Pharyngeal Residue and Aspiration and the Relationship with Clinical/Nutritional Status of Patients with Oropharyngeal Dysphagia Submitted to Videofluoroscopy

Conceptualizing Adult Dysphagia in the United States Within the International Classification of Functioning, Disability and Health (ICF)

Despite the well-documented safety concerns and effect on quality of life, there does not yet exist a wide-reaching framework that links the etiologies of swallowing disorders to the potential short- and long-term outcomes in the context of International Classification of Functioning, Disability and Health (ICF). This paper introduces an expert-reviewed conceptual framework to highlight common etiologies of dysphagia as well as integrate immediate outcomes of dysphagia with long-term outcomes of dysphagia in terms of medical problems, health-related quality of life, functional effect, and psychosocial features. It also outlines the potential cyclical nature of long-term dysphagia outcomes perpetuating the original dysphagia. This framework serves to inform clinicians of important dysphagic outcomes and to bring awareness to long-term outcomes that should be monitored by health care professionals, caregivers, or people with dysphagia.

Predictive Value of Laryngeal Penetration to Aspiration in a Cohort of Pediatric Patients

Videofluoroscopic swallow studies (VFSS) provide dynamic assessment of the phases of swallowing under fluoroscopic visualization and allow for identification of abnormalities in the process, such as laryngeal penetration and aspiration. While penetration and aspiration both reflect degrees of swallowing dysfunction, the predictive potential of penetration for subsequent aspiration is not fully elucidated in the pediatric population. As a result, management strategies for penetration vary widely. Some providers may interpret any depth or frequency of penetration as a proxy for aspiration and implement various therapeutic interventions (e.g., modification of liquid viscosity) to eliminate penetration episodes. Some may recommend enteral feeding given the presumed risk of aspiration with penetration, even when aspiration is not identified during the study. In contrast, other providers may advise continued oral feeding without modification even when some degree of laryngeal penetration is identified. We hypothesized that the depth of penetration is associated with the likelihood of aspiration. Identification of predictive factors for aspiration following laryngeal penetration events has significant implications for selection of appropriate interventions. We performed a retrospective cross-sectional analysis of a random sample of 97 patients who underwent VFSS in a single tertiary care center over a 6 month period. Demographic variables including primary diagnosis and comorbidities were analyzed. We examined the association between aspiration and degrees of laryngeal penetration (presence or absence, depth, frequency) across diagnostic categories. Infrequent and shallow penetration events of any type of viscosity were less likely to be associated with aspiration event(s) during the same clinical encounter regardless of diagnosis. In contrast, children with consistent deep penetration of thickened liquids invariably demonstrated aspiration during the same study. Our findings show that shallow, intermittent laryngeal penetration of any viscosity type on VFSS was not consistent with clinical aspiration. These results provide further evidence that penetration-aspiration is not a uniform clinical entity and that nuanced interpretation of videofluoroscopic swallowing findings is necessary to guide appropriate therapeutic interventions.

Evaluation of Post-Swallow Residue with Visual Analysis of Swallowing Efficiency and Safety in Patients with Idiopathic Parkinson's Disease

Objectives: Dysphagia is common in idiopathic Parkinson's disease (IPD) and is associated with impairments in both swallowing safety and swallowing efficiency. The goals of this study were to define post-swallow residue patterns in people with IPD and describe pathophysiological endoscopic findings affecting residue accumulation. Methods: This was a prospective single-blinded cross-sectional cohort study of patients with the diagnosis of IPD recruited from a Movement Disorder Clinic. Clinical variables included patient age, cognitive function, and measures of disease severity, and laryngoscopic examinations with a flexible endoscopic evaluation of swallowing (FEES) were completed for each patient. Visual Analysis of Swallowing Efficiency and Safety (VASES) was used to analyze FEES. Post-swallow residue outcomes and non-residue endoscopic outcomes including the Bowing index, Penetration Aspiration Scale (PAS) score, premature leakage, and build-up phenomenon were evaluated. Multiple regression models were used to evaluate factors affecting the residue at different anatomic levels. Results: Overall 53 patients completed the study. The multiple regression analyses showed a relation between (1) the presence of residue at the level of oropharynx and epiglottis with premature leakage, (2) the presence of residue at the level of the laryngeal vestibule and vocal folds with build-up phenomenon, and (3) the presence of residue at the level of the hypopharynx, laryngeal vestibule, and subglottis with airway invasion. Conclusion: Residue pattern during FEES is associated with specific swallow dysfunctions in IPD. Using residue localization and quantification may be a helpful tool in assessing the impact of targeted swallowing interventions in patients with IPD and dysphagia.

