Impaired cough suppression in chronic refractory cough.

Functional brain imaging in individuals with chronic cough demonstrates reduced activation in cortical regions associated with voluntary cough suppression. Little is known about the ability of patients with chronic cough to suppress cough. This study aimed to compare the ability to voluntarily suppress cough during inhaled capsaicin challenge in participants with chronic refractory cough with that in healthy controls. In addition, this study aimed to assess the repeatability of capsaicin challenge test with voluntary cough suppression.Participants with chronic refractory cough and healthy controls underwent inhaled capsaicin challenge tests while attempting to suppress their cough responses. After 5 days, either a conventional capsaicin challenge test with no cough suppression attempt, or a repeat test with an attempt at cough suppression was performed. Threshold capsaicin concentrations required to elicit one, two and five coughs were calculated by interpolation. Objective 24-h cough frequency was measured in individuals with chronic refractory cough.Healthy controls were able to suppress capsaicin-evoked cough while participants with chronic refractory cough were not. Geometric mean±sd capsaicin dose thresholds for five coughs with (CS5) and without (C5) suppression attempts were 254.40±3.78

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Copyright ©ERS 2019.

Déclaration de conflit d'intérêts

Conflict of interest: P.S.P. Cho reports a grant from Merck outside the submitted work. Conflict of interest: H.V. Fletcher has nothing to disclose. Conflict of interest: R.D. Turner has nothing to disclose. Conflict of interest: C.J. Jolley has nothing to disclose. Conflict of interest: S.S. Birring reports grants and personal fees for advisory board work from Merck, personal fees for advisory board work from Bayer, GSK, Menlo and Sanofi, and conference travel expenses from Boehringer Ingelheim, outside the submitted work.