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): 40.0-80.0,  Parkinson's Disease Tremor Men or non-pregnant, non-breastfeeding women 40 to 80 years-of-age who are able to read and understand English Mini Mental State Exam (MMSE) score ≥ 24 Clinical diagnosis of idiopathic Parkinson's disease and presence of at least 2 out of 3 cardinal characteristics (tremor, rigidity, and/or bradykinesia) Hoehn & Yahr Stage I III (inclusive) if not experiencing motor fluctuations. If experiencing motor fluctuations, must be Hoehn & Yahr Stage I IV (inclusive) when OFF or I-III (inclusive) when ON An MDS-UPDRS tremor score (sum of items 2.10, 3.15, 3.16, 3.17, 3.18) of a least 10 (during ON for subjects experiencing fluctuations) (centrally rated) (Forjaz et al., 2015). A limited number of subjects with an MDS-UPDRS of 8 or 9 may be included with Sponsor approval Treated with a stable regimen of anti-parkinsonian and/or anti-tremor medication (with the exception of primidone) for at least 2 weeks prior to screening. Changes to anti-parkinsonian or anti-tremor medications after screening is not permitted  Current diagnosis of: a. essential tremor / b. cerebellar disease Presence or known history of: a. significant visual hallucinations (in the opinion of the Investigator and/or Study Safety Representative) / b. significant impulse control disorder (ICD) (in the opinion of the Investigator and/or Study Safety Representative) History or clinical features consistent with an atypical parkinsonian syndrome Dyskinesia or dystonia that would, in the opinion of the investigator, central rater, or Sponsor, interfere with the assessment of tremor Exposure to tremorigenic drugs or drug withdrawal states within the 30 days prior to the first planned dose of study drug Direct or indirect trauma to the nervous system within 3 months preceding the onset of tremor History or clinical evidence of psychogenic tremor origin. Known history of other medical or neurological conditions that may cause or explain subject's tremor Prior MR-guided Focused Ultrasound or surgical intervention (e.g., deep brain stimulation, ablative thalamotomy or gamma knife thalamotomy) for treatment of tremor or Parkinson's disease Use of medication(s) in the past month that might produce tremor or interfere with the evaluation of tremor Inability to refrain from use of medication/substance(s) that might produce tremor or interfere with the evaluation of tremor on study visit days