Relationship Between Pharyngeal Residues Assessed by Bolus Residue Scale or Normalized Residue Ratio SCALE and Risk of Aspiration in Head and Neck Cancer Who Underwent Videofluoroscopy

Dysphagia affects 60-75% of patients treated for head and neck cancer (HNC). We aimed to evaluate the association between residue severity and airway invasion severity using a videofluoroscopic swallowing study and identify risk factors for poor penetration-aspiration outcomes in patients with dysphagia treated for HNC. Penetration-Aspiration Scale (PAS) was used to assess airway invasion severity, while residue severity was assessed using both the Bolus Residue Scale (BRS) for residue location and the Normalized Residue Ratio Scale (NRRS) for residue amount. Relevant covariates were adjusted in the logistic regression models to account for potential confounding. Significantly higher abnormal PAS was reported for increased piriform sinus NRRS (NRRSp) [odds ratio (OR), 4.81; p = 0.042] with liquid swallowing and increased BRS value (OR, 1.52; p = 0.014) for semi-liquid swallowing in multivariate analysis. Tumor location, older age, and poorer Functional Oral Intake Scale (FOIS) were significant factors for abnormal PAS in both texture swallowings. After adjusting for confounding factors (sex, age, and FOIS score), NRRS model in liquid swallowing (area under the curve [AUC], 0.83; standard error = 0.04, 95% confidence interval [CI]: 0.75, 0.91) and BRS in semi-liquid swallowing (AUC, 0.83; SE = 0.04; 95% CI: 0.76, 0.91) predicted abnormal PAS. The results indicate that while assessing residue and swallowing aspiration in patients with HNC, it is important to consider age, tumor location, and functional swallowing status. The good predictability of abnormal PAS with BRS and NRRS indicated that residue location and amount were both related to the aspiration event in patients with HNC.

[Nutritional Risk Screening in head-and-neck cancer patients prior to oncological therapy]

OBJECTIVE

Head-and-neck cancer patients run a high risk of peri- or post-treatment malnutrition that can severely affect the therapy outcome. However, little is known about malnutrition under the pre-treatment condition. Therefore, this study aimed to provide a systematic description of the pre-treatment nutritional status and risk of malnutrition in this population.

MATERIAL AND METHODS

Before the onset of the oncological therapy, nutritional status of 102 head-and-neck cancer patients was assessed by body mass index (BMI), their risk of malnutrition by "Nutritional Risk Screening" (NRS). Tumour stage and site, patients' age and sex as well as oropharyngeal dysphagia were analysed as possible influence factors. The latter was quantified by the Flexible Endoscopic Evaluation of Swallowing (FEES).

RESULTS

According to BMI, malnutrition (undernutrition) was found in 6% of patients, a risk of malnutrition (NRS) in 27% of patients, and oropharyngeal dysphagia in 15%. In a linear regression, only oropharyngeal dysphagia was identified as a significant influence factor for the risk of malnutrition (β = 0.380/3.776; p < .001).

CONCLUSIONS

Pre-treatment risk of malnutrition was found in a quarter of head-and-neck cancer patients. For the early identification of this risk and for the introduction of measures that would help to avoid it, a pre-treatment examination of swallowing functions and a systematic malnutrition screening by means of NRS are recommended.

