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Assessment of Parkinson disease progression using 123- I I-Ioflupane SPECT: Update from the Parkinson Progression Marker Initiative Trial

Seibyl, J; Jennings, D; Marek, K; the Parkinson\'s Progression Markers Initiative investigators
AAN: Washington, DC
Download Presentation: Seibyl-AAN-2015.pdf
OBJECTIVE: This study is an ongoing assessment of within subject changes of dopamine transporter (DAT) SPECT imaging in a large Parkinson (PD) cohort followed longitudinally over two years.

BACKGROUND: The Parkinson's progression marker initiative (PPMI) is an international, multicenter, longitudinal study assessing biochemical, clinical, and imaging biomarkers of disease progression.

DESIGN/METHODS: Baseline, 1 year, and 2 year (n=167) 123-I Ioflupane SPECT scans were acquired from 22 centers. Data we reanalyzed by the core lab using a volume of interest template for calculating striatal binding ratios (SBR) and percent SBRs changes in striatum, caudate, and putamen.

RESULTS: PD subjects at baseline had a mean age of 61.8 y and average disease duration of 6.7 months. The mean baseline total UPDRS score was 31.8 (range 6-72). For all 167 subjects baseline to year 1 percent change of SBR (left and right caudate and putamen) was -9.8% ± 17.9%, while baseline to year 2 scan was -14.2 ± 20.5%. Average putamen had baseline to year 2 SBR signal loss of -17.8% ± 20.4% and caudate -14.6% ± 15.6%. No statistical differences were noted between % SBR change in caudate and putamen.

CONCLUSIONS: Quantitative DAT 123-I ioflupane SPECT imaging acquired at baseline and two year follow-up in early PD demonstrate DAT reductions of 7% per year. DAT signal loss is greater in the first year compared with year 2 possibly reflecting more rapid degenerative changes in early PD. The magnitude of early signal loss with ioflupane SPECT suggests this technique might be useful as a biomarker interrogating effects of putative disease-modifying agents on presynaptic dopaminergic signal change.