[Huntington's chorea].

The possibility that Huntington's chorea might be due to a genetically determined biochemical derangement has been raised on a number of occasions. In 1963,Kenyon and Hardy suggested that abnormalities of magnesium metabolism might account for some of the features of Huntington's chorea and in a group of patients investigated the cellular magnesium levels using the Szvenk-Fekete titration method and a modification of the method of Baron and Bell (1957). They found raised intracellular levels of magnesium and calcium compared with a control group. However Bruyn, Mink, and Calje in 1965 reviewed the literature on this subject. They conducted tests on the magnesium levels in 35 patients with Huntington's chorea using a modification of Mann and Yoe's (1956) method, and found that the levels were all within normal limits. Nielsen and Butt in 1955, on the basis that dimercaprol (B.A.L.), a chelating agent, was of use in the treatment of Wilson's disease, tried its effect on other diseases of the basal ganglia. They treated two patients with Huntington's chorea with B.A.L. for 12 and 14 months respectively and found 'definite clinical improvement'. Because of the unsuitability of B.A.L. for long-term use (intramuscular injections into the buttocks) this treatment had to be abandoned. There are now chelating agents available which can be given orally with success to patients with Wilson's disease. The author can find no reference to a trial of chelating agents in the treatment of Huntington's chorea other than that of Nielsen and Butt (1955). The following paper describes a trial of penicillamine in patients with Huntington's chorea, carried out at St. Nicholas Hospital over a six-month period. Of the chelating agents now available for oral use penicillamine seemed to be the most suitable, on the grounds that it had been successfully used in the long-term treatment of Wilson's disease; in reactivating impaired thiol-dependent enzyme systems in cystinosis; and in ch loropromazine melanosis Penicillamine was known to sequestrate magnesium in vitro.