Laryngo-upper esophageal sphincter contractile reflex in humans deteriorates with age

Differences in velopharyngeal pressures during speech sound production in patients with unilateral cleft lip and palate (UCLP) and healthy individuals

Background

During articulation the velopharynx needs to be opened and closed rapidly and a tight closure is needed. Based on the hypothesis that patients with cleft lip and palate (CLP) produce lower pressures in the velopharynx than healthy individuals, this study compared pressure profiles of the velopharyngeal closure during articulation of different sounds between healthy participants and patients with surgically closed unilateral CLP (UCLP) using high resolution manometry (HRM).

Materials and methods

Ten healthy adult volunteers (group 1: 20-25.5 years) and ten patients with a non-syndromic surgically reconstructed UCLP (group 2: 19.1-26.9 years) were included in this study. Pressure profiles during the articulation of four sounds (/i:/, /s/, /ʃ/ and /n/) were measured by HRM. Maximum, minimum and average pressures, time intervals as well as detection of a previously described 3-phase-model were compared.

Results

Both groups presented with similar pressure curves for each phoneme with regards to the phases described and pressure peaks, but differed in total pressures. An exception was noted for the sound /i:/, where a 3-phase-model could not be seen for most patients with UCLP. Differences in velopharynx pressures of 50% and more were found between the two groups. Maximum and average pressures in the production of the alveolar fricative reached statistical significance.

Conclusions

It can be concluded that velopharyngeal pressures of patients with UCLP are not sufficient to eliminate nasal resonance or turbulence during articulation, especially for more complex sounds. These results support a general understanding of hypernasality during speech implying a (relative) velopharyngeal insufficiency.

Normative High-Resolution Pharyngeal Manometry: Impact of Age, Size of System, and Sex on Primary Metrics and Pressure Stability

There have been many reports of normative pharyngeal swallowing pressures using high-resolution pharyngeal manometry, but there is a fair amount of between-subject variance in reported pressure parameters. The purpose of this study was to put forward normative pharyngeal high-resolution manometry measures across the lifespan and investigate the effects of age, size of system, and sex. High-resolution pharyngeal manometry was performed on 98 healthy adults (43 males) between the ages 21 and 89. Pressure duration, maxima, integral, and within-individual variability metrics were averaged over 10 swallows of 10-ml thin liquid. Multiple linear and logistic regressions with model fitting were used to examine how pharyngeal pressures relate to age, pharyngeal size, and sex. Age was associated with tongue base maximum pressure, tongue base maximum variability, and upper esophageal sphincter-integrated relaxation pressure (F3,92 = 6.69; p < 0.001; adjusted R2 = 0.15). Pharyngeal area during bolus hold was associated with velopharynx integral (F1,89 = 5.362; p = 0.02; adjusted R2 = 0.05), and there was no significant model relating pharyngeal pressures to C2-C4 length (p < 0.05). Sex differences were best described by tongue base integral and hypopharynx maximum variability (χ2 = 10.27; p = 0.006; pseudo R2 = 0.14). Normative data reveal the distribution of swallow pressure metrics which need to be accounted for when addressing dysphagia patients, the importance of pressure interactions in normal swallow, and address the relative stability of swallow metrics with normal aging.

The effect of taste on swallowing: A scoping and systematic review

Consuming foods and liquids for nutrition requires the coordination of several muscles. Swallowing is triggered and modified by sensory inputs from the aerodigestive tract. Taste has recently received attention as a potential modulator of swallowing physiology, function, and neural activation; additionally, taste impairment is a sequela of COVID-19. This review presents factors impacting taste and swallowing, systematically summarizes the existing literature, and assesses the quality of included studies. A search was conducted for original research including taste stimulation, deglutition-related measure(s), and human participants. Study design, independent and dependent variables, and participant characteristics were coded; included studies were assessed for quality and risk of bias. Forty-eight articles were included after abstract and full-text review. Synthesis was complicated by variable sensory components of stimuli (taste category and intensity, pure taste vs. flavor, chemesthesis, volume/amount, consistency, temperature), participant characteristics, confounding variables such as genetic taster status, and methods of measurement. Most studies had a high risk of at least one type of bias and were of fair or poor quality. Interpretation is limited by wide variability in methods, taste stimulation, confounding factors, and lower-quality evidence. Existing studies suggest that taste can modulate swallowing, but more rigorous and standardized research is needed.

