Parkinson's Disease
Conditions
Keywords
Parkinson, brain imaging
Brief summary
This study conducted to more fully evaluate the way that carbidopa/levodopa and entacapone may work in the brain. This research study uses \[123I\]-IBZM and dynamic SPECT imaging to determine the amount and the duration of dopamine release from specific regions in the brain after treatment with either the combination of carbidopa/levodopa or the combination of carbidopa/levodopa/entacapone.
Detailed description
This is a pilot evaluation of dopaminergic function in PD using a bolus plus constant infusion protocol with \[123I\]-IBZM and SPECT to evaluate the potential for carbidopa/l-dopa alone or carbidopa/l-dopa/entacapone to produce displacement of striatal radioactivity for assessment of intrasynaptic dopamine. We will assess the feasibility of this paradigm for detecting l-dopa effects on the SPECT signal in subjects with PD with disease duration of greater than 4yrs and with a stable response to L-dopa. Each subject will undergo three \[123I\]-IBZM studies separated by 1-2 weeks. Subjects will be off medication for at least 12 h prior to study For each of the three scan days patients will receive a constant intravenous infusion of \[123I\]-IBZM over 4-5 hours to establish an equilibrium binding condition of the radiotracer at striatal D2/D3 receptors. Three baseline SPECT acquisitions will be obtained prior to medication dosing to establish a stable baseline. At approximately 5 h after the initiation of the infusion subjects will receive a single oral dose of either carbidopa/levodopa (37.5mg/150mg or 50mg/250mg), or carbidopa/levodopa/entacapone (either 37.5mg/150mg/200mg- STALEVO or 50/250mg/200mg).
Interventions
Sponsors
Molecular NeuroImaging
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
30 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Main inclusion criteria: * The patient is aged 30 years or older. * Written informed consent is obtained. * Patients have a diagnosis of idiopathic Parkinson's disease. * Hoehn and Yahr stages for patients are I-III. * Patients have a diagnosis\> 4 yrs prior to screening * Patients are treated with carbidopa/levodopa with \> 300 mg levodopa. Main
Exclusion criteria
* The patient has atypical or drug-induced Parkinson's disease. * The patient has dementia (MMSE 24). * The patient has a clinically significant clinical laboratory values, and/or medical or psychiatric illness. * The patient has any disorder that may interfere with drug absorption, distribution, metabolism, or excretion (including gastrointestinal surgery). * The patient has evidence of clinically significant gastrointestinal, cardiovascular, hepatic, renal, hematological, neoplastic, endocrine, neurological, immunodeficiency, pulmonary, or other disorder or disease. * The patient has been treated with a dopamine agonist within the past 30 days. * Concomitant treatment with Monoamine Oxidase (MAO)-inhibitors (except selegiline \<10 mg/day) within 30 days prior to the screening visit * Patient has a history of iodine allergy
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The primary outcome will be the reduction from baseline in IBZM striatal uptake during a 6-8 hour assessment period after treatment. | 6-8hrs |
Secondary
| Measure | Time frame |
|---|---|
| Secondary Measures include: Putamen and caudate uptake over time, UPDRS scores, and Pharmacokinetic analysis. | 6-8hrs |
Outcome results
None listed