[Schizophreniform symptoms in Chorea Minor--case report and literature review].

Sydenham's chorea is the most frequently acquired movement disorder in childhood and is characterized by involuntary and abrupt movement patterns. Some patients also show neuropsychiatric dysfunctions and psychiatric disorders, including anxiety, obsessive-compulsive disorders and tic disorders. In contrast, the association with psychotic symptoms has been reported very rarely up to now (n=4, two case reports, one prospective and one retrospective study). We report on a 12-year-old girl with acute paranoid hallucinatory symptoms and choreiform movements. Whereas her paranoid-hallucinatory symptoms responded to antipsychotic therapy, the negative symptoms and choreiform movement patterns only disappeared during additional prednisolone treatment. After tapering prednisolone, her negative symptoms and the choreiform movements reappeared. Dysfunctions of the corpus striatum have been linked to the pathogenesis of schizophrenia. This striatal dysfunction may secondarily affect working memory and the prefrontal cortex, resulting in impaired cognitive flexibility. Choreiform movements in chorea minor are attributed to dysfunction of the basal ganglia based on post-streptococcal autoimmune-mediated mechanisms. Huntington's disease and Wilson's disease are movement disorders caused by basal-ganglia dysfunction and are also associated with psychotic symptoms. In the present case, the association of psychotic and choreiform symptoms might be caused by dysfunction of the basal ganglia. The negative symptoms may result from disturbances of the prefrontal cortex impaired by basal-ganglia dysfunction.