STRIATAL UPTAKE OF X-123-BETA-CIT AND I-1 23 IBZM IN PATIENTS WITH EXTRAPYRAMIDAL SYMPTOMS

Aim: This pilot study deals with the question whether characteristic c hanges in local cerebral dopamine transporter function and D-2-recepto r binding capacity can be shown with SPET in idiopathic Parkinson synd rome (IPS) and secondary Parkinson syndrome (SPS). Methods: in 16 pati ents (6 with IPS, 6 with SPS except Wilson's disease, and 4 with Wilso n's disease) SPET studies were performed using I-123-beta-CIT and I-12 3-IBZM and a dual-head gamma camera. images were obtained 20-24 h and 2 h post injection, respectively. For semiquantitative analysis count density ratios of basal ganglia (BG) and cerebellum (CER) were determi ned for I-123-beta-CIT and ratios between BG and medial frontal cortex (MFC) for I-123-IBZM. Results: The BG/CER ratio in the I-123-beta-CIT studies averaged 3.04 +/- 0.83 in IPS and 7.73 +/- 3.28 in SPS (p <0, 01) (except Wilson's disease), in patients with IFS, the BG/MFC I-123- IBZM ratios of basal ganglia contralateral to the symptomatic side exc eeded that of the individual ipsilateral BGs (1.75 +/- 0.12 vs. 1.61 /- 0.16); these ratios were significantly reduced when compared with t hose of SPS patients, although the differences were less pronounced th an those of I-123-beta-CIT uptake values. In some of the patients with Wilson's disease the BG/MFC ratio for I-123-IBZM was dramatically red uced (as low as 1.29), whereas I-123-beta-CIT uptake was only slightly reduced when compared with that of SPS patients (8.00 +/- 2.90, p <0. 01). Conclusion: It is concluded that the neurochemical changes that c an be anticipated in the above diseases can be monitored with SPET. I- 123-beta-CIT, however, appears to be more adequate to differentiate IF S from SPS than I-123-IBZM.