Florbetapir F 18 PET Imaging of Beta-amyloid in Parkinson's Disease Patients

Inclusion Criteria: * Subjects may be enrolled if they (inclusion criteria): * Are males or females ≥60 years of age * Meet research diagnostic criteria for Parkinson's disease: * Diagnosis of a parkinsonian syndrome * Bradykinesia (slowness of initiation of voluntary movement with progressive reduction in speed and amplitude of repetitive actions) * At least one of the following: muscle rigidity, rest tremor, postural instability not due to visual, vestibular, cerebellar or proprioceptive causes * Supportive criteria for diagnosis of PD (two or more required) * Unilateral onset of symptoms and persistent asymmetry * Rest tremor present * Progressive illness * Excellent response to levodopa with dyskinesias * Levodopa response for 5 years or more * Clinical course of 10 years or more * Have the ability to lie flat and tolerate a 10 minute PET scan. Exclusion Criteria: * Subjects may not be enrolled if any of the following are present (exclusion criteria): * History of repeated strokes, repeated head injury, definite encephalitis * Use of neuroleptics at onset of symptoms * Sustained remission * Strictly unilateral feature persisting \> three years after onset * Significant supranuclear gaze palsy * Cerebellar, pyramidal and early severe autonomic findings * Early severe dementia suggesting a diagnosis of dementia with Lewy bodies (DLB) * Imaging study showing structural abnormality that could explain parkinsonism * Negative response to an adequate levodopa trial * Current clinically significant psychiatric disease that prohibits providing informed consent or participation in the study * Current clinically significant endocrine or metabolic disease, pulmonary, * Women of childbearing potential who are not two or more years post menopausal or surgically sterilized * Have received any investigational medications, or have participated in a trial with investigational medications within the last 30 days