Increased Bolus Volume Effect on Delayed Pharyngeal Swallowing Response in Post-stroke Oropharyngeal Dysphagia: A Pilot Study

Risk factors independently associated with the maintenance of severe restriction of oral intake and alternative feeding method indication at hospital outcome in patients after acute ischemic stroke

BACKGROUND AND AIMS

From a clinical point of view, post-stroke patients present difficulties in swallowing management. The purpose of this research was to identify risk factors that were independently related to the maintenance of a severe restriction of oral intake in patients affected by acute ischemic stroke.

METHODS

The authors conducted a prospective observational cohort study of patients with dysphagia post-acute ischemic stroke who were admitted to an Emergency Room (ER). Demographic and clinical data were collected at ER admission. Swallowing data was based on The Functional Oral Intake Scale (FOIS) and was collected at two distinct moments: initial swallowing assessment and at the patient outcome. Patients were divided into two groups according to their FOIS level assigned on the last swallowing assessment (at hospital outcome): G1 with severe restriction of oral intake and indication of feeding tube - patients with FOIS levels 1 to 4; G2 without restriction of food consistencies in oral intake - patients with FOIS levels 5 to 7.

RESULTS

One hundred and six patients were included in our study. Results of the multivariate logistic regression model for the prediction of maintenance of a severe restriction of oral intake at hospital outcome in patients post-acute ischemic stroke indicated that increasing age (p = 0.006), and dysarthria (p = 0.003) were associated with higher chances of presenting severe restriction of oral intake at hospital outcome.

CONCLUSIONS

Patients with acute ischemic stroke in an Emergency Room may experience non-resolved severe dysphagia, indicating the need to prepare for the care/rehabilitation of these patients.

Utilizing Pulmonary Function Parameters to Predict Dysphagia in Individuals With Cervical Spinal Cord Injuries

Objective

To utilize pulmonary function parameters as predictive factors for dysphagia in individuals with cervical spinal cord injuries (CSCIs).

Methods

Medical records of 78 individuals with CSCIs were retrospectively reviewed. The pulmonary function was evaluated using spirometry and peak flow meter, whereas the swallowing function was assessed using a videofluoroscopic swallowing study. Participants were divided into the non-penetration-aspiration group (score 1 on the Penetration-Aspiration Scale [PAS]) and penetration-aspiration group (scores 2–8 on the PAS). Individuals with pharyngeal residue grade scores >1 were included in the pharyngeal residue group.

Results

The mean age was significantly higher in the penetration-aspiration and pharyngeal residue groups. In this study, individuals with clinical features, such as advanced age, history of tracheostomy, anterior surgical approach, and higher neurological level of injury, had significantly more penetration-aspiration or pharyngeal residue. Individuals in the penetration-aspiration group had significantly lower peak cough flow (PCF) levels. Individuals in the pharyngeal residue group had a significantly lower forced expiratory volume in 1 second (FEV1). According to the receiver operating characteristic curve analysis of PCF and FEV1 on the PAS, the cutoff value was 140 L/min and 37.5% of the predicted value, respectively.

Conclusion

Low PCF and FEV1 values may predict the risk of dysphagia in individuals with CSCIs. In these individuals, active evaluation of swallowing is recommended to confirm dysphagia.

Visuoperceptual Analysis of the Videofluoroscopic Study of Swallowing: An International Delphi Study

INTRODUCTION

The Videofluoroscopic Swallow Study (VFSS) is a commonly used dysphagia assessment that is routinely analysed visuoperceptually. However, no consensus exists regarding which visuoperceptual measures should be used to analyse VFSSs. Current visuoperceptual measures for VFSSs are limited by poor quality and incomplete or indeterminate psychometric properties.

OBJECTIVE

This study aimed to establish the content validity for a new visuoperceptual VFSS measure for oropharyngeal dysphagia in adults, by identifying relevant domains of the construct and generating items and corresponding response scales.

METHODS

Consensus among experts in dysphagia and VFSS from over 20 countries was achieved across three rounds of anonymous online surveys, using the Delphi technique. Participants judged relevance and comprehensiveness of definitions of visuoperceptual domains of VFSS and the relevance of various domains to the overall construct. After reaching consensus on definitions of relevant domains, consensus on items were established using the same process.

RESULTS

Participants achieved consensus on definitions of 32 domains recommended for analysis, and at least one item per domain (range 1-4). Domains selected by participants included both those which occur in existing measures and domains which have not been included in any measures to date. This study will form the basis for content validity of a new measure for VFSS.

CONCLUSIONS

This first phase of developing a visuoperceptual measure of VFSS resulted in the identification of 32 domains and 60 items for oropharyngeal dysphagia. Developers can now advance to the next phase of measure construction; prototype development and psychometric testing.

