Behavioral Management of Respiratory/Phonatory Dysfunction for Dysarthria Associated With Neurodegenerative Disease: A Systematic Review.

PURPOSE: This systematic review represents an update to previous reviews of the literature addressing behavioral management of respiratory/phonatory dysfunction in individuals with dysarthria due to neurodegenerative disease. METHOD: Multiple electronic database searches and hand searches of prominent speech-language pathology journals were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards. RESULTS: The search yielded 1,525 articles, from which 88 met inclusion criteria and were reviewed by two blinded co-investigators. A large range of therapeutic approaches have been added to the evidence base since the last review, including expiratory muscle strength training, singing, and computer- and device-driven programs, as well as a variety of treatment modalities, including teletherapy. Evidence for treatment in several different population groups-including cerebellar ataxia, myotonic dystrophy, autosomal recessive spastic ataxia of Charlevoix-Saguenay, Huntington's disease, multiple system atrophy, and Lewy body dementia-were added to the current review. Synthesis of evidence quality provided strong evidence in support of only one behavioral intervention: Lee Silverman Voice Treatment Program (LSVT LOUD) in people with Parkinson's disease. No other treatment approach or population included in this review demonstrated more than limited evidence, reflecting that these approaches/populations require urgent further examination. CONCLUSION: Suggestions about where future research efforts could be significantly strengthened and how clinicians can apply research findings to their practice are provided. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24964473.

Sensorimotor Cough Dysfunction in Cerebellar Ataxias.

Cerebellar ataxias are neurological conditions with a high prevalence of aspiration pneumonia and dysphagia. Recent research shows that sensorimotor cough dysfunction is associated with airway invasion and dysphagia in other neurological conditions and may increase the risk of pneumonia. Therefore, this study aimed to characterize sensorimotor cough function and its relationship with ataxia severity. Thirty-seven participants with cerebellar ataxia completed voluntary and/or reflex cough testing. Ataxia severity was assessed using the Scale for the Assessment and Rating of Ataxia (SARA). Linear multilevel models revealed voluntary cough peak expiratory flow rate (PEFR) estimates of 2.61 L/s and cough expired volume (CEV) estimates of 0.52 L. Reflex PEFR (1.82 L/s) and CEV (0.34 L) estimates were lower than voluntary PEFR and CEV estimates. Variability was higher for reflex PEFR (15.74% coefficient of variation [CoV]) than voluntary PEFR (12.13% CoV). 46% of participants generated at least two, two-cough responses following presentations of reflex cough stimuli. There was a small inverse relationship between ataxia severity and voluntary PEFR (ß = -0.05, 95% CI: -0.09 - -0.01 L) and ataxia severity and voluntary CEV (ß = -0.01, 95% CI: -0.02 - -0.004 L/s). Relationships between reflex cough motor outcomes (PEFR ß = 0.03, 95% CI: -0.007-0.07 L/s; CEV ß = 0.007, 95% CI: -0.004-0.02 L) and ataxia severity were not statistically robust. Results indicate that voluntary and reflex cough sensorimotor dysfunction is present in cerebellar ataxias and that increased severity of ataxia symptoms may impact voluntary cough function.

The Relationship Between Lingual Strength and Functional Swallowing Outcomes in Parkinson's Disease.

The purpose of this retrospective study was to determine whether reduced lingual strength was associated with functional swallowing outcomes in individuals with Parkinson's disease (PD). Participants (N = 42) completed evaluations of maximal lingual isometric pressure (MIP) and mean lingual swallowing pressure (MSP), and flexible endoscopic evaluations of swallowing. Regression models were used to determine the association between lingual strength and functional swallowing outcomes of airway invasion, the presence of post-swallow pharyngeal residue, and the amount of pharyngeal residue (when present). Results revealed that higher MIP (p = 0.002, OR 0.93) and higher MSP (p = 0.001 OR 0.88) were associated with less airway invasion of thin liquids. Both MIP and MSP were able to differentiate between those with and without dysphagia (MIP: AUC 0.7935, p = 0.001; MSP: AUC 0.75, p = 0.026). Neither MIP nor MSP was related to the presence of residue. However, when thin liquid oropharyngeal residue was present, both MIP (p < 0.001, OR 0.99) and MSP (p < 0.001; OR 0.98) were significantly associated with the amount of residue observed. Similarly, when thin liquid hypopharyngeal residue was present, MIP (p < 0.001, OR 0.99) and MSP (p < 0.001, OR 0.98) were associated with the amount of residue observed. These findings suggest a relationship between reduced lingual strength and worse thin liquid swallowing safety and efficiency; however, the magnitude of these effects was small. This indicates that lingual strength is one important contributing factor to functional swallowing impairments in PD and may identify those with unsafe swallowing. These findings have important clinical implications for including lingual strength in the screening, assessment, and management of dysphagia in PD.

