Essential Amino Acids and Parkinsons Disease

Inclusion Criteria: * Age 55 years or older * Clinical diagnosis of idiopathic Parkinson Disease * Hoehn and Yahr stage 2-3 * Stable medication regimen with L-DOPA/carbidopa for at least 4 weeks prior to study entry Exclusion Criteria: * Findings suggestive of atypical or secondary Parkinsonism, including cerebellar sign * Use of anticoagulation drugs (including aspirin and Plavix) within one week of the protocol * Allergy to lidocaine * Supranuclear gaze palsy, apraxia, prominent autonomic failure, or other cortical signs * Multiple strokes with stepwise progression of symptoms * Neuroleptic treatment at time of study entry or time of onset of Parkinsonism * Inability to walk without a cane or walker * Deep brain stimulation * Montreal Cognitive Assessment (MoCA) score \<18 * Use of investigational drugs * Early Alzheimer's disease * Frontotemporal dementia of dementia with Lewy bodies * Major depression treated with SSRIs * Individuals with auditory or visual hallucinations * Individuals taking drugs that cause Parkinsonism like symptoms such as antipsychotics, anti-emetics, prokinectic and anti-seizure medications