Thorax. 2014 Sep;69(9):881-3. doi: 10.1136/thoraxjnl-2014-205661. Epub 2014 Jun 26.
Chronic cough or cough that lasts more than 8 weeks, once a chest x-ray and spirometry are confirmed normal, is caused by an alteration in a section of the route between peripheral receptors, mainly in the upper and lower airway and oesophagus, spinal cord and the cough centre in the brain stem involving the cortex. These mechanisms of cough have their homology in the circuit of chronic pain, and on that basis, should expand future research of chronic cough. Clinically chronic cough is easy to diagnose by an excessive response or hypertussia to low-intensity stimuli or banal stimuli, which we now call hypersensitivity cough syndrome, quantified by a positive reflex cough with capsaicin or citric acid. However, hypersensitivity cough syndrome can be impossible to quantify in the laboratory when the hyper-responsiveness originates in the central nervous system. This is normally caused by excessive peripheral input or convergence of stimuli from different sources. Once central hypersensitivity is acquired, peripheral input is not as important for activation of the cough.
慢性咳嗽或持续超过 8 周的咳嗽，一旦胸部 X 光和肺量测定被证实正常，是由于外周感受器之间的通路的改变引起的，主要在上、下呼吸道和食管、脊髓和脑干中的咳嗽中枢涉及到大脑皮层。这些咳嗽机制在慢性疼痛的回路中有其同源性，在此基础上，应该扩展对慢性咳嗽的未来研究。临床上，慢性咳嗽很容易通过对低强度刺激或普通刺激的过度反应或高敏性来诊断，我们现在称之为超敏性咳嗽综合征，通过辣椒素或柠檬酸的阳性反射咳嗽来定量。然而，当超敏性源于中枢神经系统时，超敏性咳嗽综合征在实验室中可能无法被量化。这通常是由过多的外周输入或来自不同来源的刺激会聚引起的。一旦获得中枢超敏性，外周输入对于激活咳嗽就不那么重要了。
