Swallow Physiology Research Articles

Swallowing Kinematic Differences Across Frozen, Mixed, and Ultrathin Liquid Boluses in Healthy Adults: Age, Sex, and Normal Variability.

The aim of this study was to examine the effects of frozen and mixed-consistency boluses on the swallowing physiology of younger and older adults. We also aimed to quantify factors that lead to increased variability in swallowing outcomes (i.e., age, sex, bolus type). Forty-one healthy adults (18-85 years old) swallowed 5 blocks of 5 different boluses: 10-ml ultrathin liquid, a teaspoon of iced barium, a teaspoon of room-temperature pudding, a teaspoon of frozen pudding, and ultrathin barium with chocolate chips. All data were recorded with videofluoroscopy and underwent detailed timing kinematic measurements. Neither barium ice nor frozen pudding sped up swallow responses. Many healthy adults initiated swallowing with the bolus as deep as the pyriform sinuses. Swallowing temporal kinematics for ultrathin liquid consistencies are most different from all others tested, requiring the best possible physiological swallowing performance in younger and older healthy individuals (i.e., faster reaction times, longer durations) compared with other bolus types tested. In each measure, older adults had significantly longer durations compared with the younger adults. More variability in swallowing kinematics were seen with age and laryngeal vestibule kinematics. This study provides important contributions to the literature by clarifying normal variability within a wide range of swallowing behaviors and by providing normative data from which to compare disordered populations.

Improve of dysphagia with electrostimulation after a stroke

Patients who have suffered a stroke may have dysphagia in more than 30% of cases. When the alteration is located in the bulbar area, since the neural control of swallowing is located at the bulbar level, where the centers responsible for processing the afferent sensory signals and programming the motor deglutory sequence are located this percentage increases. The goal of treatment is to obtain secure and sufficient oral intake for adequate hydration and nutrition. Treatment techniques are designed to change the physiology of swallowing. Neuromuscular electrical stimulation can also be performed as studies have shown that this treatment appears to help people with moderate dysphagia. Clinical observation: we present the case of a 44-year-old woman who suffered laterobulbar ischemic Ictus. The physical exam, showed dysarthria, facial paresis and limb dysmetry without motor deficit and severe alteration of swallowing. Fibroendoscopic studies were performed and oral diet was contraindicated thus enteral nutrition was required from the time of admission. Speech therapy plus the application of electrostimulation was initiated. After 4 months of treatment, enteral nutrition was removed and the patient was able to change to a complete oral diet. Patients who are diagnosed of a bulbar stroke have a high percentage of swallowing dysfunction. Swallowing therapy with electrical stimulation may help clinical improvement of dysphagia.

Outcome of educational workshop in swallowing rehabilitation for nurse

Swallowing problem is common in stroke survivors and aging. As imbalance healthcare professionals, swallowing rehabilitation in Thailand was approached as trans-disciplinary team. Some tasks of other health care professions has been shifting to nurses. Therefore the 2-day education program in swallowing rehabilitation was conducted to improve knowledge and skill for nurses. This study aimed to determine the knowledge of nurse in swallowing rehabilitation. The 2-days workshop which consisted of basic physiology of swallowing, dysphagia screening test, compensatory technique and exercise, diet modification, chest physical therapy and oral health care for patient with dysphagia was conducted in 2 general hospitals located in Northern and Southern part of Thailand. All participants were asked to complete the test before and after attending workshop. The test was 20 True/False questions; 7 questions about dysphagia, 8 questions about aspiration prevention and 5 questions for swallowing rehabilitation. The passing level was 16 out of 20 scores. Of the 51 nurses who completed pre-test and post-test, 78% had more than 5 years’ experience. Of those participants, 60.8% worked at tertiary healthcare, 27.5% worked at primary healthcare and 11.8% worked at secondary healthcare. Only 27% passed the passing level on pre-test. There was significantly difference in pre-test and post-test scores (15.0 ± 2.4 and 16.9 ± 2.4; P < 0.001). Although 70% of participants could get more scores after workshop, only 53% passed the passing level. Knowledge of swallowing rehabilitation among participants increased after the workshop. However, this study showed that only few days might not sufficient for empowerment, effective continuing educating program should be designed to increase quality of care.

Differences in swallow physiology in patients with left and right hemispheric strokes.

