[I-123]beta-CIT SPECT imaging demonstrates reduced density of striatal dopamine transporters in Parkinson's disease and multiple system atrophy

In vivo imaging of the dopamine transporter (DAT) with single photon emissi on computed tomography (SPELT) is a quantitative biomarker for Parkinson's disease (PD) onset and severity. This study has examined and compared the l oss of striatal DAT in PD and multiple system atrophy (MSA) using [I-123]be ta -CIT SPECT imaging. One hundred and eighty-three patients (157 PD and 26 MSA) were studied. Cli nical rating scales (Hoehn and Yahr stage and Unified Parkinson's Disease R ating Scale [UPDRS] scores) demonstrated that the MSA patients were more se verely impaired than the PD patients. The striatal [I-123]beta -CIT SPECT u ptake was markedly reduced in both the PD and MSA groups. In addition, MSA patients showed more symmetric DAT loss compared with the PD patients, cons istent with the more symmetric clinical motor dysfunction observed in MSA. While the loss of DAT was significantly reduced in all regions in both MSA and PD, comparison of the relative loss of the DAT did not significantly im prove diagnostic accuracy in distinguishing between PD and MSA. (C) 2001 Mo vement Disorder Society.