Effects of effortful swallow on esophageal function in healthy adults

Evaluating Anterior and Posterior Oral Tongue Contributions to Pressure Generation: A Comparison Between Regular and Effortful Saliva Swallows

PURPOSE

This study determined the contributions of the anterior and posterior tongue regions in tongue pressure generation during regular saliva swallows (SSs) and effortful swallows (ESs) completed under two different instructions. The association between tongue pressure and perceived effort to swallow was also examined.

METHOD

Forty healthy adults without swallowing disorders participated in this study, divided into two age groups: 20 younger (Mage = 21.95 years, SD = 4.43) and 20 older (Mage = 70.10 years, SD = 4.30). Simultaneous data acquisition involved submental surface electromyography, tongue manometry, and a visual analog scale across swallowing conditions (SS, ES with tongue emphasis, and ES with pharyngeal squeezing). The main outcome measures were tongue pressure during swallowing and perceived effort to swallow.

RESULTS

Overall tongue pressure during ESs with tongue emphasis and with pharyngeal squeezing was greater than that during SSs (R2 = .78, p < .001). Moreover, tongue pressure during the ES with tongue emphasis was greater than that during the ES with pharyngeal squeezing (t = 25.63, p < .001). The posterior tongue region generated more pressure during SSs (R2 = .64, p < .001) and the ES with tongue emphasis (R2 = .55, p < .001) than the anterior tongue. Finally, a positive correlation was found between perceived effort and tongue pressure during swallowing (r = .75, 95% CI [0.72, 0.77]).

CONCLUSIONS

Tongue pressure generation was affected by the type of instruction used to elicit ESs, and the posterior tongue showed relatively greater pressure contributions than the anterior tongue for ESs with tongue emphasis and SSs. Furthermore, age-related declines in pressure generation during swallowing were not evidenced in this study, underscoring the ability of healthy older individuals to appropriately modulate lingual pressure during ESs. Last, our results showed that the visual analog scale is a simple tool for rating swallowing effort during ESs, supporting its potential clinical use to train ESs.

Surface Electromyographic Activity of the Masseter Muscle During Regular and Effortful Saliva Swallows: A Preliminary Study

Biofeedback is a critical component in motor learning of new, complex behaviors such as modifications to swallowing. Surface electromyography (sEMG) is a commonly employed biofeedback tool in swallowing management to assess muscle activity patterns, determine amplitude and duration of swallowing, and train swallowing strategies such as the effortful swallow (EFS) maneuver. The EFS can potentially change multiple physiological components of the swallowing process such as pressure generation and movement of biomechanical structures. The purposes of this study were to determine whether the masseter muscle could differentiate a normal swallow (NS) from an EFS and whether there was a relationship between perceived muscle effort used to swallow and objective measures of muscle activity. Twenty healthy young adults participated in this study. Masseter sEMG peak amplitude and duration were measured across five regular saliva swallows and five effortful saliva swallows. Additionally, participants rated their perceived swallowing effort using a visual analog scale (VAS). Two swallowing conditions, NSs and EFSs were compared with hierarchical models, and repeated measures correlation was used to determine the relationships between the VAS and sEMG peak amplitude. Participants produced swallows with greater masseter sEMG peak amplitude and duration during the EFS. Moreover, a positive correlation was identified between perceived swallowing effort and masseter sEMG peak amplitude. These findings support the potential use of the masseter muscle to differentiate NSs from EFSs and implement the VAS during therapy for tracking patients' performance, particularly in settings with limited access to sEMG.

Impact of Effortful Swallow with Progressive Resistance on Swallow Safety, Efficiency and Quality of Life in Individuals with Post-Stroke Dysphagia: Analysis Using DIGEST- FEES and SWAL-QOL

Introduction: Effortful swallow with progressive resistance has a potential clinical implication in improving the oro-muscular strength, swallow safety, and efficiency in elderly individuals. But to date, no studies have explored its benefits in training individuals with post-stroke dysphagia. Aim: The present study investigated the long- term effect of effortful swallow with progressive resistance on swallow safety, efficiency and quality of life in persons with dysphagia following stroke. Method: The study consisted of 5 males (mean age: 41.80yrs ± 9.6yrs) diagnosed with dysphagia post-stroke.  The participants underwent 20 sessions (5 days/week) of intensive effortful swallow with progressive training spread across four weeks. In the first two weeks, the participants performed 10 × 3 sets of effortful swallows with a 50% of resistance load, which was further increased to 15 × 3 sets with a 70% resistance load. Results: DIGEST-FEES safety and overall swallow quality of life significantly improved post-therapy, whereas DIGEST-FEES efficiency and overall swallow grades showed no significant changes. Inter-rater reliability of DIGEST-FEES revealed substantial agreement between judges. Conclusion: The results are promising as the technique improved swallow safety, and swallow quality of life in persons with dysphagia following stroke.