We sought to determine the impact of lesion lateralization and lesion volume on swallow impairment on group-level by comparing patients with left and right hemisphere strokes and on patient-level by analyzing patients individually. We performed a retrospective, observational, cross-sectional study of 46 patients with unilateral (22 left, 24 right), acute, first-ever, ischemic strokes who received a diffusion weighted MRI (DW-MRI) and modified barium swallow study (MBSS) during their acute hospital stay. We determined lesion side on the DW-MRI and measured swallow physiology using the Modified Barium Swallow Impairment Profile (MBSImP™©), Penetration-Aspiration Scale (PAS), swallow timing, distance, area, and speed measures. We performed Pearson's Chi-Square and Wilcoxon Rank-Sum tests to compare patients with left and right hemisphere strokes, and Pearson or Spearman correlation, simple logistic regression, linear, and logistic multivariable regression modeling to assess the relationship between variables. At the group-level, there were no differences in MBSImP oral swallow impairment scores between patients with left and right hemisphere stroke. In adjusted analyses, patients with right hemisphere strokes showed significantly worse MBSImP pharyngeal total scores (p = 0.02), worse MBSImP component specific scores for laryngeal vestibular closure (Bonferroni adjusted alpha p ≤ 0.0029), and worse PAS scores (p = 0.03). Patients with right hemisphere strokes showed worse timing, distance, area, and speed measures. Lesion volume was significantly associated with MBSImP pharyngeal residue (p = 0.03) and pharyngeal total scores (p = 0.04). At the patient-level, 24% of patients (4 left, 7 right) showed opposite patterns of MBSImP oral and pharyngeal swallow impairment than seen at group-level. Our study showed differences in swallow physiology between patients with right and left unilateral strokes with patients with right hemisphere strokes showing worse pharyngeal impairment. Lesion lateralization seems to be a valuable marker for the severity of swallowing impairment at the group-level but less informative at the patient-level.

Swallowing outcomes in children after slide tracheoplasty

IntroductionSlide tracheoplasty is now considered gold standard treatment for long segment congenital tracheal stenosis. Outcomes are typically focused upon airway patency. Dysphagia is often reported in children undergoing cardiothoracic surgery, but not specifically after slide tracheoplasty. This study was carried out to describe the nature and prevalence of dysphagia following slide tracheoplasty for long segment congenital tracheal stenosis. MethodsRetrospective case note review was conducted on a series of patients who underwent swallow evaluation following slide tracheoplasty between 2006 and 2014. A clinical swallow assessment was carried out by a Speech and Language Therapist with videofluoroscopic evaluation of swallowing where indicated. Logistic regression assessed the impact of gender, feeding history, weight, tracheal diameter, stenting and co-morbidities on the likelihood of having post-operative dysphagia. Results43 out of 83 slide tracheoplasty patients underwent swallow evaluation. Dysphagia was identified in 30 (70%) of 43 patients. Videofluoroscopy was undertaken in 22 of these patients. All patients who had a videofluoroscopy presented with altered swallow physiology. Aspiration risk was confirmed in 15 patients with frank aspiration seen in 9. Pre-operative history of dysphagia was present in 9 patients. There were two cases of vocal fold palsy. The presence of a stent was the strongest predictor of post-operative dysphagia with an odds ratio of 10.6 (95% CI 1.2–92.8). ConclusionsThis study documents a high prevalence of post-operative dysphagia in a pediatric population following slide tracheoplasty. In most cases there was no history suggestive of dysphagia pre-operatively. Swallowing needs to be assessed after slide tracheoplasty and longitudinal studies are required.

An Investigation of the Post-laryngectomy Swallow Using Videofluoroscopy and Fiberoptic Endoscopic Evaluation of Swallowing (FEES)

This study investigates the post-laryngectomy swallow. Presence and degree of residue on the post-laryngectomy swallow as observed on videofluoroscopy and FEES is described. In addition, videofluoroscopy and FEES are assessed for reliability and inter-instrument agreement. 30 laryngectomy subjects underwent dysphagia evaluation using simultaneous videofluoroscopy and FEES. These were reviewed post-examination by three expert raters using a rating scale designed for this purpose. Raters were blinded to subject details, type of laryngectomy surgery, pairing of FEES and videofluoroscopy examinations and the scores of other raters. There was a finding of residue in 78% of videofluoroscopy ratings, and 83% of FEES ratings. Comparison of the tools indicated poor inter-rater reliability and poor inter-instrument agreement. Dysphagia is an issue post laryngectomy as measured by patient self-report and by instrumental evaluation. However, alternative dysphagia rating tools and dysphagia evaluation tools are required to enable accurate identification and intervention for underlying swallow physiology post laryngectomy.

