Impaired Topological Architecture of Structural Brain Networks in Obstructive Sleep Apnea: A DTI Study

Obstructive sleep apnea (OSA) has been associated with alterations in white-matter integrity. However, few studies have examined topological alterations of white-matter structural networks in OSA. We aimed to investigate alterations in brain structural networks in patients with OSA using diffusion tensor imaging (DTI) combined with the network-based statistic (NBS).

Clinical, neuropsychological, and DTI data were collected from 77 patients with OSA and 83 healthy controls (HCs). DTI-based structural networks were established based on whole-brain probabilistic tractography. The inter-group difference in topological properties was compared. NBS analysis was performed to assess changes in network connectivity, and the correlation between topological properties and clinical variables was evaluated.

Graph theory analysis showed reduced betweenness centrality (BC) in the left dorsolateral superior frontal gyrus (SFGdor.L) and supplementary motor area (SMA.L) and reduced nodal efficiency (NE) of the SFGdor.L in patients with OSA. NBS analysis revealed abnormalities in a sub-network with 14 nodes, where positive connectivity was observed between individual nodes in patients with OSA. Pearson correlation analysis indicated that the BC of SMA.L was positively correlated with anxious (r = 0.242, P = 0.034) and cognitive (r = 0.252, P = 0.027) scores. Compared with HCs, Patients with OSA exhibited lower cognitive scores and higher levels of depression and anxiety.

Our findings show alterations in BC and NE of the SFGdor.L and BC of the SMA.L that may reflect neurobiological features of white-matter network disruption in OSA and could represent potential imaging biomarkers of early cerebral involvement. These results are correlational and longitudinal studies are needed to determine temporal relationships and causal effects.