Sensory Innervation of the Larynx and the Search for Mucosal Mechanoreceptors

Purpose The larynx is a uniquely situated organ, juxtaposed between the gastrointestinal and respiratory tracts, and endures considerable immunological challenges while providing reflexogenic responses via putative mucosal mechanoreceptor afferents. Laryngeal afferents mediate precise monitoring of sensory events by relay to the internal branch of the superior laryngeal nerve (iSLN). Exposure to a variety of stimuli (e.g., mechanical, chemical, thermal) at the mucosa-airway interface has likely evolved a diverse array of specialized sensory afferents for rapid laryngeal control. Accordingly, mucosal mechanoreceptors in demarcated laryngeal territories have been hypothesized as primary sources of sensory input. The purpose of this article is to provide a tutorial on current evidence for laryngeal afferent receptors in mucosa, the role of mechano-gated ion channels within airway epithelia and mechanisms for mechanoreceptors implicated in laryngeal health and disease. Method An overview was conducted on the distribution and identity of iSLN-mediated afferent receptors in the larynx, with specific focus on mechanoreceptors and their functional roles in airway mucosa. Results/Conclusions Laryngeal somatosensation at the cell and molecular level is still largely unexplored. This tutorial consolidates various animal and human researches, with translational emphasis provided for the importance of mucosal mechanoreceptors to normal and abnormal laryngeal function. Information presented in this tutorial has relevance to both clinical and research arenas. Improved understanding of iSLN innervation and corresponding mechanotransduction events will help shed light upon a variety of pathological reflex responses, including persistent cough, dysphonia, and laryngospasm.

Upper Esophageal Sphincter Response to Laryngeal Adductor Reflex Elicitation in Humans

OBJECTIVE

The laryngeal adductor reflex (LAR) is an important mechanism to secure the airways from potential foreign body aspiration. An involvement of the upper esophageal sphincter (UES) in terms of a laryngo-UES contractile reflex has been identified after laryngeal mucosa stimulation. However, the LAR-UES relationship has not yet been fully explained. This study aimed to determine the magnitude, latency, and occurrence rate of the UES pressure response when the LAR is triggered in order to elucidate the functional relationship between the larynx and the UES.

METHODS

This prospective study included seven healthy volunteers (5 female, 2 male, age 22-34 years). Laryngeal penetration was simulated by eliciting the LAR 20 times in each individual by applying water-based microdroplets onto the laryngeal mucosa. UES pressures were measured simultaneously using high-resolution manometry.

RESULTS

Two distinct pressure phases (P1, P2) associated with the LAR were identified. P1 corresponded with a short-term UES pressure decrease in two subjects and a pressure increase in five subjects occurring 200 to 500 ms after the stimulus. In P2, all subjects experienced an increase in UES pressure with a latency time of approximately 800 to 1700 ms and an average of 40 to 90 mmHg above the UES resting tone.

CONCLUSION

Foreign bodies penetrating the laryngeal inlet lead to a reflex contraction of the UES. Phase P1 could be a result of vocal fold activity caused by the LAR, leading to pressure changes in the UES. The constriction during P2 could strengthen the barrier function of the UES in preparation to a subsequent cough that may be triggered to clear the airways.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1778-E1784, 2021.

Impact of balloon inflation on the insertion of endoscopic ultrasound: a prospective, randomized controlled trial

Background and study aims  During endoscopic ultrasound (EUS), patients may experience severe discomfort. The radial echoendoscope has a balloon around its tip. Balloon inflation prior to insertion may reduce contact injury and pharyngeal pain. The purpose of this study was to investigate the effect of balloon inflation on pharyngeal pain during insertion. Patients and methods  Patients who underwent radial EUS for pancreatobiliary disease were randomized into standard insertion or balloon-inflated insertion. The primary outcome was the proportion of moderate-to-severe pharyngeal pain. Secondary outcomes were the degree of pharyngeal pain, risk factors for moderate pharyngeal pain, procedure-related adverse events, and pharyngeal pain depending on the experience of the endoscopist. Results  A total of 481 patients were randomized into two groups: standard insertion (238) and balloon inflation (243). No statistically significant differences in proportion of moderate-to-severe pain were found (26.5 % vs. 20.2 %, P  = 0.107). Balloon inflation (HR 0.65; 95 % CI (0.42-0.98, P  = 0.041) was a protective factor against moderate pain. Balloon inflation reduced the proportion of patients with moderate-to-severe pain when performed by physicians with less than 3months of experience with EUS (44.7 % vs. 25.3 %, P  = 0.012). Conclusion  Balloon inflation did not reduce the absolute degree of post-procedural pain with EUS, but it reduced the number of patients with moderate-to-severe pain when performed by physicians with less than 3 months of experience.

