State of the Art for Refractory Cough: Multidisciplinary Approach

Chronic cough is a common problem that can be refractory to medical treatment. Nonpharmaceutical management of chronic cough has an important role in well selected patients. This review article outlines the history of chronic cough management, current approaches to speech pathology management of the condition and new modalities of nonpharmaceutical treatment. There is a need for further research into nonpharmaceutical options with well described randomised control trials

Chronic cough and laryngeal dysfunction improve with specific treatment of cough and paradoxical vocal fold movement

Rationale: Chronic persistent cough can be associated with laryngeal dysfunction that leads to symptoms such as dysphonia, sensory hyperresponsiveness to capsaicin, and motor dysfunction with paradoxical vocal fold movement and variable extrathoracic airflow obstruction (reduced inspiratory airflow). Successful therapy of chronic persistent cough improves symptoms and sensory hyperresponsiveness. The effects of treatment for chronic cough on laryngeal dysfunction are not known. Objective: The aim of this study was to investigate effects of therapy for chronic cough and paradoxical vocal fold movement. Methods: Adults with chronic cough (n = 24) were assessed before and after treatment for chronic persistent cough by measuring quality of life, extrathoracic airway hyperresponsiveness to hypertonic saline provocation, capsaicin cough reflex hypersensitivity and fibreoptic laryngoscopy to observe paradoxical vocal fold movement. Subjects with chronic cough were classified into those with (n = 14) or without (n = 10) paradoxical vocal fold movement based on direct observation at laryngoscopy. Results: Following treatment there was a significant improvement in cough related quality of life and cough reflex sensitivity in both groups. Subjects with chronic cough and paradoxical vocal fold movement also had additional improvements in extrathoracic airway hyperresponsiveness and paradoxical vocal fold movement. The degree of improvement in cough reflex sensitivity correlated with the improvement in extrathoracic airway hyperresponsiveness. Conclusion: Laryngeal dysfunction is common in chronic persistent cough, where it is manifest as paradoxical vocal fold movement and extrathoracic airway hyperresponsiveness. Successful treatment for chronic persistent cough leads to improvements in these features of laryngeal dysfunction

Cough reflex sensitivity improves with speech language pathology management of refractory chronic cough

Rationale: Speech language pathology is an effective management intervention for chronic cough that persists despite medical treatment. The mechanism behind the improvement has not been determined but may include active cough suppression, reduced cough sensitivity or increased cough threshold from reduced laryngeal irritation. Objective measures such as cough reflex sensitivity and cough frequency could be used to determine whether the treatment response was due to reduced underlying cough sensitivity or to more deliberate control exerted by individual patients. The number of treatments required to effect a response was also assessed. Objective: The aim of this study was to investigate subjective and objective measures of cough before, during and after speech language pathology treatment for refractory chronic cough and the mechanism underlying the improvement. Methods: Adults with chronic cough (n = 17) were assessed before, during and after speech language pathology intervention for refractory chronic cough. The primary outcome measures were capsaicin cough reflex sensitivity, automated cough frequency detection and cough-related quality of life. Results: Following treatment there was a significant improvement in cough related quality of life (Median (IQR) at baseline: 13.5 (6.3) vs. post treatment: 16.9 (4.9), p = 0.002), objective cough frequency (Mean ± SD at baseline: 72.5 ± 55.8 vs. post treatment: 25 ± 27.9 coughs/hr, p = 0.009), and cough reflex sensitivity (Mean ± SD log C5 at baseline: 0.88 ± 0.48 vs. post treatment: 1.65 ± 0.88, p < 0.0001). Conclusions: This is the first study to show that speech language pathology management is an effective intervention for refractory chronic cough and that the mechanism behind the improvement is due to reduced laryngeal irritation which results in decreased cough sensitivity, decreased urge to cough and an increased cough threshold. Speech language pathology may be a useful and sustained treatment for refractory chronic cough. Trial Registration: Australian New Zealand Clinical Trials Register, ACTRN12608000284369