Development of a Computer-Assisted Learning Courseware for Anatomy and Physiology of Swallowing

Knowledge of normal anatomy and physiology of swallowing is fundamental in the identification of individuals with or at risk for swallowing disorders. Learning anatomy and physiology however, is not an easy task thus, computer-assisted learning (CAL) approaches have been incorporated into the learning of the topics to enhance understanding. Although evidence exists on the benefits of using CAL in education, more studies are necessary in the field of swallowing. While courseware for the learning of anatomy and physiology of swallowing exist, they are not comprehensive. Therefore, this study aimed to develop a comprehensive CAL courseware for anatomy and physiology of swallowing. The current study used a designed-based research following the ADDIE (analysis, design, development, implementation, and evaluation) model to create a multimedia courseware, incorporating the use of text, still images, animations, audio narrations, and presented on a simple graphical user interface. The courseware was evaluated by 27 undergraduate students in terms of its usefulness, ease of use, and users’ satisfaction. Results indicate that the participants were satisfied with the courseware and that they perceived the courseware as useful, easy to learn and easy to use. The study represents an initiative to investigate the use of CAL in the subject and to establish the basis for further work which includes assessment on the learning outcomes from the usage of the CAL courseware. It is hoped that the use of this courseware in teaching and learning of anatomy and physiology of swallowing can enhance students’ knowledge and understanding of the area efficiently and effectively. DOI : http://dx.doi.org./10.17576/JSKM-2018-1601-21

Peptidomic study on in vitro and in vivo phosphopeptide release during the chewing of gum fortified with a commercial casein hydrolysate

The kinetics of phosphopeptide release from gum fortified with a commercial casein hydrolysate in artificial and human saliva was studied. Using mass spectrometry techniques, the caseinophosphopeptide (CPP) composition of the commercial casein hydrolysate compared with a standard tryptic casein digest from whole raw cow milk was determined. In in vitro trials, the amount of CPPs released was always the same for each chewing time; in contrast, during in vivo chewing, a decrease of peptide levels was detected, from 10% after 5 min to 0.1% at 20 min, due to physiological swallowing. It is concluded that gums are a useful vehicle for CPP intake, owing to their functional role in bone health. However, their use is less satisfactory for prevention of dental caries, due to the brief contact with the enamel surface. Moreover, more calcium would need to be added to enrich the CPP fraction of the commercial hydrolysate.

Silent aspiration in infants with Prader-Willi syndrome identified by videofluoroscopic swallow study.

Feeding intolerance in Prader–Willi syndrome (PWS) infants is well-recognized, but their swallow physiology is not well understood. Swallow dysfunction increases risks of respiratory compromise and choking, which have a high incidence in PWS. To investigate swallow pathology in PWS infants we undertook a retrospective review of videofluoroscopic swallow studies (VFSS) in infants with PWS seen at our institution. We hypothesize that VFSS will characterize swallow pathology suspected by clinical observation during a feeding evaluation and may help determine feeding safety in these infants.Retrospective review of 23 VFSS on 10 PWS infants (average age 9.7 ± 8.4 months; range 3 weeks–29 months). Logistic regression models evaluated associations between gender, genetic subtype, and growth hormone (GH) use on aspiration incidence. Polysomnographic (PSG) studies conducted on the same participant ±1 year from VFSS were examined to characterize respiratory abnormalities.There was a high rate of swallowing dysfunction (pharyngeal residue 71%, aspiration events 87%) and disordered sleep. All aspiration events were silent. There were no differences in rates of aspiration for gender, genetic subtype, or GH use.A high incidence of aspiration was identified indicating swallow dysfunction may frequently be present in infants with PWS. Comprehensive evaluation of feeding and swallowing is essential and requires a multidisciplinary approach. Providers should recognize risk factors for swallow dysfunction and consider a multidisciplinary approach to guide decision making and optimize feeding safety in PWS.

First Steps Towards Development of an Instrument for the Reproducible Quantification of Oropharyngeal Swallow Physiology in Bottle-Fed Children.

