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): 18.0-999.0,  Parkinson's Disease Essential Tremor Dystonia To be eligible for entry into the study, candidates must meet all the following Be 18 years of age or older. Able to provide informed consent. Have a clinical diagnosis of idiopathic PD, primary dystonia, or ET The diagnosis of idiopathic PD will be based on the UK Brain Bank and confirmed by the Movement Disorders Neurologists in the NIH Parkinson Clinic The diagnosis of primary (generalized or segmental), hemidystonia, or cervical dystonia will be confirmed on clinical examination in the NIH Movement Disorders Clinic The diagnosis of ET will be confirmed on clinical examination in the NIH Movement Disorders Clinic (the diagnosis of ET will be based on bilateral, largely symmetric postural or kinetic tremor involving hands and forearms that is visible and persistent. Additional or isolated tremor in head may be present but there should be the absence of abnormal posturing). History of appropriate response to dopaminergic medication, with at least a 30% improvement in motor UPDRS with L-DOPA by history or in-clinic testing, for the PD patients OR: Patients with tremor-dominant PD that do not respond to dopaminergic therapy and that exhibit a tremor score of at least 2 for tremor severity on at least one side of the body on the motor UPDRS examination. Unsatisfactory clinical response to maximal medical management (with trials of both higher and lower doses of drugs), including good benefit from dopaminergic medication but associated with insufficient duration of action or unacceptable side-effects OR intractable disabling motor fluctuations (severe off periods, dyskinesias, or freezing spells) OR intractable symptoms of ET or dystonia impacting at least 2 activities of daily living. Agree to undergo DBS if indicated to treat medically refractory movement disorder  Candidates will be excluded if they meet any of the following Clinically significant medical disease that would increase the risk of developing pre or postoperative complications, including but not limited to uncontrolled systemic hypertension with values above 170/100; active heart disease needing immediate intervention; active respiratory disease needing immediate intervention; uncorrected coagulation abnormalities or need for therapeutic anticoagulation which cannot be interrupted; current or pre-existing life-threatening respiratory disease, such as respiratory failure or ARDS. Unable to complete cognitive assessments and testing necessary to adequately evaluate risks and benefits of surgery Evidence of secondary or atypical parkinsonism/dystonia/tremor as suggested by History of CVA, exposure to toxins, neuroleptics, or encephalitis Neurologic signs of upper motor neuron or cerebellar involvement, supranuclear gaze palsy, or orthostatic hypotension MR-imaging with evidence indicative of secondary disease such as tumor, or stroke, which could cause the movement disorder Features atypical of idiopathic Parkinson s disease. Dementia as evidenced by formal neuropsychological evaluation, Mattis Dementia Rating Scale (DRS-2) score, and clinical evaluations. Depression or evidenced by self-report on the Beck Depression Inventory-2 (score above 20). Unable to undergo MR-imaging because of implanted pacemakers, medication pumps, aneurysm clips, metallic prostheses (including metal pins and rods, heart valves or cochlear implants), shrapnel fragments, permanent eye liner or small metal fragments in the eye that welders and other metal workers may have, or if candidates are uncomfortable in small closed spaces (have claustrophobia), or cannot lie comfortably on their back for up to one hour. Pregnant women. Patients with tremor-dominant PD with Scans Without Evidence of Dopaminergic Effect (SWEDD) will be excluded based on clinical and historic information, including DaT functional imaging obtained during routine clinical evaluation of PD as needed