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

Effects of different mylohyoid muscle stimulations on swallowing cortex excitability in healthy subjects

BACKGROUND

Dysphagia has been recognized by the World Health Organization as a medical disability. Improving mylohyoid muscle function plays an important role in pharyngeal dysphagia. The aim of this study was to evaluate the treatment of transcranial magnetic stimulation (TMS), peripheral magnetic stimulation (PMS), and electrical stimulation (ES) for dysphagia.

METHODS

Forty healthy subjects were randomly divided into four groups: TMS+PMS, TMS, PMS, and ES. TMS stimulated the cortical representative area of the mylohyoid muscle and the PMS was directly stimulating the mylohyoid muscle, both of them at a frequency of 10 Hz for a total of 1,800 pulses. The intensity of ES was based on the subject's tolerance level, usually 2-5 mA. Functional near infrared spectroscopy (fNIRS) and motor evoked potential (MEP) of the mylohyoid muscle were used to evaluate the immediate effects of stimulation on swallowing cortex excitability of healthy subjects before and after intervention.

RESULTS

The fNIRS results revealed notable activation across multiple channels in the four groups of healthy subjects both pre- and post- the intervention. Among these channels, the activation levels were most pronounced in the TMS+PMS group, followed by the TMS, PMS, and ES groups, respectively. Regarding the MEP results, post-intervention observations indicated a reduction in bilateral latency and an increase in bilateral amplitude in the TMS+PMS group. Additionally, the left amplitude exhibited an increase in the TMS group.

CONCLUSIONS

In fNIRS, all four stimulation methods significantly activated the swallowing cortex of healthy subjects, and the activation of TMS+PMS was the most obvious, followed by TMS, PMS, and ES.

Neurophysiological characterization of oropharyngeal dysphagia in older patients

OBJECTIVE

To characterize swallowing biomechanics and neurophysiology in older patients with oropharyngeal dysphagia (OD).

METHODS

Observational study in 12 young healthy volunteers (HV), 9 older HV (OHV) and 12 older patients with OD with no previous diseases causing OD (OOD). Swallowing biomechanics were measured by videofluoroscopy, neurophysiology with pharyngeal sensory (pSEP) and motor evoked-potentials (pMEP) to intrapharyngeal electrical and transcranial magnetic stimulation (TMS), respectively, and salivary neuropeptides with enzyme-linked immunosorbent assay (ELISA).

RESULTS

83.3% of OOD patients had unsafe swallows (Penetration-Aspiration scale = 4.3 ± 2.1; p < 0.0001) with delayed time to laryngeal vestibule closure (362.5 ± 73.3 ms; p < 0.0001) compared to both HV groups. OOD patients had: (a) higher pharyngeal sensory threshold (p = 0.009) and delayed pSEP P1 and N2 latencies (p < 0.05 vs HV) to electrical stimulus; and (b) higher pharyngeal motor thresholds to TMS in both hemispheres (p < 0.05) and delayed pMEPs latencies (right, p < 0.0001 HV vs OHV/OOD; left, p < 0.0001 HV vs OHV/OOD).

CONCLUSIONS

OOD patients have unsafe swallow and delayed swallowing biomechanics, pharyngeal hypoesthesia with disrupted conduction of pharyngeal sensory inputs, and reduced excitability and delayed cortical motor response.

SIGNIFICANCE

These findings suggest new elements in the pathophysiology of aging-associated OD and herald new and more specific neurorehabilitation treatments for these patients.

Surveying the International Prevalence and Nature of Eating, Drinking and Swallowing Difficulties in Adults Presenting with Fibromyalgia

Fibromyalgia is a centralized pain syndrome characterized by widespread pain, fatigue, sleep and sensory issues. Fibromyalgia is present in up to 8% of the global population, disproportionally affecting females. Research acknowledges that patients with similar rheumatic/neurological disorders experience eating, drinking and swallowing difficulties. There are also anecdotal reports regarding dysphagia among the fibromyalgia community. However, there is limited research exploring these issues, with potential impact on care delivery and patient outcomes. This study investigated the nature and prevalence of dysphagia in an international sample of adults with fibromyalgia. An online cross-sectional survey design was used to gather data. Questions were adapted from a criterion-based assessment and available evidence. The survey focused on demographics, dysphagia symptoms, and symptom experiences. Results were analyzed using descriptives and correlational analysis. 1983 individuals participated (age range: 18-94), located: Australia (n = 18), Ireland (n = 63), Canada (n = 174), New Zealand (n = 253), the UK (n = 434) and the USA (n = 1024). Many eating, drinking and swallowing symptoms were reported, including food sticking in the throat during swallowing (89%), and pills taking extra effort to swallow (88%), and dry mouth (85%). This study identified previously under-explored eating, drinking and swallowing difficulties among adults with fibromyalgia. These difficulties were self-reported across age, gender, and location, highlighting the potential prevalence of these concerns among a wide range of people, despite having not been explored in depth in previous studies. Timely and accurate dysphagia identification is vital given the its' potential impact on nutrition, prognosis and quality of life. This study highlighted the importance of honoring patient experiences in fibromyalgia management while also recommending input from allied health professionals such as SLTs and dietitians to improve therapeutic relationships and clinical outcomes. As such, continued research into the cause, implications, and management of these issues beyond is required to inform and optimise future patient-centred service delivery and care provision.

Oropharyngeal swallowing hydrodynamics of thin and mildly thick liquids in an anatomically accurate throat-epiglottis model

Understanding the mechanisms underlying dysphagia is crucial in devising effective, etiology-centered interventions. However, current clinical assessment and treatment of dysphagia are still more symptom-focused due to our limited understanding of the sophisticated symptom-etiology associations causing swallowing disorders. This study aimed to elucidate the mechanisms giving rise to penetration flows into the laryngeal vestibule that results in aspirations with varying symptoms. Methods: Anatomically accurate, transparent throat models were prepared with a 45° down flapped epiglottis to simulate the instant of laryngeal closure during swallowing. Fluid bolus dynamics were visualized with fluorescent dye from lateral, rear, front, and endoscopic directions to capture key hydrodynamic features leading to aspiration. Three influencing factors, fluid consistency, liquid dispensing site, and dispensing speed, were systemically evaluated on their roles in liquid aspirations. Results: Three aspiration mechanisms were identified, with liquid bolus entering the airway through (a) the interarytenoid notch (notch overflow), (b) cuneiform tubercle recesses (recess overflow), and (c) off-edge flow underneath the epiglottis (off-edge capillary flow). Of the three factors considered, liquid viscosity has the most significant impact on aspiration rate, followed by the liquid dispensing site and the dispensing speed. Water had one order of magnitude higher aspiration risks than 1% w/v methyl cellulose solution, a mildly thick liquid. Anterior dispensing had higher chances for aspiration than posterior oropharyngeal dispensing for both liquids and dispensing speeds considered. The effects of dispending speed varied. A lower speed increased aspiration for anterior-dispensed liquids due to increased off-edge capillary flows, while it significantly reduced aspiration for posterior-dispensed liquids due to reduced notch overflows. Visualizing swallowing hydrodynamics from multiple orientations facilitates detailed site-specific inspections of aspiration mechanisms.

Relative Fundamental Frequency in Individuals with Globus Syndrome and Muscle Tension Dysphagia

OBJECTIVE

Relative fundamental frequency (RFF) has been investigated as an acoustic measure to assess for changes in laryngeal tension. This study aimed to assess RFF in individuals with globus syndrome, individuals with muscle tension dysphagia (MTDg), and individuals with typical voices.

METHODS

RFF values were calculated from the speech acoustics of individuals with globus syndrome (n = 12), individuals with MTDg (n = 12), and age- and sex-matched controls with typical voices (n = 24). An analysis of variance was performed on RFF values to assess the effect of group.

RESULTS

There was no statistically significant effect of group on RFF values, with similar values for individuals with globus syndrome, individuals with MTDg, and control participants.

CONCLUSIONS

These results suggest that individuals with these disorders do not appear to possess paralaryngeal muscle tension in a locus and/or manner that directly impacts voice production.

Advancements and Challenges in Non-Invasive Sensor Technologies for Swallowing Assessment: A Review

Dysphagia is a pervasive health issue that impacts diverse demographic groups worldwide, particularly the elderly, stroke survivors, and those suffering from neurological disorders. This condition poses substantial health risks, including malnutrition, respiratory complications, and increased mortality. Additionally, it exacerbates economic burdens by extending hospital stays and escalating healthcare costs. Given that this disorder is frequently underestimated in vulnerable populations, there is an urgent need for enhanced diagnostic and therapeutic strategies. Traditional diagnostic tools such as the videofluoroscopic swallowing study (VFSS) and flexible endoscopic evaluation of swallowing (FEES) require interpretation by clinical experts and may lead to complications. In contrast, non-invasive sensors offer a more comfortable and convenient approach for assessing swallowing function. This review systematically examines recent advancements in non-invasive swallowing function detection devices, focusing on the validation of the device designs and their implementation in clinical practice. Moreover, this review discusses the swallowing process and the associated biomechanics, providing a theoretical foundation for the technologies discussed. It is hoped that this comprehensive overview will facilitate a paradigm shift in swallowing assessments, steering the development of technologies towards more accessible and accurate diagnostic tools, thereby improving patient care and treatment outcomes.

