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

The effect of breathing training on swallowing function in patients with neurogenic dysphagia: a systematic review and meta-analysis

PURPOSE

This study aimed to systematically review various breathing training methods for patients with neurogenic dysphagia, and assess their clinical efficacy to improve swallowing function in individuals with neurological disorders such as stroke.

METHODS

Relevant studies were retrieved from nine databases (PubMed, Embase, Web of Science, The Cochrane Library, CINAHL, CNKI, Wanfang, China Science and Technology Journal Database, and China Biomedical Literature Database). Articles included in the review were published from the date of establishment of each database up to January 2024. Eleven randomized control trials (RCTs) and five quasi-experimental studies that met the inclusion criteria were included in this systematic review. Data and information were extracted independently by two reviewers, with disagreements resolved through consensus with a third coauthor. The primary outcome assessed was swallow function occurrence. The quality of the included studies was evaluated using the Cochrane risk of bias assessment tool and the JBI quality assessment tool.

RESULTS

The meta-analysis results showed that expiratory muscle strength training can improve swallowing function (standard mean deviation = -0.89, 95% confidence interval [-1.23, -0.55], Z = 5.11, P < 0.01).

CONCLUSION

This paper categorized and summarized specific respiratory muscle groups targeted in different breathing training methods, providing guidance for clinicians in designing personalized regimens. The study showed that expiratory muscles strength training is the main method for improving respiratory strength and coordination between swallowing and breathing, reducing the risk of aspiration. More research is needed to assess the effectiveness of independent breathing training.

Dyspnea and dystussia in Parkinson's disease: patient-reported prevalence and determinants

BACKGROUND

The prevalence of respiratory dysfunction in PD is unknown and a better understanding of determinants contributing to respiratory dysfunction is important to facilitate early recognition and treatment.

OBJECTIVE

To examine the prevalence and determinants of self-reported symptoms of respiratory dysfunction among people with PD.

METHODS

In a cross-sectional study, we administered a self-completed questionnaire among a sample of 939 persons with PD. Respiratory dysfunction was defined as experiencing at least one of the following symptoms: breathing difficulties, breathlessness/shortness of breath, tightening of the chest, frequent throat clearing, frequent coughing, or coughing difficulties. A principal component analysis (PCA) was used to define composite constructs of respiratory dysfunction. The association with participant-reported determinants was assessed using multivariable logistic regression models (with adjustment for pulmonary diseases and COVID-19 symptoms).

RESULTS

The overall prevalence rate of respiratory dysfunction was 44% in persons with PD (42% after excluding pulmonary diseases or COVID-19). The PCA resulted in two constructs of respiratory dysfunction: 'dyspnea' and 'dystussia' (an impaired cough response), which together explained 68% of the total variance. Female sex (OR = 1.39), higher BMI kg/m2 (OR = 1.04), longer disease duration (OR = 1.35), greater self-reported rigidity (OR = 1.16), previous pulmonary disease(s) (OR = 7.12), and anxiety (OR = 1.04) were independently associated with 'dyspnea'. Pulmonary disease(s) (OR = 1.81), COVID-19 symptoms (OR = 2.20), swallowing complaints (OR = 1.48), and speech complaints (OR = 1.02) were independently associated with 'dystussia'.

CONCLUSIONS

Dyspnea and dystussia are common manifestations of respiratory dysfunction among people with PD and deserves more awareness in clinical practice. A proactive screening for the determinants of dyspnea and dystussia may contribute to earlier recognition and treatment of respiratory dysfunction.

Motor Imagery Practice to Improve Respiratory and Cough Function

Motor imagery practice (MP), or visualizing performing a task without executing it, is an effective intervention for the limbs and tongue. However, MP of expiratory muscle strength training (EMST) and voluntary cough (VC) has not been explored. We examined the feasibility and impact of MP of VC and EMST on pulmonary and cough function in twenty community-dwelling adults. Participants underwent two baseline research evaluations of maximum expiratory and inspiratory pressure (MEP, MIP), forced vital capacity (FVC), voluntary peak expiratory flow rate (PEF), and cough spirometry. After the second research evaluation, participants underwent five weeks of MP of VC or EMST (alternating assignment, 25 repetitions, 70% training load, daily) at home with weekly telehealth sessions. Participants underwent post-treatment research evaluations of MEP, MIP, FVC, PEF, cough spirometry, and the Exercise Therapy Burden Questionnaire (ETBQ). Treatment adherence and telehealth attendance were tracked. Descriptives and Wilcoxon signed rank tests were performed. MP adherence was 95% and telehealth attendance was 91%. Median (IQR) ETBQ scores were 8 (1, 15), indicating minimal burden. Across both MP groups, increases in PEF from a handheld device (+ 13.7, 95% CI: 1.8, 25.6, p = 0.03) and from cough spirometry (+ 0.71, 95% CI: 0.05, 1.4, p = 0.04) were observed. Increases in PEF from cough spirometry (+ 1.00, 95% CI: 0.12, 1.9, p = 0.04) were observed for the MP VC group. Preliminary data demonstrate MP of VC and EMST is feasible and improves voluntary cough in community-dwelling adults. Future research is needed in larger sample sizes and patient populations with pulmonary, cough, and swallowing impairments.

