Changes in Resting-State Cerebral Activity in Patients with Hyperthyroidism: A Short-Term Follow-Up Functional MR Imaging Study

To investigate the brain functional abnormality of hyperthyroid patients before and after treatment for one month using resting-state functional magnetic resonance imaging (rs-fMRI). Amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity (FC) analysis were performed in 27 new-onset untreated hyperthyroid patients relative to 30 healthy controls. In addition, follow-up data were available for 19 patients treated with methimazole for one month. Compared with healthy controls, patients exhibited lower ALFF in the right posterior cingulate cortex (PCC); increased FC in the bilateral anterior insula (AI), bilateral posterior insula (PI) and left anterior lobe of the cerebellum (ALC); and decreased FC in the bilateral lateral prefrontal cortex (LPFC), the right medial temporal gyrus (MTG) and the bilateral PCC. Compared with the hyperthyroid status, patients with improved thyroid function showed increased FC in the right LPFC and right dorsolateral prefrontal cortex (DLPFC). Subsequently, Pearson’s correlation analyses were performed between abnormal ALFF, FC, neuropsychological assessment and serum free triiodothyronine (FT3) levels. The results indicated that the alterations in regional and network-level brain functions, which might underlie different psychiatric complications were dynamic and interactional processes in hyperthyroidism. Moreover, the improvement in regional brain FC was correlated with the efficacy of anti-thyroid medication.