Longitudinal change of energy expenditure, body composition and dietary habits in Progressive Supranuclear Palsy patients

INTRODUCTION

Alterations in metabolic status, body composition, and food intake are present in all neurodegenerative diseases. Aim of this study was to detect the progression of these changes in Progressive Supranuclear Palsy (PSP).

METHODS

We conducted a longitudinal study of 15 patients with PSP. The assessments were performed at baseline (T0) and after 7(IQR = 5) months of follow-up (T1). We collected anthropometric measures including body weight, height, body mass index and waist circumference, metabolic parameters through indirect calorimeters, body composition using bioimpedance analysis, and dietary habits with a validated questionnaire. PSP-rating scale (PSP-rs) was used to evaluate disease severity and dysphagia.

RESULTS

The majority of patients (66.66%) presented PSP-Richardson Syndrome and 33.33% the other variant syndromes of the disease. At T1 there was a decrease in intake of total daily calories (p < 0.001), proteins (p < 0.001), fibers (p = 0.001), calcium (p = 0.008), iron (p < 0.001), zinc (0.034), vitamin E (p = 0.006) and folates (p = 0.038) compared to T0. No other changes were found. As for T1 data, no significant differences were shown according to disease phenotypes or the presence of clinically significant dysphagia for solids.

CONCLUSIONS

Within a mid-term follow up, PSP patients presented reduced caloric and proteins intake regardless the presence of dysphagia. The PSP-rs is likely not adequate to assess dysphagia, which should be investigated by specific clinical scales or instrumental examinations. With the goal of maintaining adequate nutritional status, the administration of protein and vitamin supplements should be considered even in the absence of dysphagia evidenced by the rating scales.

Factors associated with age-related changes in oral diadochokinesis and masticatory function in healthy old adults

BACKGROUND

This cross-sectional study aimed to identify factors associated with age-related changes in masticatory performance (MP) and oral diadochokinesis (ODK) and to provide normal values in healthy old adults for the diagnosis of oral frailty.

METHODS

A total of 385 participants were divided into three age groups (Gr1-3): 20-64 years, 65-74 years, and ≥ 75 years. To investigate tongue-lip motor function, ODK was assessed as the number of repetitions of the monosyllables /pa/ta/ka/. Four questionnaires were used to assess subjective masticatory ability, cognitive ability, and psychological status. MP, bite force, and occlusal area were tested to assess dynamic objective masticatory function, and the number of remaining teeth and functional tooth pairs were determined to assess static objective masticatory function. Handgrip strength (HG), oral dryness, and tongue pressure (TP) were assessed to identify influencing factors. Intergroup differences were evaluated by ANOVA and the Kruskal‒Wallis test, and correlations between ODK and orofacial factors were evaluated.

RESULTS

This study revealed significant age-related declines in TP, HG, and ODK, especially after 65 years of age. Factors affecting MP were posterior teeth, the Eichner index, bite force, occluding area, the Korean Mini-Mental State Examination (KMMSE) score, and ODK. Each ODK syllable was associated with different factors, but common factors associated with ODK were MP, HG, and PHQ-9 score. For the syllables /pa/ta/, the Eichner Index, TP, and oral dryness were also associated. For the syllable /ka/ in Gr3, MP, TP, HG, oral dryness, and the KMMSE score were associated.

CONCLUSIONS

These results could provide practical guidelines for oral rehabilitation in old adults and contribute to improving the understanding of age-related changes in oral function and the multidimensional nature of masticatory dynamics.

What School-Based Speech-Language Pathologists Need to Know About Pediatric Swallowing and Feeding Development and Disorders

PURPOSE

School-based speech-language pathologists are at the frontline for treating children with pediatric feeding disorders (PFDs). Often, speech-language pathologists are the primary allied health professionals who are charged with maximizing safety, supporting nutrition and neurodevelopmental growth. Due to the increasing need for assessment and treatment of PFDs in schools, it is fundamental that PFDs and dysphagia are detected, differentially diagnosed, and addressed to support developing children. This tutorial addresses the anatomy, physiology, and development of functional feeding and swallowing patterns across the spectrum of childhood for both PFDs and dysphagia.

METHOD

A clinical expert review of the anatomy, physiology, and development of functional feeding and swallowing patterns in children across the spectrum of childhood will be completed.

CONCLUSIONS

The aim of this tutorial is to support school-based speech-language pathologists in their understanding of the anatomy and physiology of feeding and swallowing. School-based speech-language pathologists should complete this tutorial with an increased understanding and breadth of knowledge related to typical anatomy and physiology versus atypical or disordered presentations. This tutorial would support school-based speech-language pathologists in determining whether a child presents with characteristics of oropharyngeal dysphagia and/or a PFD.

Polysaccharide-dextrin thickened fluids for individuals with dysphagia: recent advances in flow behaviors and swallowing assessment methods

The global aging population has brought about a pressing health concern: dysphagia. To effectively address this issue, we must develop specialized diets, such as thickened fluids made with polysaccharide-dextrin (e.g., water, milk, juices, and soups), which are crucial for managing swallowing-related problems like aspiration and choking for people with dysphagia. Understanding the flow behaviors of these thickened fluids is paramount, and it enables us to establish methods for evaluating their suitability for individuals with dysphagia. This review focuses on the shear and extensional flow properties (e.g., viscosity, yield stress, and viscoelasticity) and tribology (e.g., coefficient of friction) of polysaccharide-dextrin-based thickened fluids and highlights how dextrin inclusion influences fluid flow behaviors considering molecular interactions and chain dynamics. The flow behaviors can be integrated into the development of diverse evaluation methods that assess aspects such as flow velocity, risk of aspiration, and remaining fluid volume. In this context, the key in-vivo (e.g., clinical examination and animal model), in-vitro (e.g., the Cambridge Throat), and in-silico (e.g., Hamiltonian moving particles semi-implicit) evaluation methods are summarized. In addition, we explore the potential for establishing realistic assessment methods to evaluate the swallowing performance of thickened fluids, offering promising prospects for the future.

Swallowing kinematics and submental muscles activation during a newly designed maneuver called Mouth Open Swallowing Maneuver: A comparative study

The aim of this study was to design a new maneuver called the Mouth Open Swallowing Maneuver (MOSM), and to compare swallowing kinematics and submental muscles activation (SMA) between MOSM and two current approaches used in dysphagia rehabilitation. Fifty healthy volunteers were asked to perform three repetitions of dry swallowing (DS) (control task), the MOSM, the Mendelsohn Maneuver (MM), and the Tongue-Hold Maneuver (THM) during videofluoroscopic swallowing study accompanied with simultaneous SMA recording. Swallowing kinematics were measured by frame-by-frame analysis on hyolaryngeal movement using ImageJ. Swallowing with maximum hyolaryngeal movement and SMA during these tasks was used for comparative analysis. Vertical movement of the hyoid during the MOSM was significantly greater than those observed during the DS and the THM (p<0.001, p<0.001). Horizontal movement of the hyoid during DS and the THM was significantly greater than that observed during the MM (p = 0.001, p = 0.001). Vertical movement of the larynx during the MOSM was significantly greater than those observed during DS, MM, and THM (p<0.001). There was no significant difference between tasks in horizontal movement of the larynx (p = 0.785). SMA during the THM was significantly greater than that observed during MOSM (p = 0.002). No significant difference was found between other tasks in terms of SMA (p>0.05). The MOSM as a newly designed maneuver was significantly superior to other maneuvers in increasing vertical hyolaryngeal movement. The THM has as much effect on hyolaryngeal movement as the MM. In this study, the MOSM was shown to be effective in increasing hyolaryngeal movement. ClinicalTrials.gov Protocol Registration and Results System (PRS); the clinical trial registration number (NCT05579041).

The neurorehabilitation of post-stroke dysphagia: Physiology and pathophysiology

Swallowing is a complex process involving the precise contractions of numerous muscles of the head and neck, which act to process and shepherd ingested material from the oral cavity to its eventual destination, the stomach. Over the past five decades, information from animal and human studies has laid bare the complex network of neurones in the brainstem, cortex and cerebellum that are responsible for orchestrating each normal swallow. Amidst this complexity, problems can and often do occur that result in dysphagia, defined as impaired or disordered swallowing. Dysphagia is common, arising from multiple varied disease processes that can affect any of the neuromuscular structures involved in swallowing. Post-stroke dysphagia (PSD) remains the most prevalent and most commonly studied form of dysphagia and, as such, provides an important disease model to assess dysphagia physiology and pathophysiology. In this review, we explore the complex neuroanatomical processes that occur during normal swallowing and PSD. This includes how strokes cause dysphagia, the mechanisms through which natural neuroplastic recovery occurs, current treatments for patients with persistent dysphagia and emerging neuromodulatory treatments.

