Problems arising during chronic treatment with L-dopa for Parkinson's disease: changes in response to treatment.J Neural Transm Suppl. 1986; 22:189-99.JN
Some aspects of the problems of long-term L-dopa treatment syndrome are reviewed, with special attention to the changes in response to treatment with dopaminergic agents, specifically end-of-dose deterioration, the on-off phenomenon and hyperkinesia. The various hypotheses for interpreting these are presented, with particular stress on changes in the function of DA-ergic receptors. It is concluded that the on-off phenomenon is probably related to changes in plasma L-dopa levels and to decreased stores of intraneural dopamine.