An analysis is presented of 35 cases of chorea as a symptom of polycythaemia. This analysis reveals: (a) whereas polycythaemia occurs predominantly in males (3:2), poly-cythaemic chorea (PC) occurs predominantly in females (5:2), at a real ratio of ♀:♂ = 4:1, the prevalence being 1–2.5 of polycythaemic patients; (b) PC manifests predominantly after the age of 50 (8 cases before, 27 after 50 years), making polycythaemia the first disorder to be considered in cases of so-called ‘senile’ chorea; (c) PC is generalised, with predominant involvement of faciolingual and brachial muscles, and associated with muscular hypotonia; (d) PC may last from periods of weeks to years, usually responds to haloperidol, venesection or 32P-treatment, but may persist, or recur with treatment, or remit spontaneously, and (e) no relationship exists between the choreatic syndrome and (the rare finding of) a small infarct in the caudate nucleus. The cause of the choreatic syndrome in polycythaemia is presumably to be explained as a neostriatal hyperviscosity syndrome producing venous stasis, reduced brain blood flow and impaired tissular CVglucose metabolism. The state of dopaminergic hyperactivity is presumably enhanced by relatively increased neostriatal catecholestrogens. The hypothesis of polycythaemic excess of dopamine-laden platelets releasing excess of dopamine in the neostriatum needs to be confirmed by laboratory evidence of platel
展开▼