The incidence of feeding/swallowing impairments (deglutition disorders) in young children is rising and poses serious acute and long-term health consequences. Accurate detection and prompt intervention can lessen the impact of dysphagia-induced sequelae. Videofluoroscopic Swallow Studies (VFSSs) are used to make critical decisions for medically fragile children despite procedural variability and the lack of agreed upon measures for interpreting and reporting results. This investigation represents the first steps in the development of a novel tool for the quantification of oropharyngeal swallow physiology from full-length VFSS examinations in bottle-fed children. The Modified Barium Swallow Impairment Profile MBSImP™© served as the conceptual assessment model for development of components and operational score variants to characterize distinguishable VFSS observations. Twenty-four components of swallowing physiology were validated via expert consensus. Training materials included a library of 94 digitized video images comprised of distinct score variants for each component. Materials were disseminated to seven speech-language pathologists (SLPs) who participated in didactic and self-training sessions, and rated components. All SLPs achieved ≥80% reliability criterion after completing two or three training sessions. Agreement for 17 (71%) components was achieved after two sessions. Nutritive sucking/oral and airway-related components were most difficult to distinguish. Three sessions were required for 2 (33%) of the sucking/oral components and 4 (57%) of the airway-related components. These findings support the feasibility to standardize training and reliably score swallowing physiology using precise definitions and unambiguous visual images, and represent preliminary steps towards content validity and reliability of a standardized VFSS tool for bottle-fed children.

Differential Response Pattern of Oropharyngeal Pressure by Bolus and Dry Swallows.

The aim of this study was to determine if bolus and dry swallow showed similar pressure changes in the oropharynx using our newly developed device. A unique character of it includes that baropressure can be measured with the sensor being placed in the balloon and can assess the swallowing mechanics in terms of pressure changes in the oropharynx with less influences of direct contacts of boluses and oropharyngeal structures during swallow indirectly. Fifteen healthy subjects swallowed saliva (dry), 15ml of water, 45ml of water, and 15ml of two different types of food in terms of viscosity (potage soup-type and mayonnaise-type foods). Suprahyoid muscle activity was recorded simultaneously. Three parameters, area under the curve (AUC), peak amplitude, and duration of pressure, were analyzed from each swallow. Almost all of the bolus swallowing events had biphasic baropressure responses consisting of an early phase and late phase (99%), whereas 90% of the saliva swallowing events had a single phase. AUC, peak, and duration displayed greater effects during the late phase than during the early phase. Baropressure of the early phase, but not of the late phase, significantly increased with increasing volume; however, small but significant viscosity effects on pressure were seen during both phases. Peak pressure of the late phase was preceded by maximum muscle activity, whereas that of the early phase was seen when muscle activity displayed a peak response. These findings indicated that our device with the ability to measure baropressure has the potential to provide additional parameter to assess the swallow physiology, and biphasic baropressure responses in the early and late phases could reflect functional aspects of the swallowing reflexes.

The anatomy and physiology of normal and abnormal swallowing in oropharyngeal dysphagia.

Eating and drinking are enjoyable activities that positively impact on an individual's quality of life. The ability to swallow food and fluid is integral to the process of eating. Swallowing occupies a dual role being both part of the enjoyment of eating and being a critically important utilitarian activity to enable adequate nutrition and hydration. Any impairment to the process of swallowing can negatively affect a person's perception of their quality of life. The process of swallowing is highly complex and involves muscles in the mouth, pharynx, larynx, and esophagus. The oropharynx is the anatomical region encompassing the oral cavity and the pharynx. Food must be masticated, formed into a bolus and transported to the pharynx by the tongue whereas fluids are usually held within the mouth before being transported ab-orally. The bolus must then be transported through the pharynx to the esophagus without any matter entering the larynx. The muscles needed for all these steps are coordinated by swallowing centers within the brainstem which are supplied with sensory information by afferent nerve fibers from several cranial nerves. The swallowing centers also receive modulatory input from higher centers within the brain. Hence, a swallow has both voluntary and involuntary physiologic components and the term dysphagia is given to difficult swallowing while oropharyngeal dysphagia is difficult swallowing due to pathology within the oropharynx. Problems affecting any point along the complex swallowing pathway can result in dysphagia. This review focuses on the anatomy and physiology behind normal and abnormal oropharyngeal swallowing. It also details the common diseases and pathology causing oropharyngeal dysphagia.