Changes in the Activation Level of the Floor of the Mouth Muscles during Pressing and Swallowing Tasks According to the Degree of Tongue Pressure

The suprahyoid muscles play an important role in protecting the airway by elevating both the hyoid bone and larynx superior-anteriorly during swallowing. However, providing systematic external resistance when performing exercises to improve suprahyoid muscle strength is practically difficult. This study attempted to confirm whether systematic resistance can be provided to the suprahyoid muscles using the Iowa Oral Performance Instrument (IOPI)-a representative tongue pressure measurement device. Thirty-one healthy adults participated in this study (20.6 ± 0.96 y, 19 females). The participants performed 16 exercise tasks using the IOPI three times each in random order (Anterior/posterior tongue × pressing/swallowing task × 40/60/80/100% maximum tongue pressure). Furthermore, the floor of the mouth (FOM) muscle activity during exercise was simultaneously measured using surface electromyography. During the pressing task, there were significant differences in FOM maximal muscle activity among the four exercise intensities for both the anterior and posterior oral tongue. For the swallowing task, a significant difference was found in FOM muscle activity among the four exercise intensities for the anterior tongue. For the posterior tongue, significant differences were identified among all conditions except for the comparison between 80% and 100% maximum tongue pressure. Significant correlations between the degree of tongue pressure and maximal FOM muscle activity were found in both the pressing and swallowing tasks at the anterior and posterior oral tongue. Overall, these results indicate that objective and systematic external resistance can be applied using the IOPI-a standard tongue pressure measurement device-during the program to improve suprahyoid muscle function.

Orofacial Pain and Risk of Dysphagia in Women With Fibromyalgia: A Cross-Sectional Observational Study

OBJECTIVE

This study aims to analyze the frequency of dysphagia risk and swallowing-associated quality of life (QoL) in a sample of women with fibromyalgia syndrome (FMS) and examine the potential relationship between risk of dysphagia and chronic orofacial pain (COP) in a sample of women with FMS.

METHOD

A cross-sectional observational study was conducted in 46 women with FMS. COP was assessed by mouth opening, the orofacial visual analog scale (VAS), and the craniofacial pain and disability inventory (CF-PDI). Risk of dysphagia was assessed using the Eating Assessment Tool (EAT-10) and the volume-viscosity swallowing test (V-VST). Swallowing-associated QoL was determined using the Swallowing Quality of Life (SWAL-QOL) questionnaire.

RESULTS

Thirty patients were identified as being at risk for dysphagia (65.21%) using the EAT-10 and, according to the SWAL-QOL, 41.30% of patients had alterations in QoL associated with swallowing. The EAT-10 correlated positively with orofacial VAS, CF-PDI-total, CF-PDI-pain and disability, and CF-PDI-jaw-functional status. In relation to SWAL-QOL, negative correlations were observed for orofacial VAS, CF-PDI-total, CF-PDI-pain and disability, and CF-PDI-jaw-functional status. Patients at risk of dysphagia (EAT-10 and V-VST) had significantly higher scores in orofacial VAS (p = .002 and p = .015), CF-PDI-total (p = .006 and p = .014), and CF-PDI-pain and disability (p = .004 and p = .013).

CONCLUSIONS

In this sample of women with FMS, we identified a high rate of dysphagia risk. Also, a high percentage of these women presented alterations in QoL associated with swallowing. Patients at risk for dysphagia had significantly higher orofacial VAS and CF-PDI-total scores, supporting the relationship between dysphagia risk and COP in FMS. Further research to establish the need for appropriate assessment referrals in clinical practice to determine whether dysphagia is present in this population is needed.

Effects of Cerebellar Repetitive Transcranial Magnetic Stimulation in the Treatment of Post-Stroke Dysphagia: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

INTRODUCTION

This study aimed to comprehensively evaluate the therapeutic efficacy of cerebellar repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of post-stroke dysphagia (PSD).

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched PubMed, Cochrane Library, Embase, and Web of Science to identify relevant randomized controlled trials (RCTs) investigating the application of cerebellar rTMS in the treatment of PSD. Inclusion and exclusion criteria were rigorously applied during the screening process, and pertinent characteristics of the included RCTs were meticulously extracted. The I2 statistic was employed to assess heterogeneity, and meta-analysis was conducted using Stata 17 software. The Cochrane Risk of Bias 2 tool and PEDro scale were utilized to evaluate bias risk and literature quality.

RESULTS

Our analysis encompassed a total of 5 RCTs involving 673 patients with dysphagia who met the inclusion criteria. The findings indicated a significant positive impact of cerebellar rTMS when combined with traditional swallowing exercises on PSD, demonstrating superior efficacy compared to conventional swallowing exercises in isolation. Furthermore, the study revealed no statistically significant differences based on stimulation site (unilateral vs. bilateral cerebellum), stimulation mode (rTMS vs. intermittent theta-burst stimulation), and stimulation frequency (5 Hz vs. 10 Hz).

CONCLUSION

The amalgamation of cerebellar rTMS with conventional swallowing exercises demonstrates notable efficacy, surpassing the outcomes achievable with traditional exercises alone. The sustained effectiveness observed underscores the potential of cerebellar rTMS as an innovative avenue in the field of neurorehabilitation for PSD. This study contributes valuable insights into the prospect of utilizing cerebellar rTMS as an adjunctive therapeutic strategy in the management of PSD, emphasizing its relevance for further exploration and clinical application.

Participation of the nucleus tractus solitarius in the therapeutic effect of electroacupuncture on post-stroke dysphagia through the primary motor cortex

BACKGROUND

Post-stroke dysphagia (PSD), a common and serious disease, affects the quality of life of many patients and their families. Electroacupuncture (EA) has been commonly used effectively in the treatment of PSD, but the therapeutic mechanism is still under exploration at present. We aim to investigate the effect of the nucleus tractus solitarus (NTS) on the treatment of PSD by EA at Lianquan (CV23) through the primary motor cortex (M1).

METHODS

C57 male mice were used to construct a PSD mouse model using photothrombotic technique, and the swallowing function was evaluated by electromyography (EMG) recording. C-Fos-positive neurons and types of neurons in the NTS were detected by immunofluorescence. Optogenetics and chemical genetics were used to regulate the NTS, and the firing rate of neurons was recorded via multichannel recording.

RESULTS

The results showed that most of the activated neurons in the NTS were excitatory neurons, and multichannel recording indicated that the activity levels of both pyramidal neurons and interneurons in the NTS were regulated by M1. This process was involved in the EA treatment. Furthermore, while chemogenetic inhibition of the NTS reduced the EMG signal associated with the swallowing response induced by activation of M1 in PSD mice, EA rescued this signal.

CONCLUSION

Overall, the NTS was shown to participate in the regulation of PSD by EA at CV23 through M1.

Tongue, palatal, hyoid and pharyngeal muscle activity during chewing, swallowing, and respiration

OBJECTIVE

Chewing, swallowing, and respiration are synchronized oropharyngeal functions. This study aimed to analyze the dynamics and coordination during natural chewing and swallowing in relation to respiratory phases.

DESIGN

Eight oropharyngeal muscles in minipigs were recorded using electromyography, X-ray fluoroscopy, and nasopharyngeal dynamics. Chewing cycles and swallowing episodes were analyzed for timing and activity amplitude along respiratory cycles. Digastric and middle pharyngeal constrictor were used as zero-points for timing analysis in chewing cycles and swallowing episodes, respectively. The beginning of these cycles and episodes were used as the zero-point for timing analysis in respiration during feeding.

RESULTS

The timing of jaw closing (57.8%) was longer than opening (42.2%) during chewing. Muscle activity occurred 20% later than digastric onsets and 15% earlier than jaw closing phase. Duration of muscle activity was shorter in ipsilateral than contralateral sides except for palatal muscles. Pharyngeal, palatal, and hyoid muscles showed longer durations than tongue muscles in jaw opening (p < 0.05). Palatal and hyoid muscles showed 2-phased activity in chewing while hyoid muscles showed higher amplitude in chewing and swallowing than other muscles. About 80% of the chewing cycles and swallowing episodes occurred in expiration. Nasopharyngeal airflow velocity increased from jaw opening to swallowing while airflow pressure decreased.

CONCLUSION

These findings indicate key activity of palatal and pharyngeal muscles mostly in chewing. The respiratory cycle changes in chewing and swallowing simultaneously with the activation of the tongue, palatal, and pharyngeal muscles. These findings will be useful for further understanding the mechanisms in swallowing and breathing disorders.

Translation, and validation of Dysphagia Outcome and Severity Scale (DOSS): Swedish version

BACKGROUND

Swallowing dysfunction (dysphagia) significantly impacts patient and medical outcomes. In Sweden, there is no comprehensive outcome measure for dysphagia that incorporates holistic assessment and dysphagia impact on a person's impairment, function and participation. The Dysphagia Outcome and Severity Scale (DOSS) was developed and validated (in English) and incorporates the World Health Organisation's (WHO) aforementioned, International Classification of Functioning (ICF) aspects. This study translated then evaluated the validity and reliability of the Swedish version, DOSS-S.

METHOD

Translation occurred based on WHO recommendations. The Content Validity Index (CVI) of the translated version (DOSS-S) was assessed twice by 11 (multi-professional) dysphagia experts. Criterion validity and rater reliability was calculated using 18 Speech Pathologists assessing patient cases from International Dysphagia Diet Standardization Initiative-Functional Diet Scale (IDDS-FDS) research.

