Analysis of Brain Functional Connectivity in COPD Patients with Functional Brain MRI

Background: Cognitive dysfunction and mood disorder are well-known comorbidities in COPD. However, the mechanism is not well understood including change of brain function or connectivity in COPD. We compared the hippocampal function connectivity (FC) of COPD patients to normal controls. Method: A total of 50 patients with COPD and 30 matched healthy controls were participated. We obtained clinical data including demographics, pulmonary functions, cognitive function and mood status. Both groups of patients underwent brain magnetic resonance imaging (MRI) procedures for acquisition of T1 anatomy and resting-status (rs) functional MRI (rfMRI) data at 3T. All data were processed by FreeSufer and AFNI pack ages. The FC maps of hippocampus (HP) were obtained for each individual subject, and a Welch’s test were applied to get group differences. And, to figure out the relationship, Pearson correlation coefficients (r) were calculated. Results: Compared to normal control, COPD patients had lower BMI, more comorbidities and more cognitive dysfunction without significant difference in risk factors for stroke. In addition, COPD patients showed significantly decreased FC between HP and middle cingulate cortex (MCC) (pFWE-corrected < 0.05) compared to normal control. And, the degree of HP-MCC FC were correlated with decreased forced expiratory volume in one second (FEV1) and higher Charlson Comorbidity Index at the significance level of p < 0.05. Conclusion: The mechanism of decreased cognitive function or changed mood status in COPD patients is not fully discovered. However, our study showed that alterations in FC of hippocampal lesions might be related with the clinical course of COPD.