudes were measured from 15 people with dysphagia < 3 months post-stroke and 85 healthy participants aged 18–89 years during swallowing (NS) and when they performed the ES with and without sEMG biofeedback. Participant feedback was collected via questionnaire. Measurements were compared with repeated measures ANOVA and age effects were examined with linear regression. Both groups produced significantly greater muscle activity for the ES than NS (p < 0.001) and significantly increased activity with biofeedback (p < 0.001) with no effect of age. Participant feedback about sEMG was very positive; over 98% would be happy to use it regularly. The ES is a physiologically beneficial dysphagia exercise, increasing muscle activity during swallowing. sEMG biofeedback further enhances performance and is considered an acceptable technique by patients. These findings support the potential application of sEMG biofeedback and the ES in dysphagia therapy in stroke, justifying further investigation of patient outcome.

Detection of Aspiration, Penetration, and Pharyngeal Residue During Flexible Endoscopic Evaluation of Swallowing (FEES): Comparing the Effects of Color, Coating, and Opacity

The aim of this study was to assess the effects of color, coating, and opacity on the detection of aspiration, penetration, and residue during flexible endoscopic evaluations of swallowing (FEES). Thirty dysphagic adults underwent FEES while swallowing five 5 mL thin liquid boluses (1 × each, randomized): white water, blue water, white milk, blue milk, and barium water. To assess the effects of color, blue milk was compared to white milk. To assess the effects of coating, barium, white water, and white milk were compared to each other. To assess the effects of opacity, blue milk was compared to blue water. Videos were blindly analyzed and judged for the presence of pharyngeal residue, penetration, and aspiration. Repeated measures analyses were used to assess differences in the frequency of detection across bolus types. Pharyngeal residue was detected more frequently for liquids that were blue, had a coating effect, or were opaque (p < 0.05) when compared to liquids that were white, did not have a coating effect, or were translucent, respectively. Penetration and aspiration were detected more frequently for liquids that had a coating effect (p < 0.05), but not for liquids that were colored blue or opaque (p > 0.05). Coating appears to be the most important factor detecting thin liquid residue, penetration, and aspiration during FEES. Given these findings, standardized use of boluses that possess a coating effect (e.g., white-dyed water or barium) is highly recommended to enhance the sensitivity of identifying impairments in swallowing safety and efficiency during FEES.

A Systematic Review of the Influence of Bolus Characteristics on Respiratory Measures in Healthy Swallowing

There have been a number of studies on the effect of bolus volume, consistency, texture, temperature and taste on the oropharyngeal swallowing physiology. However, its influence on the respiratory function associated with swallow is not well understood. This study aimed at systematically analysing and documenting the prevailing research literature on respiratory functions before, during, and after healthy swallows of boluses with varied characteristics. The PRISMA guidelines were followed for retrieval of relevant research. From among the 48,329 reports screened for inclusion criteria, 25 articles were included for data extraction. Each of these reports was evaluated for its design, methodology and reporting quality and also the level of evidence provided by them. The results revealed that the scientific evidence in this regard was restricted to level II. Majority of the studies included considered bolus volume as the variable than bolus consistency, taste or temperature. Expiratory phase was preferred surrounding the apnea irrespective of volume, consistency or taste but changed with temperature variations across age groups. The reports are equivocal on the duration of respiratory apnea, and length of respiratory cycles before and after the apnea. The temporal coordination of pharyngeal swallow events was found to be independent of bolus volume. This review concluded that bolus characteristics have differential effects on the respiratory functions during swallow beyond a 'central sensory threshold' level. Objective standardization of bolus characteristics may be the immediate requirement for generalization of future research findings in this direction.

Relationship Between Tongue Pressure and Pharyngeal Function Assessed Using High-Resolution Manometry in Older Dysphagia Patients with Sarcopenia: A Pilot Study

Tongue pressure is often used to evaluate swallowing muscle strength in dysphagia patients with sarcopenia. However, the amount of tongue pressure that reflects pharyngeal swallowing function is unclear. The aims of this descriptive study were (1) to assess the association between tongue pressure and swallowing function using high-resolution manometry (HRM), (2) to evaluate whether manometric parameters were related to maximum tongue pressure (MTP) and other sarcopenia-related factors, and (3) to evaluate the manometric characteristics of pharyngeal swallowing in sarcopenic dysphagia. Sixteen patients with dysphagia (13 men; mean age 85.0 ± 6.6) who were diagnosed with sarcopenia and sixteen healthy subjects (10 men; mean age 33.6 ± 7.2) were included. Evaluation of HRM parameters including velopharyngeal contractile integral (VPCI), mesohypopharyngeal contractile integral (MHPCI), upper esophageal sphincter (UES) relaxation duration, and UES nadir pressure was performed. HRM parameters of patients were compared with MTP, sarcopenia factors, and manometric parameters of healthy subjects. The VPCI showed no statistically significant differences between patient and healthy groups. In the patient group, the MHPCI was significantly lower (126.1 ± 76.6 vs 193.2 ± 34.1 mmHg cm s; p = 0.003), UES nadir pressure was significantly higher (10.5 ± 27.5 vs - 11.2 ± 6.7 mmHg; p < 0.001), and UES relaxation duration (318.0 ± 152.4 vs 520.6 ± 60.0 ms; p = 0.007) was significantly shorter than those in the healthy group. HRM parameters were not significantly correlated with MTP and sarcopenia factors. Older dysphagia patients with sarcopenia had weaker pharyngeal contractility and UES dysfunction. Manometric evaluation of pharyngeal function may not be significantly associated with MTP and sarcopenia-related factors. Further study is needed to clinically apply tongue pressure for evaluating sarcopenic dysphagia.

Dysphagia is associated with oral, physical, cognitive and psychological frailty in Japanese community-dwelling elderly persons

OBJECTIVE

To investigate which domains of frailty are associated with dysphagia in community-dwelling elderly persons.

BACKGROUND

Dysphagia is a common cause of aspiration pneumonia in frail elderly persons in Japan. Although frailty is considered to be multidimensional, it is unclear which domains of frailty affect dysphagia.

METHODS

The participants were 3475 independent Japanese elderly persons (≥65 years; 1555 men and 1920 women). A self-report questionnaire with a frailty checklist consisting of several domains (lifestyle, physical function, nutrition, oral function, homebound status, cognitive function and depressive mood) was used to determine the participants' characteristics. Dysphagia was defined as impaired swallowing in the oral function domain. To determine the associations between dysphagia and age, sex and the other domains on the frailty checklist, adjusted odds ratios (AORs) and 95% confidence intervals (95% CIs) were calculated using multiple logistic regression analysis.

RESULTS

The multiple logistic regression analysis showed that dysphagia was independently associated with female sex (AOR = 1.35; 95% CI = 1.08-1.68), chewing ability (AOR = 1.70; 95% CI = 1.32-2.18), oral dryness (AOR = 1.94; 95% CI = 1.48-2.54), physical function (AOR = 2.19; 95% CI = 1.66-2.90), cognitive function (AOR = 1.68; 95% CI = 1.34-2.12) and depressive mood (AOR = 1.82; 95% CI = 1.41-2.35).

CONCLUSION

Dysphagia was independently associated with oral, physical, cognitive and psychological frailty. These results suggest that frailty prevention strategy including swallowing training might be useful for community-dwelling independent elderly persons aged ≥65 years.

A Systematic Review of Physiological Changes in Swallowing in the Oldest Old

Age-related swallowing changes are well-researched in deglutology, usually distinguishing those over 60 years as older aged. World-wide, older adults are healthier and forecast to live longer: many over 85 years. It is necessary for clinicians to understand healthy swallowing changes in this 'oldest old' in order to appropriately manage swallowing complaints in older patients. This systematic review collated and critically appraised studies investigating swallowing changes in adults over 85 years using instrumental assessment. Criteria for inclusion were healthy subjects over 85 years. Exclusion criteria included studies focused on anatomy and oral processing. Studies published until December 2018 were retrieved from BIOSIS, CINAHL, Embase, Medline, and Scopus, totaling 2125 articles. During data screening, 64% of studies investigating age-related swallowing changes were excluded, as the oldest old were not recruited. After PRISMA screening, 44 articles met criteria. These were further reviewed for data extraction, bias and quality. Main quantitative age-related changes in swallowing included increases in delay in swallow onset, bolus transit times, duration of UES opening, pressure above the UES and UES relaxation pressure, and reduction in pressure at the UES. Few studies detected increased residue or airway compromise in the form of aspiration. Results were not easily comparable due to differences in age ranges, methods for deeming participants 'healthy', measures used to define swallowing physiology, and swallowing tasks. Age-related swallowing changes are identified that do not compromise safety. The oldest old are underrepresented in normative deglutition research. It is essential future studies plan accordingly to recruit those over 85 years.

Age-related declines in the swallowing muscle strength of men and women aged 20-89 years: A cross-sectional study on tongue pressure and jaw-opening force in 980 subjects

Swallowing muscle strength weakens with aging. Although numerous studies have investigated tongue pressure (TP) changes with age, studies on jaw-opening force (JOF), an indicator of suprahyoid muscle strength, are lacking. We investigated differences between age-related declines in TP and JOF in a cross-sectional study of 980 healthy and independent participants (379 men, 601 women) without dysphagia. Hand grip strength (HGS), TP, and JOF were compared among decade-based age groups in multiple comparison analyses with post-hoc tests and effect size calculated. Participants were divided into adult (20 s-50 s) and elderly groups (60 s-80 s); within each group, Pearson correlations between age and muscle strength indices were evaluated. TP started to significantly decline in the 60 s and 50 s for men and women (p < .01, medium effect size and p < .05, small effect size, respectively); HGS also declined at these ages (men: p < .01, women: p < .01, medium effect size). JOF started to significantly decline in men in their 80 s (p < .01, large effect size), but remained unchanged in women. In the elderly group, all measurements declined with age more sharply in men (HGS: r = -0.56, TP: r = -0.63, JOF: r = -0.13) than in women (HGS: r = -0.38, TP: r = -0.49, JOF: r = -0.003). TP declined more steeply than did JOF. Thus, the age related-decline in TP was similar to that of the HGS, but not the JOF. The results reveal that different patterns exist in the age-related decline in swallowing muscle strength, and suggest that maintenance of JOF might contribute to safe swallowing in healthy elderly individuals.

Translation, Cross-Cultural Adaptation, Validation and Reliability of the Northwestern Dysphagia Patient Check Sheet (NDPCS) in Iran

INTRODUCTION

Speech and language therapists (SLTs) require proper tools to detect dysphagia in the early stages. One of these screening tools is the Northwestern Dysphagia Patient Check Sheet (NDPCS). However, this tool needs to be adapted, validated, and shown to be reliable for the Persian culture. The aim of the present study was to report the validity and reliability of the Persian NDPCS (P-NDPCS).

MATERIALS AND METHODS

The NDPCS has 28 items and five sections. Beaton's guidelines were followed in terms of the translation process. To report the content validity index (CVI) and the content validity ratio (CVR), eight SLTs experienced in swallowing disorders examined the content and face validities of the P-NDPCS in terms of the quality of translation, fluency, understandability, and the cultural context. In total, 140 patients with neurogenic and mechanical dysphagia were evaluated using the P-NDPCS. Internal consistency reliability was investigated using the Kuder-Richardson formula 20. The interclass correlation coefficient (ICC) was used for test-retest reliability.

RESULTS

The P-NDPCS preserved the 28 items and the five categories of the original version. However, semantic and food adjustments were applied due to cultural differences. The scoring system was changed from safe/unsafe to yes/no for four subsections and to normal/abnormal for the oromotor section. Food requirements were also changed. The CVR and CVI were both 75%. The P-NDPCS was shown to have good content validity. The internal reliability was 0.95, indicating excellent reliability.

CONCLUSION

The equivalence between the original version of the NDPCS and the P-NDPCS was preserved. Our findings indicate that the P-NDPCSis a valid and reliable screening tool for the diagnosis of dysphagia in the early phase.

Estudo da associação entre doenças crônicas naturais do envelhecimento e alterações da deglutição referidas por idosos da comunidade

RESUMO Objetivo Investigar associação entre as alterações de deglutição autorreferidas com doenças crônicas naturais do envelhecimento, aspectos socioeconômicos, demográficos, nutricionais e de saúde bucal, em idosos da comunidade. Métodos Foi realizado um estudo de corte transversal, proveniente de um inquérito de saúde com 900 idosos de 65 anos ou mais, recrutados em domicílio, na zona urbana de Campinas, São Paulo/Brasil, no contexto do estudo “Fragilidade em Idosos Brasileiros”. Todos foram submetidos a medidas sociodemográficas, antropométricas, de rastreio cognitivo, entre outras. Aos idosos sem sinais sugestivos de demência foi aplicado protocolo com questões dicotômicas (sim/não), baseadas no autorrelato de doenças crônicas, sintomas depressivos, saúde bucal e alteração da deglutição. As associações e as razões de prevalência foram investigadas por meio de regressão de Cox e valores de p<0,05 foram considerados significativos. Resultados A amostra foi composta por 507 idosos com 72 (+/-5,2) anos de idade, em média, sendo a maioria mulheres (62%). As doenças crônicas naturais do envelhecimento mais referidas foram hipertensão (62,1%) e artrite/reumatismo (43,5%). Apenas 12,4% não relataram nenhuma doença crônica. Sensação de alimento parado (16%) e engasgos ao se alimentar ou ingerir líquido (14,4%) foram as alterações de deglutição mais referidas. Sensação de boca seca, maior número de doenças crônicas, cardiopatias e osteoporose foram associados com alterações de deglutição. O aumento de idade foi relacionado apenas ao pigarro, após ingestão de algum alimento. Conclusão A coocorrência de doenças crônicas e a sensação de boca seca foram os fatores mais relacionados às alterações de deglutição. A idade foi associada apenas ao relato de pigarro após alimentação.

