Neuroanatomic Variations in Graves' Dysthyroid Ophthalmopathy as Studied With MRI.

PURPOSE

To evaluate whether patients with Graves' dysthyroid ophthalmopathy (GDO) have changes in brain anatomy that can be assessed by neuroimaging as compared to age-matched controls.

METHODS

We examined 10 female, euthyroid patients with GDO and 14 age and gender matched controls using high-resolution structural MRI scanning. An automatic cortical segmentation algorithm was used to estimate the thickness of each subject's gray matter across the brain. The resulting cortical thickness measurements were transferred to a standard reference space via a template-based warping procedure. A statistical analysis of between-group cortical thickness differences using a general linear model with a combination of cluster-based and bootstrapped corrections for multiple comparisons was performed.

RESULTS

Patients with GDO have statistically significant thinning of the gray matter sheet in a minimum of eight locations: six in the right hemisphere (insula, paracentral, precuneus, superior frontal cingulate, superioparietal and postcentral) and two in the left hemisphere (lateral occipital sulcus, fusiform gyrus). Left hemisphere thinning occurred in portions of the occipital lobe while right hemisphere thinning occurred in a set of frontal and parietal areas known to be involved in self-evaluation and emotional and cognitive regulation.

CONCLUSION

Patients with GDO exhibit localized changes in gray matter thickness. These changes may be associated with cognitive changes reported by GDO patients. Further research before and after treatment with larger patient cohorts and experimental protocols including psychiatric evaluation and functional MRI are recommended.