Mechanism Of Dysphagia Research Articles

Mapping research trends regarding the mechanism of dysphagia from 1993 to 2023: a bibliometrics study and visualization analysis.

As a common consequence of various neurogenic disorders, dysphagia has a significant impact on the quality of life for patients. To promote the development the field of swallowing, it will be helpful to clarify the pathological and therapeutic mechanisms of dysphagia. Through visual analysis of related papers from 1993 to 2023 in the Web of Science Core Collection (WoSCC) database, the research status and development trend of the pathogenesis of dysphagia were discussed. The co-occurrence study was finished using CiteSpace 6.2 R4 software, including keywords, countries, institutions, and authors. Finally, 1,184 studies satisfied the inclusion requirements. The findings of the visualization analysis suggested that aspiration and gastroesophageal reflux disease would be the areas of greatest interest for researchers studying the mechanism of dysphagia. As for the latest occurred research trends, fMRI, signals and machine learning emerging into the field of view of researchers. Based on an analysis of country co-occurrence, United States, Japan and China rank the top three, in terms of the number of publications on dysphagia. University System of Ohio is the organization that has published the most amount of articles regarding the mechanism of dysphagia. Other highly published schools in the top three include State University System of Florida and Northwestern University. For the prolific authors, German, Rebecca Z published the most articles at present, whose own research team working closely together. Several closely cooperating research teams have been formed at present, including the teams centered around German, Rebecca Z, Warnecke, Tobias and Hamdy Shaheen. This study intuitively analyzed the current research status of the mechanism of dysphagia, provided researchers with research hotspots in this field.

Diagnosis and treatment of dysphagia

Background: Dysphagia refers to an abnormality in the process of transporting food from the mouth to the stomach. Patients with dysphagia have a high risk of airway aspiration, which can often lead to fatal complications such as pneumonia and asphyxia. Recently, interest in the clinical importance of dysphagia has increased in the medical community and society at large.Current Concepts: Dysphagia can be caused by neurological diseases such as stroke and brain injury, or by non-neurological diseases such as head and neck cancer or diverticulum. Diagnosis is mainly performed using videofluoroscopic swallowing study or endoscopic evaluation of swallowing based on a detailed history and physical examination, scintigraphy or esophageal manometry may also be helpful. Recently developed imaging technology using 3-dimensional computed tomography and dynamic magnetic resonance imaging has been implemented. Treatment of dysphagia can be divided into compensatory and facilitative rehabilitation techniques. The most important principle for successful treatment of dysphagia is that it should be performed with a multidisciplinary team approach.Discussion and Conclusion: Dysphagia is an important problem that can seriously impair the patients’ quality of life. Although the general public and medical professionals are interested in dysphagia, many unknown aspects exist regarding the mechanism of dysphagia, and few treatments have been sufficiently proven in terms of safety and effectiveness. Therefore, much attention and effort is still required.

Correlation between Respiratory Dysfunction and Dysphagia in Individuals with Acute Traumatic Cervical Spinal Cord Injury.

Aspiration pneumonia is one of the most frequent and fatal life-threatening complications among individuals with acute traumatic cervical spinal cord injury (CSCI). However, the mechanism of dysphagia among individuals with CSCI is not well understood. Morbidity and mortality associated with CSCI may result from the interplay between respiratory dysfunction and dysphagia. This study aimed to elucidate the effect of respiratory dysfunction on the swallowing function of individuals with acute traumatic CSCI. A prospective cohort study was conducted involving 54 individuals with acute traumatic CSCI who were admitted within 2 weeks following injury. Dysphagia was evaluated using the Dysphagia Severity Scale (DSS) and the Functional Oral Intake Scale (FOIS). Respiratory function was evaluated by measuring the cough peak flow (CPF), forced expiratory volume in 1 s (FEV1.0), FEV1.0/forced vital capacity (FEV1.0%), and percent vital capacity (%VC). We recorded these parameters at weeks 2, 4, 8, and 12 following injury and analyzed pertinent changes over time and significant correlations. Among 54 individuals (46 men and 8 women) recruited in this study, 48 (88.9%) had restrictive ventilatory impairment and 17 (31.5%) had severe dysphagia (DSS level 1-4) 2 weeks following injury. However, respiratory function and swallowing function significantly improved thereafter. CPF, FEV1.0, and %VC were significantly correlated with the severity of dysphagia during each period. Restrictive ventilatory impairment, poor cough force, and dysphagia are closely related, and the evaluation of respiratory function plays an important role in evaluating dysphagia.