Effect of Elevation Training Mask on Swallowing Function in Individuals with Parkinson's Disease

To evaluate the impact of the elevation training mask (ETM) on swallowing safety and swallowing efficiency in patients with Parkinson's disease (PWP) when used as a respiratory muscle strengthening tool. Study Design. Prospective cohort study. Setting. Tertiary university-affiliated medical center. Thirteen PWP underwent Fiberoptic Endoscopic Evaluation of Swallowing and spirometry assessments both before and after a 4-week ETM use, which included incrementally increasing resistance each week. Measurements taken included EAT-10, swallowing disturbances questionnaire (SDQ), Penetration Aspiration Score (PAS), Yale Pharyngeal Residue Severity Rating Scale, and Peak Expiratory Flow (PEF). Disease severity was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS). Eleven out of 13 male participants (median age 70 years, UPDRS 33, disease duration 8.5 years) completed the 4-week protocol (84.6% completion rate). Vallecular residue significantly decreased for solids (median from 3.0 [IQR: 2.0-3.0] to 2.0 [IQR: 1.0-2.0], p = 0.028) and semi-solids (from 3.0 [IQR: 2.0-4.0] to 2.0 [IQR: 1.0-3.0], p = 0.025), with a non-significant improvement for liquids (from 2.0 [IQR: 2.0-2.0] to 2.0 [IQR: 1.0-2.0], p = 0.19). Patient-reported outcomes (EAT-10, SDQ, VHI-10, RSI) and PEF showed non-significant trends toward improvement. A 4-week use of ETM, serving as a form of respiratory muscle strengthening, demonstrated specific improvements in vallecular residue for semi-solid and solid consistencies in PWP with dysphagia. While other swallowing and respiratory measures showed positive trends, these changes did not reach statistical significance. Further research with a larger cohort is needed to evaluate ETM's role in swallowing rehabilitation.

Effects of LSVT LOUD and EMST in individuals with Parkinson's disease: A two arm non-randomized clinical trial

PURPOSE

This study compared the effects of Lee Silverman Voice Treatment and Expiratory Muscle Strength Training on swallow, cough, and voice function in individuals with Parkinson's disease.

METHOD

Fifty-eight individuals with mild-moderate Parkinson's disease (male = 45, M = 69 years, SD = 8) were enrolled in a two-treatment clinical trial and completed four consecutive weeks of either Lee Silverman Voice Therapy or Expiratory Muscle Strength Training. All participants completed standard protocol videofluoroscopic swallow study, spirometry-cough tests, acoustic-voice assessment, and self-rated questionnaires pre- and post-therapy. Data were analysed by masked clinicians using specialised software. Mixed-model repeated measures and t-tests were performed.

RESULT

Lee Silverman Voice Treatment resulted in greater effects in acoustic aerodynamic voice measures (loudness, pitch-range, and aerodynamic-efficiency; p < .05) compared to the Expiratory Muscle Strength Training group. There were significant effects on pharyngoesophageal segment maximum opening (p =.01) following Lee Silverman Voice Treatment. Expiratory Muscle Strength Training resulted in significantly greater change in maximum hyoid displacement (Hmax; p = .04) and decreased Hmax duration (p < .01) compared to Lee Silverman Voice Therapy group. No cough measures and self-reported questionnaires significantly differed between groups with both groups improving post-treatment.

CONCLUSION

Both Lee Silverman Voice Therapy and Expiratory Muscle Strength Training improved specific swallow efficiency and airway defence capacity despite differences in task and therapeutic dose. Only Lee Silverman Voice Thearpy improved vocal intensity. Both treatments are feasible options for individuals with mild-moderate Parkinson's disease.

Bowing Index in Individuals With Parkinson's Disease, Progressive Supranuclear Palsy, and Ataxia

PURPOSE

Variations in vocal fold bowing, as measured endoscopically with the bowing index (BI), across neurodegenerative diseases remain unexplored, which may inform interventions to minimize morbidity and mortality secondary to voice and airway protective dysfunction. The study's aim was to compare BI between people with Parkinson's disease, progressive supranuclear palsy, and cerebellar ataxia.