RESULTS

Very high CVI values (0.96-0.99) for the linguistic correlation, and high CVI values (0.84-0.94) for applicability correlation were achieved. High criterion validity of DOSS-S with IDDSI-FDS was demonstrated (rs = 0.89, p < 0.01), with very high inter and intra rater reliabilities (ICC > 0.90).

CONCLUSION

The DOSS-S demonstrated very high validity values, and very high inter and intra rater reliability. This research contributes to improved dysphagia management by providing interprofessional dysphagia clinicians with a validated scale to identify patient progression, communicate dysphagia status between regions and countries, and document patient outcomes using an ICF framework.

The lived experiences of oropharyngeal dysphagia in adults living with fibromyalgia

BACKGROUND

Fibromyalgia is a chronic pain condition which has recently been linked with eating, drinking and swallowing difficulties (dysphagia). However, to date, sample sizes within completed research are small and study designs heterogeneous, and therefore, little is known about the lived experiences of dysphagia among people with fibromyalgia. To go some way towards addressing this gap in the literature, this study collected and analysed the first-hand experiences of the physical symptoms, the psychosocial impacts and environmental factors that influenced the lived experience of a sample of people living with fibromyalgia-associated dysphagia.

METHODS

Qualitative semi-structured interviews were conducted with adults with dysphagia and fibromyalgia. Reflexive thematic analysis was employed and themes were identified regarding the reported experience and impact of swallowing problems. The same researcher conducted the interviews and extracted all data, and a second researcher analysed a random sample of 5% of the data for accuracy, with no disagreements arising between the two researchers.

RESULTS

All participants (n = 8) reported the negative psychosocial impact of their dysphagia. Participants reported managing their dysphagia independently, primarily using compensatory strategies. Participants discussed feeling unsupported in healthcare interactions due to clinicians not understanding the occurrence, nature or impact of eating, drinking and swallowing difficulties. Participants also reported that they did not have access to evidence-based management strategies that adequately addressed their fibromyalgia-related swallowing problems.

CONCLUSIONS

Despite minimal previous research in this area, findings here highlight the impact that dysphagia has on people with fibromyalgia. A broad range of physical symptoms were reported to have negative consequences across both social and emotional domains. The reported symptoms often required complex coping strategies and sometimes impeded participants from seeking suitable medical intervention from healthcare providers. There are both broad-ranging implications of fibromyalgia-associated dysphagia and reported poor perceptions of medical interactions for this cohort of patients. Therefore, there is evidently a need for clinical research into the management of this condition to develop patient-centred care delivery options and to equip healthcare professionals with the knowledge and skills necessary to provide efficacious management to this group.

PATIENT OR PUBLIC CONTRIBUTION

Before initiation of the qualitative interviews, the interview schedule was piloted with an individual living with fibromyalgia and dysphagia, with feedback provided on the appropriate wording and format of semi-structured questioning.

Isometric tongue endurance and incomplete laryngeal vestibule closure in Parkinson's disease

BACKGROUND

Dysphagia is a common symptom of Parkinson's disease (PD). A delay in laryngeal vestibule closure (LVC) and a reduction in tongue pressure, may affect swallowing safety and increase the risk of pulmonary aspiration.

OBJECTIVE

To verify the relationship between tongue pressure and airway protection in PD patients: (1) comparing tongue pressure measures and physiological events in the pharyngeal phase of swallowing between PD and controls and (2) analysing the association between tongue pressure and LVC in the PD group.

METHODS

Twenty-three patients with idiopathic PD (64.9 years) and 24 healthy controls (64.1 years) participated in this study. All participants underwent the following procedures to verify tongue pressure measurements using the Iowa Oral Performance Instrument: maximum anterior and posterior pressure, isotonic and isometric tongue endurance and anterior and posterior tongue pressure during saliva swallowing. To verify swallowing safety, videofluoroscopic swallowing studies focusing on the pharyngeal phase were performed based on the MBSImP protocol.

RESULTS

Compared to healthy controls, PD exhibited a statistically significant decline in tongue pressure tasks: posterior maximum pressure, isotonic endurance, anterior and posterior isometric endurance and tongue pressure during posterior swallowing. Patients with PD had worse pharyngeal scores, including LVC scores, than controls. PD and incomplete LVC had lower anterior isometric endurance scores when compared to those with complete LVC.

CONCLUSION

PD with incomplete LVC scored lower in the anterior isometric endurance task. We observed a potential clinical use of this task for the assessment and management of dysphagia in patients with PD.

Clinical and Acoustic Alterations of Swallowing in Children Exposed to Zika Virus during Pregnancy in a Cohort in Amazonas, Brazil: A Case Series Study

Oropharyngeal dysphagia (OD) is a swallowing disorder that involves difficulty in safely passing the food bolus from the oral cavity to the stomach. OD is a common problem in children with congenital Zika virus syndrome (CZS). In this case series, we describe the clinical and acoustic alterations of swallowing in children exposed to the Zika virus during pregnancy in a cohort from Amazonas, Brazil. From July 2019 to January 2020, 22 children were evaluated, 6 with microcephaly and 16 without microcephaly. The mean age among the participants was 35 months (±4.6 months). All children with microcephaly had alterations in oral motricity, mainly in the lips and cheeks. Other alterations were in vocal quality, hard palate, and soft palate. Half of the children with microcephaly showed changes in cervical auscultation during breast milk swallowing. In children without microcephaly, the most frequently observed alteration was in lip motricity, but alterations in auscultation during the swallowing of breast milk were not observed. Regarding swallowing food of a liquid and pasty consistency, the most frequent alterations were incomplete verbal closure, increased oral transit time, inadequacy in capturing the spoon, anterior labial leakage, and increased oral transit time. Although these events are more frequent in microcephalic children, they can also be seen in non-microcephalic children, which points to the need for an indistinct evaluation of children exposed in utero to ZIKV.

[Introduction of fiberoptic endoscopic evaluation of swallowing and increase of the range of indications in our department]

Dysphagia is a disease resulting from preparatory or transport disorder of the swallowing process and it is divided into oropharyngeal and esophageal phases according to the site of the lesion. The ear, nose and throat assessment focuses on the oropharyngeal phase, but differential diagnosis, investigation, and treatment of the cause of dysphagia is often a complex task requiring multidisciplinary approach and collaboration. The method of fiberoptic endoscopic evaluation of swallowing (FEES) has been introduced at the Department of Ear, Nose and Throat and Head-Neck Surgery, University of Szeged, enabling the examination of otorhinolaryngological and neurological disorders of swallowing as well as objective analysis of patients' swallowing quality. The fiberoptic endoscopic evaluation of swallowing is a minimally invasive procedure that allows visualization of the oropharyngeal phase of swallowing. It can identify anatomical abnormalities or neurological disorders causing dysphagia, thus playing a significant role in later patient rehabilitation. We hereby present our experiences in examinations of patients who underwent partial laryngectomy and/or pharyngectomy due to head and neck tumors as well as of those who underwent airway surgery duo to upper airway stenosis. Thanks to our collaboration with the Neurology Department, we also share our experiences gained during the examinations of patients struggling with oropharyngeal swallowing problems of various neurological origins. Orv Hetil. 2023; 164(46): 1817-1823.

Swallowing capacity and gravity of the laryngotracheal aspiration risk in atypical cerebellar stroke: case report

This case report aimed to evaluate the swallowing capacity and the severity of the risk of laryngotracheal aspiration of a 52-year-old female patient with atypical and rare stroke, with major injury in the cerebellar pathway. In order to measure swallowing capacity and risk of aspiration a routine clinical assessment used in the speech therapy clinic was performed and two valid clinical tests were used: Massey Bedside Swallowing Screen (MBSS) and Gugging Swallowing Screen (GUSS). After evaluation with the clinical tests, it was observed that the patient had reduced swallowing capacity, performance characterized as pathological, 100% dysfunction in the water swallowing test (MBSS), presence of choking, coughing, change in vocal quality and anterior escape. In the assessment of risk of aspiration with the GUSS, the patient presented moderate dysphagia and risk of laryngotracheal aspiration.This case report demonstrated that moderate dysphagia is found in a stroke patient with lesions that affect the cerebellum. Standardized and validated clinical tests such as GUSS and MBSS should also be used to assess the risk of dysphagia after stroke at ambulatory care.

Lactation physiokinetics-using advances in technology for a fresh perspective on human milk transfer

Introduction

Though the nature of breastfeeding is critical, scant information is available on how the action of the milk transfer from mother to infant is regulated in humans, where the points of dysfunction are, and what can be done to optimize breastfeeding outcomes. While better therapeutic strategies are needed, before they can be devised, a basic scientific understanding of the biomechanical mechanisms that regulate human milk transfer from breast to stomach must first be identified, defined, and understood.

Methods

Combining systems biology and systems medicine into a conceptual framework, using engineering design principles, this work investigates the use of biosensors to characterize human milk flow from the breast to the infant's stomach to identify points of regulation. This exploratory study used this framework to characterize Maternal/Infant Lactation physioKinetics (MILK) utilizing a Biosensor ARray (BAR) as a data collection method.