The molecular mechanism of the transcriptional activator SWI regulating gene ARID1B affecting swallowing dysfunction after stroke in rats.

Background: After a stroke, more than 50% of patients are suffering from dysphagia. Because the swallowing dysfunction is closely related to some neural pathways, the probing of the neuro-molecular mechanism of dysphagia is very important for future diagnosis and treatment. Methods: Our study is a typical causal study with the purpose of exploring molecular mechanisms. In this study, a rat model of dysphagia after stroke was constructed, and ARID1B overexpression plasmid was injected into the rat body through tail vein injection. The number of swallows and the swallowing response time induced by distilled water in each group of rats on the 7 th and 14 th day after modeling were detected. After 14 days of successful model establishment, the rat brain tissues were collected, part of the brainstem nucleus tractus solitarius and nucleus suspicious tissues were analyzed with a Ca2+ fluorescent indicator to analyze the intracellular concentration of Ca2+. For a part of the brainstem nucleus tractus solitarius and suspected nucleus tissues, immunohistochemistry was used to analyze the expression characteristics of genes ARID1B and TACR1 related proteins. The cerebrospinal fluid of brain tissue was collected, and the expression of gene TAC1 related protein in cerebrospinal fluid was analyzed by ELISA. For a part of the brainstem nucleus tractus solitarius and suspicious nucleus tissues, western blot was used to analyze the expression of gene SMARCA1 related protein, protein UNC80 and NALCN. Results: The detection of swallowing characteristics and the detection of intracellular Ca2+ concentration indicate the serious impact of stroke on swallowing function. The protein expression showed a consistent trend, which also showed that the overexpression of gene ARID1B can improve swallowing function to a certain extent. Conclusion: Due to our experiments, the molecular mechanism related to dysphagia was explored to a certain extent. At the same time, we found that the overexpression of the gene ARID1B can improve the swallowing function.

Factors resulting in postoperative dysphagia following esophagectomy: a narrative review.

Esophagectomy is a technically involved surgery and can have significant postoperative morbidity. Although the mortality rate following esophagectomy has decreased in recent years, this surgical procedure has a relatively high complication rate compared to other surgeries to resect cancer. One of the most common complaints after esophagectomy is dysphagia. Dysphagia after esophagectomy can significantly affect quality of life. Dysphagia is a complication following esophagectomy that can lead to respiratory deterioration and death. The most common sites of postoperative dysphagia are the gastroesophageal anastomosis, gastric conduit, pylorus and the hiatus. Without appropriate treatment of dysphagia, malnutrition and dehydration can develop. These factors can lead to significant impacts to the overall health of a patient and increase mortality. A detailed literature review provided data to support diagnostic modalities and management strategies to treat postoperative dysphagia at these common areas. A systematic, evidence-based approach to diagnosis and treatment of postoperative dysphagia allows for prompt intervention and a decrease in morbidity and mortality. Treatment options for dysphagia vary, depending on the etiology. Based on the location and mechanism of dysphagia, options include stenting, dilation and surgical revision. Early treatment of dysphagia after esophagectomy can lessen the morbidity from this complication and improve quality of life.

Distension-contraction profile of peristalsis in patients with nutcracker esophagus.

