Long-Term Dopamine Transporter Imaging and Clinical Assessment of Parkinson's Disease Progression

[123I]ß-CIT and SPECT in Vivo Three Year Imaging Assessment of Dopamine Transporter Density in Subjects With Early Parkinson's Disease Participating in Earlier vs. Later Levodopa in Parkinson's Disease

The purpose of this project is to assess the change in dopamine transporter density in Parkinson's disease subjects during a sixty month period including a nine month treatment trial of levodopa. Dopamine transporter will be assessed using [123I]ß-CIT SPECT (single photon emission computed tomography) imaging, a marker of dopamine terminal integrity and of clinical disease state.

All subjects will be imaged at the Institute for Neurodegenerative Disorders.

Subjects will be evaluated sequentially with [123I]ß-CIT SPECT and standardized clinical rating scales during a sixty month period. The subjects involved in this study will have had [123I]ß-CIT and SPECT scans at baseline and return for scanning at week 40 following the start of their participation in the ELLDOPA study.

Before each SPECT procedure subjects will be tested to ensure eligibility for the study. They will also have a neurological evaluation including tests of motor function, thinking, memory and handwriting. Some of these tests will be given with the aid of a computer.

On the first day participants are injected with [123I]ß-CIT, an investigational radioactive material that localizes in the brain. Study participants will also have a thorough neurologic examination and standard neuropsychological testing, including testing of memory, concentration, abstraction and visual spatial functions.

Twenty-four hours later study participants return to the Institute for Neurodegenerative Disorders where an investigational scanning procedure will be used to obtain SPECT (single photon emission computed tomography) images of the brain.

Inclusion Criteria:

• Prior participation in the study titled Dopamine Transporter Imaging Assessment of Parkinson's Disease Progression (DAMD17-99-1-9472) [123I] B-CIT and Spect in Vivo Imaging Assessment of Dopamine Transporter Density in Subjects With Early Parkinson's Disease Participating in Earlier Vs. Later Levodopa in Parkinson's Disease (ELLDOPA)].

Exclusion Criteria:

• Inability to sign informed consent and participate in all study procedures.
• Mini mental status exam < 25.
• Pregnancy