The micro-structural changes in white matter fibers associated with anxiety and depression in moderate-severe...

This study compared the effectiveness of Automated Fiber Quantification (AFQ) and Tract-Based Spatial Statistics (TBSS) in detecting white matter (WM) changes in patients with moderate-to-severe obstructive sleep apnea (OSA), aiming to identify the more suitable method for investigating WM alterations of OSA patients. It also explored the potential neuropathological links between WM changes and anxiety/depression in OSA. Thirty-three untreated patients with moderate-severe OSA and 28 good sleepers without sleep disorders underwent 3.0T MRI scans. TBSS was used to construct WM skeletons and compare diffusion tensor imaging (DTI) metrics between groups. AFQ was then applied to extract 20 major fiber tracts from each subject, with each tract divided into 100 nodes to precisely localize affected areas. TBSS revealed no significant group differences after correction. In contrast, AFQ identified significant changes: decreased fractional anisotropy at nodes 77-78 of the forceps major (positively correlated with anxiety scores); increased mean diffusivity at nodes 23-24 of the right thalamic radiation; and increased axial diffusivity at nodes 54-57 of the right inferior fronto-occipital fasciculus (negatively correlated with anxiety and depression scores), and nodes 66-68 of the right superior longitudinal fasciculus. AFQ is more sensitive than TBSS in detecting focal WM changes in OSA, allowing precise localization of affected fiber nodes. These WM alterations, particularly in the corpus callosum and right inferior fronto-occipital fasciculus, are linked to anxiety and depression, offering insights into the neuropathological mechanisms of anxiety and depression in OSA.