Pharyngeal swallowing in older adults: Kinematic analysis using three-dimensional dynamic computed tomography

OBJECTIVES

To assess the effect of age on swallowing with a focus on structural movement, timing and duration of physiologic events.

DESIGN

Cross-sectional study.

SETTING

Tertiary University Medical Center.

PARTICIPANTS

Community-dwelling adults (3 age groups): younger 20 to 39 (n = 23; mean 32 ± 5), middle-aged 40 to 59 (n = 29; mean 49 ± 5) and older adults 60 to 74 (n = 15; mean 67 ± 5).

INTERVENTION

One 10-mL honey-thick liquid (1700 mPa) swallow was studied using 320-row area detector computed tomography scanning.

MEASUREMENTS

Kinematic analysis was performed for each swallow including temporal characteristics and structural movements.

RESULTS

The duration of velopharyngeal closure and laryngeal closure (including epiglottis inversion, laryngeal vestibule closure, true vocal cord closure) was significantly different by age group (P = 0.002, P < 0.001, P = 0.017, P = 0.041, respectively). Events were prolonged in older adults compared with middle-aged and younger adults. The pharyngeal phase was longer for older adults. Velopharyngeal closure started earlier and continued until after complete UES opening. In younger adults, velopharyngeal and laryngeal opening occurred before complete UES opening. No differences were found in bolus movement through the oropharynx by group.

CONCLUSION

During swallowing, older adults had a longer pharyngeal phase characterised by prolonged velopharyngeal and laryngeal closure. This difference may be a protective mechanism to compensate for age-related weakness. A better understanding of the mechanism by which this adaptation occurs is needed to tailor rehabilitation strategies and to maintain swallowing function during the lifespan.

Older Age Reduces Upper Esophageal Sphincter and Esophageal Body Responses to Simulated Slow and Ultraslow Reflux Events and Post-Reflux Residue

BACKGROUND & AIMS

It is not clear how age affects airway protective mechanisms. We investigated the effects of aging on upper esophageal sphincter (UES) and esophageal body pressure responses to slow and ultraslow simulated reflux events and post-reflux residue.

METHODS

We performed a prospective study of 11 elderly (74 ± 9 years old) and 11 young (28 ± 7 years old) healthy volunteers. Participants were placed in a supine position and evaluated by concurrent high-resolution impedance manometry and an esophageal infusion technique. Potential conditions of gastroesophageal reflux were simulated, via infusion of 0.1 N HCl and saline. UES and esophageal pressure responses were measured during the following: slow infusion (1 mL/s) for 60 seconds, 60 seconds of postinfusion dwell period, ultraslow infusion (0.05 mL/s) for 60 seconds, and 60 seconds of a postinfusion dwell period. All infusions were repeated 3 times. We used the UES high-pressure zone contractile integral (UES-CI) to determine responses of the UES.

RESULTS

Young and elderly subjects each had a significant increase in the UES-CI during slow infusions and during entire passive dwell intervals compared with baseline (P < .01, both groups). Ultraslow infusions were associated with a significant increase in UES-CI in only the young group, in the late infusion period, and into the dwell interval (P < .01). During the slow infusions and their associated dwell periods, young subjects had a higher frequency of secondary peristalsis than elderly subjects (P < .05). There was more secondary peristalsis during active infusions than dwell intervals. Secondary peristalsis was scarce during ultraslow infusions in both groups.

CONCLUSIONS

UES and esophageal body pressure responses to low-volume ultraslow reflux and associated post-reflux residue are reduced in elderly individuals. This deterioration could have negative effects on airway protection for people in this age group.

