Neural correlates of cough hypersensitivity in humans: evidence for central sensitisation and dysfunctional inhibitory control

Introduction: Chronic non-productive coughing is a major complication of pulmonary disease and can also occur in many individuals without identifiable underlying pathology. The common clinical link in patients with cough is an enhanced sensitivity of the respiratory system to stimuli that subsequently evoke excessive coughing. The aetiology of this 'cough hypersensitivity syndrome' is unclear but believed to involve hypersensitivity of the sensory neural pathways that innervate the airways and lungs. Methods: In the present study, we used functional brain imaging to compare central neural responses to airway stimulation using inhaled capsaicin in healthy people and patients with cough hypersensitivity. Results: Hypersensitivity in response to inhaled capsaicin coincided with elevated neural activity in the midbrain in a region encompassing the nucleus cuneiformis (left: