Dihydroxyphenylalanine in Extrapyramidal Disease

EVIDENCE has been accumulating for the past several years which has implicated dopamine metabolism in the production of extrapyramidal symptoms. Drugs such as reserpine which tend to produce extrapyramidal symptoms as a side effect have been shown to deplete dopamine from the brain. It is also of considerable interest that dopamine is found in highest concentration in the basal ganglia¹while 1-norepinephrine and serotonin, the other important amines in the central nervous system, are present in relatively smaller concentrations in this area of the brain. More recently Ehringer and Hornykiewicz²have demonstrated that brains obtained from parkinsonian patients who died as a result of sudden trauma contained very low levels of dopamine. All of these findings suggest the possibility that a disturbance in the synthesis or degradation of dopamine might be involved in the etiology of extrapyramidal disturbances. For several years we have been conducting studies of the