Blood levels of catecholamine metabolites and brain-derived neurotrophic factor in a case of Sydenham's chorea.

We report a case of Sydenham's chorea with neuropsychiatric symptoms who was successfully treated with low-dose risperidone. We also longitudinally investigated serum BDNF levels and plasma levels of catecholamine metabolite in the patient. Serum BDNF levels were increased and plasma levels of HVA and MHPG were decreased according to the recovery from the active phase of the disease. These results suggest that dysfunctions of catecholaminergic neurons and neurotrophic factors might exist in Sydenham's chorea, and the decreasing catecholamine activities in response to risperidone might be associated with the improvement of the disease.