Temporal dynamics of cortical and subcortical responses to apomorphine in Parkinson disease: an H2(15)O PET study.

H2(15)O positron emission tomography (PET) was used to study the temporal course of central nervous system (CNS) responses to apomorphine in patients with idiopathic Parkinson disease (PD). Agonist-induced changes in regional cerebral blood flow (rCBF) were evaluated within corticostriatal-thalamocortical circuits as well as in regions that extend beyond the standard pathophysiological model for PD. Compared with controls, rCBF was increased in PD patients in subcortical regions including the basal ganglia and cerebellum and both increased and decreased in prefrontal, parietal, sensorimotor, and paralimbic cortical areas.