Predictors of malnutrition risk in neurodegenerative diseases: the role of swallowing function

BACKGROUND

Oropharyngeal dysphagia is generally recognized to increase the risk of malnutrition, however, its role in patients with neurodegenerative disease has still to be determined. The cross-sectional study aimed to investigate the impact of swallowing function on malnutrition risk in patients with neurodegenerative diseases.

METHODS

Patients with oral nutrition and diagnosis of Huntington's disease (HD), Parkinson's disease (PD), or Amyotrophic Lateral Sclerosis (ALS) were recruited. Demographic and clinical data were collected. The swallowing assessment included a fiberoptic endoscopic evaluation of swallowing, an oral phase assessment, and a meal observation scored with the Mealtime Assessment Scale (MAS). Malnutrition risk was assessed with the Mini Nutritional Assessment (MNA®).

RESULTS

Overall, 148 patients were recruited (54 HD, 33 PD, and 61 ALS). One-hundred (67.6%) patients were considered at risk of malnutrition. At the multivariate analysis, age ≥65 (OR 3.16, p=0.014), disease severity (moderate vs mild OR 3.89, severe vs mild OR 9.71, p=0.003), number of masticatory cycles (OR 1.03, p=0.044), and MAS safety (OR 1.44, p=0.016) were significantly associated with malnutrition risk.

CONCLUSION

Prolonged oral phase and signs of impaired swallowing safety during meals, together with older age and disease severity, are independent predictors of malnutrition risk in neurodegenerative diseases. The study broadens the focus on dysphagia, stressing the importance of an early detection not only of pharyngeal signs, but also of oral phase impairment and meal difficulties through a multidimensional swallowing assessment.

Diagnostic accuracy of ultrasound examination in detecting aspiration and pharyngeal residue in patients with dysphagia: A systematic review and meta-analysis

AIM

To estimate diagnostic accuracy of ultrasonography for detecting aspiration and pharyngeal residue in patients with dysphagia.

METHODS

A systematic search was conducted in MEDLINE (via PubMed), CINAHL, EMBASE, Ichushi-Web, and Cochrane Library databases to identify articles that showed diagnostic accuracy of ultrasonography for detecting aspiration and residue published in English and Japanese until August 2019. Cross-sectional studies, case-control studies, and cohort studies were included. The diagnostic accuracy results were extracted and the pooled estimated sensitivity and specificity were calculated. The risk of bias of the studies was assessed using the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies 2. The certainty of the evidence was assessed using the Grades of Recommendation Assessment, Development, and Evaluation methodology.

RESULTS

Five studies were included in this review. The pooled estimated sensitivity and specificity for detecting aspiration were 0.82 (95% CI: 0.72-0.89) and 0.87 (95% CI: 0.81-0.92), respectively. One study was included that evaluated ultrasound assessments of pharyngeal residue. The sensitivity and specificity were 0.62 (95% CI: 0.32-0.86) and 0.67 (95% CI: 0.22-0.96), respectively. The certainty of the evidence was low and very low for the diagnostic accuracy of aspiration and pharyngeal residue, respectively.

CONCLUSION

Ultrasound is a non-invasive method with good sensitivity and specificity in detecting aspiration as well as reference standards. While risk of bias and small number of studies limited the strength of this systematic review, our results suggested that ultrasound examination was useful as a bedside screening tool for detecting aspiration.

Evaluating the Efficacy of VitalStim Electrical Stimulation Combined with Swallowing Function Training for Treating Dysphagia following an Acute Stroke

OBJECTIVES

This study explored the clinical efficacy of VitalStim electrical stimulation combined with swallowing function training for patients with dysphagia following an acute stroke.