METHODS

Thirty individuals with Parkinson's disease, 23 with progressive supranuclear palsy, and 24 with cerebellar ataxia were included and underwent flexible laryngoscopy. BI was measured using ImageJ software and a linear regression model was used to compare differences in total BI between groups, controlling for age.

RESULTS

Average total BI was 14.60 (SD = 6.26, range 4.03-28.62) for people with progressive supranuclear palsy, 10.10 (SD = 6.64, range 0-34.13) for Parkinson's disease, and 8.35 (SD = 5.90, range 0-25.95) for cerebellar ataxia. Controlling for age, people with progressive supranuclear palsy demonstrated 4.74 greater BI compared to Parkinson's disease (95 CI: 1.19-8.28; p = 0.001), but there was no significant difference between people with Parkinson's disease and cerebellar ataxia (β = 0.37; 95% CI: -5.02, 5.77; p = 0.891) or people with progressive supranuclear palsy and cerebellar ataxia (β = 5.11; 95% CI: 0.01-10.21; p = 0.050).

CONCLUSIONS

The results suggest that BI is significantly greater in people with progressive supranuclear palsy compared to Parkinson's disease. It is important to recognize vocal fold atrophy and its potential impact on voice and airway protective measures in these patients.

LEVEL OF EVIDENCE

3 Laryngoscope, 2025.

Progress in dysphagia management in older patients

PURPOSE OF REVIEW

The review summarizes current knowledge, recent findings and knowledge gaps about the pathophysiology and therapy of oropharyngeal dysphagia in older persons.

RECENT FINDINGS

Oropharyngeal dysphagia is a major yet underrecognized health problem in older persons. Due to its high prevalence, its multifactorial etiology and multimodal treatment it has been classified as a geriatric syndrome. Although the knowledge of its pathophysiology and the effective diagnostic approach increased substantially during the last years, there is still minor evidence on how to effectively manage and treat dysphagia. However, treatment should be a multicomponent approach, combining swallowing training, nutritional therapy and oral hygiene. Emerging new fields are neurostimulation and chemical sensory stimulation which may be added in selected patients and indications. The individual components to be chosen should be based on the individual dysphagia pattern and severity as well as the capabilities of the patient. Frequently, the competing risks of inadequate nutrition and unsafe swallowing represent a challenge in determining the individual relevance of each component.

SUMMARY

The understanding of the pathophysiology of oropharyngeal dysphagia increased substantially during recent years. However, due the multifaceted appearance of dysphagia, which requires an individualized treatment, the evidence for therapeutic approaches increases rather slowly.

The impact of expiratory muscle strength training on voluntary cough effectiveness in Huntington's disease

BACKGROUND AND PURPOSE

Dysfunction of the airway defence system in Huntington's disease (HD) is a significant but often overlooked problem. Although expiratory muscle strength training (EMST) is frequently utilized in cough effectiveness treatment, its specific impact in HD patients has not yet been explored. This study investigated the effects of EMST on voluntary peak cough flow (vPCF) in HD patients and evaluated the retention of potential gains post-intervention.

METHODS

In this prospective case-controlled trial, 29 HD patients completed an 8-week wait-to-start period, which served to identify the natural development of expiratory muscle strength and vPCF. This was followed by 8 weeks of EMST training and an additional 8 weeks of follow-up. The study's outcome parameters, vPCF and maximum expiratory pressure (MEP), were measured against those of age- and sex-matched healthy controls.

RESULTS

Huntington's disease patients had significantly lower MEP (p < 0.001) and vPCF (p = 0.012) compared to healthy controls at baseline. Following the EMST, significant improvements in MEP (d = 1.39, p < 0.001) and vPCF (d = 0.77, p = 0.001) were observed, with HD patients reaching the cough performance levels of healthy subjects. However, these gains diminished during the follow-up, with a significant decline in vPCF (d = -0.451, p = 0.03) and in MEP (d = -0.71; p = 0.002).

CONCLUSIONS

Expiratory muscle strength training improves expiratory muscle strength and voluntary cough effectiveness in HD patients, but an ongoing maintenance programme is necessary to sustain the improvements.

Minimal Detectable Change of Cough and Lingual Strength Outcomes in Neurodegenerative Disease

OBJECTIVE

Minimal detectable change (MDC) represents the smallest amount of change required for an outcome to be considered real and not merely due to measurement error or task variability. This study aimed to examine MDC for cough and lingual strength outcomes among individuals with neurodegenerative disease.

