This is an exploratory study and the information obtained may lead to new findings regarding the inflammatory and neurodegenerative mechanisms in the progression of PD and help to develop new drugs to halt the disease progression. The study simply involves a one time blood draw.

We will ask 80 patients with Parkinson's disease, representing the full spectrum of motor and cognitive symptoms, to participate. Participation will include measurement of eye movements using two methods: the new computer-based saccade battery and the best available video-based eye-tracking equipment. The evaluation will be repeated about 30 days later. Data will be analyzed to determine whether the computer-based tasks are reliable and able to provide the same quality of information as the gold standard in eye-tracking. A comparison sample of 80 healthy older adults will also complete the behavioral saccade tests in order to establish normative data that will enable application in clinical settings.