Photostability studies on (±)-tramadol in a liquid formulation

BACKGROUND

Tramadol ((±)-TRA) is recommended for the treatment of mild to moderate cancer pain by the World Health Organization. An oral liquid formulation of (±)-TRA is preferable for patients with a compromised swallowing function. However, the stability of (±)-TRA in aqueous solution has yet to be determined in a clinical setting. The aim of this study was to evaluate the photostability of (±)-TRA in aqueous solution in a clinical setting.

METHODS

We improved high performance liquid chromatography (HPLC) method for the enantiomeric separation of (±)-TRA, and then the (±)-TRA concentration was determined using HPLC method. We investigated the photodegradation of (±)-TRA in an aqueous solution irradiated with ultraviolet (UV) light: UV-A, UV-B, and UV-C. We also evaluated the stability of liquid formulations of (±)-TRA in a clinical setting by keeping (±)-TRA aqueous solution in normal dispensing bottles and in light-shading dispensing bottles under conditions of both sunlight and diffused light in a room. Samples were collected sequentially over time.

RESULTS

(±)-TRA in aqueous solution was degraded the most rapidly when irradiated with UV-C, but was not affected by irradiation with UV-A. No significant difference was observed in the photodegradation behavior of (+)-TRA and (-)-TRA with UV-A, UV-B, and UV-C irradiation. The residual percentages of (±)-TRA were 94.6-104.3% after 14 days in the presence of either sunlight or diffused light in a room, with or without protection from light.

CONCLUSIONS

These results demonstrated the stability of (±)-TRA in aqueous solution to both sunlight and diffused light in a room. Therefore, liquid formulations of TRA are preserved at room temperature for up to 2 weeks, with or without protection from light. Our results provide additional treatment options with tramadol for pain control.

Esophageal morphometric and biomechanical changes during aging in rats

BACKGROUND

Human studies have demonstrated aging-related changes in esophagus which may contribute to the increased rate of gastro-esophageal reflux in elderly. The aim of this study was to investigate esophageal morphometric and biomechanical remodeling in aging rats to obtain detailed information about aging-related changes.

METHODS

Twenty-four male Wistar rats, aged from 6 to 22 months, were studied. Morphometric data were obtained by measuring the wall thickness and cross-sectional area. The esophageal diameter and length were obtained from digitized images of the segments at preselected luminal pressure levels and at no-load and zero-stress states. Circumferential and longitudinal stresses (force per area) and strains (deformation) were computed from the length, diameter and pressure data, and from the zero-stress state geometry.

KEY RESULTS

The esophageal parameters such as the weight per unit length, the wall thickness and the wall cross-sectional area increased slightly from 6 to 22 months (p < 0.05 to p < 0.001). The opening angle gradually decreased during aging (p < 0.05). The interface between the mucosa-submucosa and muscle layers slightly moved outwards and the neutral axis moved inwards during aging. The stress-strain data showed that the esophageal wall became stiffer circumferentially and longitudinally during aging (p < 0.05, p < 0.01). However, the circumferential wall stiffness showed no further change after 12 months.

CONCLUSIONS & INFERENCES

A pronounced morphometric and biomechanical remodeling occurred in the rat esophagus during aging.

Pill Properties that Cause Dysphagia and Treatment Failure

BACKGROUND

Pills (tablets and capsules) are widely used to administer prescription drugs or to take supplements such as vitamins. Unfortunately, little is known about how much effort it takes Americans to swallow these various pills. More specifically, it is not known to what extent hard-to-swallow pills might affect treatment outcomes (eg, interfering with adherence to prescribed medications or causing clinical complications). It is also unclear which properties (eg, size, shape, or surface texture) Americans prefer or reject for their pills. To learn more about these issues, we interviewed a small group of individuals.

METHODS

We invited individuals in waiting rooms of our tertiary health care center to participate in structured interviews about their pill-taking habits and any problems they have swallowing pills. We inquired which pill properties they believed caused swallowing problems. Participants scored capsules and pills of representative size, shape, and texture for swallowing effort and reported their personal preferences.

