Continuous dopamine-receptor stimulation in advanced Parkinson's disease
Nutt JG, Obeso JA, Stocchi F.
Dept of Neurology, Oregon Health Sciences University, Portland 97201, USA.
Intermittent or pulsatile dopamine-receptor stimulation is postulated to induce plastic changes in motor systems that are responsible for the development of the motor fluctuations and dyskinesia that complicate long-term L-dopa therapy of Parkinson's disease. As a corollary to this hypothesis, continuous dopamine-receptor stimulation can avoid or reverse these complications.
Such continuous stimulation is unlikely to mimic completely the normal function of the dopaminergic system, but should avoid the supra-physiological swings in extracellular dopamine that accompany intermittent L-dopa dosing. The concern is that this continuous stimulation might induce tolerance rather than sensitization to some effects of L-dopa.
Open clinical trials support the value of continuous dopaminergic stimulation in Parkinson's disease with established motor complications, but rigorous studies, although experimentally difficult, are needed.
CITATION Trends Neurosci. 2000 Oct;23(10 Suppl):S109-15