Electrokinesiographic Study of Oropharyngeal Swallowing in Neurogenic Dysphagia

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.

Dynamic suprahyoid muscle ultrasound in assessing oropharyngeal dysphagia in neurological disorders

BACKGROUND

Appropriate evaluation and management of dysphagia are essential in neurological disorders. However, there is currently a lack of a simple yet reliable method for dysphagia evaluation.

AIM

This study aimed to investigate the usefulness of new dynamic M-mode ultrasonography (US) parameters of suprahyoid muscle (SHM) to evaluate dysphagia.

DESIGN

Prospective observational, cross-sectional study.

SETTING

Inpatient setting at neurology department of tertiary medical center.

POPULATION

A total of 89 patients with dysphagia and 175 healthy volunteers were enrolled in the study. Patients were subdivided into mild and severe dysphagia groups depending on the need for dietary changes and disease classification, which included amyotrophic lateral sclerosis, peripheral neuromuscular diseases, and stroke.

METHODS

Dynamic M-mode US was performed during swallowing to obtain the SHM thickness (the baseline thickness of the SHM), SHM displacement (peak-to-peak amplitude of SHM movement), SHM difference (SHM displacement - SHM thickness), SHM ratio (SHM displacement/SHM thickness), peak-to-peak time, and total duration. A videofluoroscopic swallowing study (VFSS) was performed.

RESULTS

Significant differences were found in SHM displacement and SHM difference according to dysphagia severity (P<0.001). The SHM ratio, total duration (P<0.001), and peak-to-peak time (P=0.001) differed significantly according to the patients' underlying diseases. The pharyngeal delay time and penetration-aspiration scale from the VFSS demonstrated significant negative correlations with SHM displacement and difference (P<0.001). By combining SHM difference and total duration, patients with dysphagia could be distinguished from healthy controls, with the highest negative predictive value of 95.6%.

CONCLUSIONS

Dynamic M-mode US of the SHM provided added value in evaluating the severity of dysphagia and differentiating swallowing mechanics of dysphagia related to underlying neurological disorders.

CLINICAL REHABILITATION IMPACT

Dynamic M-mode US of the SHM can serve as a supportive tool for rapid screening and repetitive follow-up of patients with dysphagia, which would contribute to dysphagia rehabilitation in patients with various neurological disorders.

Effect of respiratory training on swallowing function in swallowing disorders: a systematic review and meta-analysis

PURPOSE

To determine the clinical efficacy of different respiratory training interventions on swallowing function in patients with swallowing disorders through the systematic review.

METHODS

We reviewed the literature regarding the application of respiratory training therapy in patients with swallowing disorders, followed by a PRISMA search of published literature in five databases (PubMed, Web of Science, The Cochrane Library, CINAHL and EMBASE) in December 2022. Two reviewers performed study selection, quality evaluation, and risk of bias, followed by data extraction and detailed analysis.

RESULTS

A total of six randomized controlled studies with a total sample size of 193 cases were included. Respiratory training improved swallowing safety (PAS (n = 151, SMD = 0.69, 95% CI - 1.11 to - 0.26, I2 = 36, p < 0.001)) and swallowing efficiency [residual (n = 63, SMD = 1.67, 95% CI - 2.26 to - 1.09, I2 = 23%, p < 0.001)] compared to control groups. The results of the qualitative analysis conducted in this study revealed that respiratory training enhanced hyoid bone movement but had no effect on swallowing quality of life.

CONCLUSIONS

Respiratory training interventions may improve swallowing safety and efficiency in patients with dysphagia. However, the level of evidence is low, and there is a limited amount of research on the effectiveness and physiology of this intervention to improve swallowing function. In the future, there is a need to expand clinical studies, standardize measurement tools, and improve study protocols.

Evaluating the effectiveness of video-game based swallowing function training in patients with dysphagia: study protocol for a randomized controlled trial

BACKGROUND

Dysphagia can lead to serious complications such as aspiration and aspiration pneumonia, timely and effective rehabilitation training can improve the swallowing function of patients. However, the conventional rehabilitation training methods used in clinical settings have shortcomings such as poor adherence of patients. We present the study design of a randomized controlled trial that evaluated whether video-game based swallowing rehabilitation training can effectively improve swallowing in patients with dysphagia and whether it has additional benefits compared with conventional training methods to improve swallowing function and training compliance among patients with dysphagia.

METHODS

A randomized controlled trial with 4 weeks of intervention and 4 weeks of follow-up will be conducted in a rehabilitation center in Beijing, China. We will enroll 78 patients aged 18-80 years with dysphagia. Participants will be randomly assigned to the experimental group (video-game based swallowing function training) and the control group (conventional swallowing function training). All participants will receive 30 min of training per day, 5 times per week, for a total of 4 weeks. The primary outcome is swallowing function. Secondary outcomes include patients' quality of life, training compliance, and training satisfaction. Outcomes are assessed at baseline (pre-treatment), 4 weeks of treatment (post-treatment), and 8 weeks (follow-up), and the assessor is not aware of the participants' grouping.

DISCUSSION

The protocol describes a new rehabilitation training method for dysphagia, which involves participant eligibility recruitment, recruitment strategies, and data analysis plan. The results of the study will inform the rehabilitation training and clinical care management of swallowing function in patients with dysphagia.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05978700. Registered on 28 July 2023.

Retrograde Cricopharyngeus Dysfunction effectively treated with low dose botulinum toxin. A case report from Italy

A large constellation of hitherto unexplained symptoms including inability to burp, gurgling noises from the chest and lower neck, abdominal bloating, flatulence, painful hiccups and emetophobia was defined as Retrograde Cricopharyngeus Dysfunction (R-CPD) in 2019. First choice treatment of R-CPD involves injection of botulinum toxin into the cricopharyngeus muscle under local or general anesthesia. This treatment has been found to be effective in the vast majority of subjects, with limited adverse events and prolonged therapeutic effects. Notwithstanding, R-CPD is still a poorly understood and underestimated disease, and a specific therapeutic dosage range of botulinum toxin (BT) has not been yet established. In this report, we describe the first case of R-CPD diagnosed in Italy, successfully treated with unilateral, anesthesia-free injection of 10 units of onabotulinum toxin into the cricopharyngeus muscle, representing the lowest dose reported to date.

Assessment and treatment of neurogenic dysphagia in stroke and Parkinson's disease

PURPOSE OF REVIEW

Neurogenic dysphagia worsens quality of life and prognosis of patients with different neurological disorders. Management of neurogenic dysphagia can be challenging. This review provides a comprehensive overview of current evidence on screening, diagnosis, and treatment of neurogenic dysphagia in stroke and Parkinson's disease, suggesting clues for clinical practice.

RECENT FINDINGS

The pros and cons of diagnostic techniques are discussed in the light of updated evidence. Findings from recent meta-analyses of different treatment approaches, including traditional dysphagia therapy, peripheral and central neurostimulation techniques, and treatment with botulinum toxin, are critically discussed, emphasizing inconsistencies and controversial issues.

SUMMARY

Screening tests and clinical swallow examination should be routinely performed in neurological patients at risk for dysphagia. In patients testing positive for dysphagia, first-line instrumental investigations, represented by fiberoptic endoscopic evaluation of swallowing or videofluoroscopic swallow study, should be performed to confirm the presence of dysphagia, to assess its severity, and to inform the treatment. Second-line and third-line instrumental methods can be used in selected patients to clarify specific pathophysiological aspects of oropharyngeal dysphagia. Treatment strategies should be personalized, and combination of traditional dysphagia therapy with innovative treatment approaches may increase the chance of restoring effective and safe swallowing.