RESULTS

Of 100 successive individuals, 99 participants completed the interview (65% women, mean age = 41 years, range = 23-77 years). Eighty-three percent took pills daily (mean 4 pills/d; 56% of those pills were prescribed by providers). Fifty-four percent of participants replied yes to the question, "Did you ever have to swallow a solid medication that was too difficult?" Four percent recounted serious complications: 1% pill esophagitis, 1% pill impaction, and 2% stopped treatments (antibiotic and prenatal supplement) because they could not swallow the prescribed pills. Half of all participants routinely resorted to special techniques (eg, plenty of liquids or repeated or forceful swallows). Sixty-one percent of those having difficulties cited specific pill properties: 27% blamed size (20% of problems were caused by pills that were too large whereas 7% complained about pills that were too small to sense); 12% faulted rough surface texture; others cited sharp edges, odd shapes, or bad taste/smell. Extra-large pills were widely loathed, with 4 out of 5 participants preferring to take 3 or more medium-sized pills instead of a single jumbo pill.

CONCLUSIONS

Our survey results suggest that 4 out of 5 adult Americans take several pills daily, and do so without undue effort. It also suggests that half of today's Americans encounter pills that are hard to swallow. Up to 4% of our participants gave up on treatments because they could not swallow the prescribed pills. Up to 7% categorically rejected taking pills that are hard to swallow. Specific material properties are widely blamed for making pills hard to swallow; extra-large capsules and tablets are universally feared, whereas medium-sized pills with a smooth coating are widely preferred. Our findings suggest that health care providers could minimize treatment failures and complications by prescribing and dispensing pills that are easy to swallow. Industry and regulatory bodies may facilitate this by making swallowability an essential criterion in the design and licensing of oral medications. Such policies could lessen the burden of pill taking for Americans and improve the adherence with prescribed treatments.

Mapping regional laryngopharyngeal mechanoreceptor response

Objectives

To map mechanoreceptor response in various regions of the laryngopharynx.

Methods

Five patients with suspected laryngopharyngeal reflux and six healthy control subjects underwent stimulation of mechanoreceptors in the hypopharynx, interarytenoid area, arytenoids, aryepiglottic folds, and pyriform sinuses. The threshold stimuli evoking sensation and eliciting laryngeal adductor reflex were recorded.

Results

In controls, an air pulse with 2 mmHg pressure evoked mechanoreceptor response in all regions, except bilateral aryepiglottic folds of one control. In patients, stimulus intensity to elicit mechanoreceptor response ranged between 2 mmHg and 10 mmHg and varied among the regions. Air pulse intensity differed between right and left sides of laryngopharyngeal regions in the majority of patients.

Conclusion

Laryngopharyngeal mechanoreceptor response was uniform among regions and subjects in the healthy group. Patients with suspected laryngopharyngeal reflux showed inter- and intra-regional variations in mechanoreceptor response. Laryngopharyngeal sensory deficit in patients with suspected laryngopharyngeal reflux is not limited to aryepiglottic folds.

Quantitative evaluation of age-related alteration of swallowing function: Videofluoroscopic and manometric studies

OBJECTIVE

Swallowing function progressively deteriorates with advancing age, leading to high morbidity and mortality in the elderly population. To establish strategies for treatment of age-related swallowing disorders, the mechanisms of such disorders must be quantitatively clarified. The purpose of this paper was to elucidate the swallowing function of healthy elderly individuals by comparison with that of young adults by videofluorographic and manometric examinations.

METHODS

The subjects were 70 healthy volunteers with no history of diseases affecting swallowing function. They were classified into three groups according to age: the young adult group (21-32 years of age, n=8), early elderly group (60-69 years of age, n=39), and late elderly group (70-83 years of age, n=23). Their swallowing functions were quantitatively evaluated by videofluorographic and manometric studies.

RESULTS

Videofluorographic examination showed no significant differences in the moving distances of the hyoid bone and larynx in the pharyngeal swallowing phase between the young and elderly groups. The pharyngeal transit time (PTT) of the bolus in the elderly group was longer and the percentage of laryngeal elevation (%LE) was lower than those in the young group. Manometric examination revealed higher hypopharyngeal swallowing pressure in the elderly groups. The traveling velocity of the swallowing pressure in the upper esophageal sphincter (UES) region and the UES relaxation time decreased with aging. Reduction of the UES pressure during the pharyngeal swallowing phase was insufficient in 15.4% of the early elderly group and 30.4% of the late elderly group. Additionally, the UES zone was broadened in 20.5% of the early elderly group and 26.1% of the late elderly group.