Hyolaryngeal Movement During Normal and Effortful Swallows Determined During Ultrasonography

PURPOSE

This study investigated (a) the effects of the effortful swallow under two different instructions (tongue emphasis vs. pharyngeal squeezing) on hyoid displacement and hyoid-larynx approximation, (b) the association between tongue pressure and hyolaryngeal movement during normal swallowing and the effortful swallow produced with tongue emphasis, and (c) age-related differences in hyolaryngeal movement during normal and effortful swallows (tongue emphasis vs. pharyngeal squeezing) in healthy individuals.

METHOD

Forty healthy adults (20 younger and 20 older) swallowed their saliva as they normally do (normal swallow) and performed the effortful swallow with tongue emphasis and pharyngeal squeezing. Tongue-to-palate pressure during swallowing was measured using the Iowa Oral Performance Instrument, hyolaryngeal movement was measured using ultrasonography, and submental surface electromyography was used to track swallows.

RESULTS

Results revealed differences in hyolaryngeal movement across swallowing types. Both types of effortful swallows showed greater hyolaryngeal movement than normal swallows. Additionally, hyolaryngeal movement was greater during the effortful swallow with tongue emphasis than the effortful swallow with pharyngeal squeezing. Age-related differences were found only in hyoid-larynx approximation during the effortful swallow with tongue emphasis (younger > older adults). Furthermore, moderate positive correlations were identified between tongue pressure and hyolaryngeal movement during normal swallows and the effortful swallow with tongue emphasis.

CONCLUSIONS

The findings show that varying instructions of the effortful swallow affect hyolaryngeal movement differently, suggesting that clinicians may need to individualize the effortful swallow instruction according to the physiological impairments of each patient. Additionally, natural age-related changes in swallowing physiology do not seem to affect an individual's ability to perform the effortful swallow or to impact hyolaryngeal movement. Finally, the association between tongue pressure and hyolaryngeal movement during normal swallows and the effortful swallow with tongue emphasis suggests that the tongue plays a critical role in swallowing, priming subsequent swallowing events.

The Modified Barium Swallow Study and Esophageal Screening: A Survey of Clinical Practice Patterns

PURPOSE

Modified barium swallow study (MBSS) is a videofluoroscopic evaluation of oropharyngeal swallowing. Views of esophageal bolus flow during MBSS are permitted under speech-language pathology practice guidelines. However, controversy exists over its implementation. Poor consensus and limited practice guidance may lead to clinical practice variations. Aims of the investigation were to (a) describe current practice patterns of speech-language pathologist visualizing bolus flow through the esophagus during the MBSS, (b) understand areas of variation when incorporating esophageal visualization during the MBSS, and (c) determine clinicians' willingness to modify MBSS procedures to include esophageal imaging.

METHOD

A web-based survey (Qualtrics XM) consisting of 26 questions was distributed via web posting and e-mail to members of the American Speech-Language-Hearing Association Special Interest Group 13 and Dysphagia Café. The survey was open for 3 months. Descriptive and associative statistics were completed. Field-testing was performed prior to dissemination of the survey to address content validity.

RESULTS

A total of 321 individuals participated; 265 responses were used for analysis. Ninety-three percent of respondents viewed the esophagus during the MBSS. Twelve percent followed to the proximal esophagus, 15% to the mid esophagus, 66% to the lower esophagus, and 6% to varied levels. Variability was also reported in contrast type, volume administered, and nomenclature used. Interestingly, few people (3.61%) disagreed that esophageal visualization should be performed during MBSS.

CONCLUSIONS

Speech-language pathology respondents in this study visualize contrast flow through the esophagus and are enthusiastic about expanding the standard MBSS. However, results of the survey demonstrate a lack of uniformity in assessment practices. Unfortunately, this may impact the diagnostic accuracy and clinical utility when adding esophageal visualization to the MBSS. This study highlights the need for a standardized protocol and identifies current barriers and controversies that may prevent expanding the MBSS to more comprehensively evaluate individuals with dysphagia.

