Altered thalamic functional connectivity and cerebral blood flow in insomnia disorder: a resting-state functional...

The thalamus plays a crucial role in sleep regulation, but few studies have examined functional connectivity of the thalamus in insomnia disorder. This study aimed to investigate the connectivity patterns and perfusion of the thalamus in patients with insomnia disorder using resting-state functional connectivity and three-dimensional arterial spin labeling (3D ASL).

In total, 56 patients with insomnia disorder and 59 healthy control participants with a similar age-, gender-, and education lever distribution underwent resting-state functional magnetic resonance imaging (rs-fMRI) and 3D-ASL. The thalamus was selected as the seed region. Whole-brain connectivity was assessed using rs-fMRI. Cerebral blood flow (CBF) of the bilateral thalamus was measured with 3D-ASL using region-of-interest (ROI) analysis. All participants completed a series of neuropsychological assessments. Sleep parameters were assessed via polysomnography (PSG). The relationships between imaging parameters and clinical variables were assessed with Pearson correlation analysis.

Compared with healthy controls, patients with insomnia disorder exhibited increased connectivity between the left thalamus and right precentral gyrus, and right thalamus and left middle frontal gyrus (MFG), right superior parietal lobule (SPL) and right superior frontal gyrus (SFG). Whereas decreased connectivity was noted between the right thalamus and left posterior cerebellar lobe including Crus I, Crus II, and VII b/VII. Connectivity between the right thalamus and left Crus I was positively correlated with MoCA scores (r = 0.286, P = 0.036) in insomnia disorder.

Our findings illustrate functional abnormalities in brain connectivity and their relationship with cognitive impairments in insomnia disorder, providing novel insight into the neural mechanisms of insomnia disorder.