Effect of L-Dihydoxyphenylserine on Locomotion, Postural Stability, and Fall Risk Reduction in Parkinson Disease

Inclusion Criteria: * Subject has voluntarily signed and dated an informed consent form (ICF) prior to any participation in the study. * Hoehn and Yahr Stage II, III, IV in an "on" state. * Fell more than twice in past year. * Montreal Cognitive Assessment (MOCA) score ≥ 24. * Stable dose of levodopa, dopamine agonist, amantadine, and/or monoamine oxidase B inhibitor, i.e. unchanged for 3 months. * Subject is ambulatory and able to walk ≥ 10 meters with/without the use of an assistive device. Exclusion Criteria: * Patients with atypical Parkinson disorders that result in a high number of falls.These disorders include: Progressive Supranuclear Palsy (PSP), Multiple System Atrophy (MSA), Primary Freezing of Gait (PFG), and Corticobasal Degeneration. * Patients with dementia MOCA ≤ 23. * Patients with symptomatic Orthostatic Hypotension being treated with midodrine, fludrocortisone or L-DOPS. * Patients with uncontrolled hypertension. * Patients with known allergies to L-DOPS or its excipients. * Patients with major orthopedic problems of their hips or knees, and patients who need hip or knee replacements. * Patient with schizophrenia, a schizo-affective disorder, or a bipolar disorder. * Patients with hallucinations, psychoses, or delusions. * Patients with a history of recent stroke or myocardial infarction.