Results

Participants tolerated the MILKBAR well during data collection. Changes in breast turgor and temperature were significant and related to the volume of milk transferred from the breast. The total milk volume transferred was evaluated in relation to contact force, oral pressure, and jaw movement. Contact force was correlated with milk flow. Oral pressure appears to be a redundant measure and reflective of jaw movements.

Discussion

Nipple and breast turgor, jaw movement, and swallowing were associated with the mass of milk transferred to the infant's stomach. More investigation is needed to better quantify the mass of milk transferred in relation to each variable and understand how each variable regulates milk transfer.

Effects of Age and Lingual-Palatal Pressure Levels on Submental Surface Electromyography Measures

Submental surface electromyography (sEMG) may provide information about the lingual-palatal pressure (LPP) during swallowing. However, the extent to which changes in age and LPP levels are reflected in different sEMG measures is unclear. This study aimed to understand the effects of age and different levels of submaximal LPPs on submental sEMG peak, average, and integrated values in healthy adults. Ninety community-dwelling healthy participants were categorized into three age groups (young: 20-39 years, middle age: 40-59 years, older: 60 ≥ years). sEMG and LPP measurements were collected concurrently. After placing the sEMG electrodes, the maximal isometric LPP was established using the Iowa oral performance instrument (IOPI) on the anterior tongue. sEMG recordings were conducted for three submaximal LPP levels, including 40%, 60%, and 80% of the maximum LPP. Two-way repeated measure ANOVAs were conducted to find the effects of age and varying LPP levels on mean sEMG peak, average, and integrated measures. A significant age by LPP level interaction was identified for sEMG peak [F (4, 172) = 4.116, p < 0.007, ηp2 = 0.087], sEMG average [F (4, 170) = 5.049, p < 0.001, ηp2 = 0.106], and sEMG integrated values [F (4, 170) = 4.179, p < 0.003, ηp2 = 0.090]. Post hoc testing demonstrated that, in general, sEMG values significantly increased with rising LPP levels, primarily for younger and middle-aged adults. Furthermore, at 80% of maximum LPP, older adults generated less sEMG average and integrated values than middle age (only significant for sEMG integrated value) and younger adults. Likewise, max LPP was lower in older adults compared with young and middle-aged groups. Submental sEMG has the potential to be incorporated into a skill-based lingual exercise paradigm to improve tongue function during swallowing. Moreover, submental sEMG can characterize some age-related subclinical changes in swallowing.

Cerebellar Prediction and Feeding Behaviour

Given the importance of the cerebellum in controlling movements, it might be expected that its main role in eating would be the control of motor elements such as chewing and swallowing. Whilst such functions are clearly important, there is more to eating than these actions, and more to the cerebellum than motor control. This review will present evidence that the cerebellum contributes to homeostatic, motor, rewarding and affective aspects of food consumption.Prediction and feedback underlie many elements of eating, as food consumption is influenced by expectation. For example, circadian clocks cause hunger in anticipation of a meal, and food consumption causes feedback signals which induce satiety. Similarly, the sight and smell of food generate an expectation of what that food will taste like, and its actual taste will generate an internal reward value which will be compared to that expectation. Cerebellar learning is widely thought to involve feed-forward predictions to compare expected outcomes to sensory feedback. We therefore propose that the overarching role of the cerebellum in eating is to respond to prediction errors arising across the homeostatic, motor, cognitive, and affective domains.

Airway clearance in patients with neuromuscular disease

Airway clearance is a critical component of both maintenance of respiratory health and management of acute respiratory illnesses. The process of effective airway clearance begins with the recognition of secretions in the airway and culminates in expectoration or swallowing. There are multiple points on this continuum at which neuromuscular disease causes impaired airway clearance. This can result in an otherwise mild upper respiratory illness progressing unabated from an easily managed condition to a severe, life-threatening lower respiratory illness requiring intensive therapy for patient recovery. Even during periods of relative health, airway protective mechanisms can be compromised, and patients may have difficulty managing average quantities of secretions. This review summarizes airway clearance physiology and pathophysiology, mechanical and pharmacologic treatment modalities, and provides a practical approach for managing secretions in patients with neuromuscular disease. Neuromuscular disease is an umbrella term used to describe disorders that involve dysfunction of peripheral nerves, the neuromuscular junction, or skeletal muscle. Although this paper specifically reviews airway clearance pertaining to those with neuromuscular diseases (e.g., muscular dystrophy, spinal muscular atrophy, myasthenia gravis), most of its content is relevant to the management of patients with central nervous system disorders such as chronic static encephalopathy caused by trauma, metabolic or genetic abnormalities, congenital infection, or neonatal hypoxic-ischemic injury.

Clinical practice guideline appraisal and algorithm development to identify recommendations related to nursing practice for post-stroke dysphagia

AIMS AND OBJECTIVES

To assess the methodological quality of current clinical practice guidelines related to post-stroke dysphagia and develop an algorithm using nursing process as a framework for clinical nursing.

BACKGROUND

Dysphagia is a serious complication of stroke. Yet the recommendations related to nursing in guidelines have not been systematically sorted out, so they are difficult for nurses to use to guide clinical nursing practice.

DESIGN

Systematic review.

METHODS

A systematic review of literature was performed using the PRISMA Checklist. A systematic search for relevant guidelines published between 2017 and 2022 was conducted. Appraisal of Guidelines for Research and Evaluation II instrument was used to assess methodological quality. Recommendations related to nursing practice from high-quality guidelines were summarised and developed into an algorithm to provide reference for the standardised construction of nursing practice scheme.

RESULTS

991 records were initially identified from database searches and other sources. Finally, 10 guidelines were included, of which 5 were rated as high quality. A total of 27 recommendations from the 5 highest-scoring guidelines were summarised and used to develop an algorithm.

CONCLUSIONS

This study indicated deficiencies and variability in current available guidelines. Based on five high-quality guidelines, we developed an algorithm to facilitate nurses' adherence to guidelines and contribute to evidence-based nursing. In the future, high-quality guidelines, together with large-sample and multi-centre clinical researches are suggested to give more scientific and convincing evidence to nursing of post-stroke dysphagia.

RELEVANCE TO CLINICAL PRACTICE

The findings indicate that nursing process may provide a unified framework for standardised nursing of different diseases. Nursing leaders are recommended to adopt this algorithm in their units. In addition, nursing administrators and educators should promote the application of nursing diagnosis to help nurses foster nursing thinking mode.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public involvement in this review.

A systematic review and meta-analysis on the prevalence and clinical characteristics of dysphagia in patients with dermatomyositis

BACKGROUND

Dermatomyositis (DM) is a rare autoimmune disease characterized by distinctive skin rash, muscle inflammation with symmetrical and progressive muscle weakness, and elevated serum levels of muscle-associated enzymes. DM may affect skeletal muscles involved in swallowing, leading to dysphagia, which can negatively impact individual's physical and psychosocial well-being. Despite this, dysphagia in patients with DM remains poorly understood. This systematic review and meta-analysis aimed to evaluate the prevalence and clinical features of dysphagia in patients with DM and juvenile DM (JDM).

METHODS

Four electronic databases were systematically searched until September 2022. Studies with patients with DM or JDM and dysphagia were included. The pooled prevalence of all included studies was calculated, and the clinical characteristics of dysphagia were qualitatively analyzed.

KEY RESULTS

Thirty-nine studies with 3335 patients were included. The overall pooled prevalence of dysphagia was 32.3% (95% CI: 0.270, 0.373) in patients with DM and 37.7% (95% CI: -0.031, 0.785) in patients with JDM. Subgroup analyses revealed that Sweden had the highest prevalence (66.7% [95% CI: 0.289, 1.044]), whereas Tunisia had the lowest prevalence (14.3% [95% CI: -0.040, 0.326]). Moreover, South America had the highest prevalence (47.0% [95% CI: 0.401, 0.538]), whereas Africa had the lowest prevalence (14.3% [95% CI: -0.040, 0.326]). Dysphagia in patients with DM and JDM was characterized by both oropharyngeal and esophageal dysfunctions, with predominant difficulties in motility.

CONCLUSIONS & INFERENCES

Our findings showed that dysphagia affects one in three patients with DM or JDM. However, the documentation on the diagnosis and management of dysphagia in the literature is inadequate. Our results highlighted the need to use both clinical and instrumental assessments to evaluate swallowing function in this population.

Hemodynamic signal changes and functional connectivity in acute stroke patients with dysphagia during volitional swallowing: a pilot study

BACKGROUND

Dysphagia is one of the major post-stroke complications, understanding post-stroke changes in cortical excitability and promoting early remodeling of swallowing-related cortical areas to enable accurate treatment is essential for recovery of patients.

OBJECTIVES

We aimed to investigate hemodynamic signal changes and functional connectivity in acute stroke patients with dysphagia compared to age-matched healthy participants in response to volitional swallowing using functional near-infrared spectroscopy (fNIRS) in this pilot study.

