Huntington's chorea.

The pharmacological treatment of Huntington's chorea has been based on the use of neuroleptic drugs, on the hypothesis that there is a functional dopaminergic hyperactivity in this illness (Agid, 1975). More recently, after the observation of reduced cholinergic and GABAminergic activity at the striatal level in brains of choreic subjects (McGeer et al., 1973; Stahl and Swanson, 1974; Bird and Iversen, 1974), therapeutic trials were carried out with substances which facilitate the formation and persistence of these supposed neurotransmitters. The hypothesis of reduced cholinergic activity at the striatal level is supported by the therapeutic effectiveness of physostigmine, a powerful anticholinesterase drug which also passes the bloodbrain barrier (Aquilonius and Sjostrom, 1971; Klawans and Rubovitz, 1972; Davis et al., 1976). Nevertheless, this drug cannot be used clinically because of serious and numerous side effects. Since then, there have been attempts to influence cholinergic metabolism by providing substances considered to be acetylcholine precursors. Dimethylaminoethanol acid (Deanol), a drug which has been proved to enhance the formation of acetylcholine in the CNS, has been shown to have effects on the CNS in animals (Pfeiffer et al., 1957; Haubrich et al., 1975), and in various pathological conditions in humans, such as schizophrenia, periodic headache, chronic states of fatigue, and bronchial asthma (Pfeiffer, 1958; Murphree et al., 1960). With regard to extrapyramidal pathology, dimethylaminoethanol has been used for therapy of Huntington's chorea and tardive dyskinesia. In