Influence of <scp>l</scp> -dopa and pramipexole on striatal dopamine transporter in early PD

Short-term therapy with L-dopa and, to a lesser extent, pramipexole can modestly down-regulate striatal DAT in patients with early PD. Decreased striatal DAT could increase dopaminergic neurotransmission with potential benefit, but might also play a role in the development of dopamine-related response fluctuations in patients with advanced disease. Our data also suggest caution in interpretation of longitudinal imaging studies employing DAT to assess disease progression and the efficacy of neuroprotective agents.