Pharyngeal pressure generation during tongue-hold swallows across age groups

Behavioral Interventions Targeting Base of Tongue to Posterior Pharyngeal Wall Approximation: A Scoping Review

Pharyngeal pressure generated by approximation of the base of tongue to the posterior pharyngeal wall (BOT-PPW approximation) is critical for efficient pharyngeal bolus passage and is a frequent goal of dysphagia management. This scoping review evaluated behavioral interventions available to improve BOT-PPW approximation. We searched MEDLINE, CINAHL, Ovid Emcare, Web of Science, SCOPUS, and ProQuest for studies that met the following criteria: (i) behavioral interventions targeting BOT-PPW approximation, which (ii) were assessed using BOT-PPW-specific outcome measures, and (iiia) performed over a period of time (Review Part 1) or (iiib) studied immediate effects (Review Part 2). Study quality was rated using the GRADE framework. Data were extracted and synthesized into dominant themes. Of the 150 studies originally identified, three examined long-term effects (two single cases studies of individuals with dysphagia, and a third study evaluating effortful swallowing in healthy individuals). BOT-PPW approximation only increased in the two single case studies. Twenty-one studies evaluating immediate effects were categorized as follows: (1) effortful swallowing, (2) Mendelsohn maneuver, (3) tongue-hold maneuver, (4) super supraglottic swallowing maneuver, and (5) non-swallowing exercises. Across all studies, varying levels of success in increasing BOT-PPW approximation were reported. Four of 21 immediate effects studies evaluated patients with demonstrated swallowing impairment, whereas 17 studies evaluated healthy adults. Quality assessment revealed low strength of the existing evidence base. The evidence base for rehabilitative interventions targeting BOT-PPW approximation is severely limited and translation is hindered by small sample sizes and methodological limitations. Further clinical research is warranted.

Effects of Tongue-Strengthening Exercise on Tongue Strength Reserve and Detraining Effects among Healthy Adults: A Randomized Controlled Trial

Introduction: Tongue strength reserve is the difference between the maximum isometric pressure (MIP) and swallowing pressure of the tongue. People with decreased tongue strength reserve may have a higher risk of presbyphagia or dysphagia. Thus, this study explored the effects of tongue strengthening exercise (TSE) on tongue strength reserve and detraining effects in healthy adults. Materials and Methods: In total, 102 healthy volunteers without any reported history of speech or swallowing deficits were recruited and assigned to experimental (n = 50) and control groups (n = 52). Exercises in the experimental group consisted of compressing an air-filled bulb between the tongue and hard palate for 30 min a day, 5 days a week, for 8 weeks. Thereafter, the experimental group underwent a 4-week detraining period. Results: Following the TSE training, posterior tongue strength reserve (F = 4.92, p = 0.029) of the experimental group was significantly higher than that of the control group. No significant detraining effects were observed on the MIP and swallowing pressure from 4 weeks after the completion of TSE training. Conclusions: According to the study results, TSE may be an effective approach for improving swallowing function.

Considerations for speech and language therapy management of dysphagia in patients who are critically ill with COVID-19: a single centre case series

Background/Aims

Patients treated with intubation and tracheostomy for COVID-19 infection are at risk of increased incidence of laryngeal injury, dysphagia and dysphonia. Because of the novelty of the SARS-CoV-2 virus, little is known about the type of dysphagia patients experience as a result of infection and critical illness. The aim of this case series report was to progress understanding of COVID-19 and dysphagia following admission to an intensive care unit and to guide speech and language therapy clinical practice in the ongoing pandemic.

Methods

A retrospective case review was conducted of all patients at Imperial College Healthcare NHS Trust, London who underwent a tracheostomy because of COVID-19 and received an instrumental assessment of swallowing in the early stages of the pandemic.

Results

A total of 11 patients were identified, and descriptive statistics were used to present demographic data, with a narrative account of their dysphagia profile used to describe presentation. Causes and presentation of dysphagia were heterogenous, with each patient requiring individualised clinical management to maximise outcome. A positive trend was seen in terms of recovery trajectory and progressing to oral intake.

Conclusions

This study reports on early experience of the presentation of dysphagia in patients with COVID-19 and demonstrates the value of instrumental assessment. It indicates the need for further research to consolidate knowledge and guide clinical practice.

Variables influencing manometric parameters of deglutitive and non-deglutitive upper esophageal sphincter: A study of 89 asymptomatic participants

BACKGROUND

High-resolution manometry overcomes limitations imposed by axial and radial asymmetry as well as swallow and respiration-induced movement of the upper esophageal sphincter (UES), allowing for its reliable use in evaluation of dysphagic and reflux patients. The aim of this study was to determine normative values and their variability across position, sex, age, height, weight, BMI, and volume for clinically relevant deglutitive and non-deglutitive UES parameters.

