International symposium on early dopamine agonist therapy of Parkinson's disease.

Abstract

The use of levodopa for the treatment of Parkinson's disease has had a remarkable impact on the prognosis of the disorder. Survival now approaches normal age-adjusted life expectancy and levodopa has clearly resulted in lessened morbidity as well, and, thus, an improved quality of life. The limitations of levodopa treatment, however, have become clear. Neurologic disability reappears and worsens over time despite levodopa therapy, the beneficial response to levodopa being lost steadily over several years. Levodopa is symptomatic therapy only, having no influence on the progressive loss of nigral neurons. In addition, levodopa therapy, even in combination with a peripheral levodopa decarboxylase inhibitor, is accompanied by a variety of acute and chronic side effects. The appearance of involuntary movements and fluctuations in motor performance have become major limiting side effects of chronic levodopa therapy. Due to the limitations of long-term levodopa therapy, attempts have been made to develop novel