METHODS

Seventy-two patients with dysphagia following an acute stroke were admitted to our hospital and were further divided into two groups using prospective research methods. There were 36 cases in each group according to the random number table method. The control group received conventional medical treatment and swallowing function training while the experimental group received conventional medical treatment and VitalStim electrical stimulation combined with swallowing function training.

RESULTS

The overall response rate of the experimental group (94.44%) was higher than that of the control group (77.78%), and the difference was statistically significant (p<0.05). Compared with before treatment, the upward and forward movement speeds of the hyoid bone, anterior movement speed, the grading score of the Kubota drinking water test, Caiteng's grading score, serum superoxide dismutase, 5-hydroxytryptamine, and norepinephrine levels, Fugl-Meyer Assessment score, and multiple quality of life scores of the two groups showed improvement after treatment. While the standard swallowing assessment score, serum malondialdehyde level, and National Institutes of Health Stroke Scale score decreased, the aforementioned indices showed a significant improvement in the experimental group (p<0.05).

CONCLUSION

The results of this study indicate that VitalStim electrical stimulation combined with swallowing function is effective for treating dysphagia following an acute stroke. It can effectively improve swallowing, neurological, and limb motor functions, reduce complications, promote physical recovery, and improve overall quality of life of patients.

Fiberoptic endoscopic evaluation of swallowing in early-to-advanced stage Huntington's disease

Huntington's disease (HD) is a neurodegenerative disorder characterized by motor disturbances, cognitive decline, and behaviour changes. A well-recognized feature of advanced HD is dysphagia, which leads to malnutrition and aspiration pneumonia, the latter being the primary cause of death in HD. Previous studies have underscored the importance of dysphagia in HD patients with moderate-to-advanced stage disease, but it is unclear whether dysphagia affects patients already at an early stage of disease and whether genetic or clinical factors can predict its severity. We performed fiberoptic endoscopic evaluation of swallowing (FEES) in 61 patients with various stages of HD. Dysphagia was found in 35% of early-stage, 94% of moderate-stage, and 100% of advanced-stage HD. Silent aspiration was found in 7.7% of early-stage, 11.8% of moderate-stage, and 27.8% of advanced-stage HD. A strong correlation was observed between disease progression and dysphagia severity: worse dysphagia was associated with worsening of motor symptoms. Dysphagia severity as assessed by FEES correlated with Huntington’s Disease Dysphagia Scale scores (a self-report questionnaire specific for evaluating swallowing in HD). The present findings add to our understanding of dysphagia onset and progression in HD. A better understanding of dysphagia onset and progression in HD may inform guidelines for standard clinical care in dysphagia, its recognition, and management.

Relationship between oropharyngeal dysphagia, nutritional status, antioxidant vitamins and the inflammatory response in adults and elderly: A cross-sectional study

BACKGROUND & AIM

Oropharyngeal dysphagia (OD) can lead to a deficiency of antioxidant micronutrients. The aim of the present study was to investigate the relation between OD and nutritional status, antioxidant vitamins (β-carotene, vitamin E and C) and serum markers of the inflammatory response [C-reactive protein, myeloperoxidase (MPO), nitric oxide metabolites (NOx), tumor necrosis factor-α, interleukin (IL)-1β and IL-6] in adults and elderly.

METHODS

A cross-sectional study was conducted with 69 individuals: 22 in the control group (CG) and 47 in the OD group (ODG). The ODG was subdivided into ODG-mild = normal oral feeding (OF, n = 14), ODG-moderate (OF-modified, n = 22) and ODG-severe (OF-suspended, n = 11). Associations were investigated using multiple linear regression.

RESULTS

The body mass index (BMI) was higher in the ODG compared to the CG (p = 0.008), independently of sex, age, energy intake (EI) and score on the Functional Independence Measure. BMI was significantly lower in the ODG-severe compared to the ODG-mild (p = 0.012). OD was associated with lower concentrations of β-carotene (p < 0.001) and vitamin C (p < 0.001), independently of sex, age and EI, and higher concentrations of MPO (p = 0.008) and NOx (p = 0.011), independently of sex, age and the presence of comorbidities.

