Abstract
Two siblings are reported who developed classical signs and symptoms of Parkinsonism in the first decade of life. In addition, they had evidence of cortical spinal tract disease, thus putting them in the category of Davison's pallido-pyramidal syndrome. Both deteriorated to the point of a non-productive existence until the institution of levodopa treatment, at the ages of 18 and 20 years. The response of the extrapyramidal signs plus the lack of response of the pyramidal tract signs demonstrate the specificity of a pharmacological agent in certain areas of the nervous system. The rapid response of the female patient to very low doses of levodopa is unusual in our experience. Both patients have remained well for eight months after initiation of treatment.