IBZM-SPECT as predictor for dopamimetic responsiveness of patients with de novo parkinsonian syndrome.

IBZM-SPECT is useful as a predictor for the responsiveness to oral L-DOPA therapy in de novo parkinsonian patients. A reduction of postsynaptic dopamine D2 receptors in de novo parkinsonian patients makes the diagnosis of Parkinson's disease rather unlikely. Normal IBZM binding does not prove the diagnosis of Parkinson's disease; however, together with a positive apomorphine test, it strongly supports the clinical diagnosis. At present the combination of IBZM-SPECT and apomorphine testing appears to be a useful procedure for selecting de novo patients for clinical trials with new anti-parkinsonian therapy.