Gabapentin in chronic cough

Background: Chronic cough is regarded as a challenging clinical problem due to its frequency and often limited therapeutic options. Chronic cough that remains refractory to usual medical treatment causes significant quality of life impairment. Methods: Recent developments in the treatment of cough include the use of speech pathology and pharmacotherapy with gabapentin. Relevant randomised control trials, reviews and case reports were identified through a PubMed and SCOPUS search of English-language literature referring to these concepts over the last eight years. Results: The effectiveness of neuromodulating medications such as gabapentin and pregabalin in the treatment of cough has been supported primarily through case series, case reports, prospective reviews and a double blind randomised controlled trial. Gabapentin results in a reduction in cough frequency and cough severity. It improves cough related quality of life. The effect is greatest in patients with features of central reflex sensitisation such as laryngeal paraesthesia, hypertussia and allotussia. These symptoms can be measured using the Newcastle Laryngeal Hypersensitivity Questionnaire. Side effects of gabapentin include somnolence and dizziness. Conclusion: Recent additions in the treatment of chronic cough have been significant as they consider cough to have a unifying diagnosis of cough hypersensitivity with or without the presence of a neuropathic basis. Effective treatments for refractory chronic cough that target these areas include behavioural treatment such as speech pathology and pharmaceutical treatment with neuromodulating medications such as gabapentin

Speech pathology for chronic cough: a new approach

Chronic cough may persist despite systematic evaluation and medical treatment of known associated diseases such as asthma, rhinitis, and gastro-esophageal reflux. These patients have refractory chronic cough and many exhibit laryngeal hypersensitivity that is manifest at both a sensory and motor level. Examples of this are heightened sensitivity of the cough reflex to capsaicin, and laryngeal motor dysfunction with hoarse vocal quality and paradoxical vocal cord movement. Chronic cough that persists despite medical treatment may respond to speech pathology intervention. A multidimensional speech pathology treatment programme was designed based upon methods used to treat hyperfunctional voice disorders and paradoxical vocal fold movement. This included education, vocal hygiene training, cough suppression strategies and psychoeducational counseling. When tested in a single-blind, randomized, placebo-controlled trial involving 87 patients, participants in the treatment group demonstrated a significant reduction in cough, breathing, voice and upper airway symptoms following intervention, as well as improvements in auditory perceptual ratings of voice quality (breathy, rough, strain and glottal fry) and significant improvement in voice acoustic parameters (maximum phonation time, jitter and harmonic-to-noise ratio). Speech pathology intervention can be an effective way to treat refractory chronic cough

Treating lost language: speech pathology management of aphasia in the acute hospital setting

Losing the ability to communicate verbally or understand spoken words and conversation can have devastating psycho-social consequences. For some patients admitted to hospital with stroke and other brain injury this loss of language can be a profound, life-changing occurrence. Aphasia refers to a language impairment resulting from brain injury. Speech pathology assessment and treatment for speech and language deficits following brain injury forms an integral part of clinical management within the acute hospital phase for patients with stroke. This clinical data-mining project evolved following the implementation of a formal standardised aphasia test in the acute hospital setting, the Bedside Evaluation Screening Test for Aphasia - 2 (BEST-2), applicable to such patients. Despite growing evidence regarding the benefits of providing early and high frequency aphasia therapy, aphasia therapy is typically a lower priority in the acute setting, with dysphagia {swallowing) management often consuming the majority of speech pathology time. This clinical data-mining project provides a profile of aphasia assessment and therapy in the acute setting and discusses future directions and speech pathology service delivery within this population

Chronic refractory cough as a sensory neuropathy: evidence from a reinterpretation of cough triggers

