A voxel-based morphometry study of gray matter abnormalities in patients with hypothyroidism

Objective To investigate the gray matter volume differences between adult hypothyroid subjects and healthy controls using voxel-based morphometry (VBM). Methods A total of 28 untreated hypothyroid patients and 28 age and gender-matched normal controlswere recruited.The concentrations of their freetriiodothyronine (FT3), free theroxine (FT4), and thyroid stimulating hormone (TSH)were testedfrom their venous blood on the day they accepted MR scanning.High resolution 3D-datawereobtained using 3.0 T MRI scanner. VBM analysis was performed to detect the volume differences between the groups by using voxel-wise two sample t test. Multiple regression analysis was employed to analyze the influence exerted upon gray matter volume by serum FT3, FT4, and TSH concentrationof hypothyroid patients. Results Compared to controls, gray matter volumes in the bilateral superior frontal gyri, left precentralgyrus and bilateral cerebellum were decreased in hypothyroid patients (voxels 211–2 142, t=3.36–3.69, P 0.05) was found in the multiple regression analysis. Conclusions VBM analysis revealed that hypothyroid patients exhibited reduced gray matter volume in multiple brain regions. It suggests that the lack of thyroid hormones can lead to the structural abnormalities in adult brain and selective gray matter atrophy in multiple brain regions. Key words: Hypothyroidism; Magnetic resonance imaging; Brain