Guide to Enhancing Swallowing Initiation: Insights from Findings in Healthy Subjects and Dysphagic Patients

The impact of physical therapy on dysphagia in neurological diseases: a review

A neurogenic dysphagia is dysphagia caused by problems with the central and peripheral nervous systems, is particularly prevalent in conditions such as Parkinson's disease and stroke. It significantly impacts the quality of life for affected individuals and causes additional burdens, such as malnutrition, aspiration pneumonia, asphyxia, or even death from choking due to improper eating. Physical therapy offers a non-invasive treatment with high efficacy and low cost. Evidence supporting the use of physical therapy in dysphagia treatment is increasing, including techniques such as neuromuscular electrical stimulation, sensory stimulation, transcranial direct current stimulation, and repetitive transcranial magnetic stimulation. While initial studies have shown promising results, the effectiveness of specific treatment regimens still requires further validation. At present, there is a lack of scientific evidence to guide patient selection, develop appropriate treatment regimens, and accurately evaluate treatment outcomes. Therefore, the primary objectives of this review are to review the results of existing research, summarize the application of physical therapy in dysphagia management, we also discussed the mechanisms and treatments of physical therapy for neurogenic dysphagia.

Neuromuscular electrical stimulation improves swallowing initiation in patients with post-stroke dysphagia

Objective

More than half of post-stroke patients develop dysphagia, which manifests as delayed swallowing and is associated with a high risk of aspiration. In this study, we aimed to investigate the immediate effect of neuromuscular electrical stimulation (NMES) on swallowing initiation in post-stroke patients using videofluoroscopic swallowing study (VFSS) data.

Materials and methods

This randomized, self-controlled crossover study included 35 patients with post-stroke dysphagia. All selected patients received real and sham NMES while swallowing 5 ml of thin liquid. Participants completed the conditions in random order, with a 10-min interval between conditions. The primary evaluation indicators included the Modified Barium Swallow Impairment Profile-6 (MBSImp-6) and Penetration-Aspiration Scale (PAS). Secondary indicators included oral transit time (OTT), pharyngeal transit time (PTT), and laryngeal closure duration (LCD).

Results

Modified Barium Swallow Impairment Profile-6 (P = 0.008) and PAS (P < 0.001) scores were significantly lower in the Real-NMES condition than in the Sham-NMES condition. OTT (P < 0.001) was also significantly shorter during Real-NMES than during Sham-NMES. However, LCD (P = 0.225) and PTT (P = 0.161) did not significantly differ between the two conditions.

Conclusion

Neuromuscular electrical stimulation may represent a supplementary approach for promoting early feeding training in patients with post-stroke dysphagia.

Clinical trial registration

[https://clinicaltrials.gov/], identifier [ChiCTR2100052464].

Bioelectrical Signals for the Diagnosis and Therapy of Functional Gastrointestinal Disorders

Coordinated contractions and motility patterns unique to each gastrointestinal organ facilitate the digestive process. These motor activities are coordinated by bioelectrical events, sensory and motor nerves, and hormones. The motility problems in the gastrointestinal tract known as functional gastrointestinal disorders (FGIDs) are generally caused by impaired neuromuscular activity and are highly prevalent. Their diagnosis is challenging as symptoms are often vague and difficult to localize. Therefore, the underlying pathophysiological factors remain unknown. However, there is an increasing level of research and clinical evidence suggesting a link between FGIDs and altered bioelectrical activity. In addition, electroceuticals (bioelectrical therapies to treat diseases) have recently gained significant interest. This paper gives an overview of bioelectrical signatures of gastrointestinal organs with normal and/or impaired motility patterns and bioelectrical therapies that have been developed for treating FGIDs. The existing research evidence suggests that bioelectrical activities could potentially help to identify the diverse etiologies of FGIDs and overcome the drawbacks of the current clinically adapted methods. Moreover, electroceuticals could potentially be effective in the treatment of FGIDs and replace the limited existing conventional therapies which often attempt to treat the symptoms rather than the underlying condition.

Management of Dehydration in Patients Suffering Swallowing Difficulties

Swallowing difficulties, also called dysphagia, can have various causes and may occur at many points in the swallowing process. The treatment and rehabilitation of dysphagia represent a major interdisciplinary and multiprofessional challenge. In dysphagic patients, dehydration is frequent and often accelerated as a result of limited fluid intake. This condition results from loss of water from the intracellular space, disturbing the normal levels of electrolytes and fluid interfering with metabolic processes and body functions. Dehydration is associated with increased morbidity and mortality rates. Dysphagic patients at risk of dehydration thus require close monitoring of their hydration state, and existing imbalances should be addressed quickly. This review gives an overview on dehydration, as well as its pathophysiology, risk factors, and clinical signs/symptoms in general. Available management strategies of dehydration are presented for oral, enteral, and parenteral fluid replacement.

Breathing pattern during sequential swallowing in healthy adult humans

Sequential liquid swallowing is a common daily occurrence during which coordination of deglutition and breathing are highly regulated to avoid pulmonary aspiration and to maintain hematosis. We studied the effects of sequential water swallowing (SWS) at fixed swallowing rates and with regular succession of swallows on respiration in healthy subjects. Thirty-one normal adults (19 men, 12 women) with a mean age of 27.96 ± 3.68 yr were explored at rest and during SWS (at 12 and 24 swallows/min). Respiration was recorded by intranasal air pressure changes and timing of deglutition by an acoustic method. Oxygen saturation [arterial O₂ saturation from pulse oximetry ( SpO2 )] was monitored with a finger probe. During SWS, we determined the respiratory phase (inspiration or expiration) before and after each ingestion cycle (IC; period of sustained apnea including 1 or more swallows). We also measured inspiratory time (TI), expiratory time (TE), respiratory cycle duration (TT), respiratory rate (RR) and SpO2 at rest and during SWS. We showed that respiration was interrupted by sequential swallows determining a succession of ICs that were often preceded and followed by expiration. During SWS, TI decreased and TE increased compared with rest ( P < 0.01). However, TT, RR, and SpO2 did not change. It seems that the preferential coupling of swallowing with expiration during SWS is favored by an increase in TE to ensure airway protection, although the repetitive swallows, RR, and SpO2 were not altered during SWS. These data may be useful to study the effects of aging and pathological conditions on swallowing and breathing coordination during SWS. NEW & NOTEWORTHY Sequential water swallowing induces ingestion cycles that are often preceded and followed by expiration. Moreover, inspiratory time decreases and expiratory time increases during sequential swallowing compared with rest without changes in ventilatory cycle duration, respiratory rate, and oxygen saturation.