METHODS

In a single session, individuals diagnosed with Parkinson's disease (PD), progressive supranuclear palsy (PSP), and cerebellar ataxia completed repeated measurements of voluntary sequential cough via spirometry (n = 143) and lingual isometric and swallowing pressure with the Iowa Oral Performance Instrument (n = 231). The MDC at the 95% confidence level was calculated with the following formula: MDC = 1.96 × √2 × SEM.

RESULTS

MDC for cough strength was 0.52 L/s (PD), 0.57 L/s (PSP), and 0.20 L/s (ataxia). On trials with the same number of coughs, MDC for cough strength was 0.18 L/s in PD and 0.24 L/s in ataxia. MDC for lingual isometric pressure was 5.44 kPa (PD), 2.35 kPa (PSP), and 3.41 kPa (ataxia), whereas swallowing pressure was 5.60 kPa (PD), 2.97 kPa (PSP), and 7.34 kPa (ataxia).

CONCLUSIONS

These findings elucidate MDC for cough and lingual strength outcomes and expand our understanding of change that can be considered "real" and not merely due to task variability. MDC facilitates valid interpretations of changes following treatment, as well as power analyses to determine the smallest effect size of interest before data collection. To illustrate the application of MDC, we situate these findings in the context of hypothetical case studies and research studies.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:5034-5040, 2024.

Enhancing Cough Motor Learning in Parkinson's Disease Through Variable Practice During Skill Training

BACKGROUND

When re-learning a motor skill, practicing a variety of treatment targets promotes error processing and the exploration of motor control strategies, which initially disrupts accuracy during training (motor performance), but ultimately enhances generalization, retention, and transfer (motor learning). Cough skill training (CST) is feasible and efficacious to improve cough strength; however, previous studies have used the same practice target during training.

OBJECTIVES

Our goal was to examine the impact of CST with variable practice on motor performance, motor learning, and respiratory system adaptations.

METHOD

The study was a prospective three-visit single group design. Twenty individuals with Parkinson's disease (PD) and concomitant dysphagia and dystussia completed two sessions of CST involving three randomized practice targets. Cough, lung volume, and airway clearance outcomes were assessed before and after treatment sessions with long-term retention evaluated after 1 month.

RESULTS

Peak expiratory flow rate improved after CST with variable practice for voluntary single (β = 0.35 L/s) and sequential (β = 0.22 L/s) cough, which were maintained after 1 month without treatment. The ability to expel material from the upper airway demonstrated a small magnitude of improvement (β = -1.87%). During CST, participants altered lung volume based on the treatment target and lung volume decreased during reflex cough after completing CST.

CONCLUSIONS

Individuals with PD demonstrated improvements in several aspects of motor learning after two sessions of CST with variable practice. Increasing lung volume may not be an implicit strategy to upregulate voluntary cough strength in this treatment paradigm. The findings support the need for larger investigations exploring the potential benefits of this CST approach.

Therapeutic singing and expiratory muscle strength training in Parkinson's disease: a mixed methods comparison

Introduction

The purpose of this study was to understand how two respiratory strengthening protocols, therapeutic singing (TS) and expiratory muscle strength training (EMST), compare on measures of quality of life (QOL), depression and anxiety for persons with Parkinson's disease. An equally important aim was to understand participants' perceptions of both treatments.

Methods

Quantitative and qualitative datasets were integrated in a convergent mixed methods design within a randomized crossover intervention trial. Thirteen persons with mild-moderate PD (Hoehn and Yahr stage 1-3) completed both interventions, in random order, for 4 weeks, 5 days per week, for approximately 20 min per day. Participants completed self-report questionnaires (Geriatric Depression Scale, Parkinson's Anxiety Scale, Parkinson's Disease Questionnaire-39, and a Survey after Treatment) after each intervention, and twelve participants' qualitative data were analyzed.

Results

Quantitative data did not reveal significant differences between the interventions in depression on the Geriatric Depression Scale or anxiety on the Parkinson's Anxiety Scale and the qualitative data support those findings. There were no significant differences between interventions in QOL as measured by the Parkinson's Disease Questionnaire-39, but there was a main effect of time, with a significant decline (p = 0.01) in perceived QOL between baseline and the final visit. The quantitative data diverged from the qualitative data as there were no themes that emerged to corroborate a decrease in QOL. Five qualitative themes were derived from thematic analysis: Benefits, Accessibility, Acceptability, Advice/Feedback, and Preference. Participants' perceptions of the interventions were closely aligned to individual differences and preferences, with an equal split of participants preferring TS and EMST.