CONCLUSION

Videofluorographic and manometric examinations quantitatively demonstrated that the swallowing reflex was delayed and UES opening was impaired by aging. UES dysfunction may develop secondary by increased tonicity and decreased elasticity of the cricopharyngeal muscle. Stimulation of oropharyngeal sensory function and exercising the laryngeal levator muscles may be effective for age-related swallowing disorders.

Insult of gastroesophageal reflux on airway: clinical significance of pharyngeal nozzle

At the very time of global paying the highest attention to the worst insults of smoking as well as haze on the airway, everybody knows both are exogenous and noticeable. However, people mostly, including many medical personnel, do not know how badly the gastroesophageal reflux (GER) insults on our own airway. Symptoms of GER are commonly seen as heartburn and regurgitation, which can be mostly tolerated. However, when the up going gastric content reversely passes the esophagus and then the distal pharynx, where it appears a beak like stricture, serving as a nozzle, so as to produce numerous micro-particles and reach the oro-nasal cavity and also the airway causing allergic rhinitis and asthmatic attacks, even pulmonary parenchyma lesions. It will reduce life quality or even jeopardize life. The point that the endogenous insult appears in the respiratory system, but originates from the digestive tract is not well known and often undiagnosed and not correctly treated. The GER induced airway challenge is a treatable and preventive entity, as soon as a diagnosis is made, a good relief could be expected by means of life style adjustment, medicine, or fixation of the patulous cardia through radiofrequency or fundoplication. The author Dr. Zhonggao Wang had suffered it for long and symptoms disappeared for 8 years after anti-reflux surgery. Here is a presentation of Dr. Zhonggao Wang and his team's work and would call attention to the public so as to recognize this relatively unknown entity - a treatable condition occurring from human itself, but not from outside surroundings as smoking or haze does.

Effect of aging on hypopharyngeal safe volume and the aerodigestive reflexes protecting the airways

OBJECTIVES/HYPOTHESIS

Studies on young volunteers have shown that aerodigestive reflexes are triggered before the maximum volume of fluid that can safely collect in the hypopharynx before spilling into the larynx is exceeded (hypopharyngeal safe volume [HPSV]). The objective of this study was to determine the influence of aging on HPSV and pharyngo-glottal closure reflex (PGCR), pharyngo-UES contractile reflex (PUCR), and reflexive pharyngeal swallow (RPS).

STUDY DESIGN

Comparison between two groups of different age ranges.

METHODS

Ten young (25 ± 3 standard deviation [SD] years) and 10 elderly (77 ± 3 SD years) subjects were studied. PGCR, PUCR, and RPS were elicited by perfusing water into the pharynx rapidly and slowly. HPSV was determined by abolishing RPS with pharyngeal anesthesia.

RESULTS

Frequency-elicitation of PGCR and PUCR were significantly lower in the elderly compared to the young during slow water perfusion (47% vs. 97% and 40% vs. 90%, respectively, P < .001). RPS was absent in five of the 30 (17%) slow injections in the elderly group. In these elderly subjects, HPSV was exceeded and laryngeal penetration of the water was seen. The threshold volume to elicit PGCR, PUCR, and RPS was significantly lower than the HPSV during rapid injections. Except for RPS, these volumes were also significantly lower than HPSV during slow injections.

CONCLUSIONS

PGCR, PUCR, and RPS reflexes are triggered at a threshold volume significantly lower than the HPSV in both young and elderly subjects. Lower frequency-elicitation of PGCR, PUCR, and RPS in the elderly can predispose them to the risks of aspiration.

Increase of weakly acidic gas esophagopharyngeal reflux (EPR) and swallowing-induced acidic/weakly acidic EPR in patients with chronic cough responding to proton pump inhibitors

BACKGROUND

Gastro-esophageal reflux disease (GERD)-related chronic cough (CC) may have multifactorial causes. To clarify the characteristics of esophagopharyngeal reflux (EPR) events in CC patients whose cough was apparently influenced by gastro-esophageal reflux (GER), we studied patients with CC clearly responding to full-dose proton pump inhibitor (PPI) therapy (CC patients).

METHODS

Ten CC patients, 10 GERD patients, and 10 healthy controls underwent 24-h ambulatory pharyngo-esophageal impedance and pH monitoring. Weakly acidic reflux was defined as a decrease of pH by >1 unit with a nadir pH >4. In six CC patients, monitoring was repeated after 8 weeks of PPI therapy. The number of each EPR event and the symptom association probability (SAP) were calculated. Symptoms were evaluated by a validated GERD symptom questionnaire.