METHODS

Patients with first-ever post-stroke dysphagia having an onset of 1-4 weeks and age-matched right-handed healthy subjects were recruited in our study. fNIRS with 47 channels was utilized to detect the oxyhemoglobin (HbO2 ) and reduced hemoglobin (HbR) concentration changes when volitional swallowing. Cohort analysis was performed by a one-sample t-test. Two-sample t-test was utilized to compare the difference in cortical activation between patients with post-stroke dysphagia and healthy subjects. Furthermore, the relative changes in the concentration of the HbO2 throughout the experimental procedure were extracted for the functional connectivity analysis. The Pearson correlation coefficients of the HbO2 concentration of each channel were analyzed on a time series, and then a Fisher Z transformation was then performed, and the transformed values were defined as the functional connection strengths between the channels.

RESULTS

In this present study, a total of nine patients with acute post-stroke dysphagia were enrolled in the patient group and nine age-matched healthy participants in the healthy control group. Our study observed that the extensive regions of the cerebral cortex were activated in the healthy control group, while the activation area of patient group's cortical regions was quite limited. The mean functional connectivity strength of participants was 0.485 ± 0.105 in the healthy control group, and 0.252 ± 0.146 in the patient group, with a significant difference between the two groups (p = 0.001).

CONCLUSION

Compared to the healthy individuals, cerebral cortex regions of acute stroke patients were only marginally activated during volitional swallowing task, and the average functional connectivity strength of cortical network in patients was relatively weaker.

Dysphagia in Neurological Disorders

Dysphagia is a common symptom in many neurologic disorders. Patients with oropharyngeal dysphagia present with difficulties when they start to swallow, often with coughing and choking; whereas patients with esophageal dysphagia describe the feeling that swallowed food stops in the chest. Chronic neurologic diseases such stroke, Parkinson's disease, or dementia often have dysphagia as a symptom, particularly oropharyngeal dysphagia, and the term "neurogenic dysphagia" is often used. A disruption of the sophisticated, integrated sensorimotor swallowing system is usually the main reason behind dysphagia. Dysphagia can be associated with aspiration leading to aspiration pneumonia, and chronic dysphagia can lead to weight loss and malnutrition. Patients with dysphagia, when accurately and promptly diagnosed through medical history, physical examination, and diagnostic tests, often can be treated and experience improved quality of life. The pathophysiological mechanisms behind dysphagia, its diagnosis, and potential treatments are discussed in this manuscript.

Incidence and Risk Factors for Dysphagia Following Cerebellar Stroke: a Retrospective Cohort Study

The cerebellum is known to play a supportive role in swallowing-related functions; however, wide discrepancies about the incidence rate of swallowing disorders following cerebellar strokes exist within the literature. This study aimed to investigate the incidence rate of dysphagia and the factors which may affect the presence of dysphagia and clinical recovery in individuals diagnosed with cerebellar stroke. A retrospective chart audit of 1651 post-stroke patients (1049 males and 602 females) admitted with a cerebellar stroke to a comprehensive tertiary hospital in China was conducted. Data on demographics, medical, along with swallowing function assessment were collected. Differences between dysphagic and non-dysphagic groups were evaluated using t-tests and Pearson's chi-square test. Univariate logistic regression analysis was performed to establish factors associated with the presence of dysphagia. A total of 11.45% of participants were identified with dysphagia during inpatient admission. Individuals with mixed types of stroke, multiple lesions in the cerebellum, and ages older than 85 years old were more likely to develop dysphagia. Moreover, the prognosis of dysphagia following a cerebellar stroke was associated with lesions in different parts of the cerebellum. The cumulative recovery rates from the best to worse were the right hemisphere group, the cerebellum vermis or peduncle group, and both the hemisphere group and the left hemisphere group, respectively.

Parameters to Consider for Successful Medication Use in Older Adults - an AGePOP Review

Older adults are the main users of medicine and due to their multimorbidity are often faced/confronted with a complex medication management. This review article provides a brief overview on aspects of medication management such as maintaining a stock of the required medicine, understanding and following the instructions for use, coping with the primary and secondary packaging as well as preparation prior to use. The main focus however is on the drug intake itself and provides an overview about the current understanding of real life dosing conditions of older adults and geriatric patients. Furthermore, it elaborates the acceptability of dosage forms, in particular solid oral dosage forms as they represent the majority of dosage forms taken by these patient populations. An improved understanding of the needs of older adults and geriatric patients, their acceptability of various dosage forms and the circumstances under which they manage their medications, will make the design of more patient-centric drug products possible.

Utility of Dual Monitoring of the Lower Cranial Nerve Motor-Evoked Potentials Threshold Level Criterion to Predict Swallowing Function in Skull Base and Brainstem Surgery

PURPOSE

Evaluate the value of bilateral final/baseline threshold level changes of lower cranial nerve MEPs in postoperative swallowing function deterioration prediction.

METHODS

Bilateral lower cranial nerve motor-evoked potentials (MEPs) were recorded in 51 patients who underwent treatment for skull base and brainstem tumors. Corkscrew-like electrodes were positione 2 cm below C3/C4 and Cz. The MEPs were recorded from different muscle groups, including the posterior pharyngeal wall muscle, tongue muscle, genioglossus muscle, and cricothyroid muscle through paired needle electrodes. Swallowing function was assessed clinically using the Mann Assessment of Swallowing Ability score before and after the procedure at 7 days, 1 month, and 3 months.

RESULTS

Bilateral final/baseline threshold level increases in lower cranial nerve MEPs under the dual monitoring were significantly correlated with postoperative swallowing function deterioration ( r = 0.660 at 7 days, r = 0.735 at 1 month, and r = 0.717 at 3 months; p < 0.05). Bilateral final/baseline threshold level changes of more than 20% were recorded in 23 of the 51 patients, with 21 patients experiencing swallowing function deterioration postoperatively. The other 28 patients had bilateral threshold level changes of less than 20%, with 26 patients maintaining or improving their swallowing function, and 12 of those patients presented transient deterioration of swallowing function in the early postoperative period.

CONCLUSIONS

Dual monitoring of lower cranial nerves and their different muscle groups MEPs was a safe and effective way to predict postoperative swallowing function. An increase in bilateral final/baseline threshold level change of more than 20% was predictive of permanent swallowing deterioration, especially in patients with poor swallowing function preoperatively.

Primary site of constriction during the compression phase of cough in healthy young adults

Glottal closure has been considered as the primary constriction point during the compression phase (CP); however, vocal fold adduction alone cannot resist the high pressures, providing motivation to explore other mechanisms contributing to that resistance. The goal of this study was to identify site(s) and degree of constriction during the CP of cough of varying types in healthy young adults. Twenty-five healthy young participants participated in this study. The experimental protocol was comprised of: 1) baseline pulmonary function measures; 2) cough practice to establish weak, moderate and strong coughs; 3) voluntary and reflex cough assessments with fluoroscopy and airflow measures. We used a repeated measures ANOVA to identify whether there are differences in constriction ratio between cough types. There was a significant difference in constriction of varying cough types. Degree of constriction in all cough strengths showed that the glottis was the most constricted area, followed by the laryngeal vestibule, nasopharynx, hypopharynx, oropharynx, and cervical trachea, in order, but stronger cough resulted in more constriction in all areas compared to weaker cough. Degree of constriction in reflex cough showed a similar pattern though there was greater constriction in the oropharynx than the hypopharynx. Airflow measures in voluntary cough were consistent with previous findings. Differences in upper airway constriction during the compression phase of cough may be attributed to differences in motor control between reflex and voluntary cough, and the increased constriction seen during strong cough may reflect increased muscle recruitment during that task. In the future, we can use this knowledge to develop novel methods for cough rehabilitation.

Enteral Nutrition during Radiotherapy for Oropharyngeal Cancers: Prevalence and Prognostic Factors Based on HPV Status (A GETTEC Study)

Nutritional support during radiotherapy is crucial to tolerating and completing oropharyngeal squamous cell carcinoma (OPSCC) treatment. The impact of HPV status on nutritional support is debated. The objective was to evaluate the rate of Reactive Feeding Tube (RFT) use and determine its prognostic factors during definitive radiotherapy for OPSCC. All OPSCC patients treated from 2009 to 2014 were included in this multicentric retrospective study. The impact of tumor p16 status on the risk of RFT was assessed through multivariate analyses. Among the 543 patients, 103 patients required an RFT (19.0%). The use of RFT differed between centers (5% to 32.4%). In multivariate analysis, only tongue base involvement and concurrent chemotherapy were significantly associated with RFT (OR = 2.18 and 3.7, respectively). Tongue base involvement and concomitant chemotherapy were prognostic factors for RFT. HPV status was not a prognostic factor for enteral nutrition during radiotherapy for OPSCC.

The Role of the Cerebellum in Swallowing

Swallowing is a complex activity requiring a sophisticated system of neurological control from neurones within the brainstem, cerebral cortices and cerebellum. The cerebellum is a critical part of the brain responsible for the modulation of movements. It receives input from motor cortical and sensory areas and fine tunes these inputs to produce coordinated motor outputs. With respect to swallowing, numerous functional imaging studies have demonstrated increased activity in the cerebellum during the task of swallowing and damage to the cerebellum following differing pathological processes is associated with dysphagia. Single pulses of transcranial magnetic stimulation (TMS) have been applied to the cerebellum and have been shown to evoke motor responses in the pharynx. Moreover, repetitive TMS (rTMS) over the cerebellum can modulate cerebral motor (pharyngeal) cortical activity. Neurostimulation has allowed a better understanding of the connections that exist between the cerebellum and cerebral swallowing motor areas in health and provides a potential treatment for neurogenic dysphagia in illness. In this review we will examine what is currently known about the role of the cerebellum in the control of swallowing, explore new findings from neurostimulatory and imaging studies and provide an overview of the future clinical applications of cerebellar stimulation for treating dysphagia.