CONCLUSION

Adults and elderly with OD have lower levels of antioxidant vitamins (β-carotene and vitamin C) and a high inflammatory response (MPO and NOx). The evaluation of antioxidant vitamins could be incorporated in nutritional status assessment in this population.

Relationships between high comorbidity index and nutritional parameters in patients with Oropharyngeal Dysphagia

BACKGROUND & AIMS

Oropharyngeal dysphagia (OD) and comorbidities can exert an influence on nutritional status and contribute to mortality. The aim of the present study was to examine relationships between high Charlson Comorbidity Index (CCI) scores and OD outcomes, including OD severity, feeding route, nutritional status and one-year mortality rate in adults and elderly individuals.

METHODS

A longitudinal study, whose the final sample comprised 110 patients with OD and 75 of whom were evaluated for one-year mortality outcome. Swallowing (videofluoroscopy), nutritional status [body mass index (BMI)], CCI, type of feeding route, medications and hospitalization were evaluated. Multinomial logistic regression was performed to calculate the unadjusted and adjusted odds ratios (OR) and 95% confidence intervals (95%CI).

RESULTS

Overall sample of the study were adults and elders with a median age (years) of 61.3 [interquartile range (IQR): 58.4-64.2]. The median CCI was 2.3 (IQR: 2.1-2.6) and the mortality rate was 10.8%. Hospitalization was significantly associated with underweight (p = 0.013) and number of medications (p = 0.023). After adjustment, sex/age and nº-Medications/Hospitalization (nº-M/H), CCI ≥3 was associated with nasogastric tube feeding (OR 4.57, 95%CI 1.59-13.1 and OR 3.39, 95%CI 1.21-9.51 respectively) and swallowing performance (OR 0.73, 95%CI 0.59-0.90 and OR 0.74, 95%CI 0.61-0.90 respectively).

CONCLUSIONS

A high CCI was associated with OD severity and feeding route, but not with nutritional status or mortality.

A Cross-Sectional, Quantitative Videofluoroscopic Analysis of Swallowing Physiology and Function in Individuals With Amyotrophic Lateral Sclerosis

Purpose To date, research characterizing swallowing changes in individuals with amyotrophic lateral sclerosis (ALS) has primarily relied on subjective descriptions. Thus, the degree to which swallowing physiology is altered in ALS, and relationships between such alterations and swallow safety and/or efficiency are not well characterized. This study provides a quantitative representation of swallow physiology, safety, and efficiency in a sample of individuals with ALS, to estimate the degree of difference in comparison to published healthy reference data and identify parameters that pose risk to swallow safety and efficiency. Secondary analyses explored the therapeutic effect of thickened liquids on swallowing safety and efficiency. Method Nineteen adults with a diagnosis of probable-definite ALS (El-Escorial Criteria-Revised) underwent a videofluoroscopic swallowing study, involving up to 15 sips of barium liquid (20% w/v), ranging in thickness from thin to extremely thick. Blinded frame-by-frame videofluoroscopy analysis yielded the following measures: Penetration-Aspiration Scale, number of swallows per bolus, amount of pharyngeal residue, degree of laryngeal vestibule closure (LVC), time-to-LVC, duration of LVC (LVCdur), pharyngeal area at maximum constriction, diameter of upper esophageal sphincter opening, and duration of UES opening (UESOdur). Measures of swallow physiology obtained from thin liquid trials were compared against published healthy reference data using unpaired t tests, chi-squared tests, and Cohen's d effect sizes (adjusted p < .008). Preliminary relationships between parameters of swallowing physiology, safety, and efficiency were explored using nonparametric Cochrane's Q, Friedman's test, and generalized estimating equations (p < .05). Results Compared to healthy reference data, this sample of individuals with ALS displayed a higher proportion of swallows with partial or incomplete LVC (24% vs. < 1%), increased time-to-LVC (d = 1.09), reduced UESwidth (d = 0.59), enlarged pharyngeal area at maximum constriction, prolonged LVCdur (d = 0.64), and prolonged UESOdur (d = 1.34). Unsafe swallowing (i.e., PAS ≥ 3) occurred more frequently when LVC was partial/incomplete or time-to-LVC was prolonged. Pharyngeal residue was associated with larger pharyngeal areas at maximum constriction. Unsafe swallowing occurred less frequently with extremely thick liquids, compared to thin liquids. No significant differences in pharyngeal residue were observed based on liquid thickness. Conclusions Quantitative videofluoroscopic measurements revealed moderate-to-large differences in swallow physiology between this sample of individuals with ALS and healthy reference data. Increased time-to-LVC, noncomplete LVC, and enlarged pharyngeal area at maximum constriction were associated with impaired swallow safety or efficiency. Thickened liquids may mitigate the risk of acute episodes of aspiration in individuals with ALS. Further work is needed to corroborate these preliminary findings and explore how swallowing profiles evolve throughout disease progression.