Objectives/Hypothesis: The aims of this study were to examine cough triggers in individuals with chronic cough (CC), identify sensory symptoms consistent with central reflex sensitization (paresthesia and allotussia), and interpret this information in relation to sensory laryngeal neuropathy. Study Design: Prospective observational study. Methods: Patients (n = 53) with CC that was refractory to medical management based on the anatomic diagnostic protocol completed questionnaires regarding cough triggers, anxiety and depression, and factors contributing to laryngeal irritation such as vocal hygiene and laryngopharyngeal reflux. Results: An abnormal sensation in the laryngeal area (laryngeal paresthesia) was present in 94% of people with refractory CC. Nontussive stimuli including phonation were frequent triggers for cough (allotussia), occurring in 71% of participants. Although tussive stimuli were significantly more potent than nontussive stimuli (P = 0.005), the relative clinical importance was not statistically different (P = 0.072). Most participants with refractory cough had poor vocal hygiene. Conclusion: The sensory symptom changes that accompany CC suggest central reflex sensitization and include laryngeal paresthesia and allotussia. The results are consistent with cough as a sensory neuropathic disorder

Management of chronic refractory cough

Chronic refractory cough (CRC) is defined as a cough that persists despite guideline based treatment. It is seen in 20-46% of patients presenting to specialist cough clinics and it has a substantial impact on quality of life and healthcare utilization. Several terms have been used to describe this condition, including the recently introduced term cough hypersensitivity syndrome. Key symptoms include a dry irritated cough localized around the laryngeal region. Symptoms are not restricted to cough and can include globus, dyspnea, and dysphonia. Chronic refractory cough has factors in common with laryngeal hypersensitivity syndromes and chronic pain syndromes, and these similarities help to shed light on the pathophysiology of the condition. Its pathophysiology is complex and includes cough reflex sensitivity, central sensitization, peripheral sensitization, and paradoxical vocal fold movement. Chronic refractory cough often occurs after a viral infection. The diagnosis is made once the main diseases that cause chronic cough have been excluded (or treated) and cough remains refractory to medical treatment. Several treatments have been developed over the past decade. These include speech pathology interventions using techniques adapted from the treatment of hyperfunctional voice disorders, as well as the use of centrally acting neuromodulators such as gabapentin and pregabalin. Potential new treatments in development also show promise

Development and validation of the Newcastle laryngeal hypersensitivity questionnaire

Background: Laryngeal hypersensitivity may be an important component of the common disorders of laryngeal motor dysfunction including chronic refractory cough, paradoxical vocal fold movement (vocal cord dysfunction), muscle tension dysphonia, and globus pharyngeus. Patients with these conditions frequently report sensory disturbances, and an emerging concept of the ‘irritable larynx’ suggests common features of a sensory neuropathic dysfunction as a part of these disorders. The aim of this study was to develop a Laryngeal Hypersensitivity Questionnaire for patients with laryngeal dysfunction syndromes in order to measure the laryngeal sensory disturbance occurring in these conditions. Methods: The 97 participants included 82 patients referred to speech pathology for behavioural management of laryngeal dysfunction and 15 healthy controls. The participants completed a 21 item self administered questionnaire regarding symptoms of abnormal laryngeal sensation. Factor analysis was conducted to examine correlations between items. Discriminant analysis and responsiveness to change were evaluated. Results: The final questionnaire comprised 14 items across three domains: obstruction, pain/thermal, and irritation. The questionnaire demonstrated significant discriminant validity with a mean difference between the patients with laryngeal disorders and healthy controls of 5.5. The clinical groups with laryngeal hypersensitivity had similar abnormal scores. Furthermore the Newcastle Laryngeal Hypersensitivity Questionnaire (LHQ) showed improvement following behavioural speech pathology intervention with a mean reduction in LHQ score of 2.3. Conclusion: The Newcastle Laryngeal Hypersensitivity Questionnaire is a simple, non-invasive tool to measure laryngeal paraesthesia in patients with laryngeal conditions such as chronic cough, paradoxical vocal fold movement (vocal cord dysfunction), muscle tension dysphonia, and globus pharyngeus. It can successfully differentiate patients from healthy controls and measure change following intervention. It is a promising tool for use in clinical research and practice