Study of the Effects of Dopaminergic Medications on Dopamine Transporter Density in Subjects With Parkinson's Disease

Study Overview
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Brief Summary
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This study investigates whether there is a change in 123iodine-2ß- carbomethoxy-3ß-(4-iodophenyl) tropane ([123I]ß-CIT) uptake after short-term treatment with levodopa compared to either dopamine agonist or placebo.

Detailed Description
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This is a multi-center, open-label study of short-term treatment with levodopa or cabergoline on striatal DATscan uptake in early Parkinson's disease. Approximately 120 Parkinson's disease subjects will be randomized to receive either carbidopa/levodopa, cabergoline or no treatment during a twelve week period. Subjects will undergo SPECT imaging with DATscan at screening and after 12 weeks. After twelve weeks carbidopa/levodopa and cabergoline treatment will be withdrawn and all subjects will undergo SPECT imaging with DATscan after 8 weeks (20 weeks after baseline).

Official Title
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A Single-blinded Assessment of the Short-term Effects of Cabergoline vs. Carbidopa/Levodopa on SPECT Dopamine Transporter Density in Out-patient Subjects With Parkinson's Disease

Conditions
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Parkinson Disease, Parkinsonian Syndrome

Intervention / Treatment
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* Drug: cabergoline
* Drug: carbidopa/levodopa
* Procedure: DATscan and SPECT imaging


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The subject is aged 40 years or older. Written informed consent is obtained. Subjects have a clinical diagnosis of idiopathic Parkinson's disease. Hoehn and Yahr stages for subjects are I-II. Exclusion Criteria: The subject has atypical or drug-induced Parkinson's disease. The subject has dementia. The subject has clinically significant abnormal laboratory values, and/or clinically significant or unstable medical or psychiatric illness. The subject is pregnant.

Ages Eligible for Study
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Minimum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: cabergoline|Approximately 120 Parkinson's disease subjects will be randomized to receive either carbidopa/levodopa, cabergoline or no treatment during a twelve week period. Subjects will undergo SPECT imaging with DATscan at screening and after 12 weeks. After twelve weeks carbidopa/levodopa and cabergoline treatment will be withdrawn and all subjects will undergo SPECT imaging with DATscan after 8 weeks (20 weeks after baseline).|
|Drug: carbidopa/levodopa|Approximately 120 Parkinson's disease subjects will be randomized to receive either carbidopa/levodopa, cabergoline or no treatment during a twelve week period. Subjects will undergo SPECT imaging with DATscan at screening and after 12 weeks. After twelve weeks carbidopa/levodopa and cabergoline treatment will be withdrawn and all subjects will undergo SPECT imaging with DATscan after 8 weeks (20 weeks after baseline).|
|Procedure: DATscan and SPECT imaging|Approximately 120 Parkinson's disease subjects will be randomized to receive either carbidopa/levodopa, cabergoline or no treatment during a twelve week period. Subjects will undergo SPECT imaging with DATscan at screening and after 12 weeks. After twelve weeks carbidopa/levodopa and cabergoline treatment will be withdrawn and all subjects will undergo SPECT imaging with DATscan after 8 weeks (20 weeks after baseline).|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine the influence of short-term levodopa therapy on dopamine transporter density in early Parkinson's disease |  | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine the influence of short-term treatment with cabergoline on dopamine transporter density in early Parkinson's disease |  | 1 year | 
| To further develop the AMADEUS consortium, a collaboration of clinical-imaging SPECT DAT sites able to obtain data using comparable techniques and transmit imaging to a central analysis site |  | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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parkinson, brain imaging, diagnosis