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Volitional Control of Reflex Cough
Author(s) -
Hegland Karen,
Davenport Paul W
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1111.18
Subject(s) - cough reflex , medicine , reflex , airway , capsaicin , anesthesia , brainstem , physical medicine and rehabilitation , receptor
Cough is divided into subtypes based on genesis of the behavior, specifically whether elicited reflexively or voluntarily. The goal of this project was to determine if healthy adults could volitionally modify the reflexive cough. Healthy adult participants were seated and outfitted with a facemask and pneumotacograph, and two surface EMG electrodes positioned over expiratory muscles. Capsaicin (200μM) was delivered via dosimeter attached to the facemask. Cough airflow and sEMG activity were recorded across tasks including 1. Baseline 2. Small cough, 3. Long cough, 4. Not cough (alternative behavior). All participants coughed in response to capsaicin, and were able to modify their coughing behavior. Variables exhibiting the most profound changes include those related to the peak airflow during the cough expiratory phase. Participants were unable to completely substitute other airway defensive behaviors for cough, and typically exhibited a combination of several airway defense behaviors. Results demonstrate that while it is not possible to suppress cough at reflex threshold levels of capsaicin, it is possible to volitionally modify cough motor output characteristics. This indicates that ‘reflex’ coughing is actually part of a continuum of airway defense behaviours whose motor expression reflects the interaction of brainstem and the cortex.