Effects of Bolus Holding on Respiratory-Swallow Coordination in Parkinson's Disease

The Association Between Dysphagia Symptoms, DIGEST Scores, and Severity Ratings in Individuals with Parkinson's Disease

The Swallow Disturbance Questionnaire (SDQ) is a screening tool developed to identify patients with Parkinson's Disease (PD) in need of objective swallowing evaluation. In a previous investigation, the SDQ did not predict abnormal airway protection on a videofluoroscopic swallowing study (VFSS). This investigation was undertaken to determine whether SDQ scores were more accurate when a global measure was used. The Dynamic Imaging Grade for Swallowing Toxicity (DIGEST) is a validated measure that provides a safety, efficiency, and total severity grade based on VFSS. A secondary analysis was performed using data from 20 patients with PD who had participated in a standardized VFSS protocol. The study sample was predominantly male (80%) with an average age of 71 years, and an average PD duration of 9 years. Using an established cut-off score, participants were subdivided into those with "normal" (n = 10) and "abnormal" SDQ scores (n = 10). Recordings were scored using the DIGEST protocol by two blinded raters who also rated overall dysphagia severity from the VFSS. There was good agreement between the two raters on the DIGEST and strong correlations between DIGEST scores and clinician perceptions of dysphagia severity. Higher SDQ scores were associated with poorer Efficiency on the DIGEST but not Safety or Total scores. Consistent with other PD studies, subjective perceptions of dysphagia were poorly predictive of objective findings on VFSS. There is little information about the validity of the DIGEST for rating neurogenic dysphagia. Our study provides preliminary support for the use of the DIGEST in the PD population.

A systematic review of behavioural therapies for improving swallow and cough function in Parkinson's disease

Purpose: This systematic review evaluated the efficacy of therapeutic interventions on improving swallow, respiratory, and cough functions in Parkinson's disease (PD).Method: A PRISMA systematic search was implemented across six databases. We selected studies reporting pre- and post-assessment data on the efficacy of behavioural therapies with a swallow or respiratory/cough outcome, and excluded studies on medical/surgical treatments or single-session design. Cross-system outcomes across swallow, respiratory, and cough functions were explored. Cochrane's risk of bias tools were utilised to evaluate study quality.Result: Thirty-six articles were identified and further clustered into four treatment types: swallow related (n = 5), electromagnetic stimulation (n = 4), respiratory loading (n = 20), and voice loading (n = 7) therapies. The effects of some behavioural therapies were supported with high-quality evidence in improving specific swallow efficiency, respiratory pressure/volume, and cough measures. Only eleven studies were rated with a low risk of bias and the remaining studies failed to adequately describe blinding of assessors, missing data, treatment adherence, and imbalance assignment to groups.Conclusion: Behavioural therapies were diverse in nature and many treatments demonstrated broad cross-system outcome benefits across swallow, respiratory, and cough functions. Given the progressive nature of the condition, the focus of future trials should be evaluating follow-up therapy effects and larger patient populations, including those with more severe disease.

Cross-System Integration of Respiration and Deglutition: Function, Treatment, and Future Directions

Swallowing occurs preferentially in the expiratory phase of the quiet breathing cycle and at mid-to-low tidal volume. This coordinative pattern imparts important biomechanical advantages to swallowing and airway protection and facilitate laryngeal elevation, laryngeal vestibular and vocal fold closure, and cricopharyngeal sphincter opening. This preferred coordinative relationship between breathing and swallowing is impaired in a variety of patient populations, including head and neck cancer survivors with dysphagia. We developed a training protocol to re-establish more optimal phasing of swallowing with breathing in these patients with striking outcomes, including reduced swallowing physiological impairments and improved airway protection. This motivated us to continue to refine and expand this training protocol and develop new assistive technologies for swallowing monitoring outside of the lab. In this review, we highlight the origins of our optimal respiratory-swallowing coordination hypothesis, describe the biomechanical advantages it provides, carefully describe our training protocol and findings, and chart a course for the next phase of this work. Our overall goal is to harness technology combined with carefully constructed learning paradigms to improve the lives of patients with impaired respiratory-swallowing coordination consequent to a variety of pathologies including head and neck cancer and degenerative neurological conditions such as Parkinson's disease.

Normative Reference Values for FEES and VASES: Preliminary Data From 39 Nondysphagic, Community-Dwelling Adults

PURPOSE

The aim of this study was to establish preliminary reference values for the Visual Analysis of Swallowing Efficiency and Safety (VASES)-a standardized rating methodology used to evaluate swallowing safety and efficiency for flexible endoscopic evaluation of swallowing (FEES).

METHOD

FEES were completed in nondysphagic, community-dwelling adults using a standardized protocol of 15 swallowing trials that varied by bolus size, consistency, contrast agent, and swallowing instructions. FEES were blindly analyzed using VASES. Primary outcome measures included bolus location at swallow onset, Penetration-Aspiration Scale (PAS) scores, and percentage-based residue ratings for six anatomic landmarks. Secondary outcome measures included sip size, bite size, and number of swallows.

RESULTS

Thirty-nine healthy adults completed the study, yielding an analysis of 584 swallows. Swallows were initiated with the bolus in the pharynx for 41.8% of trials. PAS 1 was the most common score, accounting for 75.3% of trials, followed by PAS 3, which accounted for 18.8% of trials. When residue was present (> 0%), the amount was relatively small across all anatomic landmarks, with median residue ratings of 2.0% (oropharynx), 1.5% (hypopharynx), 3.0% (epiglottis), 3.0% (laryngeal vestibule), and 3.5% (vocal folds). Five events of aspiration were observed, which were characterized by subglottic residue ratings of 1%, 3%, 10%, 24%, and 90%. The average sip size of self-selected volume cup sips of water was 19.8 ml, and the average bite size of a 3.0-g saltine cracker was 1.33 g. Moreover, 78% of the trials in this study protocol (except 90-ml trials) were completed in a single swallow.

