Abnormal excretion of phenolic acids in rheumatic chorea

Sydenham's chorea can be successfully treated with haloperidol, an agent that is known to interfere with the binding of dopamine to its receptors. This suggests that dopamine and its metabolic end product, homovanillic acid (HVA), might be elevated in Sydenham's chorea. To test this hypothesis, the urine of three patients with the clinical diagnosis of Sydenham's chorea was analyzed for HVA and vanillylmandelic acid (VMA). Urinary HVA and the HVA:VMA ratio were significantly higher in these three patients compared with seven control children. Urinary VMA was not different in these two groups. It is suggested that increased dopamine metabolism is involved in the pathogenesis of Sydenham's chorea and that the determination of urinary HVA and the HVA:VMA ratio may be helpful in establishing this diagnosis. We report a case that demonstrates the use of urinary HVA determination in the diagnosis of Sydenham's chorea.