High amplitude peristaltic esophageal contractions, that is, nutcracker esophagus, were originally described in association with "angina-like pain" of esophageal origin. However, significant number of nutcracker patients also suffer from dysphagia. High-resolution esophageal manometry (HRM) assesses only the contraction phase of peristalsis. The degree of esophageal distension during peristalsis is a surrogate of relaxation and can be measured from the intraluminal esophageal impedance measurements. Determine the amplitude of distension and temporal relationship between distension and contraction during swallow-induced peristalsis in nutcracker patients. HRM impedance (HRMZ) studies were performed and analyzed in 24 nutcracker and 30 normal subjects in the Trendelenburg position. A custom-built software calculated the numerical data of the amplitudes of distension and contraction, the area under the curve (AUC) of distension and contraction, and the temporal relationship between distension and contraction. In normal subjects, the distension peaks similar to contraction traverse sequentially the esophagus. The amplitude of contraction is greater in the nutcracker esophagus but the amplitude of distension and area under the curve of distension are smaller in patients compared to controls. Distension peaks are aligned closely with contraction in normal subjects, but in patients, the bolus travels faster to the distal esophagus, resulting in a smaller time interval between the onset of swallow and distension peak. Receiver operative characteristics (ROC) curve reveals high sensitivity and specificity of the above parameters in patients. Abnormalities in the distension phase of peristalsis are a possible mechanism of dysphagia in patients with nutcracker esophagus.

Mechanism of Dysphagia after Acute Traumatic Cervical Spinal Cord Injury.

Swallowing dysfunction, which may cause aspiration pneumonia, is one of the most important complications of treatment of traumatic cervical spinal cord injury (CSCI); however, the mechanism of dysphagia is not well understood. No previous studies have reported the association between morphological changes of the soft tissue and dysphagia. We aimed to determine the factors associated with severity of dysphagia after CSCI and elucidate its mechanism. We conducted a prospective analysis of patients with acute traumatic CSCI who were admitted within 2 weeks of the injury. Dysphagia was evaluated using the Dysphagia Severity Scale (DSS) 2 weeks after the injury. The widths of the retropharyngeal and retrotracheal spaces were measured to assess soft tissue damage owing to the injury using sagittal images of computed tomography. We also assessed age, surgery of the injured cervical spine, presence of tracheostomy, osteophyte behind the pharynx, level of injury, and motor score 2 weeks after the injury. A total of 136 persons met our criteria. Given that 44 persons were categorized under grades <5 of the DSS, which were defined as different types of aspirations, the incidence of aspiration was 32%. The multiple regression analysis revealed that age, motor score, tracheostomy, and retropharyngeal space were significantly associated with DSS. Severe paresis, tracheostomy, old age, and swelling of the retropharyngeal space were significantly affected by dysphagia after CSCI. Morphological changes in the pharynx, situated right behind the larynx, after the injury affects the mechanism of dysphagia.

Successful Treatment with the Chin-down Maneuver of Dysphagia Secondary to Descending Necrotizing Mediastinitis: A Case Study

ABSTRACTBackground:Descending necrotizing mediastinitis is a potentially fatal polymicrobial infection that often leads to dysphagia after treatment. Such dysphagia is likely the result of fibrosis and scarring from inflammatory changes in the fascial space. A case is presented in which the mechanism of dysphagia was verified using two-dimensional analysis of the muscle lengths of the suprahyoid and infrahyoid muscles. Case:A 57-year-old woman presented with a hyoid and laryngeal movement disorder with pharyngeal residue secondary to descending necrotizing mediastinitis. To treat this disorder, the chin-down maneuver was performed, and it immediately improved hyoid and laryngeal elevation and reduced pharyngeal residue at the epiglottic valleculae and pyriform sinus. Analysis of the mechanism of these improvements revealed that combined head and neck flexion, compared with neck flexion, decreased the distance between the origin and insertion (DOI) of the sternohyoid muscle (SM) and increased the muscle contraction rate and the maximum contraction duration of the geniohyoid muscle (GM) during swallowing. Discussion:In the present case, the patient had restrictions in extension of the SM that applied resistance to GM contraction. Compensation of this condition was achieved by combined head and neck flexion, which decreased the DOI of the SM, thereby improving the contractile function of the GM.

Posture-Dependent Dysphagia After Botulinum Toxin Type A Injection at Sternocleidomastoid in a Patient With Athetoid Cerebral Palsy.