METHODS

We studied 89 asymptomatic volunteers age 19-90 years, (45 female) during 3-10 repetitions of dry, 5 and 10 ml water swallows at 30-s intervals using high-resolution manometry.

KEY RESULTS

Upper esophageal sphincter high-pressure zone was longer in men than women and in supine than upright position. UES basal contractile integral and mean basal pressure were higher in supine compared to upright; higher in men than women, inversely correlated with age, correlated positively with height and with weight in the supine position only. UES relaxation duration was longer in upright than in supine position but not affected by age, sex, height, weight, or BMI. It was longer with 5 and 10 ml compared with dry swallows. UES minimum/nadir relaxation and mean relaxation pressures were lower in upright than supine position, increased with increase in age and were higher in men than women.

CONCLUSIONS AND INFERENCES

Position, sex, age, height, weight, and volume affect some deglutitive and non-deglutitve UES manometric parameters. BMI does not affect the studied manometric parameters. These effects should be taken into consideration in clinical evaluation of UES.

Effect of tongue-hold swallow on posterior pharyngeal wall using dynamic area detector computed tomography

Purpose

The purpose of this study was to elucidate the effects of the tongue‐hold swallow (THS) on the pharyngeal wall by quantifying posterior pharyngeal wall (PPW) anterior bulge during the THS. In addition, the effect of tongue protrusion length on the extent of pharyngeal wall anterior bulge was analysed.

Methods

Thirteen healthy subjects (6 males and 7 females, 23–43 years) underwent 320‐row area detector CT during saliva swallow (SS) and THS at two tongue protrusion lengths (THS1 protrude the tongue as much as 1/3 of premeasured maximum tongue protrusion length (MTP‐L) and THS2 protrude the tongue as much as 2/3 of MTP‐L). To acquire images of the pharynx at rest, single‐phase volume scanning was performed three times during usual breathing with no tongue protrusion (rest), protrusion of the tongue at 1/3 of MTP‐L (rTHS1) and protrusion of the tongue at 2/3 of MTP‐L (rTHS2). Length from cervical spine to PPW (PPW‐AP) and the volume of pharyngeal cavity was measured and was compared between rest, rTHS1 and rTHS2 and between SS, THS1 and THS2. Correlation between MTP‐L and PPW‐AP was calculated in three conditions, SS, THS1 and THS2.

Results

PPW‐AP at rest, rTHS1 and rTHS2 was 2.9 ± 0.6 mm, 3.0 ± 0.5 mm and 3.0 ± 0.5 mm, respectively, showing no significant differences across swallows. PPW‐AP at the maximum pharyngeal constriction was 8.1 ± 2.0 mm, 9.1 ± 2.4 mm and 8.7 ± 2.0 mm in SS, THS1 and THS2, respectively. Compared to SS, PPW‐AP in THS1 was significantly larger (p = 0.04) and PPW‐AP in THS2 was not significantly different (p = 0.09). Pharyngeal volume at rest, rTHS1 and rTHS2 was 16.4 ± 5.2 mm³, 18.4 ± 4.5 mm³ and 21.3 ± 6.2 mm³, respectively. It was significantly larger during rTHS2 compared with rest or rTHS1 (rTHS2‐rest p = 0.007, rTHS2‐rTHS1 p = 0.007). Pharyngeal volume was completely obliterated (zero volume) at maximum pharyngeal contraction in all except one subject. There was no correlation between MTP‐L and PPW‐AP in any of the three conditions (SS, THS1 and THS2).

Discussion

This study demonstrated that the expanded pharyngeal cavity due to the tongue protrusion was completely obliterated by the increase in anterior motion of pharyngeal wall during THS. It also became clear that the degree of tongue protrusion did not linearly correlate with the movement of PPW during THS. There was no relationship between PPW motion and the MTP‐L, suggesting that the effect of tongue protrusion is better determined in each subject by analysing the motion of PPW using imaging tools.

Effect of Tongue-Hold Swallow on Pharyngeal Contractile Properties in Healthy Individuals

Tongue-hold swallow (THS) is a swallow exercise in which an individual swallows saliva while holding the anterior portion of the tongue between the front teeth. The effect of THS on pharyngeal contractile vigor is still unclear. The purpose of this study was to quantify THS using high-resolution manometry with a contractile integral analysis. Twenty-two healthy participants performed three different saliva swallow tasks: normal swallow, weak THS (in which the tongue was protruded 1 cm outside the upper incisors), and strong THS (in which the tongue was protruded 2 cm outside the upper incisors). The participants repeated each task twice randomly. Pharyngeal and upper esophageal sphincter metrics, including the pharyngeal contractile integral, were analyzed. Both weak and strong THS enhanced the velopharyngeal contractile integral and peak pressure compared with normal swallow (P < 0.01). THS also prolonged mesopharyngeal contraction (P < 0.01). Holding the tongue anteriorly during swallow requires significant biomechanical changes to pharyngeal contractile properties at the superior and middle pharyngeal constrictor levels; thus, it may serve as a resistance exercise for the muscles that are involved in bolus propulsion.