Abnormal Esophageal Clearance Identified During Modified Barium Swallow Study in an Acute Poststroke Cohort

PURPOSE

Dysphagia impacts many poststroke survivors with wide-ranging prevalence in the acute and chronic phases. One relatively unexplored manifestation of poststroke swallowing impairment is that of primary or co-occurring esophageal dysphagia. The incidence of esophageal dysphagia in this population is unknown despite the shared neuroanatomy and physiology with the oropharynx. We aimed to determine the presence of abnormal esophageal clearance in an acute poststroke sample using the Modified Barium Swallow Impairment Profile (MBSImP) Component 17 (esophageal clearance) as our outcome measure.

METHOD

We performed a retrospective, cross-sectional, cohort study of 57 poststroke patients with acute, first-ever, ischemic strokes. All participants received a modified barium swallow study (MBSS) using the MBSImP protocol and scoring metrics. Swallowing impairment was determined using a combination of MBSImP scores and Penetration-Aspiration Scale scores. Swallowing outcome measures were collected including Functional Oral Intake Scale and International Dysphagia Diet Standardization Initiative (IDDSI) scores. We performed tests of association and logistic regression analysis to determine if statistically significant associations exist between judgments of esophageal clearance and other swallowing impairments and/or swallowing outcome measures.

RESULTS

In our study of poststroke patients who received an MBSS as part of their care, 57.9% had abnormal esophageal clearance. Statistically significant associations were also identified in measures of pharyngeal physiology (MBSImP scores) and swallowing outcome measures (IDDSI scores and alternate means of nutrition).

CONCLUSIONS

Abnormal esophageal clearance was identified in greater than half of our poststroke patients. There is a dearth of scientific research regarding esophageal function poststroke. While esophageal visualization during the MBSS is not diagnostic of esophageal impairment, it may serve as an indicator for those poststroke patients who require dedicated esophageal testing to best determine the full nature of their swallowing pathophysiology and make the most effective treatment recommendations.

A Systematic Review of the Physiological Effects of the Effortful Swallow Maneuver in Adults With Normal and Disordered Swallowing

Purpose This systematic review summarizes the biomechanical and functional effects of the effortful swallow in adults with and without dysphagia, highlighting clinical implications and future research needs. Specifically, the effects of the effortful swallow on swallowing physiology, safety, and efficiency were identified, as well as the strengths and limitations of current research. Method Recommendations specified by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed. A literature search of three databases and relevant articles cited in the searched studies was performed. Two evaluators independently analyzed the studies for eligibility criteria, and final inclusion of studies was decided by consensus. Evaluators also assessed each study for quality of evidence. Results Twenty-three studies were included in this systematic review. Main findings indicated that the effortful swallow generated greater pressures in the tongue-to-palate, pharynx, upper esophageal sphincter, and esophageal regions. Inconsistent results for hyolaryngeal excursion were reported, as well as for swallowing function. Instructions of the effortful swallow varied greatly across studies. Two of the 23 studies were judged to be of high quality, and the remaining studies were of medium quality based on the quality indicators of this review. Conclusions Biomechanical effects of the effortful swallow included increased pressures in the oral, pharyngeal, and esophageal regions. Future investigations should address the effects of the effortful swallow in individuals with dysphagia and its potential role as a rehabilitative maneuver. Moreover, standardization of the effortful swallow instructions based on its physiological and functional effects is essential.

The Emerging Importance of High-Resolution Manometry in the Evaluation and Treatment of Deglutition in Infants, Children, and Adults: New Opportunities for Speech-Language Pathologists

Purpose Diagnostic precision and prolonged testing before, during, and after deglutition is lacking across the age spectrum. Conventional clinical evaluation and radiologic methods are widely used but are reliant on human perception, carrying the risk of subjectivity. High-resolution manometry (HRM) is an emerging clinical and research tool and has the capability to objectively measure the dynamics, kinetics, regulatory, and correlation aspects of deglutition. Method We review the basics of manometry and the methods, metrics, and applications of this technology across the age spectrum. The goal is to aid in the translation of HRM from research tool to clinical use by the speech-language pathologist in the development of better global plans to understand normal and abnormal deglutition. Results HRM is an easily adaptable precise diagnostic tool that can be used to examine deglutition phases and abnormalities across the age spectrum from neonates to nonagenarians and can be a valuable adjunct to specialty evaluation of persistent deglutition disorders. Conclusion New opportunities will emerge upon further research for larger-scale translation once normative data and recognition of biomarkers of abnormality are ascertained.

Motor Learning, Neuroplasticity, and Strength and Skill Training: Moving From Compensation to Retraining in Behavioral Management of Dysphagia

Purpose Learning a motor skill and regaining a motor skill after it is lost are key tenets to the field of speech-language pathology. Motor learning and relearning have many theoretical underpinnings that serve as a foundation for our clinical practice. This review article applies selective motor learning theories and principles to feeding and swallowing across the life span. Conclusion In reviewing these theoretical fundamentals, clinical exemplars surrounding the roles of strength, skill, experience, compensation, and retraining, and their influence on motor learning and plasticity in regard to swallowing/feeding skills throughout the life span are discussed.

Change in Excitability of Cortical Projection After Modified Catheter Balloon Dilatation Therapy in Brainstem Stroke Patients with Dysphagia: A Prospective Controlled Study

Although the modified balloon dilatation therapy has been demonstrated to improve pharyngeal swallowing function post stroke, the underlying neural mechanisms of improvement are unknown. Our aims are (1) to investigate the effect of modified balloon dilatation on the excitability of corticobulbar projections to the submental muscle in dysphagic patients with brainstem stroke and (2) the relation between changes in excitability and pharyngeal kinematic modifications. Thirty patients with upper esophageal sphincter (UES) dysfunction due to unilateral brainstem stroke were recruited into two groups. The patients in dilatation group received modified balloon dilatation and conventional therapies, and those in control were only treated by conventional therapies (twice per day). The amplitudes of bilateral submental motor evoked potentials (MEPs) induced by transcranial magnetic stimulations over bilateral motor cortex, diameters of UES opening (UOD) and maximal displacement of hyoid (HD) were all assessed at baseline and the endpoint of treatments. Repeated ANOVA analysis revealed significant main effect of group, time and MEP laterality on MEP amplitudes (p = 0.02). There were no differences in the pretreatment measures between groups (all p > 0.05). After treatment, the amplitudes of affected submental MEP evoked by ipsilateral cortical pulse as well as UOD and HD were significantly different in dilatation group compared to control (amplitude: p = 0.02, UOD: p < 0.001, HD: p = 0.03). The differences of pre- and post-treatment amplitudes of the affected MEP evoked by ipsilateral stimulation showed a positive correlation with the improvement of HD (dilatation: R ² = 0.51, p = 0.03; control: R ² = 0.39, p = 0.01), rather than UOD in both groups (all p > 0.05). In conclusion, modified balloon dilatation therapy can increase the excitability of affected projection in patients with unilateral brainstem stroke.

Objective Measures of Swallowing Function Applied to the Dysphagia Population: A One Year Experience

Quantitative, reliable measures of swallowing physiology can be made from an modified barium swallowing study. These quantitative measures have not been previously employed to study large dysphagic patient populations. The present retrospective study of 139 consecutive patients with dysphagia seen in a university tertiary voice and swallowing clinic sought to use objective measures of swallowing physiology to (1) quantify the most prevalent deficits seen in the patient population, (2) identify commonly associated diagnoses and describe the most prevalent swallowing deficits, and (3) determine any correlation between objective deficits and Eating Assessment Tool (EAT-10) scores and body mass index. Poor pharyngeal constriction (34.5 %) and airway protection deficits (65.5 %) were the most common swallowing abnormalities. Reflux-related dysphagia (36 %), nonspecific pharyngeal dysphagia (24 %), Parkinson disease (16 %), esophageal abnormality (13 %), and brain insult (10 %) were the most common diagnoses. Poor pharyngeal constriction was significantly associated with an esophageal motility abnormality (p < 0.001) and central neurologic insult. In general, dysphagia symptoms as determined by the EAT-10 did not correlate with swallowing function abnormalities. This preliminary study indicates that reflux disease is common in patients with dysphagia and that associated esophageal abnormalities are common in dysphagic populations and may be associated with specific pharyngeal swallowing abnormalities. However, symptom scores from the EAT-10 did not correspond to swallowing pathophysiology.