Conclusions

Findings from this mixed methods comparison of two respiratory interventions will help to improve the acceptability and accessibility of the interventions to better facilitate adherence to the interventions and promote continued engagement, thereby delaying respiratory decline in those with PD.

mHealth-assisted expiratory muscle strength training in Parkinson's disease patients: A proof-of-concept study

BACKGROUND

Expiratory muscle strength training (EMST) is acknowledged for its therapeutic benefits in Parkinson's disease (PD), yet long-term adherence remains a challenge.

OBJECTIVE

The primary aim of this study was to assess the preliminary effects of EMST coupled with a mobile health app (SpiroGym) on self-efficacy and exercise adherence in PD patients. The secondary aim was to assess the usability of the SpiroGym app.

METHODS

This single-group, multicenter, multinational proof-of-concept study involved 63 PD patients across four tertiary PD centers. Participants were enrolled in either a 1-week (n = 35) or 24-week (n = 28) EMST program coupled with SpiroGym app. Self-efficacy was assessed using the Self-Efficacy for Home Exercise Program scale (SEHEPS) and exercise adherence was monitored by SpiroGym app. Usability was evaluated using the System Usability Scale.

RESULTS

Post-intervention, significant improvements in SEHEPS were observed in 1-week group (d = 0.48; p = 0.02) and 24-week group (d = 0.57; p = 0.002). Adherence rates in the 24-week PD patient group were high throughout the course of the study. Post-training SEHEPS was found to correlate (rho = 0.55; adjusted p = 0.016) with adherence to EMST during the non-supervised maintenance phase. The SpiroGym app exhibited high usability (>85th percentile score), with no significant differences noted between short-term and long-term use, indicating sustained user satisfaction.

CONCLUSIONS

The results of our study suggest a promising role for SpiroGym app in supporting adherence to home-based EMST in PD patients. Nevertheless, future comparative studies are required to confirm SpiroGym's effectiveness.

Effects of Expiratory Muscle Strength Training on Oropharyngeal Swallow Physiology in Persons with Obstructive Sleep Apnea (OSA): A Preliminary Study

Despite the high estimated prevalence of dysphagia in OSA, there is a paucity of evidence supporting behavioral interventions for treatment. The purpose of this study was to assess the impact of expiratory muscle strength training (EMST) on validated, standardized metrics of swallow and airway clearance capacity functions in moderate-to-severe OSA. 10 participants with OSA (mean age = 65.2 years) completed four weeks of EMST training employing a prospective single-arm, double-baseline interventional design. The Modified Barium Swallow Impairment Profile (MBSImP) Component and Composite (Oral Total [OT] and Pharyngeal Total [PT]) scores measured swallow physiology. Airway clearance capacity measures included maximum expiratory pressure (MEP) and peak cough flow (PCF). A historical normative database was used for OSA patient comparison of swallowing metrics. A total of 234 swallows were analyzed. At baseline, impairments in lingual control, oral residue and esophageal clearance were observed. However, no significant differences in the MBSImP Composite (OT/PT) scores were observed between the OSA and healthy referent group. After EMST intervention, there were no significant differences in pre- to post-intervention Composite (OT/PT) scores. However, large effect size was observed for MEP (p < 0.001, d = 3.0), and non-significant, but moderate effect size was observed in PCF (p = 0.19, d = 0.44). Study findings further quantify swallowing in moderate-to-severe OSA and provide preliminary evidence supporting the impact of EMST on airway clearance capacity.

Relationship between oral status, swallowing function, and nutritional risk in older people with and without Parkinson's disease

PURPOSE

To compare oral status, swallowing function (through instrumental and SLH assessment), and nutritional risk between dysphagic individuals with and without Parkinson's disease.

METHOD

This is a cross-sectional retrospective study based on data collected from medical records. It included 54 dysphagic older adults, divided into two groups according to the diagnosis of Parkinson's disease. The study collected data on the speech-language-hearing assessment of postural control, tongue mobility and strength, maximum phonation time (MPT), and cough efficiency. Oral status was assessed using the number of teeth and the Eichner Index. The level of oral intake and pharyngeal signs of dysphagia were analyzed with four food consistencies, according to the International Dysphagia Diet Standardization Initiative classification, using fiberoptic endoscopic evaluation of swallowing, for comparison between groups. The severity of pharyngeal residues was analyzed and classified with the Yale Pharyngeal Residue Severity Rating Scale, and the nutritional risk was screened with the Malnutrition Screening Tool.

