Chronic Cough-Related Differences in Brain Morphometry in Adults: A Population-Based Study

BACKGROUND: Individuals with cough hypersensitivity have increased central neural responses to tussive stimuli, which may result in maladaptive morphometric changes in the central cough processing systems. RESEARCH QUESTION: Are the volumes of the brain regions implicated in cough hypersensitivity different in adults with chronic cough compared with adults without chronic cough? STUDY DESIGN AND METHODS: Between 2009 and 2014, participants in the Rotterdam Study, a population-based cohort, underwent brain MRI and were interviewed for chronic cough, which was defined as daily coughing for at least 3 months. Regional brain volumes were quantified with the use of parcellation software. Based on literature review, we identified and studied seven brain regions that previously had been associated with altered functional brain activity in chronic cough. The relationship between chronic cough and regional brain volumes was investigated with the use of multivariable regression models. RESULTS: Chronic cough was prevalent in 9.6% (No. = 349) of the 3,620 study participants (mean age, 68.5 ± 9.0 years; 54.6% female). Participants with chronic cough had significantly smaller anterior cingulate cortex volume than participants without chronic cough (mean difference, ˗126.16 mm(3); 95% CI, −245.67 to −6.66; P = .039). Except for anterior cingulate cortex, there were no significant difference in the volume of other brain regions based on chronic cough status. The volume difference in the anterior cingulate cortex was more pronounced in the left hemisphere (mean difference, −88.11 mm(3); 95% CI, −165.16 to −11.06; P = .025) and in male participants (mean difference, −242.58 mm(3); 95% CI, −428.60 to −56.55; P = .011). INTERPRETATION: Individuals with chronic cough have a smaller volume of the anterior cingulate cortex, which is a brain region involved in cough suppression. CLINICAL TRIAL REGISTRATION: The Netherlands National Trial Registry (NTR; www.trialregister.nl) and the World Health Organization’s International Clinical Trials Registry Platform (ICTRP; www.who.int/ictrp/network/primary/en/) under the joint catalogue number NTR6831.