The case for and concerns about continuous dopamine stimulation in Parkinson's disease.

Delivery of levodopa or other dopaminergic agents to the striatum is a critical determinant of the clinical response and may account for many of the fluctations in response ("on-off"). This should be manageable with innovative delivery systems for the drugs. However further studies are required to determine if continuous dopaminergic stimulation will be complicated by increased levels of drug metabolites or down regulation of dopaminergic neurotransmission.