Cervical dystonia is a common issue in patients with athetoid cerebral palsy. Botulinum toxin injection to dystonic cervical muscles is a well-recognized treatment option, but it is known to be associated with dysphagia. Previously reported cases of dysphagia after botulinum toxin injection to the sternocleidomastoid muscle were related to the regional spread of toxin to the pharyngeal muscles. We report a unique case of posture-dependent dysphagia due to preactivation of the suprahyoid and infrahyoid muscles to compensate for impaired head stabilization by the weakened sternocleidomastoid muscle while swallowing. This case suggests a possible mechanism of dysphagia in patients with athetoid cerebral palsy.

Risk factors for severe dysphagia in acute cervical spinal cord injury.

A retrospective, consecutive case series. The relationship between dysphagia and acute cervical spinal cord injury (CSCI) has been recently reported; however, the cause and mechanism of dysphagia are still not well understood. No definitive factors have yet been established according to multivariate analysis. The objective is to elucidate the incidence and risk factors of dysphagia in patients with acute CSCI. Spinal Injuries Center, Fukuoka, Japan. A total of 298 patients with acute CSCI, who were evaluated for neurological impairment within 3 days after injury, were reviewed. CSCI patients with tube dependence due to obvious aspiration after injury were defined as having dysphagia. The factors postulated to increase the risk for dysphagia, including the patient's age, sex, American Spinal Injury Association (ASIA) impairment scale at 3 days after injury, level of injury, tracheostomy and operative treatment, were analyzed using a multiple logistic regression model. Of 298 patients, 21 were suffering from severe dysphagia after acute CSCI (7.0%). Of these 21 patients, 12 (57%) had CSCI at the C3-C4 level. Multivariable logistic regression analysis revealed that old age (>72 years), severe ASIA impairment scale (A or B) and presence of tracheostomy were significant risk factors of dysphagia. Level of injury ⩾C3-C4 was not a significant risk factor after adjustment for several potential confounders. The incidence of severe dysphagia associated with aspiration was 7%. Old age, severe paralysis and presence of tracheostomy may be the risk factors for dysphagia. The risk for dysphagia should be evaluated to prevent aspiration pneumonia.

P.10.12 Difference of the mechanism of dysphagia between Duchenne muscular dystrophy and myotonic dystrophy type 1

Duchenne muscular dystrophy (DMD) and myotonic dystrophy type 1 (DM1) show clinically similar myopathic symptoms on initial examination, but usually very different swallowing difficulties become apparent. In this study we aimed to demonstrate the distinctive features of dysphagia in patients with DM1 and DMD. Diet-type score (DTS) and maximum tongue pressure (MTP) were measured in 20 DM1 and 24 DMD patients; all patients were also examined by video-fluoroscopy (VF). We used VF to measure the range of hyoid bone excursion (RHBE) during pharyngeal transit time and the area of pharyngeal residue (APR) after the first swallow. RHBE and APR values for DM1 patients were significantly greater than those for DMD patients. DTS and MTP did not differ between patients. A significant correlation was observed between DTS, MTP and RHBE in DMD patients, but not in DM1 patients. Our findings reveal the differences in the distinctive features of dysphagia in DM1 and DMD. Adjustments in the diet of DMD patients in accordance with swallowing ability could be useful.

Intensity‐modulated versus conventional radiation therapy for oropharyngeal carcinoma: Long‐term dysphagia and tumor control outcomes

The purpose of this study was to determine the relative clinical benefits of intensity-modulated radiation therapy (IMRT) versus conventional radiotherapy (CRT) in the treatment of patients with oropharyngeal carcinoma. We compared tumor control and toxicity outcomes in 132 patients with stage III to IVA/B oropharyngeal carcinoma treated with definitive chemoradiation in the human papillomavirus (HPV) era. Patients treated with IMRT had lower rates of xerostomia (p = .01) and shorter duration of gastrostomy-tube dependence (p < .0001), but increased risk of cervical esophageal stricture (p = .03). The overall rates of late dysphagia were not different between the 2 groups (p = .40). In multivariate analysis, IMRT was a significant predictor of decreased disease-specific mortality (hazard ratio [HR] = 0.24; p = .03) after adjustment for T-category and active smoking. After adjustment for T classification, IMRT use was associated with a trend toward a significant decrease in locoregional failure (HR = 0.17; p = .08). The incidence of late dysphagia is similar in IMRT and CRT, but the mechanism of dysphagia is different.