The association between temporal measures of swallowing with penetration and aspiration in patients with dysphagia: A meta-analysis

INTRODUCTION

Temporal features of swallowing physiology vary with age in healthy normals and have the potential to impact swallow safety and efficiency in patients with dysphagia. We conducted a meta-analysis to assess the relation between temporal features of swallowing with penetration, aspiration and residue in adult patients with dysphagia regardless of etiology.

METHODS

Operational definitions of relevant terms were defined a priori. A search of 5 databases was conducted to November 2016 without restriction to language. Two independent raters reviewed abstracts and full articles, with discrepancies resolved by consensus. All accepted articles advanced to data extraction and critical appraisal according to Cochrane standards. Analysis of pooled data compared measures between groups.

RESULTS

Of the 11 articles accepted, the temporal measures used in three or more studies were grouped into morphofunctional categories: bolus transit time; pharyngeal response time; laryngeal closure time; and upper esophageal opening time. Across all selected articles, definitions varied for abnormal swallow and only 4 articles reported rater blinding and reliability for measures related to timing. Pooled data identified two main findings: a. longer pharyngeal response time was associated with penetration and/or aspiration (MD = 0.40 95% CI 0.59 - 0.22), and longer upper esophageal opening duration was associated with only aspiration (PAS ≥ 6) (MD = 0.09 95% CI 0.16 - 0,02). No studies were found that related temporal measures and residue.

CONCLUSION

Our pooled findings identified an association of two temporal measures with penetration and/or aspiration but none with residue. The current evidence remains limited due to the heterogeneity across studies in how swallow measures were operationalized. Future work with a standardized and reproducible approach is direly needed.

Resíduos faríngeos nas disfagias orofaríngeas neurogênicas

RESUMO Objetivo Comparar os resíduos faríngeos por consistência de alimento entre indivíduos com disfagia orofaríngea neurogênica. Método Estudo clínico transversal. Realizada análise de 30 exames de videoendoscopia de deglutição de indivíduos com diagnóstico de doenças neurológicas e disfagia orofaríngea, independentemente do tempo ou estágio das doenças. Os indivíduos foram divididos em três grupos: o grupo I composto por 10 indivíduos pós-Acidente Vascular Cerebral, 8 homens e 2 mulheres, faixa etária entre 51 e 80 anos (média 67 anos); o grupo II por 10 indivíduos com Esclerose Lateral Amiotrófica, 5 homens e 5 mulheres, faixa etária entre 39 e 78 anos (média 57 anos), e o grupo III por 10 indivíduos com Doença de Parkinson (DP), 5 homens e 5 mulheres, faixa etária entre 65 e 88 anos (média 74 anos). Para análise dos resíduos faríngeos em valéculas e seios piriformes, foi aplicada a Yale Pharyngeal Residue Severity Rating Scale, considerando a primeira deglutição de 5 mL nas consistências pastosa e líquida espessada, por dois juízes independentes e de forma cega. Resultados Não houve diferença estatística significativa nos resíduos faríngeos, em valéculas (p= 0,25/ p= 0,18) e seios piriformes (p= 1,41/ 0,49), respectivamente nas consistências pastosa e líquida espessada, nas diferentes doenças estudadas. Conclusão Os níveis de resíduos faríngeos na consistência pastosa ou líquida espessada na população estudada foram semelhantes e mais frequentes nos níveis menos grave.