RESULTS

The group of older adults with Parkinson's disease was significantly different from the other group in that they had fewer teeth, unstable postural control, reduced tongue strength, reduced MPT, weak spontaneous coughing, pharyngeal signs, less oral intake, and nutritional risk.

CONCLUSION

Dysphagic older people with Parkinson's disease had different oral status, swallowing function, and nutritional risk from those without the diagnosis.

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 (β = -0.05, 95% CI: -0.09 - -0.01 L) and ataxia severity and voluntary CEV (β = -0.01, 95% CI: -0.02 - -0.004 L/s). Relationships between reflex cough motor outcomes (PEFR β = 0.03, 95% CI: -0.007-0.07 L/s; CEV β = 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.

Hypotussic cough in persons with dysphagia: biobehavioral interventions and pathways to clinical implementation

Cough is a powerful, protective expulsive behavior that assists in maintaining respiratory health by clearing foreign material, pathogens, and mucus from the airways. Therefore, cough is critical to survival in both health and disease. Importantly, cough protects the airways and lungs from both antegrade (e.g., food, liquid, saliva) and retrograde (e.g., bile, gastric acid) aspirate contents. Aspiration is often the result of impaired swallowing (dysphagia), which allows oral and/or gastric contents to enter the lung, especially in individuals who also have cough dysfunction (dystussia). Cough hyposensitivity, downregulation, or desensitization- collectively referred to as hypotussia- is common in individuals with dysphagia, and increases the likelihood that aspirated material will reach the lung. The consequence of hypotussia with reduced airway clearance can include respiratory tract infection, chronic inflammation, and long-term damage to the lung parenchyma. Despite the clear implications for health, the problem of managing hypotussia in individuals with dysphagia is frequently overlooked. Here, we provide an overview of the current interventions and treatment approaches for hypotussic cough. We synthesize the available literature to summarize research findings that advance our understanding of these interventions, as well as current gaps in knowledge. Further, we highlight pragmatic resources to increase awareness of hypotussic cough interventions and provide support for the clinical implementation of evidence-based treatments. In culmination, we discuss potential innovations and future directions for hypotussic cough research.

Post-Radiotherapy Dysphagia in Head and Neck Cancer: Current Management by Speech-Language Pathologists

OPINION STATEMENT

Dysphagia, difficulty in eating and drinking, remains the most common side effect of radiotherapy treatment for head and neck cancer (HNC) with devastating consequences for function and quality of life (QOL). Over the past decade, 5-year survival has improved due to multiple factors including treatment advances, reduction in smoking, introduction of the human papillomavirus (HPV) vaccine and more favourable prognosis of HPV-related cancers. Increased prevalence of HPV-positive disease, which tends to affect younger individuals, has led to an elevated number of people living for longer with the sequelae of cancer and its treatment. Symptoms are compounded by late effects of radiotherapy which may lead to worsening of dysphagia for some long-term survivors or new-onset dysphagia for others. Speech-language pathology (SLP) input remains core to the assessment and management of dysphagia following HNC treatment. In this article, we present current SLP management of dysphagia post-radiotherapy. We discuss conventional treatment approaches, the emergence of therapy adjuncts and current service delivery models. The impact of adherence on therapy outcomes is highlighted. Despite treatment advancements, patients continue to present with dysphagia which is resistant to existing intervention approaches. There is wide variation in treatment programmes, with a paucity of evidence to support optimal type, timing and intensity of treatment. We discuss the need for further research, including exploration of the impact of radiotherapy on the central nervous system (CNS), the link between sarcopenia and radiotherapy-induced dysphagia and the benefits of visual biofeedback in rehabilitation.

A Preliminary Study of Voluntary Cough Motor Performance and Learning With Skill Training and Biofeedback

PURPOSE

Sensorimotor cough skill training (CST) has been shown to improve cough strength, as well as facilitate changes during training (i.e., motor performance) and generalization to untrained tasks (i.e., motor learning). However, there is a gap in our understanding of the effects of voluntary CST (without sensory stimuli) on motor performance and learning. Furthermore, the contribution of physiologic factors, such as lung volume, a driver of cough strength in healthy adults, and treatment-specific factors, such as biofeedback, remains unexamined.

METHOD

Twenty individuals with Parkinson's disease (PD) completed pre- and post-CST single voluntary, sequential voluntary, and reflex cough testing. Participants were randomized to biofeedback or no biofeedback groups. They completed one CST session involving 25 trials of voluntary coughs, with the treatment target set 25% above baseline peak flow. Participants were instructed to "cough hard" to exceed the target. In the biofeedback group, participants received direct visualization of the target line in real time.

