[123I]β-CIT SPECT distinguishes vascular parkinsonism from Parkinson's disease

We investigated whether [I-123]-beta-CIT and single-photon emission computed tomography (SPECT) imaging distinguishes patients with clinically Suspected vascular parkinsonism (VP) from patients with idiopathic Parkinson's disease (PD). [I-123]beta-CIT SPECT is a sensitive marker of dopaminergic degeneration, and the degree of striatal binding reduction in PD correlates with disease severity. Thirteen patients who fulfilled rigid clinical criteria for VP (mean +/- S.D.: age. 76.5 +/- 5.3 years; disease duration, 3.6 +/- 2.8 years), 20 PD patients (,we, 66.2 +/- 9.5 years disease duration, 4.3 +/- 2.7 years). and 30 healthy persons (age, 44.6 +/- 19.2 years) underwent [I-123]beta-CIT SPECT imaging. Age-corrected striatal beta-CIT binding was reduced on average by 40.8% in PD but was near normal in the VP group (mean reduction, 1.2%). This difference was statistically significant (Z = 4.68: P < 0.001). The left-right asymmetry of striatal beta-CIT binding was significantly increased in the PD group compared with normal controls and the VP group (F(2) = 17.4 P <0.001). Moreover, putamen-caudate nucleus ratios were significantly reduced in PD compared with both VP patients and healthy controls (F(2) = 65.5, P < 0.001). Whole striatal beta-CIT binding was more than one standard deviation above the mean PD values in all but 1 of the individual VP patients. Our findings suggest that the presynaptic dopaminergic deficits seen in PD are absent in most patients with VP. [I-123]beta-CIT SPECT imaging may be useful to help distinguish between PD and VP patients during life. (C) 2002 Movement Disorder Society.