Patient description: A 57-year old farmer was diagnosed with Parkinson's disease a year ago. He experiences slowness of movement and tremors. His past medical history is significant for hypertension and hypercholesterolemia. He lives with his wife. They have three children. He used to be active with planting and taking care of their farm animals before his diagnosis. The patient complains of shaking and slow movement. He had difficulty entering through a door, as he was frozen and needed guidance to step in. His handwriting is getting smaller. He is on Levodopa and Trihexyphenidyl. He stated his medications help with shaking and slow movement. But he still has difficulty initiating movements, stiffness and slowness in general. He is an alert and cooperative man who doesn't have any signs of dementia. He doesn't smoke or use any illicit drugs.

Clinical trial eligibility criteria: eligible ages (years): 40.0-999.0,  Parkinson's Disease Primary Parkinsonism Lewy Body Parkinson's Disease Males or females ≥ 40 years of age Presenting (within the last 3 months) for an initial evaluation to a movement disorders specialist with signs or symptoms suggestive of a movement disorder The subject's signs or symptoms were previously evaluated by a physician who was not a movement disorders specialist during the previous six months Absence of an established clinical movement disorder diagnosis Symptoms mild in intensity, this includes Hoehn & Yahr ≤ 2 (Exceptions are allowed for subjects who meet for Hoehn & Yahr stage 3 due to early onset of postural instability and/or gait impairment out of proportion to his/her other Parkinson signs and symptoms) Montreal Cognitive Assessment (MoCA) score ≥ 22 Can tolerate imaging visit procedures; and Provide written informed consent prior to study entry  Have been referred to the movement disorders clinic primarily for the purpose of disease management (no diagnostic uncertainty exists on the part of the non-specialist or referring physician) Have a previous movement disorder diagnosis given by a movement disorders specialist prior to the time of enrollment Have received a total of more than 90 days treatment with dopaminergic medications, including direct dopamine agonists or precursors (levodopa) or have received a total of more than 180 days treatment with MAO-B inhibitors, amantadine, anticholinergics or primidone or beta-blockers prescribed for treatment of tremor or signs of parkinsonism Have had a sustained and clinically meaningful response to anti-parkinsonian medications Are currently taking or have taken MAO-B inhibitors in the past 4 weeks Have a known CNS structural lesion such as stroke or tumor that likely accounts for their symptoms Have clinically meaningful cognitive impairment or dementia (mild cognitive problems as might be expected in the earliest stages of PD are not exclusionary) Have current clinically significant cardiovascular disease or clinically important abnormalities on screening ECG (including but not limited to QTc > 450 msec) Are currently taking medications that are known to cause QT-prolongation Are currently taking medications with narrow therapeutic windows (e.g. warfarin or other anticoagulant therapies)