Answers are grounded in this paper and cite their sources.
A patient with severe end-stage Parkinson's disease and troublesome fluctuations in motor function was treated with a long-term intraventricular infusion of dopamine. There was modest improvement in speech and mentation and there was smoother control of motor symptoms that was superior to that achieved by conventional oral medications.
No takes yet. Share an insight, caveat, or question.
Horne et al. (1989) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: