Inherent regional brain activity changes in male obstructive sleep apnea with mild cognitive impairment: A resting-state magnetic resonance study

Abstract

Obstructive sleep apnea (OSA) is the most common sleep disorder worldwide. Previous studies have shown that OSA patients are often accompanied by cognitive function loss, and the underlying neurophysiological mechanism is still unclear. This study aimed to determine whether there are differences in regional homogeneity (Reho) and functional connectivity (FC) across the brain between OSA patients with MCI (OSA-MCI) and those without MCI (OSA-nMCI) and whether such differences can be used to distinguish the two groups. Resting state magnetic resonance data were collected from 48 OSA-MCI patients and 47 OSA-nMCI patients. The brain regions with significant differences in Reho and FC between the two groups were identified, and the Reho and FC features were combined with machine learning methods for classification. Compared with OSA-nMCI patients, OSA-MCI patients showed significantly lower Reho in bilateral lingual gyrus and left superior temporal gyrus. OSA-MCI patients also showed significantly lower FC between the bilateral lingual gyrus and bilateral cuneus, left superior temporal gyrus and left middle temporal gyrus, middle frontal gyrus, and bilateral posterior cingulate/calcarine/cerebellar anterior lobe. Based on Reho and FC features, logistic regression classification accuracy was 0.87; sensitivity, 0.70; specificity, 0.89; and area under the curve, 0.85. Correlation analysis showed that MoCA scale score in OSA patients was significant positive correlation sleep efficiency and negatively correlation with neck circumference. In conclusion, our results showed that the OSA-MCI group showed decreased Reho and FC in specific brain regions compared with the OSA-nMCI group, which may help to understand the underlying neuroimaging mechanism of OSA leading to cognitive dysfunction and may serve as a potential biomarker to distinguish whether OSA is accompanied by cognitive impairment.

Keywords: functional connectivity; mild cognitive impairment; obstructive sleep apnea; regional homogeneity; rs-fMRI.

Figure 1

Reho spatial patterns at the group mean level of the OSA-MCI and OSA-nMCI groups.

Figure 2

Significantly different Reho was observed between the OSA-MCI and OSA-nMCI groups. Reho values decreased significantly in the MCI group compared to the nMCI group (blue). B, bilateral; L, left; STG, superior temporal gyrus.

Figure 3

Significantly different FC values seeded as ROI in B-Lingual (A) and L-STG (B). In figure (A), red represents the lingual gyrus and yellow represents the cuneus; In figure (B), red represents the left superior temporal gyrus, green represents the left middle frontal gyrus, blue represents the left middle temporal gyrus, and yellow represents the bilateral posterior cingulate/calcarine/left cerebellum anterior lobe. The FCs between significantly different regions and ROIs in OSA-MCI group was significantly reduced compare with OSA-nMCI group. L, left; B, bilateral; ROI, region of interest; FC, functional connectivity; STG, superior temporal gyrus; MTG, middle temporal gyrus; MFG, middle frontal gyrus; PC, posterior cingutate; CAL, cerebellum anterior lobe.

Figure 4

The MoCA scale scores was negatively correlated with neck circumference (A) and positively correlated with sleep efficiency (B).

Figure 5

ROC curve of classifier based on altered Reho and FC values, AUC is 0.85. LR, logistic regression; ROC, receiver operating characteristic.