DOPAMINE AGONISTS IN PARKINSONS-DISEASE

The main pathologic hallmark of Parkinson's disease is a degeneration of the dopaminergic cells in the substantia nigra, pars compacta and-t o a lesser extent-in the ventral tegmental area. Striatal dopamine con centrations are significantly reduced before clinical symptoms become apparent. Recent neuroanatomic and function studies have revealed that the nigrostriatal dopaminergic projection is only one of the neuronal elements integrated into extensive basal ganglia-thalamocortical circ uits that are intimately involved in the regulation of motor activity. The possibilities for therapeutic intervention at the level of the di fferent dopamine receptor subtypes and their effect on the regulation of motor behavior will be briefly reviewed. Dopamine precursors are co nsidered to provide the best symptomatic treatment, whereas dopamine a gonists, although less effective, might be important in slowing the pr ogression of the disease. Our results with pergolide as monotherapy an d in combination therapy in patients with Parkinson's disease also are discussed.