Oral perception of liquid volume changes with age

Bolus volume has been widely studied, and research has demonstrated a variety of physiological impacts on swallowing and swallowing disorders. Oral perception of bolus volume has not, to our knowledge, been investigated in association with normal ageing 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. The purpose of this study was 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. Results suggest 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.

Swallowing dysfunction in healthy older people using pharyngeal pressure-flow analysis

BACKGROUND

Age-related loss of swallowing efficiency may occur for multiple reasons. Objective assessment of individual dysfunctions is difficult and may not clearly differentiate these from normal. Pharyngeal pressure-flow analysis is a novel technique that allows quantification of swallow dysfunction predisposing to aspiration risk based on a swallow risk index (SRI). In this study, we examined the effect of ageing on swallow function.

METHODS

Studies were performed in 68 healthy subjects aged 20-91 years (mean 59 years; 29 male), asymptomatic for oropharyngeal disease. Swallowing of liquid and viscous boluses was recorded with a pressure-impedance catheter. Indices of swallow function including the SRI, postswallow residues, upper esophageal sphincter opening and bolus transit time were derived using purpose designed software.

KEY RESULTS

Swallow function worsened with increasing age with a significant decline after 80 years. Higher SRI correlated with increasing age (r = 0.257, p < 0.05 for liquids and r = 0.361, p < 0.005 viscous bolus). Subjects over 80 years were overrepresented amongst those with an SRI considered diagnostically relevant (SRI > 15). In addition, upper esophageal sphincter opening was reduced and postswallow residues increased in older subjects.

CONCLUSIONS & INFERENCES

Pharyngeal pressure-flow analysis reveals multiple functional abnormalities in older individuals. The higher SRI levels seen in asymptomatic elders possibly reflect a loss of functional reserve with ageing. Automated impedance manometry analysis of swallow function may allow the risk of developing disordered swallowing to be quantified numerically.

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.

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.

Relationship between swallowing problems and tooth loss in community-dwelling independent elderly adults: the Fujiwara-kyo study

OBJECTIVES

To investigate the relationship between swallowing problems and the number of remaining teeth in healthy elderly people.

DESIGN

Cross-sectional.

SETTING

Nara, Japan.

PARTICIPANTS

Three thousand six hundred sixty-three male and female volunteers aged 65 and older who were living independently were analyzed.

MEASUREMENTS

Swallowing problems were defined operationally using a questionnaire and the 30-mL water swallow test. Data were collected on the number of remaining teeth, maximum bite force, occlusal status, presence or absence of oral dryness, and medical history.

RESULTS

The prevalence of swallowing problems was 15.1% (n = 554) in this population. A positive correlation was observed between the number of remaining teeth and maximum bite force. The number of remaining teeth was categorized according to tertiles. Multiple logistic regression analysis revealed that the adjusted odds ratios for 0 to 13 or 14 to 24 remaining teeth to 25 to 32 remaining teeth for swallowing problems were 2.04 (95% confidence interval (CI) = 1.60-2.60) and 1.31 (95% CI = 1.02-1.70), respectively. Significant increases in these odds ratios were found in a trend test (P < .001).

CONCLUSION

Tooth loss is associated with swallowing problems. Having fewer teeth inhibits masticatory ability, which disturbs the execution of smooth swallowing. Preventive measures against tooth loss at a younger age may be effective at reducing the risk of laryngeal penetration and aspiration at an older age.

Significance of nonrespiratory airflow during swallowing

This study was designed to further our understanding of a potentially significant clinical event of negative nasal airflow near the end of the respiratory pause (inhibition) to accommodate swallowing. This negative flow, referred to as "SNIF," or swallow noninspiratory flow, occurs at the onset of airway reestablishment at the conclusion of the oropharyngeal swallow. Using simultaneous digital video fluoroscopic and nasal respiratory airflow recordings on 82 healthy adults (21-97 years old), the objectives of this study were to determine (1) the frequency of occurrence of SNIF during a 5-ml natural cup-drinking task, (2) differences in SNIF occurrence by age group, and (3) the temporal relationship between SNIF and other swallowing events. Results revealed that for most participants SNIF was observed in both swallowing trials. There was a statistically significant difference in SNIF occurrence by age category, with SNIF observed less frequently in the oldest participants. The peak onset of SNIF is closely related to the first release of contact between the soft palate and tongue base with the posterior pharyngeal wall and opening of the laryngeal vestibule. Based on this, and in agreement with previous investigators, we suggest that this negative flow may be related to a partial vacuum established by the relaxation of pharyngeal contraction near the conclusion of the pharyngeal swallow. The more frequent occurrence of SNIF in younger adults and less in older adults suggests a reduction in pharyngeal pressure associated with healthy aging.

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.