The effects of intermittent theta burst stimulation of the unilateral cerebellar hemisphere on swallowing-related brain regions in healthy subjects

Objective

We aimed to investigate the effects and mechanisms of swallowing-related brain regions using resting-state functional magnetic resonance imaging (rs-fMRI) in healthy subjects who underwent intermittent theta burst stimulation (iTBS) on dominant or non-dominant cerebellar hemispheres.

Methods

Thirty-nine healthy subjects were randomized into three groups that completed different iTBS protocols (dominant cerebellum group, non-dominant cerebellum group and sham group). Before iTBS, the resting motor threshold (rMT) was measured by single-pulse transcranial magnetic stimulation (sTMS) on the cerebellar representation of the suprahyoid muscles, and the dominant cerebellar hemisphere for swallowing was determined. Forty-eight hours after elution, iTBS protocols were completed: in the dominant cerebellum group, iTBS was administered to the dominant cerebellar hemisphere, and the non-dominant cerebellar hemisphere was given sham stimulation; in the non-dominant cerebellum group, iTBS was administered to the non-dominant cerebellar hemisphere, and sham stimulation was delivered to the dominant cerebellar hemisphere; in the sham group, sham stimulation was applied to the cerebellum bilaterally. Rs-fMRI was performed before and after iTBS stimulation to observe changes in the fractional amplitude of low-frequency fluctuation (fALFF) in the whole brain.

Results

Compared with baseline, the dominant cerebellum group showed increased fALFF in the ipsilateral cerebellum, and decreased fALFF in the ipsilateral middle temporal gyrus and contralateral precuneus after iTBS; the iTBS of the non-dominant cerebellum group induced increased fALFF in the ipsilateral superior frontal gyrus, the calcarine fissure and the surrounding cortex, and the contralateral inferior parietal lobule; and in the sham group, there was no significant difference in fALFF. Exploring the effects induced by iTBS among groups, the dominant cerebellum group showed decreased fALFF in the contralateral calcarine fissure, and surrounding cortex compared with the sham group.

Conclusion

Intermittent theta burst stimulation of the dominant cerebellar hemisphere for swallowing excited the ipsilateral cerebellum, and stimulation of the non-dominant cerebellar hemisphere increased the spontaneous neural activity of multiple cerebrocortical areas related to swallowing. In conclusion, regardless of which side of the cerebellum is stimulated, iTBS can facilitate part of the brain neural network related to swallowing. Our findings provide supporting evidence that cerebellar iTBS can be used as a potential method to modulate human swallowing movement.

Tongue base augmentation to improve swallow function in a cadaveric model

Objectives

To evaluate the feasibility of using Calcium Hydroxylapatite (CaHA) to augment the tongue base for patients with swallowing impairment due to tongue base atrophy.

Methods

A fresh human cadaver was obtained through the institution's body donation program and baseline lateral fluoroscopic images were obtained. A total of 2 mL of CaHA (Prolaryn Plus) were injected into three sites of the base of tongue under flexible endoscopic guidance with a 22G, 1.5-inch needle (Monoject, Cardinal Health). Post-lateral fluoroscopic images were obtained and pharyngeal area (cm²) and tongue base to pharyngeal wall distance (cm) was measured pre- and postinjection using SwallowTail fluoroscopic measurement software (Belldev Medical).

Results

The procedure was easily performed and the CaHA flowed easily into the cadaveric tongue without evidence of extrusion. The pre-procedural pharyngeal area decreased from 24.36 to 23.14 cm after augmentation. The base of tongue to pharyngeal wall distance decreased from 2.21 to 1.32 cm after augmentation.

Conclusion

Tongue base augmentation with CaHA may be a feasible adjuvant therapy for the management of swallowing impairment secondary to tongue base atrophy. Further investigation is necessary to evaluate the clinical safety and efficacy.

Level of Evidence

4.

Deep Learning for Automatic Hyoid Tracking in Videofluoroscopic Swallow Studies

The hyoid bone excursion is one of the most important gauges of larynx elevation in swallowing, contributing to airway protection and bolus passage into the esophagus. However, the implications of various parameters of hyoid bone excursion, such as the horizontal or vertical displacement and velocity, remain elusive and raise the need for a tool providing automatic kinematics analysis. Several conventional and deep learning-based models have been applied automatically to track the hyoid bone, but previous methods either require partial manual localization or do not transform the trajectory by anatomic axis. This work describes a convolutional neural network-based algorithm featuring fully automatic hyoid bone localization and tracking and spine axis determination. The algorithm automatically estimates the hyoid bone trajectory and calculates several physical quantities, including the average velocity and displacement in horizontal or vertical anatomic axis. The model was trained in a dataset of 365 videos of videofluoroscopic swallowing from 189 patients in a tertiary medical center and tested using 44 videos from 44 patients with different dysphagia etiologies. The algorithm showed high detection rates for the hyoid bone. The results showed excellent inter-rater reliability for hyoid bone detection, good-to-excellent inter-rater reliability for calculating the maximal displacement and the average velocity of the hyoid bone in horizontal or vertical directions, and moderate-to-good reliability in calculating the average velocity in horizontal direction. The proposed algorithm allows for complete automatic kinematic analysis of hyoid bone excursion, providing a versatile tool with high potential for clinical applications.

Brain functional activity of swallowing: A meta-analysis of functional magnetic resonance imaging

BACKGROUND

Swallowing is one of the most important activities in our life and serves the dual roles of nutritional intake and eating enjoyment.

OBJECTIVE

The study aimed to conduct a meta-analysis to investigate the brain activity of swallowing.

METHODS

Studies of swallowing using functional magnetic resonance imaging were reviewed in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Database (VIP) and Wan Fang before 30 November 2021. Two authors analysed the studies for eligibility criteria. The final inclusion of studies was decided by consensus. An activation likelihood estimation (ALE) meta-analysis of these studies was performed with GingerALE, including 16 studies.

RESULTS

For swallowing, clusters with high activation likelihood were found in the bilateral insula, bilateral pre-central gyrus, bilateral post-central gyrus, left transverse temporal gyrus, right medial front gyrus, bilateral inferior frontal gyrus and bilateral cingulate gyrus. For water swallowing, clusters with high activation likelihood were found in the bilateral inferior frontal gyrus and the left pre-central gyrus. For saliva swallowing, clusters with high activation likelihood were found in the bilateral cingulate gyrus, bilateral pre-central gyrus, left post-central gyrus and left transverse gyrus.

CONCLUSION

This meta-analysis reflects that swallowing is regulated by both sensory and motor cortex, and saliva swallowing activates more brain areas than water swallowing, which would promote our knowledge of swallowing and provide some direction for clinical and other research.

A Within-Subject Comparison of Face-to-Face and Telemedicine Screening Using the Timed Water Swallow Test (TWST) and the Test of Mastication and Swallowing of Solids (TOMASS)

The Timed Water Swallow Test (TWST) and the Test of Mastication of Solids (TOMASS) are dysphagia screening procedures that have been shown to be reliably assessed from video. The reliability of the procedures performed over telemedicine has not previously been assessed. TWST and TOMASS outcomes in two situations (both face-to-face and over telemedicine) were compared for 48 participants (aged 60-90; 27 with clinical conditions and 21 older persons). Both testing situation and test performed order were randomized, and all assessment procedures were performed within 3 h of each other. The results indicated a high level of agreement between face-to-face and telemedicine screening outcomes for TWST and TOMASS, respectively. The assessments indicated an 83% and 76% agreement in classifications of individual participants as within or outside normal limits for the TWST and TOMASS for the two test situations. The TWST showed a balanced distribution in differing classification in telemedicine (0.16-0.19 error rates). The TOMASS procedure classified more participants as outside normal limits over telemedicine compared to face-to-face administration. Agreement in the observed number of swallows was substantially lower than other outcome measures, which is attributed to increased difficulty in observing this property over video. Most participants (60%) reported that they would prefer telemedicine over face-to-face assessments, and 90% viewed the procedure as more accessible than expected. All participants were satisfied with the telemedicine procedures. The results suggest that clinical assessment of dysphagia over telemedicine using the TWST and TOMASS are viable alternatives to face-to-face administration of the procedures.

