[Radionuclide techniques in the diagnosis of parkinsonian syndromes]

The differential diagnosis of most parkinsonian syndromes can be adequately established on the basis of clinical criteria alone. The characterization of the dopaminergic system using nuclear imaging techniques such as PET and SPECT, is gaining in importance, in particular for the diagnosis of clinically unclear cases. For the first time, these techniques permit the investigation of the presynaptic and postsynaptic dopaminergic system in vivo, and thus the establishment of the differential diagnosis of parkinsonian syndromes at an early stage. Furthermore, the severity and progression of the disease can be assessed and the effect of putative neuroprotective drugs can be documented.