QUALIDADE DE VIDA EM DEGLUTIÇÃO E CÂNCER DE CABEÇA E PESCOÇO: REVISÃO DE LITERATURA

Objective: This study aimed to review the literature on the quality of life related to swallowing of patients with head and neck cancer. Methods: We searched for studies describing the physiology of swallowing and aspects involved in dysphagia, such as definition, causes and their impact on quality of life. We used the electronic databases Pubmed, Medline, Scielo, books, as well as articles identified in the references. Results: Deglutition disorders may occur due to disease and / or treatment modality, persisting during or after termination of treatment. The frequency and severity of dysphagia will depend on the modality of treatment used, location and stage of the tumor, when involved in structures that participate in swallowing. Patients with tumors in more advanced stages and located in the pharynx try to present worsening of swallowing function. Such factors may directly affect swallowing and quality of life of the patient, especially in family, social and lifestyle relationships. Conclusion: Although it does not replace clinical and instrumental evaluations, investigating the quality of life in swallowing may contribute to assess specific aspects of patient well-being that are not contemplated.

QUALIDADE DE VIDA EM DEGLUTIÇÃO E CÂNCER DE CABEÇA E PESCOÇO: REVISÃO DE LITERATURA

Objetivo: O estudo teve como objetivo revisar a literatura a respeito da qualidade de vida relacionada à deglutição de pacientes com câncer de cabeça e pescoço. Métodos: Buscou-se estudos relatando a fisiologia da deglutição e os aspectos envolvidos na disfagia, como definição, causas e seu impacto na qualidade de vida. Foram utilizados os bancos de dados eletrônicos Pubmed, Medline, Scielo, livros, assim como de artigos identificados nas referências. Resultados: Distúrbios da deglutição podem ocorrer devido à doença e/ou modalidade de tratamento, persistindo durante ou após o término do tratamento. A frequência e gravidade da disfagia dependerão da modalidade de tratamento utilizada, localização e estágio do tumor, quando envolvidos em estruturas que participem da deglutição. Pacientes com tumores em estágios mais avançados e localizados na faringe tentem a apresentar piora na função da deglutição. Tais fatores poderão interferir diretamente na deglutição e qualidade de vida do paciente, sobretudo nas relações familiares, sociais e no estilo de vida. Conclusão: Apesar de não substituir as avaliações clínicas e instrumentais, investigar a qualidade de vida em deglutição pode contribuir para avaliar aspectos específicos sobre o bem-estar do paciente que não são contemplados.

Therapeutic intervention in oropharyngeal dysphagia.

Oropharyngeal dysphagia is a frequent consequence of several medical aetiologies, and even considered part of the normal ageing process. Early and accurate identification provides the opportunity for early implementation of dysphagia treatments. This Review describes the current state of the evidence related to dysphagia therapies - focusing on treatments most clinically utilized and of current interest to researchers. Despite successes in select studies, the level of evidence to support the efficacy of these treatments remains limited. Heterogeneity exists across studies in both how interventions are administered and how their therapeutic value is assessed, thereby making it difficult to establish external validation. Future work needs to address these caveats. Also, to be most efficacious, dysphagia therapies need to account for influences from pre-morbid patient characteristics as these factors have potential to increase the risk of dysphagia and the resulting complications of aspiration, malnutrition and psychological burden. Dysphagia therapies therefore need to incorporate the medical aetiology that is at its root, the resulting swallow physiology captured from comprehensive clinical and/or instrumental assessments, and the existing needs and supports of patients.

Calculation of upper esophageal sphincter restitution time from high resolution manometry data using machine learning

ObjectiveAfter swallowing, the upper esophageal sphincter (UES) needs a certain amount of time to return from maximum pressure to the resting condition. Disturbances of sphincter function not only during the swallowing process but also in this phase of pressure restitution may lead to globus sensation or dysphagia. Since UES pressures do not decrease in a linear or asymptotic manner, it is difficult to determine the exact time when the resting pressure is reached, even when using high resolution manometry (HRM). To overcome this problem a Machine Learning model was established to objectively determine the UES restitution time (RT) and moreover to collect physiological data on sphincter function after swallowing. Methods and materialHRM-data of 15 healthy participants performing 10 swallows each were included. After manual annotation of the RT interval by two swallowing experts, data were transferred to the Machine Learning model, which applied a sequence labeling modeling approach based on logistic regression to learn and objectivize the characteristics of all swallows. Individually computed RT values were then compared with the annotated values. ResultsEstimates of the RT were generated by the Machine Learning model for all 150 swallows. When annotated by swallowing experts mean RT of 11.16s±5.7 (SD) and 10.04s±5.74 were determined respectively, compared to model-generated values from 8.91s±3.71 to 10.87s±4.68 depending on model selection. The correlation score for the annotated RT of both examiners was 0.76 and 0.63 to 0.68 for comparison of model predicted values. ConclusionsRestitution time represents an important physiologic swallowing parameter not previously considered in HRM-studies of the UES, especially since disturbances of UES restitution may increase the risk of aspiration. The data presented here show that it takes approximately 9 to 11s for the UES to come to rest after swallowing. Based on maximal RT values, we demonstrate that an interval of 25–30s in between swallows is necessary until the next swallow is initiated. This should be considered in any further HRM-studies designed to evaluate the characteristics of individual swallows. The calculation model enables a quick and reproducible determination of the time it takes for the UES to come to rest after swallowing (RT). The results of the calculation are partially independent of the input of the investigator. Adding more swallows and integrating additional parameters will improve the Machine Leaning model in the future. By applying similar models to other swallowing parameters of the pharynx and UES, such as the relaxation time of the UES or the activity time during swallowing, a complete automatic evaluation of HRM-data of a swallow should be possible.

