After a screening evaluation including baseline clinical laboratory testing, a physical and neurological evaluation, subjects will be asked to undergo an injection of ALTROPANE® followed by up to 60 minutes of serial dynamic imaging. Subjects will undergo a second injection of ALTROPANE® followed by up to 60 minutes of serial dynamic imaging within 2-6 weeks of the injection 1.

The underlying goal of this open label imaging study is to optimize the imaging outcome for ALTROPANE® in mild to moderate PD subjects. All study procedures will be conducted at the Institute for Neurodegenerative Disorders (IND) and Molecular NeuroImaging (MNI) in New Haven, CT. Subjects with PD (n=15) will be recruited to undergo ALTROPANE® SPECT. All subjects will undergo written informed consent and a screening evaluation including baseline clinical laboratory testing, a physical and neurological evaluation. Subjects will be asked to undergo an injection of ALTROPANE® followed by up to 60 minutes of serial dynamic imaging. Subjects will be asked to undergo a second imaging visit two-six weeks following the initial imaging visit to assess the reproducibility of the imaging outcome. The imaging analyses will be performed by an image-processing specialist who will remain masked to clinical severity. The primary imaging outcome measure will be the brain regional distribution volumes expressed as a target region to occipital ratio. Striatal regions of interests for caudate and putamen will be defined and placement standardized based on previously optimized region placement protocols. Imaging data will also be analyzed using an automated objective striatal analysis software package.

Inclusion Criteria:

• The participant is 30 years or older at time of PD diagnosis.
• Written informed consent is obtained.
• Participants have a clinical diagnosis of idiopathic Parkinson's disease of < 7 years.
• Hoehn and Yahr stages I-III.
• Negative drug screen

Exclusion Criteria:

• The participant has atypical or drug-induced Parkinson's disease.
• The participant has dementia.
• The participant has a clinically significant clinical laboratory value and/or clinically significant unstable medical or psychiatric illness.
• Treatment within the six months prior to screening with bupropion, methylphenidate, reserpine, alpha methyldopa, or amphetamine.
• The participant has a history of alcohol, narcotic, or any other drug abuse within the past 2 years.
• The participant has received an investigational drug within 60 days of screening visit.
• Pregnancy