fMRI Study on Iron Deficiency in the Pathological Mechanism of Tourette Syndrome

Tourette syndrome (TS) is a childhood-onset chronic neuropsychiatric disorder with an increasing prevalence (range 0.05-3%).The investigators previous study showed that lower serum ferritin and iron levels in children with Tourette syndrome than in healthy children. The exact mechanism explaining how iron deficiency contributes to the pathophysiology of TS is unclear.One question is whether or not peripheral iron deficiency in children with Tourette syndrome can inflence the brain extrapyramid structure and resting state brain function？Another question is how well peripheral iron indices correlate with central iron content？ The third question is for TS children with peripheral iron deficiency, oral iron supplement (5mg/Kg/d) at least 8 weeks, the peripheral iron indicies return to normal levels, how the brain iron contents and the relative structure and brain function change?, To test the above-metioned hypothesis, functional magnetic resonance imaging (fMRI) , diffusion tensor imaging (DTI) and susceptibility weighted imaging (SWI) are applied to investigate the volume change of extrapyramid structure such as caudate nucleus and putamen, resting-state brain function and brain iron content before and after oral iron supplementation in TS children with peripheral iron deficiency, TS children with peripheral normal iron levels and normal healthy controls. The investigators hope to confirm that iron deficiency may play a causal role in the dopamine metabolism and it helps to further explore the pathophysiology of Tourette syndrome and also would contribute to significant advance in the therapeutic option for TS children with peripheral iron deficiency.