The Cerebellum Posterior Lobe Associates with the Exophthalmos of Primary Hyperthyroidism: A Resting-State fMRI Study

Abstract

Background Exophthalmos occurs in patients with primary hyperthyroidism. There were few studies about the changes of brain functional networks of patients with exophthalmos of primary hyperthyroidism (EOPH). However, differences in spontaneous brain activity in patients with EOPH remain unclear. Objective This study explored alterations in the brain functional networks of patients with EOPH using a voxel-wise degree centrality (DC) method. Methods A total of 20 patients with EOPH (8 men and 12 women) were enrolled. In addition, 20 patients with primary hyperthyroidism without exophthalmos, matched in age, sex, and education status, were enrolled as a control group. The Hospital Anxiety and Depression Scale was used to assess the anxiety and depression status of participants. All participants were examined using resting-state functional MRI. Changes in spontaneous brain activity were investigated using the DC method. To distinguish between the DC values of the patients with EOPH and those of the control group, we analyzed the receiver operating characteristic (ROC) curve. The interrelationships between the DC values and clinical variables in the patients with EOPH were evaluated using Pearson's correlation coefficient. Results Patients with EOPH exhibited notably lower DC values in the cerebellum posterior lobe than the control group. In addition, there were negative correlations between the anxiety scores (AS) and the depression scores (DS) and DC values of the cerebellum posterior lobe. The ROC curve analysis of the cerebellum posterior lobe demonstrated that the area under the curve method had a high diagnostic accuracy. Conclusions Our study was the first, to our knowledge, to explore changes in the brains of patients with EOPH using the DC method. The DC value was significantly different in the cerebellum posterior lobe in patients with EOPH, indicating that the cerebellum posterior lobe is associated with EOPH.

Aberrant brain voxel‐wise resting state fMRI in patients with thyroid‐associated ophthalmopathy

“…Furthermore, DC in the left PoCG was negatively correlated with disease duration, indicating that the impairment might be aggravated with the progression of the disease process. Interestingly, previous studies on hyperthyroidism 30 and exophthalmos of primary hyperthyroidism 26 consistently reported decreased DC in the cerebellum, which was not found in our study. Considering that they both included hyperthyroid patients while we enrolled patients in short-term euthyroid state, we speculate that this discrepancy might be associated with the differed thyroid hormone levels of subjects.…”

“…Specifically, fractional amplitude of low‐frequency fluctuation (fALFF) and regional homogeneity (ReHo) are commonly used functional segregation methods: fALFF measures the power of resting‐state‐specific low‐frequency brain activity in a given voxel, 23 while ReHo measures how similarly a given voxel activates compared with its neighboring voxels 24 . For functional integration, degree centrality (DC) is a useful method, which measures the network architecture of functional connectivity within the human brain connectome at the voxel level 25–28 . It represents the number of direct connections for a given voxel in the voxel‐wise connectome, reflecting the importance of each node in brain network 29,30 .…”

“…24 For functional integration, degree centrality (DC) is a useful method, which measures the network architecture of functional connectivity within the human brain connectome at the voxel level. [25][26][27][28] It represents the number of direct connections for a given voxel in the voxel-wise con-nectome, reflecting the importance of each node in brain network. 29,30 In contrast to traditional seed-based approaches, DC requires no priori definition of regions of interest (ROIs), thus can objectively and comprehensively reflect the abnormalities of the functional connectivity within the whole-brain network.…”

Altered Static and Dynamic Interhemispheric Resting-State Functional Connectivity in Patients With Thyroid-Associated Ophthalmopathy

“…A combined voxel-based morphometry and diffusion tensor imaging study ( Wu et al, 2020 ) demonstrated that TAO patients exhibited aberrant structural brain abnormalities corresponding to visual and cognitive deficits. A resting-state functional magnetic resonance imaging (rs-fMRI) study ( Liu W. F. et al, 2019 ) showed decreased degree centrality in the cerebellum posterior lobe of TAO patients, which was correlated with anxiety and depression scores. Another rs-fMRI study ( Tu et al, 2020 ) revealed that TAO patients with optic neuropathy had altered functional connectivity density (FCD) in the right orbital gyri of the frontal lobe and the left precuneus.…”

Alternation of brain intrinsic activity in patients with hypertensive retinopathy: a resting-state fMRI study

“…It can be repeated in a variety of ways to scan the subject. FMRI data can be used as a preliminary reflection of mental representations and information processing [ 8 ]. Briefly, fMRI technology can display slight changes in MR signals caused by blood oxygenation in venous capillaries in various brain regions.…”