Application of Ultrasonography in Neurogenic Dysphagia: A Systematic Review

Swallowing disorders are common in neurological diseases, with dysphagia representing one of the most prevalent complications that may cause poor quality of life, reduce independence, and increase mortality. Rapid identification of dysphagia is necessary to reduce the risk of penetration and aspiration, and to early start rehabilitation protocols. Among the methods that can be used to evaluate dysphagia and its components, ultrasound imaging has been suggested to support the evaluation of dysphagia by providing measures of both static and dynamic anatomical components. The aim of this systematic review is to evaluate the usefulness of ultrasonography in neurogenic dysphagia according to current literature. From 2000 to 2020, 633 studies with the appropriate search terms for ultrasound and dysphagia were identified. After screening them, 10 studies were included in the qualitative analysis. Patients with the following neurologic conditions were studied with ultrasonography for dysphagia: Parkinson's disease, muscle dystrophy, amyotrophic lateral sclerosis, and stroke. The main outcomes of ultrasonography were swallowing muscles thickness (e.g., tongue), and dynamic measures such as hyoid displacement. The different protocols used in the studies, as well as their outcomes, did not allow to provide standard procedures and normative or cut-off values in the presented diseases. Because there are a variety of tools, methods, and techniques that have been used in the studies that were reviewed, it is difficult to evaluate them using established standards. However, ultrasonography correlates well with clinical evaluation of dysphagia and therefore has prognostic and rehabilitation potential. Future studies should aim to develop and utilize a common interdisciplinary protocol that includes standard procedures and outcomes to define normative values applicable in the different conditions.

Pediatric Dysphagia: A Look Into the Training Received During Graduate Speech-Language Pathology Programs to Support This Population

PURPOSE

The purpose of this study was to examine academic preparation in pediatric swallowing and feeding, specifically, how speech-language pathology graduate programs were addressing pediatric swallowing and feeding, both academically and clinically, prior to guideline changes and modifications in 2020 due to updates and the global health pandemic.

METHOD

To gain a rounded image of speech-language pathology academic programs, two different methodological approaches were utilized. First, courses from 272 accredited programs were analyzed. Second, survey results from 100 participants were analyzed to investigate clinical clock hours and experiences received during participation in a graduate speech-language pathology academic program.

RESULTS

Less than 1% (0.4%) of academic courses analyzed were categorized as pediatric swallowing and feeding. Greater than 90% of participants reported receiving 20 hr or less in pediatric dysphagia, assessment, or treatment. Sixty percent of participants reported not feeling well prepared at all to provide pediatric swallowing and feeding services.

CONCLUSIONS

There are a growing number of children requiring swallowing and feeding services, a trend that looks to continue its rise. Pediatric dysphagia is a complex area requiring unique knowledge and skills. Academic programs have a responsibility to their students, and the individuals requiring speech-language pathology services, to provide experiences that allow for knowledge and skill development across the entire scope of practice and life span.

Effects of bilateral cerebellar repetitive transcranial magnetic stimulation in poststroke dysphagia: A randomized sham-controlled trial

BACKGROUND

Although increasing evidence indicates that cerebellar repetitive transcranial magnetic stimulation (rTMS) may be beneficial in the treatment of dysphagia, its clinical efficacy is still uncertain.

OBJECTIVE

To evaluate the effect of high-frequency cerebellar rTMS on poststroke dysphagia.

METHODS

This was a randomized, sham-controlled, double-blind trial. A total of eighty-four study participants were randomly assigned into the cerebellum and control groups. The cerebellum group received bilateral 10 Hz rTMS treatment of the pharyngeal motor area of the cerebellum. The control group was administered with sham rTMS of the pharyngeal motor area of the cerebellum. All patients underwent the same conventional swallowing rehabilitation training after the intervention 5 days a week for a total of 10 days. Assessment of swallowing function was done before treatment (baseline), after treatment (2 weeks), and during follow-up (2 weeks after treatment) using the Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS) and the Penetration-Aspiration Scale (PAS).

RESULTS

The interaction between time and intervention had a significant effect on PAS (P < 0.001) and FEDSS (P < 0.001). Compared to the control group, the cerebellum group exhibited significantly improved clinical swallowing function scores (PAS: P = 0.007, FEDSS: P = 0.002).

CONCLUSION

Bilateral cerebellar rTMS is a potential new neurorehabilitation technique for post-stroke dysphagia. Studies should aim at investigating the therapeutic mechanism of cerebellar rTMS and improve this technique.

Alterations in deglutition in children with congenital Zika virus syndrome

PURPOSE

To characterize swallowing in children with congenital Zika virus syndrome in comparison to typical children.

METHODS

This cross-sectional study enrolled 45 children diagnosed with congenital Zika virus syndrome and 45 others with typical development. Swallowing was evaluated through clinical feeding evaluations Protocolo de Avaliação Clínica da Disfagia Pediátrica and using acoustic swallowing parameters (Doppler sonar).

RESULTS

The mean age of children with congenital Zika virus syndrome was 26.69 ± 4.46 months and the mean head circumference was 29.20 ± 1.98 cm. Moderate/severe oropharyngeal dysphagia was found in 32(71.1%) of the children with congenital Zika virus syndrome. Significant differences were found between the groups on clinical evaluation: Children with congenital Zika virus syndrome presented insufficient lip closure 42(93.3%) and altered tonus of the tongue 35(77.8%) and cheeks 34(75.6%). In the children in the comparison group, only 6(13.3%) presented insufficient lip closure and 1(2.2%) had inadequate tongue posture. Changes during swallowing with liquid and spoonable food were not observed in the comparison group. When liquid/food was offered, affected children presented difficulties in sipping movements 14(77.8%) and lip/spoon contact 35(75%). The presence of residual food in the oral cavity after swallowing 38(86.4%) and clinical signs indicative of laryngotracheal penetration/aspiration, such as coughing, gagging and/or labored breathing, were also notable. No differences were found between the groups with regard to the acoustic parameters evaluated instrumentally.

CONCLUSION

Children with congenital Zika virus syndrome present alterations in the oral phase of swallowing, as well as clinical signs indicative of pharyngeal phase impairment.

Physiological Mechanisms and Associated Pathophysiology of Dysphagia in Older Adults

Dysphagia can be a common secondary sequela of neurological and neurodegenerative disorders in older adults. Early screening, identification, and management of dysphagia is essential to avoid serious complications, including malnutrition, dehydration, aspiration pneumonia; and promote quality of life. Although individuals of all ages may experience swallowing difficulties, dysphagia and its complications are more common in older adults. This literature review aims to provide an overview of the physiological mechanisms of normal swallowing in healthy individuals and age-related changes to swallowing function, the pathophysiology of dysphagia associated with three common neurological disorders affecting older adults (stroke, Parkinson's disease, and dementia), and implications for interdisciplinary clinical practice. Increased awareness of these issues may contribute to a more timely and efficient identification of older adults with dysphagia and to improve overall dysphagia management.

Swallowing Apraxia Post Ischemic Stroke

A 55-year-old male patient with a known medical history of diabetes mellitus type 2 and treated lymphoma was first admitted with a sudden left-sided facial asymmetry and mouth deviation to the left side with no other neurological symptoms. A Computerized Tomography (CT) scan of the brain showed acute infarct and small left basal ganglia old lacunar infarction. He was discharged on a dual antiplatelet. One week later, the patient's condition had worsened and, therefore, was admitted with an impression of ischemic stroke. A bedside swallowing assessment, VFSS, and FEES study were conducted to diagnose this case. The bedside assessment did not reveal any sensory or motor deficits in his oral cavity and the FEES examination was also unable to rule out pharyngeal dysphagia. However, a videofluoroscopic swallowing study (VFSS) revealed a significant dysfunction of oral preparation and oral phases and presented difficulty initiating the pharyngeal phase. Given these features, we believe that this swallowing difficulty is caused by swallowing apraxia. This case provides additional information and understanding on management from the swallowing side.

The therapeutic effect of capsaicin on oropharyngeal dysphagia: A systematic review and meta-analysis

OBJECTIVES

Capsaicin is a specific agonist of TRPV1 (multimodal sensory receptor), which improves oropharyngeal dysphagia by increasing sensory input from the oropharynx and hypopharynx and by increasing repetitive stimulation of the cerebral cortex. The aim of this systematic review was to evaluate the therapeutic effect of capsaicin on swallowing disorders in stroke patients and the elderly.

METHOD

We searched Medline, Embase, PubMed, and Cochrane Library databases. We used the Mesh terms search database to screen all clinical trials that complied with the inclusion criteria. Studies were subjected to literature screening, quality assessment, and data extraction to remove studies that did not meet the inclusion criteria. After literature screening, quality assessment, and data extraction, a systematic review and meta-analysis of the included study were performed.

RESULTS

This systematic review and meta-analysis were prospectively registered on PROSPERO under registration number CRD42022313958. Five high-quality randomized controlled trials were ultimately included. The results of our meta-analysis showed a more significant reduction in swallowing function score change in the capsaicin group compared to the control group [SMD = -1.30, 95% CI: (-2.35, -0.25), P = 0.01] and on the Water swallowing test the improvement was significantly higher in the capsaicin group [RR = 2.46, 95% CI: (1.73, 3.50), P < 0.0001].

CONCLUSIONS

Although the results of our meta-analysis showed that capsaicin improved swallowing function, most studies had an unclear bias and included few studies. More studies are needed to support this in the future.

SYSTEMATIC REVIEW REGISTRATION

www.crd.york.ac.uk/prospero/display_record.php?RecordID=304061, identifier: 304061.