Laryngeal sensory dysfunction in laryngeal hypersensitivity syndrome

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background and objective</jats:title><jats:p>Diseases associated with laryngeal dysfunction include chronic refractory cough (<jats:styled-content style="fixed-case">CRC</jats:styled-content>), paradoxical vocal fold movement (<jats:styled-content style="fixed-case">PVFM</jats:styled-content>), muscle tension dysphonia (<jats:styled-content style="fixed-case">MTD</jats:styled-content>) and globus pharyngeus. We hypothesized the presence of a common sensory laryngeal dysfunction, the ‘laryngeal hypersensitivity’ syndrome, in these conditions. The aim of the study was to compare symptoms and sensory function in patients with <jats:styled-content style="fixed-case">CRC</jats:styled-content>, <jats:styled-content style="fixed-case">PVFM</jats:styled-content>, <jats:styled-content style="fixed-case">MTD</jats:styled-content> and globus.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>The 103 participants included healthy controls (<jats:italic>n</jats:italic> = 13) and four case groups: <jats:styled-content style="fixed-case">CRC</jats:styled-content> (<jats:italic>n</jats:italic> = 33), <jats:styled-content style="fixed-case">PVFM</jats:styled-content> (<jats:italic>n</jats:italic> = 28), globus pharyngeus (<jats:italic>n</jats:italic> = 11) and <jats:styled-content style="fixed-case">MTD</jats:styled-content> (<jats:italic>n</jats:italic> = 18). Participants completed self‐report questionnaires: <jats:styled-content style="fixed-case">S</jats:styled-content>ymptom <jats:styled-content style="fixed-case">F</jats:styled-content>requency and <jats:styled-content style="fixed-case">S</jats:styled-content>everity <jats:styled-content style="fixed-case">S</jats:styled-content>cale, <jats:styled-content style="fixed-case">V</jats:styled-content>oice <jats:styled-content style="fixed-case">H</jats:styled-content>andicap <jats:styled-content style="fixed-case">I</jats:styled-content>ndex and the <jats:styled-content style="fixed-case">L</jats:styled-content>aryngeal <jats:styled-content style="fixed-case">P</jats:styled-content>araesthesia <jats:styled-content style="fixed-case">Q</jats:styled-content>uestionnaire; and quantitative sensory testing: capsaicin cough reflex sensitivity, hypertonic saline challenge, the timed swallow test, acoustic voice testing, cough frequency monitor and a voice stress test.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>All case groups reported a high‐symptom burden in comparison to controls. The case groups showed a similar pattern of symptoms, with impairment in each of the cough, respiration, vocal and upper airway symptom domains. Objective testing revealed significant sensory impairment in the case groups compared to controls and also showed an overlap in sensory dysfunction between the four case groups. Furthermore, there was cross‐sensory stimulation of symptoms whereby stimulation of a particular response resulted in symptoms in another domain.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>These discrete clinical laryngeal syndromes display considerable overlap in their clinical features and a common sensory dysfunction, supporting the ‘laryngeal hypersensitivity’ hypothesis. Reconceptualizing functional laryngeal disorders as a form of laryngeal hypersensitivity syndrome provides an alternative approach to management of these perplexing conditions.</jats:p></jats:sec>