Treatment of young-onset Parkinson's disease: role of dopamine receptor agonists.

For mostly arbitrary reasons, the term "juvenile parkinsonism" is restricted to patients aged 20 years or younger, and "young-onset PD" (YOPD) is onset between ages 21 and 40 years. Previous studies suggest that YOPD has a slower disease progression and a greater incidence and earlier appearance of L-dopa-induced dyskinesias and motor fluctuations. Therefore, our therapeutic strategies have to respect the fact that YOPD patients face many years of gradual progression of disease and disability, a greater probability for developing various adverse effects of treatment, and worsening of quality of life. As an individually tailored treatment should be our primary goal, we must bear in mind that the needs and expectations of YOPD patients are different from those of their older counterparts. The therapeutic strategy for YOPD patients should include a relatively low threshold for initiation of treatment, and initiating treatment with a dopamine receptor agonist while maintaining an individually adjusted, moderately high threshold for switching to or adding L-dopa in cases where treatment response is suboptimal or if problematic adverse effects develop. It has been shown that some dopamine receptor agonists may also have antidepressive efficacy, thus potentially managing an additional problem associated with PD.