Rehabilitating Cough Dysfunction in Parkinson's Disease: A Randomized Controlled Trial.

BACKGROUND: Disorders of airway protection (cough and swallowing) are pervasive in Parkinson's disease (PD) resulting in a high incidence of aspiration pneumonia and death. However, there are no randomized controlled trials comparing strength and skill-based approaches to improve airway protection in PD. OBJECTIVES: The aim of this study was to compare expiratory muscle strength training (EMST) and sensorimotor training for airway protection (smTAP) to improve cough-related outcomes in people with PD. METHODS: Participants with PD and dysphagia were recruited for this prospective phase II randomized-blinded controlled clinical trial. Participants completed baseline assessment, 5 weeks of EMST or smTAP, and a post-training assessment. Primary outcome measures included maximum expiratory pressure (MEP) and voluntary cough peak expiratory flow rate (PEFR). Mixed effects models were used to assess the effects of EMST and smTAP on outcomes. RESULTS: A total of 65 participants received either EMST (n = 34) or smTAP (n = 31). MEP improved from pre- to post-treatment for smTAP (P < 0.001, d = 0.19) and EMST (P < 0.001, d = 0.53). Voluntary PEFR increased from pre- to post-treatment for smTAP (P < 0.001, d = 0.19) and EMST (P < 0.001, d = 0.06). Moreover, reflex cough PEFR (P < 0.001, d = 0.64), reflex cough expired volume (P < 0.001, d = 0.74), and urge to cough (P = 0.018, OR = 2.70) improved for the smTAP group but not for the EMST group. CONCLUSIONS: This clinical trial confirmed the efficacy of smTAP to improve reflex and voluntary cough function, above and beyond EMST, the current gold standard. © 2022 International Parkinson and Movement Disorder Society.

Visual Analysis of Swallowing Efficiency and Safety (VASES): A Standardized Approach to Rating Pharyngeal Residue, Penetration, and Aspiration During FEES.

The primary aim of this study was to describe the development of the Visual Analysis of Swallowing Efficiency and Safety (VASES)-a standardized method to rate pharyngeal residue, penetration, and aspiration during FEES. As a secondary aim, we explored the feasibility of training novices to interpret FEES using VASES. Literature review and consensus panel discussions were used to develop standardized rules for VASES. A training protocol was developed and criterion ratings were established. Twenty-five novice raters completed VASES training and pre-/post-training assessments. Statistical analyses were used to examine pre- to post-training differences in the accuracy, reliability, and time to rate each video clip using VASES. Four sets of VASES rules were developed, including 'what', 'where', 'when', and 'how' to rate FEES. Large, significant post-training improvements in rating accuracy were observed across all seven VASES outcome measures (Cohen's d range 0.74-1.59). Additionally, inter-rater reliability increased for four of the seven outcome measures, and the amount of time to rate each video clip decreased from 2.6 min pre-training to 1.5 min post-training. VASES is a standardized FEES rating method used to enhance the subjective analysis of pharyngeal residue, penetration, and aspiration. It can be feasibly taught to novice raters with a high level of success and may be an effective method to analyze swallowing safety and efficiency in clinical and research practices. Future research is needed to test the validity of VASES by examining its relationship with other validated FEES rating scales.

Characterizing Quality of Life in Caregivers of People with Parkinson's Disease and Dysphagia.

Caring for a family member with dysphagia can negatively impact caregiver wellbeing, although little is known about how dysphagia severity or specific symptoms influence this. The purpose of this study was to examine how objective measures of dysphagia in people with Parkinson's disease influenced their caregivers' quality of life. Fifty caregivers (mainly spouses) of people with Parkinson's disease completed a caregiver quality of life survey. Results were compared to medical chart reviews, interviews, and instrumental evaluations of swallowing from the care recipients. Outcomes included caregiver quality of life score, ratings of airway invasion and pharyngeal residue, and Parkinson's disease duration. Descriptive and regression analyses were completed. All caregivers reported reduced quality of life, with 28% having severely disturbed adaptation. Every care recipient with Parkinson's disease demonstrated airway invasion and/or pharyngeal residue. Together, the combination of older care recipient age and longer disease duration was associated with poorer caregiver quality of life [adj. R2 = 0.10-0.12, p = 0.03-0.4]. Neither airway invasion nor pharyngeal residue was related to caregiver quality of life (p > 0.05). Findings confirmed that caregivers of people with Parkinson's disease and dysphagia experience reduced quality of life; however, current methods of assessing caregivers' quality of life may not adequately account for dysphagia-specific burden. Results highlight the urgent need for the development of dysphagia-specific assessments of caregivers' quality of life to facilitate identification of high-risk caregivers and aid the development of support systems to improve health outcomes for caregivers and care recipients.