Reduced pharyngeal constriction is associated with impaired swallowing efficiency in Amyotrophic Lateral Sclerosis (ALS)

BACKGROUND

Swallowing inefficiency is a prevalent but understudied problem in individuals with Amyotrophic Lateral Sclerosis (ALS). Although reduced pharyngeal constriction has been identified as a mechanism contributing to swallowing inefficiency following stroke, this relationship has not been empirically tested in the ALS population. This study sought to characterize profiles of swallowing efficiency in a sample of ALS patients and investigate relationships between pharyngeal constriction and swallowing efficiency.

METHODS

Twenty-six adults with ALS underwent videofluoroscopic swallowing studies, involving 3 mL-thin, 20 mL-thin, and 3 mL-pudding boluses. Full-length recordings were segmented into bolus clips and randomized for analysis. We recorded the total number of swallows per bolus and obtained normalized pixel-based measures of pharyngeal constriction area and post-swallow residue in the vallecular and pyriform sinuses. Linear mixed models with Spearman's correlations were used to determine relationships between pharyngeal constriction and swallowing efficiency, with added factors of bolus volume and thickness.

KEY RESULTS

Individuals with ALS demonstrated reduced pharyngeal constriction and increased vallecular and pyriform sinus residue, compared to norms. Reduced pharyngeal constriction had a significant effect on the presence of vallecular and pyriform sinus residue as well as the number of swallows per bolus. Increased bolus thickness was associated with increased vallecular residue, while increased bolus volume was associated with reduced pharyngeal constriction. Results were significant at P < 0.05.

CONCLUSIONS & INFERENCES

Our results suggest that reduced pharyngeal constriction is a significant physiological parameter related to swallow inefficiency in ALS. Future work is needed to corroborate these preliminary results and investigate factors to mitigate such impairments.

Trends in Research Literature Describing Dysphagia in Motor Neuron Diseases (MND): A Scoping Review

Dysphagia in motor neuron diseases (MNDs) is highly complex, affecting all stages of swallowing and leading to impaired swallowing safety and efficiency. In order to explore the degree to which research is capturing the symptom of dysphagia in MND, we conducted a scoping review of the existing literature. The primary aims of this review were to identify common themes within the literature on dysphagia in MND, explore patterns and trends in research focus, and identify if any imbalances exist between the research themes related to dysphagia description and management. A comprehensive search strategy yielded 1690 unique articles for review. Following relevance screening, a total of 157 articles were included in the synthesis. Relevant data and keywords were extracted from each article and grouped into themes. Frequency estimates were calculated for each theme to identify trends across research literature. Swallowing impairment in MNDs is described in a variety of ways across current research. The most commonly reported theme was Aspiration/Penetration, mentioned in 73.2% of all included articles; a significant imbalance was identified between reports of swallowing safety and efficiency (p = 0.008). The most frequently reported theme related to dysphagia management was Enteral Nutrition, and very few studies have reported on the efficacy of Rehabilitation/Compensatory recommendations. It is suggested that researchers and clinicians remain mindful of imbalances and gaps in research, and aim to characterize dysphagia in MNDs in a comprehensive manner. Further research investigating discrete, measureable changes in swallowing pathophysiology would be beneficial to delineate the key factors contributing to impaired swallowing safety and efficiency.