Mechanisms underlying dysphagia in eosinophilic oesophagitis

Eosinophilic oesophagitis (EO) is essentially a new disease not generally recognised in the UK or many other western European countries until early this decade. It is characterised by dysphagia, usually...

Functional magnetic resonance imaging study on dysphagia after unilateral hemispheric stroke: a preliminary study

Background:Swallowing dysfunction is common and disabling after acute stroke; however, the mechanism of dysphagia or recovery of swallowing from dysphagia remains uncertain. The purpose of this study was to explore...

An unusual cause of dysphagia

A case of dysphagia caused by anterior cervical osteophytes is presented. Although dysphagia and cervical spondylosis are common presenting problems, they are often unrelated to each other. The association between the two should, therefore, be accepted with caution; adequate investigation is necessary to avoid misdiagnosis. Review of the literature showed that this condition is relatively rare. The most likely mechanism of dysphagia is interference with swallowing at the pharyngo-oesophageal junction, although osteophytes in the lower cervical spine may also interfere with oesophageal peristalsis. Apart from the osteophytes of cervical spondylosis, those resulting from Forestier's disease, or Diffuse Idiopathic Skeletal Hyperostosis (DISH) have also been described to cause dysphagia.

Familial gastrointestinal stromal tumors associated with dysphagia and novel type germline mutation of KIT gene

A family with multiple gastrointestinal stromal tumors (GISTs), a new type of germline mutation of KIT gene, and dysphagia is reported. The mutation was observed at Asp-820 in tyrosine kinase (TK) II domain. Mutations in TK II domain have been found in mast cell and germ cell tumors but not in GISTs, and the present family members are the first reported cases of GISTs with TK II domain mutations, including sporadic GISTs. Because interleukin 3-dependent Ba/F3 murine lymphoid cells transfected with the mutant KIT complementary DNA grew autonomously without any growth factors and formed tumors in nude mice, the mutation was considered to be gain-of-function type. Family members with the germline KIT mutation reported dysphagia, but those without the mutation did not. The mechanism of dysphagia was examined with gastrointestinal fiberscopy, endoscopic ultrasonography, and esophageal manometry. No mechanical obstruction was found, and the esophagus was not remarkably dilated. In the family members with dysphagia, endoscopic ultrasonography at the esophagocardiac junction showed a thickened hyperechoic layer between the circular and longitudinal muscle layers, suggesting hyperplasia of interstitial cells of Cajal at the myenteric plexus layer. Manometry showed low resting lower esophageal sphincter pressure and abnormal simultaneous contractions of the esophagus without normal peristalsis. These findings indicate that the dysphagia of the present family is different from typical achalasia. This is the first report of familial dysphagia caused by germline gain-of-function mutation of the KIT gene at the TK II domain.

Analysis and surgical treatment of persistent dysphagia after Nissen fundoplication.

