Chronic homeostatic vagal efferent activity turndown: a theory of asthma

There is an abundance of evidence of an autonomic nervous system (ANS) imbalance in asthma, and most theories have suggested that a defect in the ANS is the fundamental pathology in asthma. This paper proposes that there is no ANS defect in asthma. It assumes that the normal homeostatic response to bronchial obstruction is a reduction in the vagally mediated, normal bronchoconstricting tonus of the airways. It then discusses how many of the pathological features of asthma may be shown to result from chronic vagal efferent activity turndown which itself results from protracted intense and continuous bronchial obstruction.