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Sydenham’s chorea may be a risk factor for drug induced parkinsonism

Sydenham’s chorea, the most common cause of acquired chorea in childhood, is a delayed complication of group A β-haemolytic streptococcal infection.1 It is thought to be caused by antibodies induced by streptococci which cross react with basal ganglia antigens.2 Despite the decrease in Sydenham’s chorea in developed countries, there is a renewed interest in this condition because of the hypothesis that a similar mechanism may play a role in the pathogenesis of a subset of patients with tics and other neuropsychiatric disorders.3

The treatment of Sydenham’s chorea is based on the combination of penicillin and antichoreic drugs (valproic acid and/or dopamine antagonists). At the movement disorders clinic of the Federal University of Minas Gerais (MDC-UFMG), located in an area where Sydenham’s chorea remains endemic, we have been struck by the occurrence of drug induced parkinsonism among patients with Sydenham’s chorea. We therefore decided to investigate the incidence of this complication in a cohort of patients with the condition, as well as in a group of subjects with Tourette’s syndrome. The latter is an interesting choice for a control group as Tourette’s syndrome and Sydenham’s chorea share several clinical features—for example, childhood onset, the constellation of motor and behavioural disturbances, and the response to neuroleptic agents.4

In the first part of the study we undertook a retrospective …