Morphological and microstructural brain changes in thyroid-associated ophthalmopathy: a combined voxel-based morphometry and diffusion tensor imaging study.

PURPOSE: To explore the morphological and microstructural changes of grey and white matter in the patients of thyroid-associated ophthalmopathy (TAO). METHODS: Twenty-five TAO patients and 25 well-matched healthy controls were recruited. Structural T1- and diffusion-weighted magnetic resonance imaging data were analyzed using voxel-based morphometry and voxel-based analysis of diffusion tensor imaging. RESULTS: Compared with healthy controls, TAO group showed significantly decreased grey matter volume in the brain region of the right middle frontal gyrus. Meanwhile, TAO group showed significantly decreased fractional anisotropy (FA), but increased mean, axial and radial diffusivities in the brain regions of the right superior occipital gyrus, middle occipital gyrus and cuneus in TAO group. In addition, the FA value in significant brain regions showed a positive correlation with visual acuity (r = 0.456, P = 0.025) and a negative correlation with disease duration (r = - 0.609, P = 0.003). CONCLUSION: Significant morphological and microstructural abnormalities in areas corresponding to known functional deficits of vision and cognition could be found in TAO patients. These results extended our understanding of neural relationships with TAO.