Aberrant Insular Functional Network Integrity in Patients with Obstructive Sleep Apnea

Area of Science:

• Neuroimaging
• Sleep Medicine
• Neurology

Background:

• Obstructive sleep apnea (OSA) is linked to tissue injury in the insular cortices, which are crucial for autonomic, pain, and mood regulation.
• Dysregulation of insular functions in OSA is suspected to involve aberrant functional connectivity (FC) with other brain regions, though this remains largely undescribed.

Purpose of the Study:

• To investigate resting-state functional connectivity (FC) of the insular cortices in individuals with OSA compared to control subjects.
• To identify specific brain regions exhibiting altered FC with the insular cortices in OSA.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) data were acquired from 67 treatment-naïve OSA patients and 75 control subjects using a 3.0-Tesla MRI scanner.
• Standard fMRI processing was applied, followed by analysis of resting-state FC for both the left and right insular cortices.

Main Results:

• OSA subjects displayed complex aberrant insular FC with numerous brain regions, including frontal, parietal, cingulate, temporal, limbic, basal ganglia, thalamus, occipital, cerebellar, and brainstem areas.
• Altered FC in OSA was linearly associated with sleep-related and neuropsychological variables, unlike in control subjects where no such relationships were observed.

Conclusions:

• Aberrant insular FC in OSA impacts autonomic, affective, sensorimotor, and cognitive control networks, potentially explaining impaired sympathetic/parasympathetic interactions and sensorimotor integration.
• These observed functional connectivity changes in OSA are likely secondary to previously identified structural alterations in the brain.