DISCUSSION

The results from this study provide preliminary norms for VASES that could be used as a reference when assessing functional swallowing outcomes during FEES. While this is an important first step in establishing norms for FEES and VASES, clinicians and researchers should be mindful that the normative reference values from this study are from a relatively small study sample (N = 39), with most people below the age of 60 years (n = 30). Future research should expand on these norms by including a greater number of people across the age continuum and with greater racial, ethnic, and gender diversity.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23504325.

A prospective examination of swallow and cough dysfunction after lung transplantation

OBJECTIVES

Swallow and cough dysfunction are possible surgical complications of lung transplantation (LT). We examined voluntary cough strength, sensorimotor reflexive cough integrity, and swallow-related respiratory rate (RR) across swallowing safety and aspiration response groups in recovering LT recipients.

METHODS

Forty-five LT recipients underwent flexible endoscopic evaluation of swallowing indexed by the validated Penetration Aspiration Scale. RR before and after a 3-ounce water drinking task was measured. Voluntary and reflexive cough screening were performed to index motor and sensory outcomes. T-tests, one-way ANOVAs, and chi-square (odds ratios) were used.

RESULTS

60% of patients exhibited laryngeal penetration (n = 27) and 40% demonstrated tracheal aspiration (n = 18); 72% (n = 13) demonstrated silent aspiration. Baseline RR was higher in aspirators versus non-aspirators (26.5 vs. 22.6, p = 0.04) and in silent aspirators compared to non-silent aspirators (27.9 vs. 20.7, p = 0.01). RR change post-swallowing did not differ between aspiration response groups; however, it was significantly higher in aspirators compared to non-aspirators (3 vs. -2, p = 0.02). Compared to non-silent aspirators, silent aspirators demonstrated reduced voluntary cough peak expiratory flow (PEF; 166 vs. 324 L/min, p = 0.01). PEF, motor and urge to cough reflex cough ratings did not differ between aspirators and non-aspirators. Silent aspirators demonstrated a 7.5 times higher odds of failing reflex cough screening compared to non-silent aspirators (p = 0.07).

CONCLUSIONS

During the acute recovery period, all LT participants demonstrated some degree of unsafe swallowing and reduced voluntary cough strength. Silent aspirators exhibited elevated RR, reduced voluntary cough physiologic capacity to defend the airway, and a clinically distinguishable blunted motor response to reflex cough screening.

Respiratory-Swallow Coordination in Individuals with Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Swallowing impairment, including altered physiology and aspiration, occur across the progression of Parkinson's disease (PD). The phase of respiration during which a swallow is initiated has been linked to swallowing impairment and aspiration in cohorts with dysphagia following stroke and head and neck cancer treatment, but has been understudied in PD. If similar findings are shown in individuals with PD, the implications for swallowing assessment and treatment are significant.

OBJECTIVE

The aim of this systematic review and meta-analysis of literature was to examine respiratory-swallow coordination measures and potential implications on swallowing physiology in individuals with PD.

METHODS

An extensive search of 7 databases (PubMed, EMBASE, Central, Web of Science, ProQuest Dissertations & Theses, Scopus, and CINAHL) with predetermined search terms was conducted. Inclusion criteria were individuals with PD and the use of objective evaluations of respiratory-swallow coordination.

RESULTS

Of the 13,760 articles identified, 11 met the inclusion criteria. This review supports the presence of atypical respiratory swallow patterning, respiratory pause duration and lung volume at swallow initiation in individuals with PD. The meta-analysis estimated an occurrence of 60% of non-expiration-expiration and 40% of expiration-expiration respiratory phase patterns surrounding swallowing.

CONCLUSION

Although this systematic review supports the occurrence of atypical respiratory-swallow coordination in individuals with PD, the evidence is limited by the variability in the methods of data acquisition, analysis, and reporting. Future research examining the impact of respiratory swallow coordination on swallowing impairment and airway protection using consistent, comparable, and reproducible methods and metrics in individuals with PD is warranted.

Pilot Study of Respiratory-Swallow Coordination in Amyotrophic Lateral Sclerosis

PURPOSE

Amyotrophic lateral sclerosis (ALS) impacts bulbar and respiratory musculature, which may contribute to impaired swallow function (dysphagia) and respiratory-swallow coordination. The purpose of this pilot study was to examine if respiratory-swallow coordination in individuals with ALS was perturbed compared to healthy controls. We further explored relationships between measures of respiratory function and self-reported swallowing outcomes on respiratory-swallow coordination.

METHOD

We employed a cross-sectional design with eight participants with ALS and eight age- and sex-matched healthy participants. Respiratory inductance plethysmography and a nasal cannula were used to capture respiratory-swallow phase patterns during a standardized clinical swallow examination. The advantageous respiratory-swallow phase pattern was defined if exhalation surrounded the swallow (E-E). Spirometry was used to capture indices of respiratory function (forced vital capacity % predicted, peak cough flow [PCF]). Validated questionnaires were used to collect information regarding ALS-related bulbar functional status and swallowing-related concerns.

RESULTS

Compared to the matched healthy cohort, individuals with ALS demonstrated higher rates of non-E-E respiratory-swallow phase patterning and worse bulbar/swallow dysfunction. Group (ALS), swallow tasks, and PCF were significantly associated with respiratory-swallow phase pattern.

CONCLUSIONS

These preliminary findings support altered respiratory-swallow phase patterning in ALS. Future work should employ an instrumental assessment to quantify swallowing physiology and elucidate the relationship between perturbed respiratory-swallow coordination and swallowing function.