RESULTS

Cough peak flow showed positive improvements in motor performance (β = .02; 95% credible interval [CI]: 0.01, 0.03) and learning (β = .26; 95% CI: 0.03, 0.47). Changes in lung volume from pre- to post-CST did not predict treatment response. No differences in treatment response were detected between the biofeedback groups.

CONCLUSIONS

A single session of voluntary CST improved voluntary cough motor performance and learning. Although lung volume increased during CST, changes to lung volume did not predict treatment response. These findings demonstrate the potential of voluntary CST to improve motor performance and motor learning among individuals with PD and cough dysfunction.

SUPPLEMENTAL MATERIAL AND OPEN SCIENCE FORM

https://doi.org/10.23641/asha.25447444.

Concurrent Validity of a Low-Cost Manometer for Objective Assessments of Respiratory Muscle Strength

OBJECTIVE(S)

This study examined the agreement in maximal expiratory (MEP) and inspiratory (MIP) pressure readings between two digital manometers: (1) the MicroRPM - the gold-standard manometer for respiratory muscle strength testing; and (2) the LDM - a low-cost, commercially available, alternative manometer.

METHODS

Positive (MEP) and negative (MIP) pressures were simultaneously applied to the MicroRPM and LDM using a 3-liter syringe within a controlled laboratory setting. Pressure readings were compared, and agreement was analyzed using Lin's concordance correlation (ρc ). Agreement was interpreted as 'poor' if <0.90, 'moderate' if 0.90 - <0.95, 'substantial' if 0.95 - <0.99, and 'excellent' if ≥0.99. Twenty percent of the pressure trials were repeated by a second researcher to examine test-retest reliability.

RESULTS

A total of 150 trials were completed, ranging from -167 to +208 cmH2 O. There was a median absolute difference of 0.3 cmH2 O in pressure readings between the MicroRPM and the LDM. Lin's concordance correlation revealed 'excellent' agreement between the LDM and MicroRPM devices, with test-retest reliability assessment revealing 'substantial-to-excellent' agreement between the LDM and MicroRPM devices, with a concordance correlation coefficient of ρc  = 0.999 (95% CI: 0.999-0.999).

CONCLUSIONS

There was a median difference of 1.0% in MEP and MIP pressure readings consistently observed between the LDM and MicroRPM. Despite these relatively small differences, excellent agreement between the two manometers was present. These data suggest the LDM may be a valid, lower cost alternative to the MicroRPM for objectively assessing respiratory strength in clinical practice; however, additional research is needed in healthy adults and in patient populations.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1831-1836, 2024.

Cough Correlates of Functional Swallow Outcomes in Atypical Parkinsonism

BACKGROUND

Swallow and cough impairments lead to aspiration and reduced clearance of aspirate material. Both behaviors are impaired in Parkinson's disease, but it is unknown whether a similar relationship of dysfunction exists in forms of atypical Parkinsonism (APD). Elucidating this association in APD may lead to early, comprehensive airway protection treatment.

OBJECTIVES

We tested the hypotheses that swallow deficits in APD are associated with impaired cough and that airway protective dysfunction is associated with longer disease duration.

METHODS

Swallowing difficulty was described by 11 participants with APD. Penetration-Aspiration Scale (PAS) and DIGEST scores for thin liquid trials were extracted from medical records of videofluoroscopic swallow study reports. Voluntary and capsaicin induced-reflex cough measures of flow, volume, and timing were analyzed.

RESULTS

While most participants did not have post-swallow residue, ~80% received abnormal PAS scores and reported swallowing difficulty. Those with abnormal PAS scores had lower voluntary cough expired volume (P = 0.037; mean rank difference = 5.0); lower reflex inspiratory flow rate (P = 0.034; mean rank difference = 5.5); and longer reflex expiratory flow rise time (P = 0.034; mean rank difference = 5.5). Higher PAS scores and reduced reflex cough volume acceleration were significantly correlated (r = -0.63; P = 0.04) and longer disease duration predicted larger voluntary cough expired volume (R2  = 0.72) and longer flow rise times (R2  = 0.47).

CONCLUSIONS

As swallow safety worsens, so might the ability to clear the airways with effective cough in in APD; particularly with longer disease duration. Assessing cough in conjunction with swallowing is important for informing airway protection treatment plans in APD.

