Study on brain functional networks and cortical morphological structures in patients with primary insomnia

Introduction The prevalence of primary insomnia (PI) has been increasing year by year. This study aims to explore its neurobiological mechanisms and provide neuroimaging evidence for clinical diagnosis and treatment. Methods A total of 33 patients with PI and 25 healthy controls were recruited. All participants completed assessments of sleep status, cognitive function, and evaluations using neuropsychological scales. Voxel-based degree centrality (DC) analysis was used to identify abnormal functional network hubs, and differentially activated brain regions were further used as seed points for whole-brain functional connectivity (FC) analysis. Surface-based morphometry (SBM) was employed to analyze cortical morphological parameters. Additionally, DC values, FC values, and cortical morphological parameters of the differentially activated brain regions were extracted from the PI group for the differentially activated brain regions, and further correlation analyses were performed with neuropsychological scale scores. Results In patients with PI, the DC of the bilateral precuneus/posterior cingulate gyrus was increased, while the DC of brain regions related to the right parietal lobe was decreased; FC was reduced in some brain regions; the cortex of the left frontoparietal region was thinner with an elevated gyrification index (GI); and the fractal dimension (FD) of the right parieto-occipital cortex/left occipital cortex was decreased. Discussion PI patients show abnormal functional hubs (posterior DMN, CEN parietal lobe), reduced FC (CEN-right cerebellum, posterior DMN-occipital lobe), and cortical morphological changes (left frontoparietal thinning, etc.). These neuroimaging indices are correlated with patients’ sleep quality, which can provide a basis for mechanistic research and clinical diagnosis of PI.