Oropharyngeal dysphagia: manifestations and diagnosis

Swallowing disorders (dysphagia) have been recognized by the WHO as a medical disability associated with increased morbidity, mortality and costs of care. With increasing survival rates and ageing of the population, swallowing disorders and their role in causing pulmonary and nutritional pathologies are becoming exceedingly important. Over the past two decades, the study of oropharyngeal dysphagia has been approached from various disciplines with considerable progress in understanding its pathophysiology. This Review describes the most frequent manifestations of oropharyngeal dysphagia and the clinical as well as instrumental techniques that are available to diagnose patients with dysphagia. However, the clinical value of these diagnostic tests and their sensitivity to predict outcomes is limited. Despite considerable clinical research efforts, conventional diagnostic methods for oropharyngeal dysphagia have limited proven accuracy in predicting aspiration and respiratory disease. We contend that incorporation of measurable objective assessments into clinical diagnosis is needed and might be key in developing novel therapeutic strategies.

Efficacy of exercises to rehabilitate dysphagia: A critique of the literature

PURPOSE

This review critiques the benefit of commonly used rehabilitative exercises for dysphagia.

METHOD

Common goals of rehabilitation for dysphagia and principles of neuroplasticity are introduced as they apply to swallowing and non-swallowing exercises. A critique of published studies is offered regarding their evidence for showing benefit from the exercise.

RESULT

One of five swallow exercises had preliminary evidence for long-term benefit and two of four non-swallow exercises have strong evidence for long-term benefit.

CONCLUSION

Only a minority of exercises prescribed for patients with dysphagia have sufficient evidence for long-term improvement in swallowing.

Evaluating the tongue-hold maneuver using high-resolution manometry and electromyography

The tongue-hold maneuver is a widely used clinical technique designed to increase posterior pharyngeal wall movement in individuals with dysphagia. It is hypothesized that the tongue-hold maneuver results in increased contraction of the superior pharyngeal constrictor. However, an electromyographic study of the pharynx and tongue during the tongue-hold is still needed to understand whether and how swallow muscle activity and pressure may change with this maneuver. We tested eight healthy young participants using simultaneous intramuscular electromyography with high-resolution manometry during three task conditions including (a) saliva swallow without maneuver, (b) saliva swallow with the tongue tip at the lip, and (c) saliva swallow during the tongue-hold maneuver. We tested the hypothesis that tongue and pharyngeal muscle activity would increase during the experimental tasks, but that pharyngeal pressure would remain relatively unchanged. We found that the pre-swallow magnitude of tongue, pharyngeal constrictor, and cricopharyngeus muscle activity increased. During the swallow, the magnitude and duration of tongue and pharyngeal constrictor muscle activity each increased. However, manometric pressures and durations remained unchanged. These results suggest that increased superior pharyngeal constrictor activity may serve to maintain relatively stable pharyngeal pressures in the absence of posterior tongue movement. Thus, the tongue-hold maneuver may be a relatively simple but robust example of how the medullary swallow center is equipped to dynamically coordinate actions between tongue and pharynx. Our findings emphasize the need for combined modality swallow assessment to include high-resolution manometry and intramuscular electromyography to evaluate the potential benefit of the tongue-hold maneuver for clinical populations.

Dysphagia therapy in stroke: a survey of speech and language therapists

BACKGROUND

Dysphagia is common after stroke, leading to adverse outcome. There is a paucity of high-quality evidence for dysphagia therapy, thus making it difficult to determine the best approaches to treatment. Clinical decisions are often based on usual practice, however no formal method of monitoring practice patterns exists.

AIMS

To determine speech and language therapists' (SLTs) approaches to direct dysphagia therapy with stroke patients in the UK and Ireland.

METHODS & PROCEDURES

A 24-item questionnaire was developed, piloted and delivered in a web-based cross-sectional survey targeting all SLTs working with stroke patients in the UK and Ireland.

OUTCOMES & RESULTS

A total of 138 SLTs responded from a range of clinical settings and levels of experience. There was variation in the responses to all questions. Respondents reported treating patients a median of once a day, 3 days a week for 15 min. The most commonly recommended direct exercises were supervised swallow trials (recommended 'frequently or always' by 73%). Despite most respondents having access to an instrumental swallowing assessment, over half reported rarely or never conducting one before recommending exercises. Most (93%) did not use a protocol for systematically progressing patients' exercises and only 37% reported using standardized outcome measures.

CONCLUSIONS & IMPLICATIONS

This survey gives valuable insight into the direct dysphagia therapy practices of SLTs based in the UK and Ireland working in stroke. It highlights discrepancies between reported approaches and recommendations from existing evidence and clinical guidelines. The variation in responses indicates a need to develop a consensus statement and further research to guide practice.