Delivery of Allied Health Therapies to People with Parkinson's Disease in Africa

Allied health therapies refer to a range of healthcare professionals, including physiotherapists, occupational and speech-language therapists, who aim to optimize daily function and quality of life in conjunction with medical care. In this narrative review of literature on allied health therapies in people with Parkinson's disease (PD), we focused on the diversity in healthcare access, state of the art, current challenges in the African continent, and proposed solutions and future perspectives. Despite the increasing prevalence and awareness of PD in Africa, numerous challenges persist in its management. These include resource limitations, geographical barriers, sociocultural beliefs, and economic constraints. Nevertheless, innovative solutions, including telerehabilitation and community-based rehabilitation, offer hope. Collaborative efforts within the continent and internationally have shown potential in bridging training and resource gaps. Significant strides can be made with tailored interventions, technological advancements, and multifaceted collaborations. This review offers practical insights for healthcare professionals, policymakers, and caregivers to navigate and optimize PD care in the African context.

Specialized Allied Health Care for Parkinson's Disease: State of the Art and Future Directions

People with Parkinson's disease (PD) experience a range of progressive motor and non-motor symptoms, that negatively affect their daily functioning, social participation and quality of life. Allied health therapies have emerged as an effective treatment approach-complementary to pharmacological and neurosurgical treatments-which reduces the impact of PD in daily life. In this article, we propose criteria for what constitutes specialized allied health care for PD, and we review allied health research in PD in terms of meeting these criteria and its outcomes for monodisciplinary approaches as well as multi- or interdisciplinary allied health interventions. We focus on the three most studied allied health disciplines in PD: physical therapy, occupational therapy and speech-language therapy. Overall, the available evidence underscores the importance and potential benefits of specialized allied health care for people with PD. Our proposed criteria and recommendations for future research might help in further delineating specialized allied health care.

Motor Performance During Sensorimotor Training for Airway Protection in Parkinson's Disease

INTRODUCTION

Cough dysfunction is highly prevalent in Parkinson's disease (PD) and associated with pneumonia, a leading cause of death. Although research suggests that cough can be volitionally upregulated, patterns of improvements that occur during cough skill training and potential correlates remain unexamined. Therefore, we sought to characterize changes to peak flow during cough skill training, examine whether early variability predicted motor performance trajectories during treatment, and explore the relationship between peak flow during cough skill training and motor learning on a similar but untrained task (i.e., reflex cough testing).

METHOD

This secondary analysis of treatment data from a randomized controlled trial included 28 individuals with PD who participated in five sessions of sensorimotor training for airway protection (smTAP). During this novel cough skill training, participants completed 25 repetitions of coughs targeting peak flow 25% above their baseline. Reflex and voluntary cough testing was performed pre- and posttreatment. Bayesian multilevel growth curve models provided group and individual-level estimates of peak flow during training.

RESULTS

The magnitude and consistency of peak flow increased during cough skill training. Variability in peak flow during the first treatment session was associated with greater improvements to peak flow in later sessions. There was no relationship between changes to peak flow during cough skill training and motor learning.

CONCLUSIONS

Individuals with PD improved the strength and variability of cough peak flow during cough skill training. These findings provide a clinically relevant characterization of motor performance during cough skill training and lend insight into potential correlates to guide future treatment paradigms.

[Dysphagia in Parkinsonian Syndromes]

Dysphagia is a clinically relevant problem in Parkinson's disease as well as in atypical Parkinsonian syndromes, such as multiple system atrophy and diseases from the spectrum of 4‑repeat tauopathies, which affect most patients to a varying degree in the course of their disease. This results in relevant restrictions in daily life due to impaired intake of food, fluids, and medication with a subsequent reduction in quality of life. This article not only gives an overview of the pathophysiological causes of dysphagia in the various Parkinson syndromes, but also presents screening, diagnostic and treatment procedures that have been investigated for the different diseases.

Dysphagia in Parkinson Disease: Part II-Current Treatment Options and Insights from Animal Research

Purpose of Review

Dysphagia is highly prevalent in Parkinson disease (PD) but is not typically identified nor treated until later in the disease process. This review summarizes current pharmacological, surgical, and behavioral treatments for PD-associated dysphagia and contributions from translational animal research.

Recent Findings

Swallowing is a complex physiologic process controlled by multiple brain regions and neurotransmitter systems. As such, interventions that target nigrostriatal dopamine dysfunction have limited or detrimental effects on swallowing outcomes. Behavioral interventions can help target PD-associated dysphagia in mid-to-late stages. Animal research is necessary to refine treatments and useful in studying prodromal dysphagia.

Summary

Dysphagia is an early, common, and debilitating sign of PD. Current pharmacological and surgical interventions are not effective in ameliorating swallowing dysfunction; behavioral intervention remains the most effective approach for dysphagia treatment. Animal research has advanced our understanding of mechanisms underlying PD and PD-associated dysphagia, and continues to show translational promise for the study of dysphagia treatment options.