Striatal dopamine transporter binding assessed by [I-123]IPT and
single photon emission computed tomography in patients with early
Parkinson's disease: implications for a preclinical diagnosis.

BACKGROUND: Specific binding to dopamine transporters may serve as a tool to detect early loss of nigrostriatal dopaminergic neurons in patients with Parkinson's disease.

OBJECTIVE: To determine striatal dopamine transporter binding using the cocaine analogue [I-123]N- (3-iodopropen-2-yl)- 2beta-carbomethoxy- 3beta- (4-chlorophenyl) tropane ([I-123]IPT) and single photon emission computed tomography.

PATIENTS AND METHODS: We studied 9 control subjects (mean age, 58 years; range, 41-69 years) and 28 patients with early Parkinson's disease (Hoehn and Yahr stages I [n = 14] and II [n = 14] [symptom duration, <5 years]; mean age, 55.5 years; range, 36-71 years).

Single photon emission computed tomography was performed 90 minutes after injection of 120 to 150 MBq of radioactive [I-123]IPT.

RESULTS: Specific striatal [I-123] IPT binding (mean +/- SD) was significantly reduced in patients with early Parkinson's disease (ipsilateral striatum: 4.09+/-0.97; range, 2.46-6.40; contralateral striatum: 3.32+/-0.76; range, 1.80-5.13) compared with controls (left striatum: 7.28+/-0.94; range, 5.78-8.81; right striatum: 7.41+/-1.28; range, 5.58-9.44).

IPT binding ratios (mean +/- SD) were significantly lower in patients with Hoehn and Yahr stage II (ipsilateral striatum: 3.47+/-0.75; contralateral striatum: 2.96+/-0.73) compared with those with Hoehn and Yahr stage I (ipsilateral striatum: 4.72+/-0.75; contralateral striatum: 3.69+/-0.61) (P<.001).

The ipsilateral striatum of patients with Hoehn and Yahr stage I showed a significant mean+/-SD reduction of IPT binding (ipsilateral striatum: 4.72+/-0.75) compared with either right or left striatum of controls (P<.001).

Only in 1 patient was IPT binding to the ipsilateral striatum (ratio, 6.40) higher than the lowest value observed in the striatum of a control subject (ratio, 5.58).

CONCLUSIONS: Use of [I-123] IPT and single photon emission computed tomography demonstrates a reduction of dopamine transporter binding in patients with early Parkinson's disease.

Significantly reduced IPT binding already observed in the ipsilateral striatum of patients with Hoehn and Yahr stage I demonstrates the potential of this method to detect preclinical disease.


Arch Neurol 2000 Feb;57(2):205-8
Schwarz J, Linke R, Kerner M, Mozley PD, Trenkwalder C, Gasser T, Tatsch K
Department of Neurology, University of Ulm, Germany.
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PMID: 10681078, UI: 20143313

http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10681078&dopt=Abstract

janet paterson
52 now / 41 dx / 37 onset
a new voice: http://www.geocities.com/janet313/
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