Dual Tasking Influences Cough Reflex Outcomes in Adults with Parkinson's Disease: A Controlled Study.

Coughing is an essential airway protective reflex. In healthy young adults, cough somatosensation changes when attention is divided (dual tasking). Whether the same is true in populations at risk of aspiration remains unknown. We present findings from a controlled study testing the effects of divided attention (via a dual-task paradigm) on measures of reflex cough in Parkinson's disease. Volunteers with Parkinson's disease (n = 14, age = 43-79 years) and 14 age-matched controls underwent five blocks of capsaicin-induced cough challenges. Within each block, capsaicin ranging from 0 to 200 µM was presented in a randomized order. Two blocks consisted of cough testing only (single task), and two blocks consisted of cough testing with simultaneous tone counting (dual task). Finally, participants completed a suppressed cough task. Measures of cough motor response, self-reported urge to cough, cough frequency, and cough airflow were collected. Historical data from healthy young adults was included for comparison. Between-group analyses revealed no differences between single- and dual-cough-task responses. However, post hoc analysis revealed a significant relationship between dual-task errors and cough frequency that was strongest in people with Parkinson's disease [p = 0.004, r2 = 0.52]. Specifically, greater errors were associated with fewer reflexive coughs. Unlike healthy participants, participants with Parkinson's disease did not change the number of coughs between the single-, dual-, and suppressed-task conditions [p > 0.05]. When distracted, people with Parkinson's disease may prioritize coughing differently than healthy controls. Abnormal cortical resource allocation may be a mechanism involved in aspiration in this population.

Relationship of vocal fold atrophy to swallowing safety and cough function in Parkinson's disease.

OBJECTIVES: When swallowing function is compromised in patients with Parkinson's disease (PD), cough plays a crucial role in clearing the airway and preventing pulmonary complications. The aim of this study was to determine the influence of vocal fold atrophy severity as measured by the bowing index (BI) on airway protection in PD. METHODS: Thirty participants with PD completed measures of voluntary and reflex cough. Flexible laryngoscopy with endoscopic evaluation of swallowing allowed for measurement of BI using ImageJ software. Swallowing safety was scored on the Penetration-Aspiration Scale (PAS). Regression and receiver operating characteristic (ROC) analyses were performed to test our study aim. RESULTS: Twenty-four of 30 participants had some degree of vocal fold atrophy (BI >0). When controlling for age, disease duration did not significantly influence BI. BI was not predictive of any sensorimotor parameters of cough including measures of cough airflow, reflex cough threshold, or urge to cough. BI discriminated participants with near-normal (PAS 1-3) swallowing safety from participants with impaired (PAS 4-8) swallowing safety (P = .01, sensitivity: 87.0%, specificity: 71.4%, cutoff value BI >4.6). CONCLUSION: Vocal fold atrophy is a potential factor contributing to poor swallowing safety in PD. BI was not associated with cough function in this PD cohort, contrary to prior studies that have shown improved cough measures after vocal fold augmentation. Vocal fold atrophy in PD remains an important area of study as a targetable intervention for patients with airway protective dysfunction. Future studies should include measures of glottic closure during vocal fold adduction. LEVEL OF EVIDENCE: Level 3 Laryngoscope, 130:303-308, 2020.

The association between oral bacteria, the cough reflex and pneumonia in patients with acute stroke and suspected dysphagia.

OBJECTIVE: To establish how oral bacteria are related to cough sensitivity and pneumonia in a clinical stroke population. BACKGROUND: Stroke patients are at risk of colonisation by respiratory pathogens due, in part, to sudden discontinuation of effective oral hygiene. When combined with reduced cough reflex sensitivity, aspiration of contaminated oropharyngeal contents and can lead to pneumonia. Relationships between oral bacteria, cough sensitivity and pneumonia have not been established. MATERIALS AND METHODS: A total of 102 patients with acute stroke underwent saliva sampling and cough reflex testing at admission to hospital, discharge and one month. A qPCR assay compared levels of bacteria in saliva. Pneumonia events were recorded. RESULTS: Relative levels of bacteria were lowest at admission to hospital (6.04 × 10-6 ). There was a slight (non-significant) increase in bacterial levels at discharge (1.69 × 10-2 , P = .73). By one month, bacterial levels had significantly increased (9.17 × 10-2 ) relative to admission [P < .001] and discharge [P < .001]. Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli are not typically found in healthy mouths, yet were detected in 22% of patients during hospitalisation. Combined bacterial levels measured at one month was associated with pneumonia (P = .004) but there was no relationship to cough sensitivity. CONCLUSION: Acute stroke patients were at increased risk of colonisation from respiratory pathogens throughout their recovery. The presence of these pathogens in saliva at one month was associated with adverse respiratory events. Data support the development of protocols to explore risk factors and sequelae of microbiological changes in stroke.