KEY RESULTS

Weakly acidic gas EPR and swallowing-induced acidic/weakly acidic EPR only occurred in CC patients, and the numbers of such events was significantly higher in the CC group than in the other two groups (P < 0.05, respectively). Symptom association probability analysis revealed a positive association between GER and cough in three CC patients. Proton pump inhibitor therapy abolished swallowing-induced acidic/weakly acidic EPR, reduced weakly acidic gas EPR, and improved symptoms (all P < 0.05).

CONCLUSIONS & INFERENCES

Most patients with CC responding to PPI therapy had weakly acidic gas EPR and swallowing-induced acidic/weakly acidic EPR. A direct effect of acidic mist or liquid refluxing into the pharynx may contribute to chronic cough, while cough may also arise indirectly from reflux via a vago-vagal reflex in some patients.

Sensory input pathways and mechanisms in swallowing: a review

Over the past 20 years, research on the physiology of swallowing has confirmed that the oropharyngeal swallowing process can be modulated, both volitionally and in response to different sensory stimuli. In this review we identify what is known regarding the sensory pathways and mechanisms that are now thought to influence swallowing motor control and evoke its response. By synthesizing the current state of research evidence and knowledge, we identify continuing gaps in our knowledge of these mechanisms and pose questions for future research.

Manometric evidence for a phonation-induced UES contractile reflex

The mechanism against entry of gastric content into the pharynx during high-intensity vocalization such as seen among professional singers is not known. We hypothesized that phonation-induced upper esophageal sphincter (UES) contraction enhances the pressure barrier against entry of gastroesophageal contents into pharynx. To determine and compare the effect of phonation on luminal pressures of the esophagus and its sphincters, we studied 17 healthy volunteers (7 male, 10 female) by concurrent high-resolution manometry and voice analysis. We tested high- and low-pitch vowel sounds. Findings were verified in six subjects by UES manometry using a water-perfused sleeve device. Eight of the volunteers (2 male, 6 female) had concurrent video fluoroscopy with high-resolution manometry and voice recording. Fluoroscopic images were analyzed for laryngeal movement. To define the sex-based effect, subgroup analysis was performed. All tested phonation frequencies and intensities induced a significant increase in UES pressure (UESP) compared with prephonation pressure. The magnitude of the UESP increase was significantly higher than that of the distal esophagus, the lower esophageal sphincter (LES), and the stomach. Concurrent videofluoroscopy did not show posterior laryngeal movement during phonation, eliminating a purely mechanical cause for phonation-induced UESP increase. Subgroup analysis demonstrated phonation-induced UESP increases in males that were significantly greater than those of females. Phonation induces a significant increase in UESP, suggesting the existence of a phonation-induced UES contractile reflex. UESP increase due to this reflex is significantly higher than that of the distal esophagus, LES, and stomach. The phonation-induced UESP increase is influenced by sex.

Dysphagia in the elderly--a management challenge for nurses

Dysphagia (swallowing difficulties) is relatively common in the general population, but the prevalence increases with age and poses particular problems in the older patient, potentially compromising nutritional status, complicating the administration of solid medications, increasing the risk of aspiration pneumonia and undermining the quality of life. The repercussions of dysphagia are not only physical but also emotional, affecting patient morale and leading to feelings of social isolation. There are various causes, including carcinoma, stroke and advanced Alzheimer's disease. The diverse range of causes may manifest in a number of different ways, but should always act as a warning sign, which requires further investigation. Management is multidisciplinary, depending on the underlying cause, extent of dysphagia and likely prognosis. This article examines the incidence, causes and management of dysphagia, based on a review of recent literature. The focus is on the nurse's role in the management of this challenging disorder with particular emphasis on the care of the elderly patient.

Age-related neurodegenerative changes and how they affect the gut

The enteric nervous system (ENS) is the division of the autonomic nervous system that regulates gastrointestinal (GI) function. Although large numbers of enteric neurons may be lost with age, the GI tract remains surprisingly functional. Exceptions to this generality include swallowing disorders and reduced colonic motility in the elderly. Evidence of age-related neurodegenerative changes in structure and function of the ENS is briefly reviewed in this Perspective.