Feeding/Swallowing Disorders: Maintaining Quality of Life in Persons with Intellectual Disability

Persons with intellectual disability (ID) have received little attention in systematic studies of healthcare and quality of life. Less attention has been provided to specific disorders, such as those impacting the swallowing mechanism. In comparison to the general population, persons with ID experience noticeably greater healthcare inequalities and despite greater life expectancy, it is still lower than the general population. This paper serves as an introduction to healthcare colleagues regarding the risks involved in choking and swallowing disorders in persons with ID, how to evaluate these potential risks and possible treatments. Associated etiologies are presented. A discussion on feeding disorders versus swallowing disorders is also introduced. The inadequacy of swallowing assessment services to persons with ID may be related to the lack of professionals with specialized training in working with this population, reduced funding for research to explore options for improved nutrition and reduced risk of choking and minimal research on changes in feeding skills and/or swallow physiology in this select group of individuals

Assessing Upper Esophageal Sphincter Function in Clinical Practice: a Primer.

The upper esophageal sphincter constitutes an important anatomic and functional landmark in the physiology of pharyngeal swallowing. A variety of clinical circumstances may call for a dedicated evaluation of this mechanism, from the etiologic evaluation of indeterminate symptoms to the generation of complex locoregional therapeutic strategies. Multiple diagnostic tools exist for the assessment of pharyngeal swallowing generally and of upper esophageal sphincter function specifically, some well established and others not yet settled into routine practice. This report reviews five specific modalities for use in making this assessment, outlining the strengths, weaknesses, and logistical considerations of each with respect to its potential use in clinical settings. In many cases, these studies will provide complementary information regarding pharyngeal function, suggesting the relative advantage of a multimodal evaluation.

Comparative Study of VDR and the Electrical Activity of the Anterior Temporal and Masseter Muscles using Physiologic rest Position, Phonetics and Swallowing methods

Comparative Study of VDR and the Electrical Activity of the Anterior Temporal and Masseter Muscles using Physiologic rest Position, Phonetics and Swallowing methods

Evaluating muscles underlying tongue base retraction in deglutition using muscular functional magnetic resonance imaging (mfMRI)

PurposeTongue base retraction during swallowing is critical to bolus propulsion in normal physiological swallowing. A better understanding of the hyoglossus and styloglossus, muscles thought to be key to tongue base retraction, will improve the quality of physical rehabilitation in dysphagic patients in addition to preventing iatrogenic damage to structures critical to deglutition. This study utilized muscle functional MRI in healthy adult human subjects in order to determine if the hyoglossus and styloglossus are active during swallowing. Methods and materialsData were collected for 11 subjects with mfMRI before and after swallowing, and after performing the Mendelsohn maneuver. Whole muscle relaxation time profiles (T2 signal in milliseconds) were calculated from weighted averages of multiple dual echo MRI slices, allowing for comparison of physiological response for the muscles in each test condition. Changes in effect size (Cohen’s d) of whole muscle T2 profiles were used to establish whether or not the hyoglossus and styloglossus are utilized during swallowing and during the Mendelsohn maneuver. ResultsPost-swallowing effect size changes (where a d value of >0.20 indicates significant activity) for the T2 signal profiles of the hyoglossus and styloglossus were found to be d=1.19 and 0.22, respectively. The hyoglossus showed an effect size change of d=0.26 for the Mendelsohn maneuver. ConclusionsMuscle functional MRI indicates a physiological response of the hyoglossus and styloglossus during swallowing, and the hyoglossus during the Mendelsohn maneuver.