RT Journal Article
SR Electronic
T1 Loss of Dopamine Transporter Binding in Parkinson’s Disease Follows a Single Exponential Rather Than Linear Decline
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1694
OP 1697
VO 45
IS 10
A1 Schwarz, Johannes
A1 Storch, Alexander
A1 Koch, Walter
A1 Pogarell, Oliver
A1 Radau, Perry E.
A1 Tatsch, Klaus
YR 2004
UL http://jnm.snmjournals.org/content/45/10/1694.abstract
AB Imaging of l-dopa uptake or dopamine transporter binding can monitor the progression of Parkinson’s disease. Most follow-up studies have provided data best fitted by a linear decline of their outcome measure. However, in these studies, patients were repeatedly scanned during their first years after a diagnosis had been established. Methods: We followed 6 patients with early Parkinson’s disease for 7.5 y using 123I-labeled N-(3-iodopropene-2-yl)-2β-carbomethoxy-3β-(4-chlorophenyl) tropane and SPECT. Results: Loss of dopamine transporter binding was best fitted using a single exponential approximation. A 63% loss (τ [time constant tau]) was calculated as 5.18 ± 7.62 y in the putamen and 10.62 ± 31.4 y in the caudate nucleus when a 3-parameter fit was used. Conclusion: These data approximate, for what is to our knowledge the first time, the decline of dopamine transporter binding as expected in biologic systems and may allow for models that correct for exponential decline to be developed and for disease-modifying effects in patients with advanced disease to be determined.