Structural and functional brain changes after glucocorticoid therapy in thyroid-associated ophthalmopathy
Author Block: Q. Wu, J. Zhou, W-H. Jiang, X-Y. Pu, X-Q. Xu, H. Hu, F-Y. Wu; Nanjing/CN
Purpose: The purpose of this study was to investigate the brain structural and functional alterations in patients with thyroid-associated ophthalmopathy (TAO) before and after glucocorticoid therapy, using voxel-based morphometry (VBM) as well as resting-state functional magnetic resonance imaging (MRI) with amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo).
Methods or Background: Between 2019 and 2022, 32 patients with TAO and 23 healthy controls were recruited to undergo pre-therapy MRI scans. Intravenous glucocorticoid therapy was administered to all patients. Twenty-six of the patients were available for rescanned MRI three months after the end of therapy. The VBM, ALFF and ReHo methods were used to evaluate the brain structural and functional differences.
Results or Findings: Before therapy, TAO patients showed significantly decreased grey matter volume in the left orbital part of superior frontal gyrus (ORBsup) and the medial superior frontal gyrus (SFGmed) than healthy controls. Patients had higher ALFF values in bilateral gyrus rectus and olfactory cortex as well as lower values in bilateral cuneus. The patients also showed decreased ReHo values in bilateral lingual gyrus. After therapy, increased grey matter volume in left anterior cingulate gyrus and SFGmed, increased ALFF values in bilateral cuneus and superior occipital gyrus, as well as increased ReHo values in bilateral SFGmed were found in TAO patients compared to the pre-therapy cohort. Compared to controls, decreased grey matter volume in the left ORBsup was observed in post-therapy TAO patients.
Conclusion: Our results indicated that TAO might cause functional and structural deficits in the visual and emotional regions of the brain, with recovery in the former and partial restoration in the latter after effective glucocorticoid therapy. These findings may lead to a deeper understanding of the pathophysiological mechanism behind TAO.
Limitations: The sample size was relatively small.
Funding for this study: Funding was received from the National and Natural Science Foundation of China (NSFC) (81801659 to Hao Hu), Jiangsu Province Capability Improvement Project through Science, Technology and Education (JSDW202243 to Fei-Yun Wu), and Jiangsu Province Hospital (the First Affiliated Hospital, Nanjing Medical University) Clinical Capability Enhancement Project (JSPH-MC-2021-8 to Xiao-Quan Xu).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Review Board of the First Affiliated Hospital, Nanjing Medical University.