Management of chronic refractory cough

Abstract

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.

An update and systematic review on drug therapies for the treatment of refractory chronic cough

“…The term sensory neuropathic cough is now often recognized in cough guidelines. It has overlap with laryngeal hypersensitivity and cough hypersensitivity [7,8] syndromes and is a component of refractory CC [9]. Early systematic evaluation and treatment guidelines for CC by Irwin and colleagues (1977) were based on the anatomic locations of the receptors and afferent pathways involved in the cough reflex [10].…”

“…CHS is associated with hypersensitivity of the larynx and upper airway and is often diagnosed by clinical history [23] and sometimes through quantitative sensory testing such as with hypertonic saline challenge, transnasal laryngoscopy with odor provocation, and cough reflex sensitivity testing with capsaicin [7,8]. Although some features of refractory CC are encompassed by the term CHS, many patients localize symptoms to the larynx [9,24] and therefore laryngeal hypersensitivity syndrome maybe a better description. CHS is known to overlap with other laryngeal hypersensitivity syndromes including PVFM [7] and muscle tension dysphonia.…”

A 57-year-old chronic cougher with somatically evoked cough

“…The differential diagnosis of chronic cough is extensive [2]. Uncommon causes of chronic cough may be missed unless an adequate history is obtained, a detailed examination performed and appropriate investigations arranged [3].…”

Dirglių Gerklų Sindromas: Šiuolaikinė Diagnostika Ir Gydymas

“…Istoriškai šiai patologijai apibūdinti naudojama daug skirtingų terminų -tai paradoksiniai balso klosčių judesiai, funkcinė kvėpavimo takų obstrukcija, netikra astma, paradoksinė balso klosčių disfunkcija, epizodinė gerklų diskinezija, psichogeninis stridoras, gerklų hiperjautrumas, gerklų hiperjautrumo sindromas, epizodinis paroksizminis gerklų spazmas ir nuo 1999 m. Morrison su kolegomis įves-tas ir plačiausiai paplitęs terminas -dirglių gerklų sindromas [1][2][3][4][5][6]. Taip pat šis sindromas susijęs su tokiais terminais kaip laringofaringine neuropatija, povirusine klajoklio nervo neuropatija, idiopatine gerklų sensorine neuropatija ar neurogeniniu kosuliu [7][8][9][10][11][12][13]. …”

“…Skirtingos kilmės nespecifiniai už-degiminiai mediatoriai įjautrina klajoklio nervo inervuojamų organų gleivinių aferentinius nervus per jų galūnėlių greito impulso plitimo skaidulas (vadinamąsias C tipo, neturinčių mielino skaidulas), tokiu būdu sumažindami jutiminių receptorių slenksčius [2,9]. Atkaklaus lėtinio kosulio atveju, šis procesas yra susijęs su padidėjusia tranzitorinio potencialo vaniloidinių 1-ojo tipo receptorių raiška ne adrenerginėse ir ne cholinerginėse nervų galūnėlėse [9]. CNS įjautrinimas charakterizuojamas padidėjusiu sužadinimu centriniuose jutiminiuose laiduose.…”