Changes of Structural and Functional Attention Control Networks in Subclinical Hypothyroidism

Jingjing Yin; Lei Xie; DongXue Luo; Jinzhuang Huang; Ruiwei Guo; Yanmin Zheng; Wencan Xu; Shouxing Duan; Zhirong Lin; Shuhua Ma

doi:10.3389/fnbeh.2021.725908

Changes of Structural and Functional Attention Control Networks in Subclinical Hypothyroidism

Front Behav Neurosci. 2021 Oct 29:15:725908. doi: 10.3389/fnbeh.2021.725908. eCollection 2021.

Authors

Jingjing Yin^{1

2

3}, Lei Xie^{1

2

3}, DongXue Luo⁴, Jinzhuang Huang^{1

2

3}, Ruiwei Guo^{1

2

3}, Yanmin Zheng^{1

2

3}, Wencan Xu⁵, Shouxing Duan^{3

6}, Zhirong Lin¹, Shuhua Ma^{1

2

3}

Affiliations

¹ Department of Radiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China.
² Department of Medical Imaging and Nuclear Medicine, Shantou University Medical College, Shantou, China.
³ Laboratory of Medical Molecular Imaging, The First Affiliated Hospital of Shantou University Medical College, Shantou, China.
⁴ Department of Nuclear Medicine, The First Affiliated Hospital of Shantou University Medical College, Shantou, China.
⁵ Department of Endocrinology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China.
⁶ Department of Pediatric Surgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China.

Abstract

Objective: This study aimed to explore the structural changes in patients with subclinical hypothyroidism (SCH) using voxel-based morphometry (VBM) and to investigate the altered attentional control networks using functional MRI (fMRI) during the performance of a modified Stroop task with Chinese characters. Methods: High-resolution three-dimensional (3D) T1-weighted images and an fMRI scan were taken from 18 patients with SCH and 18 matched control subjects. The Montreal Cognitive Assessment Chinese-revised (MoCA-CR) and the Stroop task were used to evaluate the cognitive and attention control of the participants. Results: Compared to controls, the VBM results showed decreased gray matter volumes (GMVs) in bilateral prefrontal cortices (PFCs, including middle, medial, and inferior frontal gyri), cingulate gyrus, precuneus, left middle temporal gyrus, and insula in patients with SCH. The fMRI results showed a distributed network of brain regions in both groups, consisting of PFCs (including superior and middle and inferior frontal cortices), anterior cingulate cortex (ACC), posterior cingulate cortex, and precuneus, as well as the insula and caudate nucleus. Compared to controls, the SCH group had lower activation of the above brain areas, especially during the color-naming task. In addition, the normalized GMV (nGMV) was negatively correlated with thyroid-stimulating hormone (TSH) level (r = -0.722, p < 0.001). Conclusion: Results indicate that patients with SCH exhibit reduced GMVs, altered BOLD signals, and activation in regions associated with attention control, which further suggest that patients with SCH may have attentional control deficiency, and the weakened PFC-ACC-precuneus brain network might be one of the neural mechanisms. Negative correlations between nGMV and TSH suggest that TSH elevation may induce abnormalities in the cortex.

Keywords: attention; brain function; functional magnetic resonance imaging; subclinical hypothyroidism; voxel-based morphometry.