Dual Tasking Influences Cough Sensorimotor Outcomes in Healthy Young Adults.

Purpose Reflex cough is an essential airway protective mechanism that often occurs in the context of divided attention. The effect of divided attention on measures of reflexive cough airflow and sensitivity remains unknown. We present findings from a study testing the effects of divided attention (via a dual-task paradigm) on measures of reflex cough in healthy young adults. Method Volunteers (N = 20, age = 20-40 years) underwent 4 blocks of capsaicin-induced cough challenges. Within each block, capsaicin ranging from 0 to 200 µM was presented in a randomized order. Two blocks consisted of cough testing only (single task). During the other 2 blocks, participants counted tones while simultaneously undergoing cough testing (dual task). Measures of cough motor response, self-reported urge-to-cough, cough frequency, and cough airflow were collected. Results Participants coughed more in the single-task condition compared to the dual-task condition (p ≤ .001). Participants' urge-to-cough ratings were lower in the dual-task condition (x̅ = 2, "slight") compared to the single-task condition (x̅ = 3, "moderate"; p = .007). Participants' cough reflex sensitivity thresholds were significantly increased in the dual-task condition (p = .002). Cough peak expiratory flow rates did not change between the 2 conditions (p = .34). Conclusions Somatosensation of tussive stimuli changes during dual tasking. Abnormal cortical resource allocation may be a mechanism involved in silent aspiration.

The Dysphagia in Stroke Protocol Reduces Aspiration Pneumonia in Patients with Dysphagia Following Acute Stroke: a Clinical Audit.

Cough reflex testing has been evaluated as a component of the clinical swallowing assessment as a means of identifying patients at risk of aspiration during swallowing. A previous study by our research group found good sensitivity and specificity of the cough reflex test for identifying patients at risk of aspiration post-stroke, yet its use did not decrease pneumonia rates, contrary to previous reports. The aim of this study was to expand on our earlier work by implementing a clinical management protocol incorporating cough reflex testing within the same healthcare setting and compare patient outcomes to those from the original study and to evaluate clinical outcomes in patients with acute stroke who were managed using the Dysphagia in Stroke Protocol (DiSP). Secondarily, to compare those outcomes to historical data prior to implementation of the DiSP. This clinical audit measured outcomes from 284 patients with acute stroke managed per the DiSP, which guides use of videofluoroscopic swallowing study and patient management based on clinical exam with cough reflex testing. Data from our previous trial were included for comparison of pre- and post-DiSP patient outcomes. Data collection took place between November 2012 and April 2016 at four urban hospitals within New Zealand. Following implementation of the DiSP, the rate of aspiration pneumonia (10%) was substantially lower than the pre-DiSP rate (28%), with no pneumonia readmissions within 3 months. Pneumonia-related mortality was unchanged. By 3 months, 81% of the patients were on a normal diet and 67% had returned home, compared to pre-DiSP outcomes of 55% and 55% respectively. Previous work has suggested that simply implementing cough reflex testing in dysphagia management may not be sufficient to improve patient outcomes. The present study adds to this picture by suggesting that the true variable of influence may be the way in which the results of the test are applied to patient care. There is a strong case to support the use of a structured protocol if cough reflex testing is to be implemented in clinical practice.

Variability in Ultrasound Measurement of Hyoid Bone Displacement and Submental Muscle Size Using 2 Methods of Data Acquisition.

OBJECTIVE: This study compares variability in measures of hyoid bone displacement and submental muscle size using 2 methods of ultrasound transducer placement: fixed and hand-held. PATIENTS AND METHODS: Twenty-four healthy participants (11 males, 13 females) aged between 51 and 84 years were scanned using both methods. Repeated measures were collected within and across 3 sessions. RESULTS: A nonlinear mixed effects model was used to estimate the effects of the method, trial, and session. The fixed transducer produced greater within- and across-session variability on several measures compared to the hand-held method. Fixed-transducer measurements of hyoid bone displacement were 9.4% smaller compared to hand-held measurements (F[1, 24.34] = 3.58, p = 0.07). CONCLUSION: Results suggest that using a fixed transducer does not necessarily improve measurement accuracy of swallowing outcomes in a healthy system. The wide variability in individual measures indicates that further research is required before ultrasound is used for outcome measurement in rehabilitation.