A Study Of Neurological Basis For Dysfunction Of Mood And Cognition In Hyperthyroid Patients

Objective:We aimed to investigate neurological basis for dysfunction of mood and cognition in hyperthyroidism by amplitude of low frequency fluctuation (ALFF) and regional homogeneity (ReHo) using resting-state functional magnetic resonance imaging (rs-fMRI).Method:33 hyperthyroid patients and 33 age-and gender-matched healthy controls (HC) received resting-state fMRI scans and neuropsychological assessment of mood and cognition. ALFF and ReHo values were calculated by REST 1.8. Partial correlation analyses between the scores of neuropsychological tests and values of ALFF and ReHo were performed using SPSS 21.Results:Compared with HC, the Z scores of Hamilton Anxiety Rating Scale (HARS) and Hamilton Depression Rating Scale (HDRS) in hyperthyroidism were elevated significantly, and a remarkable reduce in Z scores of executive function and visuospatial skills was detected. Hyperthyroid patients showed decreased ALFF in left medial frontal gyrus, superior frontal gyrus and bilateral posterior cingulate. Besides, the hyperthyroidism group had decreased ReHo value in left medial frontal gyrus and brain stem, but increased ReHo value in left cuneus, bilateral parietal lobe, left superior frontal gyrus, right middle frontal gyrus and postcentral gyrus (P< 0.05, AlphaSim corrected). Within the hyperthyroidism group, ALFF value in superior frontal gyrus was negatively correlated with processing speed Z scores (r=-0.4, P= 0.032), and ALFF value in medial frontal gyrus was negatively correlated with HARS Z scores (r=-0.502, P= 0.006). In addition, ReHo value in right parietal lobe was negatively correlated with episodic memory Z scores (r=-0.458, P= 0.012), otherwise, there was a positive correlation between HARS Z scores and ReHo value in both middle frontal gyrus (r= 0.444, P= 0.016) and postcentral gyrus (r= 0.377, P = 0.044).Conclusion:Hyperthyroid patients have extensive emotional and cognitive impairments. And the dysfunction of emotion and cognition is related to abnormal spontaneous brain activity in superior frontal gyrus, medial frontal gyrus, right parietal lobe and postcentral gyrus in patients with hyperthyroidism.