Buspirone, a new drug for the management of patients with ineffective esophageal motility?

Ineffective esophageal motility (IEM) is the most frequently encountered esophageal motility disorder. Patients may present with a variety of symptoms, such as dysphagia, heartburn, odynophagia, and regurgitation. Over the past years, the landscape of esophageal motility testing has been revolutionized; however, our current treatment options for IEM still remain limited. Previous studies have suggested that buspirone, a serotonin receptor agonist, enhances esophageal peristalsis and lower esophageal sphincter (LES) function. Recent work provides the first evidence that buspirone may influence LES resting pressure in patients with systemic sclerosis. Future research should evaluate whether the beneficial effects of buspirone also apply to the broad clinical entity of esophageal dysphagia patients with IEM.

Adoption into clinical practice of two therapies to manage swallowing disorders: exercise-based swallowing rehabilitation and electrical stimulation

PURPOSE OF REVIEW

To review recent literature depicting a shift in dysphagia rehabilitation in adults. Distinguishing rehabilitation from compensation in dysphagia management, a review of basic exercise principles is followed by description of recent publications depicting exercise-based therapies. Subsequently, transcutaneous electrical stimulation (TES) is reviewed as it may contribute to exercise-based dysphagia rehabilitation in adults.

RECENT FINDINGS

Surveys have documented extensive variability in the clinical application of dysphagia therapy techniques. Despite this variability, two trends are emerging in dysphagia rehabilitation research: documentation of physiologic and functional changes within the swallowing mechanism subsequent to therapy; and prophylactic exercise-based therapies. In addition, extensive efforts have emerged describing the potential application of TES in dysphagia rehabilitation. Though results of these efforts are conflicted, TES may serve a useful role as an adjunct to well developed exercise-based rehabilitation for dysphagia.

SUMMARY

The focus of dysphagia rehabilitation in adults is changing. Current efforts indicate that exercise-based therapies should incorporate multiple principles of exercise physiology and document physiologic change within the impaired swallowing mechanism. TES may function as an adjunctive modality; however, current practices should be evaluated to develop additional parameters of stimulation that are focused toward specific dysphagia impairments.

Sequential coordination between lingual and pharyngeal pressures produced during dry swallowing

The aim of this study was to investigate oropharyngeal pressure flow dynamics during dry swallowing in ten healthy subjects. Tongue pressure (TP) was measured using a sensor sheet system with five measuring points on the hard palate, and pharyngeal pressure (PP) was measured using a manometric catheter with four measuring points. The order and correlations of sequential events, such as onset, peak, and offset times of pressure production, at each pressure measuring point were analyzed on the synchronized waveforms. Onset of TP was earlier than that of PP. The peak of TP did not show significant differences with the onset of PP, and it was earlier than that of PP. There was no significant difference between the offset of TP and PP. The onset of PP was temporally time-locked to the peak of TP, and there was an especially strong correlation between the onset of PP and TP at the posterior-median part on the hard palate. The offset of PP was temporally time-locked to that of TP. These results could be interpreted as providing an explanation for the generation of oropharyngeal pressure flow to ensure efficient bolus transport and safe swallowing.

Combined impedance-manometry for the evaluation of esophageal disorders

PURPOSE OF REVIEW

Combined impedance-manometry was introduced just over 20 years ago for the assessment of esophageal motor function. Since then, technical developments have led to the introduction of high-resolution impedance-manometry (HRIM). However, analysis of the impedance and manometry recordings has remained separate and relatively unchanged since the introduction of HRIM, and it is unclear whether the addition of impedance has had a significant impact on the management of esophageal motor disorders.

RECENT FINDINGS

The major technical advance over the past 12 months or so has been the development of automated impedance-manometry (AIM) analysis, in which the impedance and manometric data are analyzed together to assess the interactions between pressure and flow. This analysis has revealed subtle abnormalities in esophageal function in patients with nonobstructive dysphagia who have normal manometry and conventional impedance analyses. AIM analysis has also revealed preoperative characteristics in patients that may predict the occurrence of postfundoplication dysphagia.

SUMMARY

Through ongoing technical development, impedance-manometry is becoming increasingly useful clinically to assess esophageal motility disorders as well as to provide further insights into esophageal physiology.