After Nissen fundoplication, troublesome dysphagia develops in 5-10 per cent of patients. The mechanism of dysphagia has not been fully resolved, in spite of a number of studies focusing on oesophageal motility and lower oesophageal sphincter (LOS) dynamics. Tightness and length of the wrap have had considerable attention, without giving a fully satisfactory explanation of the pathophysiological mechanism. Eighteen patients with persistent dysphagia after Nissen fundoplication needing reoperation were studied. Eighteen patients, matched for age and sex, without dysphagia after Nissen fundoplication were used as controls. Reoperation consisted of conversion of a 360 degrees into a 270 degrees wrap. Barium swallow, endoscopy, oesophageal manometry and 24-h pH monitoring were performed before and after (re)operation. Peristaltic amplitude, velocity and duration of contraction were not significantly influenced by operation. In 16 of 18 patients with dysphagia, LOS relaxation was incomplete and the residual relaxation pressure was significantly higher than that in the group without dysphagia (P < 0.01). No correlation was found between LOS pressure and peristaltic amplitude, nor between LOS pressure and ramp pressure in the distal oesophagus. After reoperation, basal LOS pressure decreased significantly (P < 0.01) and LOS relaxation was complete in all but three patients; residual relaxation pressure decreased (P < 0.01) and was significantly lower than that after uncomplicated Nissen fundoplication. In the latter group, LOS pressure, residual relaxation pressure and ramp pressure increased significantly after operation (P < 0.01). A return to complete LOS relaxation and a decrease in residual relaxation pressure play an important role in resolving dysphagia.

Dysphagia Caused by Anterior Cervical Osteophytes

Anterior cervical osteophytosis – isolated and/or resulting from Forestier's disease – is commonly asymptomatic and can only occasionally produce dysphagia. In fact, although the cervical spondylosis and the dysphagia are common presenting problems, they are often unrelated each other. Review of literature showed that the association between the two conditions is relatively unfrequent and hence often unrecognized entity. The most likely mechanism of dysphagia is the interference with swallowing at the pharyngo-esophageal junction by mechanical obstruction of bony protuberance, although osteophytes in the lower cervical spine may also act on esophageal peristalsis inducing soft tissue inflammation. In first instance the diagnosis may be clearly suggested by conventional X-ray of the spine, avoiding potentially dangerous investigation (i.e. endoscopy); then it should be established by esophagogram, and CT. MRI of the spine should be additionally required if neurological impairement occurs.The therapeutic approach depends both on the extent of dysphagic complaints and on the presence of spinal cord involvement. There may be a role for medical therapy in the first instance under special circumstances (i.e. small osteophytes, transient dysphagia…). Surgical treatment is required after failure of conservative treatment and/or when bony spurs are located also on the posterior and postero-lateral aspects of vertebral body, thus extending into the spinal canal to impinge on the cord and roots. We report three cases of progressive spondylotic dysphagia with striking radiographic findings. The patients were treated conservatively in the initial stages. After unsuccessful medical therapy, surgical resection of the cervical osteophytes via the anterior cervical approach was performed and resulted in excellent relief of dysphagia in all cases.

The mechanism of dysphagia after nissen fundoplication

The mechanism of dysphagia after nissen fundoplication

Recent Studies of the Pathophysiology and Diagnosis of Esophageal Symptoms

The three main symptoms of esophageal disease or disorder are dysphagia, chest pain, and heartburn. Dysphagia in achalasia is mainly due to a non-relaxing lower esophageal sphincter (LES). The mechanism of dysphagia in diffuse esophageal spasm and related motor disorders is related to a combination of several factors including incomplete LES relaxation, failed or weak peristalsis (pressure less than 30 mmHg in the distal esophagus, and orad positive pressure gradient). Meal manometry and balloon distention may prove to be useful provocation tests. Chest pain of esophageal origin may be due to gastroesophageal reflux and esophageal motility disorders; it may also be a manifestation of an irritable esophagus, in which the esophagus is hypersensitive to various stimuli (chemical, mechanical, ischemic). Esophageal provocation tests may suggest the esophageal origin of the pain but do not give information on the nature of the esophageal disorder. Twenty-four-hour pH and pressure measurements may, however, yield this information. Heartburn and acid regurgitations are the most typical symptoms of gastroesophageal reflux. Transient relaxations of the LES are considered to be an important contributory mechanism of reflux. Absent basal LES pressure is another mechanism, which accounts for about one-fourth of the reflux episodes in patients with severe reflux esophagitis. During long-lasting inappropriate relaxations, swallows often produce deglutitive contraction waves that die out in the upper esophagus, suggesting that reflux often occurs during periods of inhibition of both LES tone and peristaltic esophageal activity.