A comprehensive review of the diagnosis and treatment of Parkinson's disease dysphagia and aspiration

INTRODUCTION

Bulbar dysfunction is common in Parkinson's disease (PD) with more than 80% of affected individuals developing dysphagia during the course of the disease. Symptoms can begin in the preclinical stage and individuals may remain clinically asymptomatic for years. Furthermore, patients may be unaware of swallowing changes, which contributes to the difference between the prevalence of self-reported dysphagia and deficits identified during instrumental evaluations. Dysphagia is underrecognized and contributes to the development of aspiration pneumonia which is the leading cause of death in PD. Dysphagia in PD is complex and not completely understood. Both dopaminergic and nondopaminergic pathways likely underpin dysphagia.

AREAS COVERED

This comprehensive review will cover the epidemiology, pathophysiology, clinical evaluation, and expert management of dysphagia and aspiration in patients with PD.

EXPERT OPINION

A multidisciplinary team approach is important to properly identify and manage PD dysphagia. Regular clinical screenings with objective instrumental assessments are necessary for early detection of dysphagia. Studies are needed to better understand the mechanism(s) involved in PD dysphagia, establish markers for early detection and progression, and develop evidence-based treatment options.

Swallow Safety is Determined by Bolus Volume During Infant Feeding in an Animal Model

Feeding difficulties are especially prevalent in preterm infants, although the mechanisms driving these difficulties are poorly understood due to a lack of data on healthy infants. One potential mechanism of dysphagia in adults is correlated with bolus volume. Yet, whether and how bolus volume impacts swallow safety in infant feeding is unknown. A further complication for safe infant swallowing is recurrent laryngeal nerve (RLN) injury due to patent ductus arteriosus surgery, which exacerbates the issues that preterm infants face and can increase the risk of dysphagia. Here, we used a validated animal model feeding freely to test the effect of preterm birth, postnatal maturation and RLN lesion and their interactions on swallow safety. We also tested whether bolus size differed with lesion or birth status, and the relationship between bolus size and swallow safety. We found very little effect of lesion on swallow safety, and preterm infants did not experience more penetration or aspiration than term infants. However, term infants swallowed larger boluses than preterm infants, even after correcting for body size. Bolus size was the primary predictor of penetration or aspiration, with larger boluses being more likely to result in greater degrees of dysphagia irrespective of age or lesion status. These results highlight that penetration and aspiration are likely normal occurrences in infant feeding. Further, when comorbidities, such as RLN lesion or preterm birth are present, limiting bolus size may be an effective means to reduce incidences of penetration and aspiration.

Use of the Penetration-Aspiration Scale in Dysphagia Research: A Systematic Review

The penetration-aspiration scale (PAS) is an 8-point scale used to characterize the depth and response to airway invasion during videofluoroscopy. Though widely used in the field of deglutition, there is a lack of consensus regarding the statistical properties of the scale. In order to better understand the state of the literature and the statistical use of the PAS, a systematic review was undertaken to descriptively examine trends in statistical and reporting practices of the PAS since its inception. Online databases were searched for studies citing the original PAS article, which yielded 754 unique articles. Of these, 183 studies were included in the review. Results showed inconsistencies in the statistical use of the scale; 79 studies treated the PAS as ordinal, 71 as categorical, and 49 as interval. Ten types of categorizations were identified. Reporting of power analyses (9%), as well as inter- (26%) and intra-rater (17%) reliability, was uncommon. Among studies that administered multiple bolus volumes or consistencies, 55% reported PAS analyses at the participant/group level only. This review confirms the existence of discrepancies in the statistical treatment of the PAS. A lack of consensus among researchers limits comparisons between studies. The approach to handling this scale dictates the statistical tests used, potentially affecting results and interpretations. Consistent application of statistically sound approaches to PAS analyses is vital for the future of deglutition research.

Reduced tongue force and functional swallowing changes in a rat model of post stroke dysphagia

PURPOSE

Dysphagia is a common problem after stroke that is often associated with tongue weakness. However, the physiological mechanisms of post-stroke tongue muscle weakness and optimal treatments have not been established. To advance understanding of physiological mechanisms of post stroke dysphagia, we sought to validate the unilateral transient middle cerebral artery occlusion (MCAO) rat model of ischemic stroke as a translational model of post stroke dysphagia. Our goal was to establish clinically relevant measures and chronicity of functional deficits; criteria that increase the likelihood that findings will translate to the clinic. We hypothesized that MCAO would cause tongue weakness and functional swallowing changes.

METHODS

Maximum voluntary tongue forces and videofluoroscopic swallowing studies were collected in 8-week old male Sprague-Dawley rats prior to receiving either a left MCAO (N = 10) or sham (N = 10) surgery. Tongue forces and VFSS were reassessed at 1 and 8 weeks post-surgery.

RESULTS

Maximum voluntary tongue force, bolus area, and bolus speed were significantly reduced in the MCAO group at the 1 and 8-week timepoints.

CONCLUSION

Clinically relevant changes to swallowing and tongue force support the use of the MCAO rat model as a translational model of post stroke dysphagia. This model will allow for future studies to improve our understanding of the physiology contributing to these functional changes as well as the impact of therapeutic interventions on physiological targets and function.